1) Intro to Urinary

Question 1

Why is the kidney susceptible to ischaemia?

Answer 1

Receives 22% of the cardiac output, so requires a good perfusion to function

Question 2

Where is the upper pole of the kidneys?

Answer 2

T11/T12

Question 3

Where is the lower pole of the kidneys?

Answer 3

L2/L3

Question 4

Why aren’t kidneys at the same height?

Answer 4

Position of liver pushes right kidney down

Question 5

List some of the functions of the kidney:

Answer 5

Control concentration of ions and small organic molecules
Excretes waste products
Synthesis of renin, erythropoietin, prostaglandins
Active form of Vit D, catabolism of insulin

Question 6

How are the body fluid compartments distributed?

Answer 6

Intracellular fluid (28L)
Extracellular fluid (14L)

Question 7

How is the extracellular fluid distributed?

Answer 7

Interstitial fluid (11L)
Plasma (3L)
Lymph
Other: synovial, CSF

Question 8

What is osmolality?

Answer 8

Solute per kg of solvent

Question 9

What is osmolarity?

Answer 9

Number of osmoles per litre

Question 10

How can serum osmolality be estimated?

Answer 10

Doubling serum sodium

Osmolality of ECF is determined by Na+ and CL- (80%)

Question 11

Which way would water move if ECF osmolarity is high?

Answer 11

Out of the cells

Question 12

What happens if ECF volume isn’t controlled?

Answer 12

Changes to BP and cell function

Question 13

What happens if ECF osmolarity isn’t controlled?

Answer 13

Cells shrink or swell

Question 14

Why are tubular cells described as being polarised?

Answer 14

Different membrane properties on luminal and basolateral membranes
Tight gap junctions mean transporters stay on each membrane

Question 15

What system controls sodium recovery and therefore ECF volume?

Answer 15

Renin-angiotensin-aldosterone system

Question 16

What system controls water recovery and therefore ECF osmolarity?

Answer 16

ADH