Urinary system

Question 1

Cell types for bowman’s capsule

Answer 1

Visceral cells: podocytes, attached to capillary network of glomerulus
Parietal cells: simple squamous

Question 2

Cell types for PCT

Answer 2

Cuboidal w/ villi
a bunch of mitochondria
function: secretion + absorption

Question 3

Cell types for Descending limb

Answer 3

Simple squamous

Question 4

Cell types for Ascending limb

Answer 4

thin part: simple squamous
thick part: cuboidal/columnar

Question 5

Cell types for DCT

Answer 5

cuboidal, few villi
Function: secretion>reabsorption

Question 6

Cell types for collecting duct (CD)

Answer 6

Principal cells
- short microvilli
- maintain H2O / Na+ balance

Intercalated cells
- cuboidal + bunch of microvilli
- acid/base balance

Question 7

What are the two types of nephrons?

Answer 7

1. Cortical nephron
   - short loop, majority of nephrons
   - glomerulus farther away from cortex-medulla junction, basically entirely in cortex
   -efferent arteriole –> peritubular capillaries
   -2 capillary beds connected in series (glomerulus capillaries + peritubular capillaries)
2. Juxtamedullary nephrons
   - long loop
   -glomerulus closer to cortex-medulla junction
   -ascending limbs have thick + thin segments
   - 3 capillary beds, parallel (glomerulus capillaries, peritubular capillaries + vasa recta)
   -efferent arteriole –> vasa recta (important for water + salt) + peritubular capillaries
   - important in producing concentrated urine
   - need to conserve water –> these are very important

Question 8

What are the 3 types of capillaries + explain their function

Answer 8

1. glomerular capillaries
   - for filtration
   -high pressure
2. peritubular capillaries
   - found only in PCT and DCT in cortex
   - arises from efferent arteriole
3. vasa recta
   - found only parallel to loop of juxtamedullary nephrons
   - arises from efferent arteriole
   - important in forming concentrated urine

Question 9

Describe the juxtaglomerular complex (JGC)

Answer 9

• regulates the function of the nephron
• 3 cell types:

1. macula densa cells
   - found in ascending limb of loop
   - chemoreceptors –> sense NaCl
2. granular cells/ JG cells
   - smooth muscle of arteriole
   -mechanoreceptors: sense b.p in afferent arteriole –> secretes renin
3. extraglomerular mesangial cells
   -located between tubule cells + arteriole
   - connected via gap junctions
   - helps communicate between macula densa + granular