Urine Composition, Concentration, Storage + Secretion

Question 0

Composition of urine %

Answer 0

95% water

5% solutes

Question 1

Normal ph range of urine is 4.5- 8.0

Answer 1

Normal ph of 6

Question 2

Solute composition of urine

Answer 2

Urea
Sodium 
Potassium 
Phosphate and sulphate ions
Creatinine
Uric acid

Question 3

Body fluid homeostasis includes

Answer 3

Regulating urine concentration and volume.

Kidneys keep the solute load of body fluids constant at around 300 mosm/L

Question 4

Vasa rectangle is

Answer 4

Acts as a countercurrent exchanger, carrying away reabsorbed water whilst maintaining concentration gradient.

Question 5

Characteristics of the ureters

Answer 5

Convey urine from kidney to bladder.
10-12 inch long 
1-10mm diameter 
Extends from renal pelvis to bladder
3 layers (mucosa, muscularis, adventitia)

Question 6

Micturition (act of emptying the bladder) process includes

Answer 6

200ml stretch receptors activated
Detrusor muscle contracts
Internal sphincter relaxes
Urine passes into upper urethra

Question 7

Adh increases the permeability of the principal cells in the late distal tubule and collecting ducts.

Answer 7

Micturition relies on input from visceral afferent fibres

The loop of Henle concentrates the medulla allowing water to be drawn out of the collecting ducts if adh is present