Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 8 Excretion Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

11th Bio Zoology Guide Excretion Text Book Back Questions and Answers

Part – I

Question 1.
Arrange the following structures in the order that a drop of water entering the nephron would encounter them.
a) Afferent arteriole
b) Bowman’s Capsule
c) Collecting duct
d) Distal tubule
e) Glomerulus
f) Loop of Henle
g) Proximal tubule
h) Renal Pelvis
Answer:
(a), (e), (b), (g), (f), (d), (c), (h)

Question 2.
Name the three filtration barriers that solutes must come across as they move from plasma to the lumen of Bowman’s capsule. What components of the blood are usually excluded by these layers.
Answer:
The three filtration barriers that solutes must come across as they move from plasma to the lumen of Bowman’s capsule are,

  1. Glomerular capillary endothelium
  2. Basal lamina or basement membrane
  3. Epithelium of Bowman’s capsule.
  4. Blood corpuscles and plasma protein are excluded by these layers.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 3.
What forces promote glomerular filtration? What forces oppose them? What is meant by net filtration pressure?
Answer:

  • Glomerulus hydrostatic pressure
  • Glomerulus pressure
  • Opposing pressure: Colloidal osmotic pressure, Capsular hydrostatic pressure
  • Net filtration pressure = Glomerular hydrostatic pressure – (Colloidal osmotic pressure + capsular hydrostatic pressure.

Question 4.
Identify the following structures and explain their significance in renal physiology?
Answer:
a) Juxtaglomerular apparatus It is a specialized tissue in the afferent arteriole of the nephron that consists of macula densa and granular cells.

  • Action: The macula densa cells sense distal tubular flow and aspect afferent arteriole diameter.
  • Actions of Glandular cells: When there is a fall in glomerular blood flow it can activate Juxta glomerulus cells to release renin from the liver which converts angiotensinogen to angiotensin I.
  • Angiotensin converting enzyme converts angiotensin I to angiotensin II.
  • It stimulates Na+ reabsorption in the proximal convoluted tubule by vasoconstriction of the blood vessel and increases the glomerular blood pressure.

b) Podocytes:

  • The visceral layer of Bowman’s capsule is made of epithelial cells called podocytes.
  • The podocytes and the foot processes and the basement membrane of glomerulus act as a filtering membrane.
  • Podocytes act in glomerulus filtration.

c) Sphincters in the bladder:

  • The sphincters of the bladder regulate urination.
  • When the bladder is full the stretching of the urinary bladder stimulates the CNS through the sensory neurons of the parasympathetic nervous system and brings about contraction of the bladder.
  • Somatic motor neurons induce the sphincters to close.
  • Smooth muscles contract results in the opening of the internal sphincters and relaxing the external sphincter.
  • The sphincter opens and the urine is expelled out.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 5.
In which segment of the nephron most of the re-absorption of substances takes place?
Answer:
In the proximal convoluted tubule.

Question 6.
When a molecule or ion is reabsorbed from the lumen of the nephron, Where does it go?
Answer:
When a molecule or ion is reabsorbed from the lumen of the nephron, it goes to the bloodstream through an efferent arteriole which carries blood away from the glomerulus. If a solute is filtered and not reabsorbed from the tubule, it goes along with urine.

Question 7.
Which segment is the site of secretion and regulated reabsorption of ions and pH homeostasis?
Answer:

  • 1. Distal tubule; 2. Collecting duct
  • In the renal tubules H+ and NH4 are secreted and liberated into the tubules and excreted through
    urine thus maintaining acid base balance.
  • For each H+ ions from the liberated filtrate one Na+ is reabsorbed in the tubules.
  • The secreted HCO3, PO3 and NH3 combines to form carbonic acid and phosphoric acids.
  • Thus the H+ are maintained and their reabsorption is prevented.

Question 8.
What solute is normally present in the body to estimate GFR in humans?
Answer:

  • The glomerulus filtrate consists of water glucose amino acids creatinine protein salts and urea.
  • These solutes decide the glomerular filtration rate.

Question 9.
Which part of the autonomic nervous system is involved in the micturition process?
Answer:
Parasympathetic nervous system.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 10.
If the afferent arteriole of the nephron constricts, what happens to the GFR in that nephron? If the efferent arteriole constricts what happens to the GFR in that nephron? Assume that no autoregulation takes place.
Answer:

  • Blood enters the glomerulus faster with greater force through the afferent arteriole and leaves the glomerulus through the efferent arterioles much slower.
  • Because afferent arteriole is wider than efferent arteriole.
  • The constriction of this does not affect the rate of filtration.

Question 11.
The concentration of urine depends upon which part of the nephron.
Answer:
a) Bowman’s capsule
b) Length of Henle’s loop
c) PCT
d) network of capillaries arising from the glomerulus.
Answer:
b) Length of Henle’s loop

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 12.
If Henle’s loop were absent from mammalian nephron, which one of the following is to be expected?
a) There will be no urine formation
b) There will be hardly any change in the quality and quantity of urine formed.
c) The urine will be more concentrated
d) The urine will be more dilute
Answer:
d) The urine will be more dilute

Question 13.
What will happen if the stretch receptors of the urinary bladder wall are totally removed?
a) Micturition will continue
b) Urine will continue to collect normally in the bladder
c) There will be micturition
d) Urine will not collect in the bladder
Answer:
a) Micturition will continue

Question 14.
The end product of the Ornithine cycle is
a) Carbon dioxide
b) Uric acid
c) Urea
d) Ammonia
Answer:
c) Urea

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 15.
Identify the wrong match.

a) Bowman’s capsule Glomerular filtration
b) DCT Absorption of glucose
c) Henle’s loop Concentration of urine
d) PCT Absorption of Na+ and K+ ions

Answer:
b) DCT – Absorption of glucose

Question 16.
Podocytes are the cells present on the
a) Outer wall of Bowman’s capsule
b) Inner wall of Bowman’s capsule
c) Neck of the nephron
d) Wall glomerular capillaries
Answer:
b) Inner wall of Bowman’s capsule

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 17.
Glomerular filtrate contains
a) Blood without blood cells and proteins
b) Plasma without sugar
c) Blood with proteins but without cells
d) Blood without urea
Answer:
c) Blood with proteins but without cells

Question 18.
Kidney stones are produced due to the deposition of uric acid and Silicates
b) Minerals
c) Calcium Carbonate
d) Calcium oxalate
Answer:
d) Calcium oxalate

Question 19.
Animal requiring the minimum amount of water to produce urine is
a) Ureotelic
b) Ammonotelic
c) Uricotelic
d) Chemotelic
Answer:
c) Uricotelic

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 20.
Aldosterone acts at the distal convoluted tubule and collecting duct resulting in the absorption of water through
a) Aquaporins
b) Spectrins
c) GLUT
d) Chloride channels
Answer:
a) Aquaporins

Question 21.
The hormone which helps in the reabsorption of water in kidney tubules is
a) Cholecystokinin
b) Angiotensin Il
c) Antidiuretic hormone
d) Pancreozymin
Answer:
c) Antidiuretic hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 22.
Malpighian tubules remove excretory products from
a) Mouth
b) Oesophagus
c) Haemolymph
d) Alimentary canal
Answer:
c) Haemolymph

Question 23.
Identify the biological term excretion, glomerulus, urinary bladder, glomerular filtrate, ureters, urine, Bowman’s capsule, urinary system, reabsorption, micturition, osmosis, proteins.
Answer:

  • A liquid which gathers in the bladder – Urine
  • Produced when blood is filtered in a Bowman’s capsule – Glomerular filtrate
  • The temporary storage of urine – Urinary bladder
  • A ball of intertwined capillaries – Glomerulus
  • Removal of unwanted substances from the body – Excretion
  • Each contains a glomerulus – Bowman’s Capsule
  • Carry urine from the kidneys to the bladder – Ureter
  • The scientific term for urination – Micturition
  • Regulation of water and dissolved substances in the blood and tissue fluid – Osmoregulation
  • Consists of the kidneys ureters and bladder Excretory system
  • Removal of useful substances from glomerular filtrate reabsorption
  • What solute the do blood contain that is not present in the glomerular filtrate? – Plasma Protein

Question 24.
With regards to toxicity and the need for dilution in water how different are ureotelic and ureocotelic excretions? Give examples of animals that use these types of excretions?
Answer:

  • The type of nitrogenous end product (Urea or Uric acid or ammonia) of an animal excretion depends upon the habitat of the animal.
  • For the Excretion of Ammonia, more water is needed.
  • Animals that excrete most of their nitrogen in the form of ammonia are called ammonites.
  • Fishes Amphibians. Uric acid can be eliminated with a minimum loss of water and is called Uricoteles.
  • Reptiles, birds insects, landrails. Mammals and terrestrial amphibians excrete urea and are called ureoteles.
    Nitrogenous

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 1

Question 25.
Differentiate protonephridia from metanephridia.
Answer:

Protonephridia Metanephridia
1. Proto – first it is a network of dead-end tubules lacking internal opening. (E.g) Platyhelminthes Meta – after They have a tubular internal opening called nephrostome. (E.g) Earthworm
2. Flame cells are excretory structures. The excretory products are filters and selectively reabsorbed.
3. Excretory product excretes through nephridiopore The excretory product excretes through the nephridiopore.
4. Excretory structure are usually osmo regulators Excretory structures are osmo regulators and helps in excretion.

Question 26.
What is the nitrogenous waste produced by amphibian larvae and by adult animals?
Answer:
The adult amphibian’s excretory product is urea. The larval form of amphibian’s excretory product is ammonia.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 27.
How is urea formed in the human body?
Answer:
Urine formation involves three main processes namely Glomerular Alteration, tubular reabsorption and tubular secretion.

I. Glomerular filtration:

  • Blood enters the kidney from the renal artery into the glomerulus.
  • Blood is composed of water colloidal proteins, sugars and nitrogenous end product.
  • The filteration is started in the glomerulus. The fluid that leaves the glomerular capillaries and enters the Bowman’s capsule is called the glomerular filtrate. It formed 170-180 litre within 24 hours.
  • Glomerular membrane has large surface area. Blood enters the glomerulus faster with greater force through the afferent arteriole and leaves the glomerulus through the efferent arterioles much slower.
  • This is because afferent arteriole is wider than efferent arteriole and the glomerular hydrostatic pressure is around 55 mm Hg.
  • Molecules larger than 5mm are barred from entering the tubule.

The two opposing forces are contributed by the plasma proteins in the capillaries.

  1. Colloidal osmotic pressure – 30 mm Hg
  2. Hydrostatic pressure -15 mm Hg

Both pressures combine. 30 mm Hg + 15mm Hg = 45mm Hg

  • The net filtration pressure of 10mm Hg is responsible for the renal filtration.
  • Net filtration pressure – Glomerular
  • Hydrostatic Pressure – Colloidal Osmotic pressure + Capsular hydrostatic pressure.

Net filteration pressure = 55 mm Hg – (30mm Hg +15mm Hg) = 10mm Hg

Substance Concentration in blood Plasm / g dm-3 Concentration in glomerular filtrate / g dm-3
Water 900 900
Proteins 80. 0.05
Aminoacids 0.5 0.5
Glucose 1.0 1.0
Substance Concentration in blood PIasm /gdm-3 Concentration glomerular filtrate/gdm-3
Urea 0.3 0.3
Uric Acid 0.04 0.04
Creatinine 0.01 0.01
Inorganic ions (mainly (Na+, K+and Cl) 7.2

 

7.2

II. Tubular reabsorption:

  • The volume of filtrate formed per day is around 170 – 180l.
  • Urine released is around 1.51 per day. 99% of the glomerular filtrate is reabsorbed by the renal tubules.

Reabsorption in proximal convoluted tubule:

  • Glucose lactate amino acids Na in the filtrate are reabsorbed in the PCT.
  • Sodium is reabsorbed by active transport through a sodium-potassium pump in the PCT.
  • Small amounts of urea and uric acid are reabsorbed.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 2

Reabsorption in Henle Loop:

  • Descending limb of Henle’s loop is permeable to water due to the presence of aqua porlns but not permeable to salts.
  • Water is lost in the descending limb. Hence Na and Cl get concentrated in the filtrate.
  • Ascending limb of Henle’s loop is impermeable to water but permeable to Na+, Cl andK+.

Distal Convoluted Tubule:

  • It recovers water and secretes potassium into tubule.
  • Na+, Cl-, and water remain in the DCT.
  • Reabsorption of HCO3 takes place to regulate the blood pH.
  • Collecting the tubule is permeable to water potassium ions are actively transported into the tubule and Na+ to produce concentrated urine.

Tubular Secretion:

  • Once it enters the collecting duct water is absorbed and concentrated hypertonic urine is formed.
  • For every H secreted into the tubular filtrate, a Na+ is absorbed by the tubular cell.
  • The H+ secreted combines with HCO+3, HPO3, and NH+ and gets fixed as H2CO3, H2PO3, and NH4+.
  • Since H+ gets fixed in the fluid reabsorption of H+is prevented.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 28.
Differentiate cortical from medullary nephrons.
Answer:
In the renal tubules proximal convoluted tubule and distal convoluted tubule are situated in the cortical region of the kidney and the loop of Henle is in the medullary region.

Cortical Nephron Medullary Nephron
1. The loop of Henle is too short and extends only very little into the medulla. Nephrons have a long loop of Henle that run deep in to the medulla.
2. There is no vasa recta. Vasa recta is present.

Question 29.
What vessels carry blood to the kidneys? Is this blood arterial or venous?
Answer:
Renal artery right and left artery. The blood is arterial.

Question 30.
Which vessels drain filtered blood from the kidneys?
Answer:
Renal vein. The filtered blood is taken from the kidney to inferior vena cava through renal vein.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 31.
What is tubular secretion? Name the substances secreted through the renal tubules?
Answer:

  • In the distal convoluted tubule the urine becomes hypotonic.
  • It contains urea and salts pass from peri tubular blood in to the cells of DCT.
  • For every H+ secreted a Na+ is absorbed by the tubular cell.
    The H+ secreted combines HCO3, HPO3 and NH3 and becomes carbonic acid phosphoric acid and ammonium.
  • Since H+ gets fixed in the fluid reabsorption of H+ is prevented.

Question 32.
How are the kidneys involved in controlling blood volume? How is the volume of blood in the body related to arterial pressure?
Answer:

  • When the volume of blood decreases the flow pressure, decreases.
  • This can be sensed by hypothalamus and osmo receptors are stimulated and anti diuretic hormone is secreted from the neuro hypophysis.
  • The aquaporins in the proximal convoluted tubules and collecting tubule reabsorb water. Hence the blood volume increases and the blood pressure increases.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 33.
Name the three main hormones that are involved in the regulation of the renal function?
Answer:

  • Renin
  • Angio Tensin I
  • AngioTensin II

Question 34.
What is the function of anti diuretic hormone? Where is it produced and What stimuli increases or decreases its secretion?
Answer:

  • ADH which is also called as vasopressin or Anti diuretic hormone is secreted from neuro hypophysis.
  • Fluid loss or if blood pressure increases the osmoreceptors of hypothalamus is stimulated and hence neuro hypophysis is stimulated and secretes ADH.
  • When the fluid level and pressure is maintained due to the negative feed back mechanism ADH secretion stops.

Question 35.
What is the effect of aldosterone on kidneys and where is it produced?
Answer:

  • Due to the stimulation of Angiotensin II the adrenal cortex secretes aldosterone. That causes reabsorption of Na+, K+ excretion and absorption of water from distal convoluted tubule and collecting tubule.
  • This mechanism is known as Renin – Angio tensin Aldosterone system.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 36.
Explain the heart’s role in secreting a hormone that regulates renal function? What hormone is this?
Answer:

  • Excessive stretch of cardiac atrial cells cause an increase in blood flow to the atria of the heart and release Atrial Natriuretic Peptide or factor (ANF) travels to the kidney where H increases Na+ excretion and increases the blood flow to the glomerulus,
  • Acting on the afferent glomerular arterioles as a vasodilator or an efferent arterioles as a vasoconstrictor.
  • The first identical natri uretic hormone is atrial natriuretic horome of heart.

Part – II.

11th Bio Zoology Guide Excretion Additional Important Questions and Answers

I. Choose The Correct Answer.

Question 1.
Name the organ that regulates the acid base and water regulation?
a) Kidney
b) Liver
c) Skin
d) Lungs
Answer:
a) Kidney

Question 2.
Whether the following statements are true or false find the correct sequence. Find the correct sequence.
I) According to the environmental changes organism change their osmotic concentration and are called osmo confirmers.
II) Osmo regulators maintain their internal osmotic concentration irrespective of their external osmotic environment.
III) The Euryhaline animals are able to tolerate only narrow fluctuations in the salt concentration?
IV) The steno haline animals can tolerate wide fluctuations in the salt concentration.
Series:
a) I – False, II – True, III – False, IV – True
b) I – True, II – True, III – False, IV- False
c) I – False, II – True, III – False, IV – True
d) I – False, II – False, III – True, IV – True
Answer:
b) I – True, II – True, III – False, IV- False

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 3.
Name the toxic formed due to the degeneration of amino acid.
a) Urea
b) Uric Acid
c) Ammonia
d) Carbonic Acid
Answer:
c) Ammonia

Question 4.
Find out the odd one out.
a) Ammonoteles – Aquatic Amphibians
b) Urico teles – Birds
c) Ureoteles – Land amphibians
d) Ureoteles – Earthworm (When it is in water)
Answer:
d) Ureoteles – Earthworm (When it is in water)

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 5.
What is the functional unit of kidney?
a) Nephron
b) Neuron
c) Synapsis
d) Glomerulus
Answer:
a) Nephron

Question 6.
What type of Urine is formed in organism with long Henle’s loop?
a) Isotonic
b) less concentrated
c) Concentrated
d) None of the above
Answer:
c) Concentrated

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 7.
In the marine organism the kidney with glomerulus produce ………………. type of concentrated urine.
a) Concentrated than body fluid
b) Equal to the concentration of body
c) Less than the concentration of body fluids
d) None of the above
Answer:
b) Equal to the concentration of body

Question 8.
The average weight of human kidney,
a) 100-120g
b)150-200g
c) 120-170g
d) 120-150g
Answer:
c) 120-170g

Question 9.
What is the outer covering of the kidney?
a) Renal fascia perirenal fat capsule pleura
b) Renal fascia perirenal fat capsule peri cardial membrane
c) Renal fascia, Peri renal fat capsule meninges
d) Renal fascia perirenal fat capsule fibrous capsule
Answer:
d) Renal fascia perirenal fat capsule fibrous capsule

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 10.
What is meant by renal corpuscle?
a) Glomerulus and Bowman’s Capsule
b) Glomerulus and Malpighian capsule
c) Glomerulus and nephron
d) Glomerulus and Henle’s loop
Answer:
d) Glomerulus and Henle’s loop

Question 11.
Regarding renal tubules find the correct sequences.
a) Glomerulus Bowman’s capsule Malpighian capsule uriniferous tubules.
b) Proximal convoluted tubules thick descending loop thin ascending limb distal convoluted tubule.
c) Proximal convoluted tubule, Henle’s loop. Distal convoluted tubule.
d) Proximal convoluted tubule, thin descending limb thick ascending limb distal convoluted tubule.
Answer:
d) Proximal convoluted tubule, thin descending limb thick ascending limb distal convoluted tubule.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 12.
Urea is synthesisted through this cycle.
a) Citric cycle
b) Carboxylic Acid cycle
c) Ornithinecycle
d) Arginine cycle
Answer:
c) Ornithinecycle

Question 13.
What is the pressure in the afferent arthery of Glomerulus?
a) 55 mm Hg
b) 50 mm Hg
c) 57 mm Hg
d) 58 mm Hg
Answer:
a) 55 mm Hg

Question 14.
What is the amount of filteration of the glomerulus in 24 hours?
a) 200l
b) 180l
c)190l
d) 170l
Answer:
b) 180l

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 15.
What should be the size of the molecule that can pass through the tubules from the plasma filtrate?
a) 7 nm
b) 4 nm
c) 5 nm
d) 6 nm
Answer:
c) 5 nm

Question 16.
What is the pressure in glomerulus?
a) 50 mm Hg
b) 60 mm Hg
c) 55 mm Hg
d) 62 mm Hg
Answer:
c) 55 mm Hg

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 17.
The glomerular pressure encounter ………….. of colloidal osmotic pressure and …………… of hydrostatic pressure.
a) 30mmHg;15mmHg
b) 15mmHg;30mmHg
c) 40 mm Hg; 30 mm Hg
d) 30mmHg;40mmHg
Answer:
a) 30mmHg;15mmHg

Question 18.
What is the net filteration pressure?
a) 55mmHg – (15mmHg + 30mmHg) = 10mm Hg
b) 55 mm Hg – (30 mm Hg +15 mm Hg) =10 mm Hg
c) 55 mm Hg – (35 mm Hg + 5 mm Hg) = 15 mm Hg
d) 55 mm Hg – (5 mm Hg + 35 mm Hg) = 15 mm Hg
Answer:
b) 55 mm Hg – (30 mm Hg + 15 mm Hg) =10 mm Hg

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 19.
What is the amount of filtrate formed in one minute?
a) 100 ml -125 ml
b) 100 ml -150 ml
c) 120 ml -125 ml
d) 130 ml -140 ml
Answer:
c) 120 ml -125 ml

Question 20.
What is the amount of filtrate formed in a day?
a) 170 ml-200 ml
b) 170 ml-190 ml
c) 170 ml-180 ml
d) 170 ml-185 ml
Answer:
c) 170 ml-180 ml

Question 21.
What is the amount of urine excreted in a day?
a) 1.5l
b) 1l
c) 2l
d) 2.5l
Answer:
a) 1.5l

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 22.
Which of the following hormones are secreted by the kidney?
a) Renin
b) Gastrin
c) Calcitriol
d) secretin
a) (ii) and (iii)
b) (i) and (iii)
c) (ii) and (iv)
d) (i) and (ii)
Answer:
b) (i) and (iii)

Question 23.
Where is aquaporins present?
a) Proximal convoluted tubule
b) Distal convoluted tubule and ascending limb of Henle
c) The descending limb of Henle and distal convoluted tubule
d) All the above
Answer:
b) Distal convoluted tubule and ascending limb of Henle

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 24.
Name the hormone that helpsin the reabsorption of water in distal convoluted tubule.
a) Vasopressin
b) Serotonin
c) Oxytocin
d) All the above
Answer:
a) Vasopressin

Question 25.
Where is Renin synthesized in Kidney?
a) Afferent arteriole
b) Efferent arteriole
c) Vasarecta
d) Collecting duct
Answer:
a) Afferent arteriole

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 26.
Name the hormone that helpsin the conversion of plasma protein angioten- sinogen into angiotensin I
a) Renin
b) Vasopressin
c) ADH
d) STH
Answer:
a) Renin

Question 27.
What is micturition?
a) Excretion of urine from the urinary bladder
b) The formation of urine in the glomerulus
c) Urine formation in distal convoluted tubule
d) the absorption of urine in Bowman’s capsule
Answer:
a) Excretion of urine from the urinary bladder

Question 28.
According to the food that maneats the pH of urine ……………… to ……………. can be altered.
a) pH 4.8-7.5
b) PH 4.9-7.9
c) pH 4.5-8.0
d) pH 4.4 -7.4
Answer:
c) pH 4.5-8.0

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 29.
What is the reason for the yellow colour of the urine?
a) Urochrome
b) Haemoerythrin
c) Haemocyanin
d) None
Answer:
a) Urochrome

Question 30.
What is the normal pH of urine?
a) pH 6.0
b) pH 5.3
c) pH 6.4
d) pH 5.9
Answer:
a) pH 6.0

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 31.
What is the amount of CO2 released from lungs in a day?
a) 20l
b) 19l
c)18l
d)119l
Answer:
c)18l

Question 32.
Confirm
Statement A: The important function of sweat gland is to cool the body.
Statement B: The sweat glands excrete sodi¬um chloride urea and lactic acid.
a) Statement A-True B-True
b) Statement A-True B-False
c) Statement A-FalseB-True
d) Statement A – False B – False
Answer:
a) Statement A-True B-True

Question 33.
Confirmation:
Statement S: When kidney fails suddenly there is more chance of recovery.
Statement T: In the chronic kidney failure there may not be any chance of recovery.
a) Statement S-True T-True
b) Statement S-True T-False
c) Statement S-True T-True
d) Statement S – True T – False
Answer:
c) Statement S-True T-True

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 34.
Confirmation:
Statement A: The kidney infection leads to inflammation of bladder and kidney
Statement B: Urination with pain, urinary urgency bloodytinged urine.
a) Statement A – True Statement B explain the symptom of A.
b) A – True – The statement B does not explains the statement A
c) A and B are false
d) A False B – True
Answer:
a) Statement A – True Statement B explain the symptom of A.

Question 35.
What is the normal urea level in the blood
a) 17-30mg/100ml
b) 30-35mg/ 100ml
c) 10-15 mg/100 ml
d) 5-10 mg/100 ml
Answer:
a) 17-30mg/100ml

Question 36.
Find the wrong pair.
a) Renal stone – nephrolithiasis
b) Urine – Urochrome
c) Deficiency of ADH – Urine out put decreases
d) Skin- Lactic acid excretion
Answer:
c) Deficiency of ADH – Urine out put decreases

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 37.
Confirmation:
Statement A: Bright’s disease is due to the infection of streptococcus in children
statement B: There is inflammation of glomerulus.
a) Statement A and Bare false
b) Statement A True B explain the A
c) A True B False
d) A False B – True
Answer:
b) Statement A True B explain the A

Question 38.
Find the wrong pair.
a) Heporin – Anticoagulating factor
b) Glomerulo nephritis – Accumulation of water in the body
c) Primary kidney – Meso nephridia
d) Uremia – Increase in the blood urea level
Answer:
c) Primary kidney – Meso nephridia

Question 39.
How much urine can be stored up in the bladder?
a) 300-600 ml
b) 200-300 ml
c) 400-700 ml
d) 500-800 ml
Answer:
a) 300-600 ml

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 40.
For how much time urine can be held in the bladder?
a) 6 hours
b) 2 hours
c) 5 hours
d) 3 hours
Answer:
c) 5 hours

Question 41.
The urinary bladder is made up this muscle ……………………….
a) Detrusor muscle
b) Striated muscle
c) Sphincter muscle
d) None of the above
Answer:
a) Detrusor muscle

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 42.
Match the following:

1. Steno haline I Shark
2. Eurihaline II Otter
3. Osmo regulators III Goldfish
4. Osrno confirmers IV Salmon

a) 1-IV 2-III 3-II 4-1
b) 1 -II 2-II 3-IV 4-1
c) 1 -III 2-IV 3-II 4-1
d) 1-1 2-II 3-IV 4-III
Answer:
c) 1 -III 2-IV 3-II 4-1

Question 43.
Find out the less toxic waste among the following:
a) Urea
b) Uric acid
c) Ammonia
d) Creatinine
Answer:
a) Urea

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 44.
Find out the ammonotelic organisms?
a) Reptiles
b) Birds
c) Aquatic amphibians
d) Frog
Answer:
c) Aquatic amphibians

Question 45.
Find out the wrong pair.
a) Rennette cells – Annelida
b) Molluscs – Metanephridia
c) Amphioxus – Mesonephridia
d) Tapeworm – Flame cells
Answer:
c) Amphioxus – Mesonephridia

Question 46.
Find the excretory structure of prawn?
a) Malpighian tubules
b) Green glands
c) Rennette cells
d) Peyer gland
Answer:
b) Green glands

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 47.
Kidney with noglomerulus form this types of urine?
a) Hypertonic
b) Isotonic
c) Hypotonic
d) Neutrotonic
Answer:
c) Hypotonic

Question 48.
Match the following:

1. Conical tissue masses a) Columns of Bertini
2. Extension in renal b) Renal pelvis
3. Broad part of Hilum c) Calyces
4. Projection of pelvis d) Medullary pyramids

a) 1-d 2-a 3-b 4-c
b) 1-a 2-b 3-c 4-d
c) 1-b 2-a 3-c 4-d
d) 1-a 2-c 3-b 4-d
Answer:
a) 1-d 2-a 3-b 4-c

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 49.
How much urine can be held in the urinary bladder?
a) 300-800ml
b)300-600ml
c) 100-400ml
d)200-300ml
Answer:
b)300-600ml

Question 50.
The muscles of urinary bladder is called by this name?
a) sphincter muscle
b) Detrusor muscle
c) constricting muscle
d) Peristaltic muscle
Answer:
b) Detrusor muscle

Question 51.
Name the nephron where the Henle’s loop is short?
a) Medullary nephron
b) Cortical nephron
c) Juxta medullary nephron
d) Medulla nephron
Answer:
b) Cortical nephron

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 52.
The vessel which runs parallel to the loop of Henle is called by this name.
a) Efferent artery
b) Afferent artery
c) Vasarecta
d) Vasanervosa
Answer:
c) Vasarecta

Question 53.
What is the process of urea formation?
a) Ross cycle
b) Ornithine cycle
c) Urea cycle
d) b and c
Answer:
b) Ornithine cycle

Question 54.
What is the pressure in the afferent arteriole?
a) 35 mm Hg
b) 55 mm Hg
c) 20 mm Hg
d) 40 mm Hg
Answer:
b) 55 mm Hg

Question 55.
What is the filtrate entered into the Bowman’s capsule from glomerulus?
a) Secondary urine
b) Primary urine
c) Tertiary urine
d) Quarternary urine
Answer:
b) Primary urine

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 56.
Find the correct option
Assertion: The glomerular filtrate resembles the blood
Reason: The glomerulus filtered the blood received from efferent artery
a) Assertion True Reason True
b) Assertion False Reason False
c) Assertion True The Reason does not explains the statement
d) Assertion True Reason explains A
Answer:
c) Assertion True The Reason does not explains the statement

Question 57.
What is the fate of water in the descending limb of Henle?
a) The concentrations of Na reduces
b) The concentration of Cl ions reduces
c) Na and Cl gets concentrated in the filtrate.
d) Formation of Hypotonic solution.
Answer:
c) Na and Cl gets concentrated in the filtrate.

Question 58.
How can the pH of blood be regulated?
a) Due to glucose reabsorption
b) Due to the reabsorption of HCO3
c) Due to the reabsorption of Na+
d) Due to the reabsorption of Cl
a) 1-2 II-4 III-3 IV-1
b) 1-1 II-2 III-3 IV-4
c) 1-4 II-3 III-2 IV-1
d) 1-2 II-l III-3 IV-4
Answer:
b) 1-1 II-2 III-3 IV-4

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 59.
Match the following
Answer:

I. Potassium 1. Descending limb of Renie
II. Water 2. Active transport
III. Glucose 3. Proximal convoluted tubule
IV. Na, cl, lc 4. Aqua porin

Question 60.
How is osma regulation in medulla maintained?
a) Juxtamedullary
b) Counter current
c) Positive current exchanger
d) Negative control
Answer:
b) Counter current

Question 61.
Find the wrong pair.
a) Vasa recta – Proximal convoluted tubule
b) ADH – Neuro hypophysis
c) Specialized nephron tissue – Juxtaglomerular apparatus
d) Renin – Glanularcell
Answer:
a) Vasa recta – Proximal convoluted tubule

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 62.
This synthesizes angio tenginogen.
a) Kidney
b) Liver
c) Malpighian tubule
d) Glomerular
Answer:
b) Liver

Question 63.
This increases the absorption of sodium ions.
a) Renin
b) Angiotensin I
c) Angio tensin II
d) Angio tensinogen
Answer:
c) Angio tensin II

Question 64.
Name the hormone that decreases the blood pressure
a) Angiotensin I
b) Atrial natriuretic peptide
c) Vasopressin
d) ADH
Answer:
b) Atrial natriuretic peptide

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 65.
This decreases the excretion of Renin?
a) Aldosterone
b) vasopressin
c) Atrial natriuretic peptide
d) Ventrical natriuretic peptide
Answer:
c) Atrial natriuretic peptide

Question 66.
What is the pH of Urine?
a) 6.5
b) 7.0
c) 6.0
d) 8
Answer:
c) 6.0

Question 67.
What is the reason for the yellow colour of urine?
a) Uro chrome
b) Cytochrome
c) Chlorochrome
d) Phyto chrome
Answer:
a) Uro chrome

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 68.
The increase in the level of urea
a) Uremia
b) ureomia
c) Uricmia
d) Ketosis
Answer:
a) Uremia

Question 69.
The accumulation of salt in the blood.
a) Poly urea
b) Oligo urea
c) Polydipsia
d) Polyphagia
Answer:
b) Oligo urea

Two marks

II. Very short answer 

Question 1.
What is meant by stenohaline organism?
Answer:
The stenohaline animals can tolerate only narrow fluctuations in the salts concentration. (eg) Goldfish.

Question 2.
What is meant by Eury haline animals.
Answer:
Eury haline animals are able to tolerate wide fluctuations in the salt concentrations. (eg) Salmons Tilapia.

Question 3.
What is meant by Osmoregulation?
Answer:
It is the control of tissue osmotic pressure which acts as a driving force for movement of water across biological membrances.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 4.
What is meant by Ionic regulation?
Answer:
It is the control of ionic composition of body fluids.

Question 5.
What are the nitrogenous waste formed due to the degen ration of aminoacid?
Answer:

  • Ammonia
  • Urea
  • Uric acid

Question 6.
Write is kidney situated in the body?
Answer:

  • The kidney lie in the superior lymbar region between the levels of the last thoracic and third lumber vertebra close to the dorsal inner wall of the abdominal cavity.
  • The right kidney is placed lower than the left kidney.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 7.
What is meant by renal hilum?
Answer:
The centre of the inner concave surface of the kidney has a notch called the renal hilum through which ureter blood vessels and nerves innervate.

Question 8.
What is meant by malpighian capsule or renal corpuscle?
Answer:
The Bowman’s capsule and the glomerulus together constitute the renal corpuscle.

Question 9.
What are podocytes?
Answer:

  • The visceral wall of gromerulus is made of epithelial cells called podocytes.
  • The podocytes end in foot processes which cling to the basement membrance of the glomerulus.

Question 10.
What are cortical nephrons?
Answer:
The loop of Henle is too short and extends only very little into the medulla and are called cortical nephrons.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 11.
What is meant by Juxta medullary nephrons?
Answer:
Some nephrons have very long loop of Henle that run deep in to the medulla and are called Juxta medullary nephrons.

Question 12.
What is vasa recta?
Answer:
The efferent arteriole serving the juxta medullary nephron forms bundles of long straight vessel called vasa recta and runs parallel to the loop of Henle.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 13.
List the three important process of urine formation?
Answer:

  1. Glomerulus filtration
  2. Tubular reabsorption
  3. Tubular secretion

Question 14.
What is meant by Glomerulus filtrate? What is its composition?
Answer:
The blood comes to the glomerulus are filtered and enters the Bowman’s capsule is called glomerular filtrate
Composition Water glucose aminoacids and nitrogenous wastes.

Question 15.
What is meant by Net filtration pressure?
Answer:
The two opposing forces against the glomerular blood pressure

  1. Collodial osmotic pressure is 30 mm Hg
  2. Capsular hydrostatic pressure is 15mm Hg

Net filtration pressure- Glomerular
Hydrostatic pressure – Colloidal
Osmotic pressure + Capsular hydrostatic pressure = 55 mm Hg – 30 mm Hg + 15 mm Hg = 10 mm Hg

Question 16.
What is meant by Glomerular filtration rate?
Answer:
It is the volume of filtrate formed in a minute in all nephrons of both the kidneys.

Question 17.
What is the amount of glomerular filtrate?
Answer:
In adults the GFR is 120 -125 ml per minute.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 18.
What is meant by primary filtrate?
Answer:
The filtrate enters from glomerulus to the Bowman’s capsule is called as primary filtrate.

Question 19.
Why glomercular filtrate resembles blood plasma?
Answer:
In the glomerular filtrate all the contents that present in the blood except the plasma protein is present.

Question 20.
How much filtrate is formed in one day?
Answer:
The amount of filtrate formed in a day is 170 to 180l.

Question 21.
What is meant by selective permeability?
Answer:

  • Some substances present in the glomerular filtrate is essential for our body.
  • Hence these molecules are reabsorbed in a tubules. This process is called as selective reabsorption.

Question 22.
Name the process in which selective reabsorption is taking place?
Answer:

  • Passive transport
  • Active transport
  • Diffusion
  • Osmosis

Question 23.
What are aqua porins?
Answer:
Aquaporins are membrane transport proteins that allow water to move across the epithelial cells.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 24.
What are the molecules that move into the filtrate of nephron?
Answer:
Nitrogen potassium ammonia creatinine and organic acids.

Question 25.
What is meant by Isotonic solution?
Answer:
Isotonic condition of a solution indicates no passage of water across the membrane separating two such solution.

Question 26.
What is meant by Hypotonic solution?
Answer:
The solution in which there is a loss of water then that solution is a hypotonic solution.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 27.
What is meant by hypertonic solution?
Answer:
When two solutions A and B are separated by a semi permeable membrane when water move from solution A to B across the membrane then the B solution is hypertonic and the solution A where the water loses is known as hypotonic solution.

Question 28.
Name the organ that the angiotensin II acton?
Answer:

  • Heart
  • Kidney
  • Brain
  • Adrenal cortex

Question 29.
What are the symptoms of diabetes mellitus?
Answer:

  • Excess glucose and ketone bodies in the urine
  • Poly dipsia – Excessive drinking of water
  • Polyurea – Excretion of large quantities of urea
  • Polyphagia – Excessive appetite

Question 30.
Name the organ that excrete nitrogen other than kidney?
Answer:

  • Lungs
  • Liver
  • Skin

Question 31.
What are the significance of sweat glands?
Answer:

  • Sweat produced by the sweat glands helps to cool the body.
  • It excretes Na+ and Cl small quantities of urea and lactate.

Question 32.
What is meant by nephrolithiasis?
Answer:
It is the formation of hard stone like masses in the renal tubules of renal pelvis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 33.
What is meant by phleothotomy or lithotripsy?
Answer:
Renal stones can be removed by the technique pyleothotomy or lithotripsy.

Question 34.
What is meant by Bright’s disease?
Answer:
The inflammation of the glomeruli of both kidney of children due to the streptococcal infection is called as Bright’s disease.

Question 35.
What is meant by haemodialysis?
Answer:
The process of removing toxic urea from the blood of renal failure patients is known as haemodialysis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 36.
Why females are prone to urinary tract infection than men?
Answer:
Females are prone to recurring urinary tract infection as they have shorter urethra.

Question 37.
Why men are finding difficult to urinate in their old age?
Answer:
With age prostate in males may enlarge which forces urethra to tighten restricting a normal urinary flow.

Question 38.
What is the change in Urine formation when there is a deficiency of ADH?
Answer:
When there is a deficiency of ADG the reabsorption of water from the proximal convoluted tubule decreases leads to dilute urine formation.

Question 39.
Why there is a increase in the body fluid when we drink large volume of water with out eating anything salty?
Answer:

  • When we drink or eat salty products the Na+ enters into the body fluids.
  • The sodium ions helps in the reabsorption of water
  • But when we drink only water as there is no sodium ions the tubules cannot reabsorb water.
  • Hence there is a increase in the urine output.

Question 40.
Consider how different foods affect water and salt balance and how the excretory system must respond to maintain homeostasis.
Answer:

  • When we eat different foods the salt present in them goes to renal tubules.
  • If sufficient salts are present in the body fluids this salt may not be reabsorbed when it goes through nephron and excreted through urine.
  • If there is a decrease in the volume of water in body fluids sodium ions are reabsorbed. Hence water is reabsorbed from filtrate and water volume is increased.

Question 41.
Name the different process that maintains water level? When there is a severe loss of water in the body?
Answer:

  • The blood vessels supplies to skin constricts and thus there is a decrease in the secretion of sweat prevents loss of water.
  • There is a reduction in the glomerular blood pressure and the rate of filtration decreases.
  • The reaborption of water in the proximal distal convoluted tubules increase.
  • There is absorption of water from the small intestine and large intestine and thus increases the water content in the blood.

Question 42.
What is meant by Osmolarity?
Answer:

  • The solute concentration of a solution of water is known as osmolarity,
  • The unit is millosmoles / litre (mOsm /l)

Question 43.
What is meant by aquaporins? What are its functions?
Answer:
Aqua porins are water permeable channels.
Functions
It helps in allowing water to move across the epithelial cells in relation to the osmotic difference from the lumen to the interstitial fluid.

Question 44.
How can we measure that there is a efficient glomerular filtration?
Answer:
If the renal clearance is equal to the glomerular filtration rate with little reabsoption and secretion. Then we know the kidney is functioning efficiently.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 45.
What is the Significance of having long and short Henle’s loop of Nephrons?
Answer:

  • The main function of Henle’s loop is to reabsorb water from filtrate.
  • If the length of the loop is longer then there is more reabsorption of water and if the lengh of Henle’s loop is shorter then the reabsorption of water is less.

Question 46.
Give notes on Capillary to capsule.
Answer:
Bloodcells and most blood proteins are too big to cross the capsular membrane into the capsule space. But the membrane’s slits and pores allow through water mineral salts polypeptides and other small molecules including waste such as urea ammonia and creatinine.

Question 47.
Give short notes on Blood enters the glomerulus.
Answer:
Blood flows from renal arteriole into the knot of capillaries. It enters at pressure which will force water and other out of the capillaries into the capsular space.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 48.
Give notes on filteration in proximal convoluted tubule?
Answer:
Proximal tubule is nearer to the Bowman’s capsule. This region allows much water to be reabsorbed into the capillaries and surronding fluids as well as glucose mineral salts and other useful substances.

Question 49.
Give notes on filteration in peritubular capillaries.
Answer:
It is also called the vasarecta this network reabsorbs upto 99 percent of the water in the tubule as well as various other substance using active pumps it also moves sodium from the blood to the tubule.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 50.
Give notes on filteration in Henle’s loop (Ascending)
Answer:

  • As the loop of the Henle dipsin to the renal medcula more water moves from the tubule into the blood as well as small amounts of salts and some urea and creatinine.
  • Some acids and amines may move into the tubule in which ammonia cango in both the direction.

Question 51.
Give notes on filteration in distal tubule?
Answer:

  • Distal tubule is far from capsule. This region may see water go in or out of the tubule depending on the concentration of water already in the tubule/ while hydrogen and potassium ions move to regulate both blood and urine pH.
  • Acids amines and ammonia compounds may also transported into the tubule.

Question 52.
Give notes on filteration in collecing duct.
Answer:

  • Fine adjustment of urine composition continues into the collecting duct system.
  • About 5 percent of all the water and sodium being reabsorbed into the blood is recovered here.

Question 53.
Give notes on venousflow?
Answer:

  • Blood flowing away from the nephrons carries 99 % of its orginal water.
  • 98% of its sodium calcium and cholrides and about 40% of its urea.

Question 54.
We are not consuming urea. But in our body area is produced. Why?
Answer:
Through Arnithine cycle in the lives the nitrogenous waste formed due to the breakdown of amino acid creates urea.

Question 55.
What is meant by Ionic regulation?
Answer:
It is the control of the ionic composition of body fluids.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 56.
What are stenohaline animals?
Answer:
They can tolerate only narrow fluctuations in the salt concentration. Ex: Goldfish

Question 57.
What are Euryhaline animals?
Answer:

  • They are able to tolerate wide fluctuations in the salt concentrations. Ex: Artemia Salmons.
  • Acids amines and ammonia compounds may also transported into the tubule.

Question 58.
List the nitrogenous wastes
Answer:
Ammonia urea uricacid.

Question 59.
What are the other nitrogenous wastes of protein metabolism?
Answer:
Alantonin Alantoic acid, Ornithuriacid creatinine creatine purines pyramidines and pterines.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 60.
Which are called ammoneteles?
Answer:
Animals that excreate most of its nitrogen inthe form of ammonia are called ammonoteles.

Question 61.
What are called as uricoteles?
Answer:
Animals that excrete uric acid crystals with minimum loss of water are called uricoteles.

Question 62.
What are ureoteles?
Answer:
Mammals and terrestrial amphibians mainly excrete urea are called ureoteles.

Question 63.
How is Reptiles produced lesshypotonic urine?
Answer:
Reptiles have reduced glomerulus or lack glomerulus and Henles loop and hence produce very little hypotonic urine.

Question 64.
How is mammals produced concentrated urine?
Answer:
Mammalian kidneys produce concentrated urine due to the presence of Henle’s loop.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 65.
What are the three coverings of kidney?
Answer:

  • Renal facia
  • Perirenal fat capsule
  • Fibrous capsule

Question 66.
What are medullary pyramids?
Answer:
The medulla is divided into a few conical tissue masses called medullary pyramids.

Question 67.
What is meant by renal columns of Bertini?
Answer:
The part of cortex that extends in between the medullary pyramids is the renal columns of Bertini.

Question 68.
What is meant by renal pelvis?
Answer:
A broad funnel shaped space inner to the hilum is called renal pelvis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 69.
What is calyces?
Answer:
The projection in the pelvis is called calyces.

Question 70.
What are cortical nephrons?
Answer:
The loop of Henle is too short and extends only very little in to the medulla and are called cortical nephrons.

Question 71.
What is meant by juxta medullary nephron?
Answer:
Some nephrons have very long loop of Henle that run deep into the medulla and are called Juxta medullary nephrons.

Question 72.
What is the functions of aquaporins?
Answer:
This helps in allow water to move across the epithelial cells in relation to the osmotic difference from the human to the interstitial fluid.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 73.
What is meant by juxta glomerular apparatus?
Answer:
It is a specialized tissue in the afferent arteriole of the nephron that consists of maculadensa and granular cells.

Question 74.
What is meant by micturition?
Answer:
The process of release of urine from the bladder is called micturition.

Question 75.
What are the symptoms of diabetes mellitus?
Answer:
Presence of glucose and ketone bodies in the urine.

Question 76.
How is lung acting as a excretory organ?
Answer:
Lungs remove large quantities of carbondixide 181 / day and significant quantities of water every day

Question 77.
What is meant by renal clearnace?
Answer:
The amount of solute passing from the urine in a given period of time is renal clearance.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 78.
How can we estimate the efficiency of kidney?
Answer:

  • The renal clearance is equal to the glomerular filtrate then there is efficient filtration with little reabsorption and secretion.
  • Thus we can estimate the clearance is equal.

Three Marks

Short Answer –

Question 1.
a) List the ma j or nitrogenous wastes.
b) What are other wastes formed during protein metabolism?
Answer:
a) 1. Major nitrogenous wastes.

  • ammonia
  • Urea
  • Uricacid

b) Other Wastes:

  • Trimethy lamine oxide TMO
  • Quanine
  • Allantonin
  • Creatinine
  • Creatine
  • Purines

Question 2.
Give notes on ammonoteles uricoteles and ureoteles.
Answer:
Ammonoteles:

  • Animals that excrete most of its nitrogen in the form of ammonia are called ammonoteles.
    (e.g) fishes Amphibians aquatic insects.
  • In bony fishes ammonia diffuses out acrossthe body surface.

Uricoteles:

  • Animals which excrete uricacid crystals with a minimum loss of water is called.
  • Uricoteles (e.g) Reptiles Birds land snails and insects.

Ureoteles:

  • Animals which excrete urea as a nitrogenous wastes are called ureoteles
  • (e.g) Mammals, terrestrial amphibians.

Question 3.
Nephrons are the functional and structural unit of kidney’s. What is the relationship between glomerulus, Henle’s loop and urine formation?
Answer:

  • Reptiles have reduced glomerulus or lack glomerulus and Henle’s loop and produce hypotonic urine (dilute)
  • Mammalian kidneys produce concentrated urine due to the presence of long Henle’s loop.
  • Aglomerular kidneys of marine fishes produce little urine that is iso osmotic to the body fluid.
  • Amphibians and fresh water fishlack Henle’s loop hence produce dilute urine.

Question 4.
Differentiate the cortical nephron fron juxta medullary nephron
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 3

Question 5.
Give Short notes on capillary bed of the nephron:
Answer:
The first capillary bed of the nephron is the glomerulus.
The other is peritubular capillaries.
1. Glomerulus:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 4
Blood enters into the glomerulus through afferent arteriole and drained by the efferent arteriole.

2. Peritubular capillaries:

  • The efferent arteriole forms a fine cappillary network around the renal tubule called the peritubular capillaries.
  • The efferent arteriole serving the juxta medullary nephrons forms bundles of long straight vessel called vasa recta.
  • Vasa recta is absent in cortical nephrons.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 5

Question 6.
What happens to the filtrate that comes to the proximal convoluted tubule? (or) Explain about reabsorption?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 6

  • In the proximal convoluted tubule glucose lacticacid aminoacid sodium ions are reabsorbed.
  • Sodium is reabsorbed – potassium pump in the proximal convoluted tubule.
  • Small amounts of urea and uric acid are also reabsorbed.

Question 7.
What happen to the filtrate that comes to the Henle’s loop? (or) Explain the reabsorptionin the Henle’s loop?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 7

Descending Loop:
The aquaporin present in the descending limb of Henle permeable to water but not permeable to salts.
Hence Na+ and cl gets concentrated in the filtrate.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 8

Ascending Limb:
It is impermeable to water but permeable to solutes like Na+cl and K+.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 8.
Give an account of tubular reabsorption?
Answer:
The volume of filterate formed perday is 170-180 is and the urine released in a day is 1.5l

  • Nearly 99 % of the glomerular filtrate is reabsorbed by the renal tubules. It is called selective reabsorption.
  • Reabsorption is taken place by the tubular epithelial cells in different segments of the nephron by active transport or passive transport diffusion and osmosis.

Question 9.
What is happenning to the filtrate in distal convoluted tubule (or) Reabsorption taking place here?
Answer:

  • Depending on the body’s need the reabsorption taking place here and is regulated by hormones.
  • Reabsorption of bicarbonate HCO3 takes place to regulate the blood pH.
  • Homestasis of K+ and Na+ in the blood is also regulated in this region.

Question 10.
Name the structures that regulate the functioning of kidney?
Answer:

  • Hypothalamus
  • Juxta glomerular apparatus
  • Heart

Question 11.
What is meant by diabetes incipidus?
Answer:
If there is deficiency or absence of ADH that leads to dilute urine called diabetes incipidus.
Symptoms.

  • Excessive thirst
  • Excretion of large quantities of dilute urine.
  • FaIl in blood pressure.

Question 12.
Give notes on juxta glomerular apparatus?
Answer:

  • Specialized tissue in the afferent arteriole of ncphron is the juxta glomerular apparatus.
  • It consists of macula densa and granular cells.
  • The macula densa cells sense distal tubular flow and affect afferent alteriole diameter.
  • The granular cells secrete renin.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 13.
Why female are prone to urinary tract infections? (Urethritis)
Answer:

  • Female’s urethra is very short and its external opening is close to the analopening.
  • Hence improper toilet habits can easily carry faecal bacteria into the urethra.
  • The urethral mucusa is continuous with the urianary tract and the inflammation of the urethra is called urethriti’s.

Question 14.
What is cystitis?
Answer:
The urinary tract infection leads to inflammation of bladder called cystiti’s.
Symptoms:

  • Painful urination
  • Urinary Urgency
  • Cloudy or bloodtingedurine
  • Back pain head ache offen occurs

Question 15.
What is meant by renal failure? What are its types?
Answer:
When the kidney fails to excrete wastes may lead to accumulation of urea with marked reduction in the out put called renal failure.
Types
Acute renal failure
Chronic renal failure

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 16.
Why the chronic renal failure is dangerous than acute renal failure?
Answer:

  • Though the kidney stops its function abruptly there are chances for recovery of kidney function in acute renal failure.
  • But in chronic failure there is a progressive loss of function of the nephron which gradually decreases the function of kidney.

Question 17.
What is meant by glomerulo nephritis or Bright’s disease? What are its symptoms?
Answer:
Inflammation of the glomerulus of both the kidneys due to the strepto coccal infection in children is called as Bright’s disease Symptoms

  • Haematuria
  • Proteinuria
  • Salt and water retention – Oligouria (Low urine out put)
  • Hypertension and Pulmonaryoedema

Question 18.
a) What is meant by kidney transplantations.
b) Where is graft kidney received from?
c) What are the steps to be taken to avoid graft rejection?
Answer:

  • Transfer of healthy kidney from one person (donor) to another person with kidney failure is called kidney transplantation.
  • The donated kidney may be taken from a healthy person who is declared brain death or from sibling or close relatives.
  • Immuno supressive drugs are administered to the patient to avoid tissue rejection.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 19.
a) Name the hormone that the dipsticks contain which tests urine?
b) Which colour indicates the presence of glucose in the urine?
Answer:

  • Glucose oxidase and peroxidase.
  • Brown coloured compound is produced.

Question 20.
What are Osmo confirmers?
Answer:
Osmo confirmers are able to change their internal osmotic concentration with change in external environments asin marine and sharks. molluscs

Question 21.
What are Osmo regulators?
Answer:
They maintain their internal osmotic concentration irrespective of their external osmotic environment, (eg) Otters.

Question 22.
List the excretory structures of different organisms.
Answer:

  • Protonephridia
  • Meta nephridia
  • Flame cells – Platy helminthes
  • Rennette cells – Nematodes
  • Malpighian tubules – Insects
  • Greenglands – Prawns

Question 23.
What is meant by filtration slits?
Answer:

  • The visceral layer of glomerulus is made of epithelial cells called podocytes and ends in foot processes which cling to the basement membrane of the glomerulus.
  • The openings between the foot processes are called filtration slits.

Question 24.
Draw the diagram of ornithine cycle?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 9

Question 25.
Why there is a pressure reduction when the blood goes through efferent arteriole?
Answer:

  • Blood enters the glomerulus faster with greater force through afferent arteriole.
  • Because the afferent arteriole is broader than efferent arteriole that is why the pressure reduces when it goes through the efferent arteriole.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 26.
What are the changes taking place in our body when there is a fluid loss?
Answer:

  • The osmo receptors in the hypothalamus is stimulated.
  • The neurohypophysis is stimulated and anti diuretic hormone is liberated.
  • The aquaporins in the tubuler are increased and water is reabsorbed and enters into the interstitial cell and the water loss is rectified.

Question 27.
How is skin acted as a excretory organ?
Answer:

  • Skin excretes Na+ and Cl small quantities of urea and lactate.
  • Sebaceous glands eliminated certain substances like steroids, hydrocarbons and waxes.

Question 28.
What is meant by urethritis?
Answer:
The urethral mucosa is continuous with the urinary tract. The infection in the urethra is called urethritis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 29.
What is meant by Cystitis?
Answer:
The infection in the urethra can ascend the tract to cause bladder inflammation called cystitis.

Question 30.
What is meant by Phelitis or Pyelone phritis?
Answer:
The bladder infection ascend to the renal inflammation called pyelitis or pyelonephritis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 31.
What are the two types of renal failure?
Answer:

  1. Acute renal failure
  2. Chronic renal failure

1. Acute renal failure

  • In acute renal failure the kidney stops its function abruptly.
  • There are chances for recovery of kidney function.

2. Chronic renal failure
In chronic renal failure there is a progressive loss of function of the nephron which gradually decreases the function of kidneys.

Question 32.
What is meant by Uremia?
Answer:
Uremia is characterized by increase in Urea uric acid and creatinine in blood.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 33.
What is meant by Nephrolithiasis?
Answer:
It is a formation of hard stone like masses in the renal tubules of renal pelvis.

Question 34.
How is water excess taken through drinking too much fruit juice regulated?
Answer:

  • When we drink much fruit juice the osmo receptors in hypothalamus is not stimulated and hence the secretion of vaso pressin from neuro hypophysis is reduced.
  • The aquaporin escapes from collecting duct to cytoplasm and hence water reabsorption is prevented and formed dilute urine.

Question 35.
What is uremia?
Answer:
Uremia is a condition in which there is a increase level of urea uric acid and creatinine in blood.

Question 36.
What is the amount of Urea present in the blood?
Answer:

  • The level of urea in the blood is 17 -30 mg /100ml.
  • In chronic kidney failure there is 10 times increase in urea level.

Five marks

IV. Detailed Answers –

Question 1.
Name the different excretory structure and different organisms.
Answer:
1. Invertebrate – Protonephridia / Meta nephridia
2. Platvhelminthes – Flamecells
3.  Amphioxues – Solenocytes
4 Nematodes – Rennette cells
5. Annelida – Metanephridia
6. Insects – Malpighian tubules
7. Prawn / Crustaceans – Green glands / Antenna! glands

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 2.
The concentration of urine depends on the structure of nephron? Explain?
Answer:

  1. In the reptiles the glomerulus is reduced or there may be no glomerulus and 1-lenle’s loop and hence produces dilute urine (chypotonic).
  2. In the mammals the long Henle’s loop produces concentrated urine (hypertonic)
  3. A glomerular kidneys of marine fishes produce little urine that is isoosmotic to the body fluid.
  4. Amphibians and fresh water fish lack Henle’s loop hence produce dilute urine.

Question 3.
Draw the following diagram and mark the following parts.
Answer:
A) Aorta
B) Renal vein
C) Ureter
D) Urinary bladder
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 10

Question 4.
a. What is the weight of kidneys? What are its outer coverings?
b. Draw the L.S of kidney and name the parts.
c. Explain the internal structure of kidney
Answer:
a. Each kidney weighs an average of 120 – 170 gms.
The outer layer of the kidney is covered by three layers of supportive tissue namely renal fascia perirenal fat capsule fibrous capsule.

b. Draw the LS of kidney and name the parts.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 18

c. Internal Structure of kidney

  • The longitudinal section of kidney shows an outer cortex inner medulla and pelvis.
  • The inner concave surface of the kidney is renal hilum through which ureter blood vessels and nerves enter.
  • Inner to the hium is a funnel shaped renal pelvis with projection called calyces.
  • The calyces collect the urine and empties in to the ureter.
  • The medulla consists of conical tissues called medullary pyramids or renal pyramids.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 5.
a) What is the structural and functional unit of kidney.
b)Draw the diagram of nephron and name the parts.
c) Give short notes on Malpighian body or Renal Corpuscle.
Answer:
a) Hie structural and functional unit of kidney is nephron. It is composed of Malpighian body or renal corpuscle and Urine ferous tubule.
b) Structure of nephron
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 11
c. Malpighian body/Renal Corpuscle.

  • The Bowman’s capsule and the glomerulus together constitutes Malpighian corpuscle.
  • Bowman’s capsule is made up of two layers. It contains blood vessels called glomerules.
  • The endothelial of glomerulus has many pores. The viscral layers of glomerulus is made of epithelial cells called podocytes.
  • Tire podocytes end in foot processes which cling to the basement membrance of the glomerulus.
  • The openings between the foot processes are called filtration slits.

Question 6.
a) Give the different regions of renal tubule.
b) Where is renal tubule present in the kidney?
c) How is renal tubules differentiated depending on the Henle’s loop?
Answer:
a)
1. proximal convoluted tubule.
2. Henle’s loop
a. Thindescending limb of Henle’s loop.
b. Thick ascending limb.

2. Distal convoluted tubules
The distal convoluced tubules opens in to acollecting duct.
Several collecting ducts fuse to form papillary duct that delivers urine in to the calvces which opens into the renal pelvis.
b) The PCT and DCT are situated in the cortical region of the kidney.
The loop of Henle is in the medulla region.
c) The loop of Henle is too short and extends only very little into the medulla and are called cortical nephron.
Some nephrons have very long loops of Henle that run deep into the medulla and are called Juxta medullary nephrons.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 7.
a) Give notes on capillaries of nephron
b) Give an account of blood vessels of glomerulus.
c) What is vasa recta? Where is it seen?
Answer:
Capillaries of nephron
1. Glomerulus capillary bed
2. Peritubular capillaries

1. Glomerular capillarybed

  • It consists of afferent and efferent arteriole.
  • The afferent arteriole is broader than efferent arteriole.
  • The efferent arteriole that comes out of the glomerulus forms a fine capillary network around the renal tubule called the peritubular capillaries.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 12
Vasa recta
The efferent arteriole serving the juxta medullary nephrons form bundles of long straight vessel called vasa recta and runs parallel to the loop of Henle.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 8.
a) Describe the three important process in the urine formation?
b) Give an account on glomerular filtration
Answer:
a. Main Processes

  • Clornerular Filtration
  • Tubular reabsorption
  • Tubular secretion

b. Glomerular filtration

  • Blood enters the kidney from the renal artery.
  • Blood enters the glomerulus faster with greater force through the afferent arterioles because the afferent arteriole is wider than efferent arteriole.
  • The glomerular hydrostatic pressure is around 55 mm Hg.
  • The colloidal osmotic pressure is 30 mm Hg. Capsular hydrostatic pressure is 15 mm Hg. The net pressure of 10 mm Hg is responsible for the renal filtration.
  • Next filtration pressure 55 mm Hg – (30 mm Hg +15 mm Hg) 10 mm Hg.
  • The kidneys produce 1801 of glomerular filtrate 24 hours and 120 -125 ml/min.
  • This filtrate will enter into the Bowman’s capsule and called primary urine. It contains more water colloidal protein, glucose salts and nitrogenous waste.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 13

Question 9.
a) Why glomerular filtrate resembles blood plasma?
b) Tabulate the concentration of substances in the blood plasma and in the glomerular filtrate.
Answer:
As the glomerular filtrate forms it contain all the substances except plasma protein of blood. Hence it resembles blood.

Substance Concentration in blood Plasma / g dm-3 Concentration in glomerular filtrate / g dm-3
Water 900 900
Proteins 80.0 0.05
Aminoacids 0.5 0.5
Glucose 1.0 1.0
Urea 0.3 0.3
Uric Acid 0.04 0.04
Creatinine 0.01 0.01
Inorganic ions (mainly (Na+, K+ and Cl ) 7.2 7.2

Question 10.
a) What is meant by Tubular Secretion?
b) Give an account of tubular secretion of nephron.
Answer:
Tubular Secretion:

  • The collecting tubule of nephron secrete H+ NH4 , Creatinine and Organic acid and liberated into the tubules and excreted through urine.
  • Most of the water is absorbed in the proximal convoluted tubule.
  • Na is exchanged for water in the loop of Henle.
  • The hypotonic fluid enters the distal convol uted tubule.
  • Substances such as urea and salts pass from peritubular blood into the cells as distal convoluted tubule and then to collecting duct.
  • Water is absorbed and concentrated hypertonic urine is form ed.
  • For every H+ secreted into the tubular filtrate a Na+ is absorbed by the tubular cell.
  • The H secreted combines with HCO3, HPO3 and NH3 and gets fixed as carbonic acid CH2CO3 and Phosphoric acid CH2PO4
  • Since H+ gets fixed in the fluid reabsorption of H+ is prevented.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 11.
a) In which process concentrated urine is formed?
b) How is concentrated urine formed in the Hen le’s loop.
Answer:
a) The major function of Henle’s loop is to concentrate Na+ and Cl.

  • There is low osmolarity near the cortex and high osmolarity towards the medulla.
  • This osmolarity in the medulla is due to the presence of the solutes transporters and is maintained by
    the arrangement of the loop of Henle collecting duct and vasa recta.
  • The osmolarity of interstitial fluid is 300 m Osm.
  • The Henle’s loop create a countercurrent multiplier.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 14

  • As the fluid enters the descending limb water moves from the lumen into the inter stitial fluid the osmolarity reduces.
  • To counteract this dilution the region of the ascending limb actively pumps solutes from the lumen into the interstitial fluid and the osmolarity increases to about 1200 m OSM in medula.

b) The vasa recta maintains the medullary osmotic gradient via counter current exchanger.

  • The counter current exchanger of vasa recta preserves the medullary gradient while removing reabsorbed water and solutes.
  • The vasa recta leaves the kidney at the junction between the cortex and medulla.
  • When the blood leaves the efferent arteriole and enters vasa recta the osmolarity in the medulla increases (1200 rnOsm) and result in passive up take of solutes and loss of water.
  • As the blood enters the cortex the osmolarity in the blood decreases and the blood loses solutes and gain water to form concentrated urine.

Question 12.
How is vasa recta helps in producing concentrated urine?
Answer:
Vasa recta maintains the medullary osmotic gradient via counter current exchanger.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 15

  • Vasa recta preserves the medullary gradient while removing reabsorbed water and solutes through counter current exchanges.
  • The vasa recta leave the kidney at the junction between the cortex and medulla.
  • The interstitial fluid at this point is iso – osmotic to blood.
  • When the blood leaves the efferent arteriole and enters the vasa recta the osmalarity in the medulla increases (1200 mOsm) and results in passive up take of solutes and loss of water.
  • As the blood enters the cortex the osmolarity in the blood decreases (300mOsm) and the blood loses solutes and gains water to form concentrated urine.
  • Human kidneys can produce urine nearly four times concentrated than the initial filtrate formed.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 13.
a) What are the structures that regulate kidney functioning?
b) What is the role of ADH in Urine formation.
c) What are the symptoms of diabetes insipidus.
Answer:
a) The structures that regulate kidney functioning

  • Hypothalamus
  • Juxta glomerular apparatus
  • Heart

b) The functions of ADH

  • When there is excessive loss of fluid from the body or when there is an increase in the blood pressure the osmo receptors of the hypothalamus is stimulated.
  • The osmo receptors stimulate the neurohypophysis to secrete antidiuretic hormone (AOH) or vasopressin.
  • ADH facilitates reabsorption of water by increasing the number of aquaporins on the cell surface of the distal convoluted tubule and collecting duct and prevents excessloss of water.

Question 14.
a) Name the cell that secretes the enzyme renin.
b) Where is granular cell present?
c) What is the role of renin in Osmoregulation.
Answer:
a) Renin is secreted by granular cells.
b) Granular cells are present in the afferent arteriole.
c) The role of renin

  • A fall in glomerular blood flow blood pressure and filtration rate can activate granular cells of juxta glomerular cells to release renin.
  • Renin converts the plasma protein angiotensinogen into angiotensis I and angiotensin II.
  • Angiotensis II stimulates Na+ reabsorption in the proximal convoluted tubule by vaso constriction of the blood vessels and increases the glomerular blood pressure.
    Angiotensis II stimulates adrenal cortex to secrete aldo sterone that causes reabsorption of Na+ ,K+ excretion and absorption of water.
  • This increases the glomerular blood pressure and glomerular filtration rate.
  • Hence renin regulates the osmoregulation.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 15.
a) Where is atrial natriuretic peptide liberated from?
b) Write its significance in short.
Answer:
a) This is liberated from atrium of heart.
b) Use of Atrial natriuretic peptide

  • It increases Na excretion and increases the blood flow to the glomerulus.
  • It acts on the afferent glomerular arteriole as a vaso dilator or an efferent arteriole as a vaso constrictor.
  • It reduces aldosterone from adrenal cortex and renin secretion.
  • Thus decreases the angiotensin II.
  • The atrial natri uretic factor acts antagonistically to renin angiotensin system aldosterone and vasopressin.

Question 16.
a) What is micturition?
b) How is central nervous system regulates urination?
Answer:
a) The process of release of Urine from the bladder is called micturition or urination.
b) Urine formed by the nephrons is ultimately carried to the urinary bladder where it is stored till it receives a signal from the central nervous system.

  • The stretch receptors present inthe urinary bladder are stimulated when it gets filled with urine.
  • At the same time the internal sphincters opens and relaxing the external sphincter.
  • The sphincter opens and the urine is expelled out.

Question 17.
Answer for the following questions.
a) What is the average excretion of an adult human?
b) What is the pH of Urine
c) How much pH is differed due to the food we eat?
d) What is the reason for the yellow colour of urine?
e) How much urea is excreted in a day?
f) If there is more glucose, and ketone what does it indicates?
Answer:

  • 1.5l
  • pH = 6
  • pH = 4.5-8
  • Uro chrome
  • 25 – 30 g
  • Diabetes melitus

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 18.
Answer for the following question in excretion by other organs.
a) What are the other structures that excrete nitrogenous wastes rather than kidney?
b) How much CO2 is excreted through lungs?
c) What are the wastes excreted by digestive systems? ’
d) What are the glands that excrete waste through skin?
e) What is the main function of sweat glands?
f) What is the second important function of sweat gland?
g) Name the substance excreted by sebaceous glands.
h) Name the substances excreted by sebaceous glands.
i) Name the waste excreted through saliva.
Answer:

  • Lungs, Liver and skin
  • 18 Litre, much Water
  • Bilirubin, Biliverdin, Cholesterol, Vitamins and drugs.
  • Sweat glands and sebaceous glands
  • To cool the body
  • Na+ and Cl, small quantities of Urea and Lactate excretion.
  • Sebum
  • Steroid Hydrocarbon and wax.
  • Nitrogenous wastes

Question 19.
Draw the schematic representations of renin hormone in the regulation of body fluid concentration.
Answer:

Question 20.
a) What is meant by Haemodialysis?
b) Why is it called as artifical kidney?
c) Give an account of Haemodialysis.
Answer:
a) in the patients of kidney failure toxic urea can be removed from the blood by a process called haemodialysis.
b) The dialyzing machine is a artificial kidney.
c) Hameodialysis
Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion 17

  • A dialyzing machine consists of a long cellulose tube surrounded by the dialysing fluid in a water bath.
  • A patient’s blood is drawn from a convenient artery and pumped into the dialysing unit after adding an anti coagulant like heparin.
  • The tiny poresin the dialysis tube allows small molecules such as glucose salts and urea to enter into the water bath.
  • Where as blood cells and protein molecules do not enter these pores the cleared blood is then pumped back tothe body through a vein.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

Question 21.
Give notes on kidney transplantation?
Answer:

  • This involves transfer of healthy kidney from one person (donor) to another person who is with kidney failure.
  • The donated kidney may be taken from a healthy person who is declared brain dead or from sibling or close relatives to minimize the chances of rejection by the immune system of the host.
  • Immuno suppressive drugs are usually administered to the patient to avoid tissue rejection.