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1. What is excretion?
The removal of waste substances from the body or the cell which have accumulated as a result of chemical (metabolic) activity is called excretion.
2. What is Thermoregulation?
Thermoregulation is the regulation of body temperature. It is an important part of homeostasis.
3. What is Osmoregulation?
Osmoregulation is an important homeostatic mechanism. It is the regulation of water and salt balance in the body.
4. What is Ultrafiltration?
Ultrafiltration is filtration under pressure. It occurs in the glomerulus where high pressure, forces the liquid part of blood with dissolved molecules into the Bowman's capsule.
5. What is Reabsorption?
Reabsorption is the process by which useful substance are reabsorbed from the nephric filtrate into the blood. It is an energy requiring process and takes place primarily in the proximal and distal convoluted tubules of the nephron.
6. What is a nephron?
A nephron is the functional unit of the kidney. It consists of a minute tubule and associated blood vessels and serves to filter the blood, reabsorb useful substance, adjust water and salt levels and excrete substance like urea in urine.
7. The vessel that supplies blood to the kidney.
Renal artery
8. The hormone that increases water reabsorption.
ADH (Antidiuretic hormone)
9. The tube that carries water away from the kidneys.
Ureter
10. The outer part of the kidney containing Bowman's capsule.
Cortex
11. The pigment produced by the breakdown of haemoglobin.
Bilepigment
12. The blood vessel which enters Malpighian capsule
Afferent arteriole
13. The blood vessels which bring pure blood to the kidneys.
Renal artery
14. The term used for Bowman's capsule and glomerulus together.
Renal capsule
15. Any two organic constituents of normal human urine.
Urea and Uric acid
16. The pigment that gives yellow colour to the urine.
Urochrome.
17. State the functions of sphincter muscle.
Urine is expelled from the bladder by the simultaneous contraction of the bladder and the relaxation of the sphincter muscle.
18. Name the substances reabsorbed in the kidney tubules.
Usable substances such as glucose and salts of sodium.
19. Why does a dog pant when it is hot?
It has no sweat glands. It loses moisture by evaporation from the mouth and lungs instead.
20. Name the following:
The duct which carries urine from the urinary bladder to the outside of the body.
Urethra.
21. Why is the right kidney at a slightly lower level than the left?
The right kidney is slightly lower level than the left kidney due to the position of liver on the right side.
22. Differentiate between Ureter and Urethra.
| Ureter | Urethra |
| It is a tube which carries the urine from the kidney to the urinary bladder. | It is a tube which carries the urine from the urinary bladder to the outside. |
23. Differentiate between Secretion and excretion.
| Secretion | Excretion |
| It is the production of something useful for the body | It is the removal of something harmful for the body |
24. Differentiate between Urine and Urea.
| Urine | Urea |
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1. It is produced in the kidney 2. It contains urea, excessive water and mineral salts. |
1. It is formed in the liver. 2. It is a part of urine. |
25. Differentiate between Renal cortex and renal medulla.
| Renal Cortex | Renal medulla |
| It is the outer region of the kidney that contains the glomeruli and Bowman's capsule. | It is the inner region of the kidney that contains elements of Henle's loop and collecting tubules. |
26. Differentiate between Afferent arteriole and efferent arteriole.
| Afferent arteriole | Efferent arteriole |
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1. It is formed by the branching of the renal artery and is thicker than efferent arteriole. 2. It brings oxygenated blood into the kidney. |
1. It is formed by the fusing of glomerular capillaries and is narrower than afferent arteriole. 2. It carries deoxygenated blood away from the kidney. |
27. Differentiate between Osmoregulation and ultra filtration.
| Osmoregulation | Ultrafiltration |
| The process by which osmotic concentration (amount of water and minerals salts) of the blood inside the body is maintained is known as osmoregulation. |
Ultrafiltration is filtration under pressure. It occurs in the glomerules where high pressure due to narrowing of the renal anterior forces the liquid part of the blood along with dissolved molecules in the Bowman's capsule. |
