Urinary system

Question 1

What is in the urinary tract?

Answer 1

Two kidneys, two ureters, one bladder, one urethra

Question 2

List the functions of the kidney

Answer 2

1. Regulation of fluid volume
2. Water balance
3. Excretion of waste
4. Production of some hormones

Question 3

What is in a nephron?

Answer 3

Starts with glomerulus in the Bowman’s capsule, then the Proximal convoluted tubule (PCT), the Loop of Henle, the Distal convoluted tubule and then the collecting duct into the papillary duct.

Question 4

How is a nephron positioned int he kidney?

Answer 4

The bulk of the nephron is in the cortex, with the Loop of Henle dipping down into the medulla, and the papillary duct into the medulla.

Question 5

Outline the flow of blood through the kidney

Answer 5

Renal artery –> Segmental artery –> Interlobar artery –> Arcuate artery –> Interlobular artery –> Glomerulus –> Efferent arteriole –> Peritubular capillaries –> Venules –> Interlobular veins –> Arcuate veins –> Interlobar veins –> Renal vein

Question 6

Explain the forces of filtration

Answer 6

Bulk flow- movement of fluid by pressure difference
The afferent arteriole is wider than the efferent arteriole, so the blood is forced through at a higher pressure in the capillaries.
Hydrostatic pressure caused by the volume of blood in the capillaries is greater than the oncotic pressure caused by the proteins so fluid forced out of the capillaries.

Question 7

Why is GFR high?

Answer 7

Pressure created by the arterioles
Small capillaries
Hugh glomerular pressure

Question 8

What structural adaptations make GRF high?

Answer 8

Capsule- many fenestrations in the capillary wall, covered by Bowman’s capsule, followed by interlocking podocytes which have gaps between the ‘fingers’