Renal sys.

Question 1

Function of the kidneys

Answer 1

1. Filter blood => remove wastes (excretion)
2. Regulate blood vol.
3. Regulate BP
4. Regulate body fluid composition
5. Release of hormones (erythropoietin & calcitriol)

Question 2

Name protective coverings of kidney and state their function (3)

Answer 2

1. Renal capsule: fibrous CT - surround each kidney
2. Perirenal fat: protect kidney
3. Renal fascia: support kidney (attach onto post. wall of abdominal)

Question 3

Name 2 types of nephron

Answer 3

1. Juxtamedullary (80%): long LOP & Bowman’s C near base of medulla
2. Cortical (20%): short LOP & bowman’s C in cortex

Question 4

Describe path of blood from renal artery to renal vein

Answer 4

Renal artery -> arcuate artery -> inter lobular -> afferent arteriole -> glomerulus ->effernt arteriole -> peritubular capilarries -> vasa recta -> interlobular vein -> arcuate vein -> renal vein

Question 5

Identify components of nephron and state each function

Answer 5

1. Bowman’s capsule: filtration
2. PCT: Majority of reabsorbtion and secrete solutes
3. LOP: set up salt gradient in medulla
4. DCT: some reabsorbtion and secrete solutes
5. CD: water reabsorption

Question 6

How is filtration membrane modified to assist blood filtration?

Answer 6

1. filtrate due to size: small molecules move out of blood (glucose, small AA chains & FA)
2. due to charge: podocytes (AA) are -vely charged so cations move out of blood

Question 7

Describe forces that allow formation of filtrate

Answer 7

1. Glomerular capillary pressure: BP in glomerulus => fluid out of blood
2. Capsular hydrostatic pressure: fluid move in blood bc ‘rebounds’ from surface of capsule
3. Blood colloid osmotic pressure: osmotic gradient due to the proteins in plasma => fluid move in blood
   GCP - (CHP + BCOP)