Renal physiology: Glomerulus

Question 1

what is the glomerulus

Answer 1

• Loop of capillaries in ball shape
• Surrounded by the bowmans capsule
• Ultrafiltration site

Question 2

components of the renal corpuscle

Answer 2

glomerulus
bowmans capsule

Question 3

3 features of the filtration barrier

Answer 3

fenestrated endothelial cells
basement membrane
podocytes

Question 4

fenestrated endothelial cells of the glomerular capillaries

Answer 4

perforations called fenestrae
prevent filtration of the blood cells
surrounding the luminal surface is glycocalyx which has negative glycosaminoglycans to hinder diffusion of negatively charged particles

Question 5

glomerular basement membrane

Answer 5

type 4 collagen, heparan sulfate, proteoglycans and laminin
heparan for the prevention of movement of negatively charged particles
3 layers:
inner thin= lamina rare interna
thick= lamina densa
outer dense= lamina rare externa

help limit filtration of intermediate and large sized molecules

Question 6

podocytes

Answer 6

epithelial cells of the bowmans capsule
form visceral layer of capsule
foot like processes project and interdigitate to form filtration slits
bridges by slit diaphragm with small pores
prevent proteins crossing
coated in glycoproteins to repel the negative charge

Question 7

ultrafiltration

Answer 7

• Occurs under pressure
• Afferent and efferent responsible for generating pressure
• Afferent dilates and efferent constricts
• Creates pressure gradient
• Filtration rate of same charge is inversely proportional to their molecular weight

Question 8

cell types in the glomerulus

Answer 8

mesangial
juxtaglomerular /granular

Question 9

mesangial cells

Answer 9

phagocytose macromolecules stuck in the slit diaphragm, contain actin to contract for blood flow, gap junctions to connect cell

Question 10

juxtaglomerular / granular cells

Answer 10

baroreceptors that secrete renin

Question 11

what are the different pressures present

Answer 11

glomerular hydrostatic pressure
colloid osmotic
capsular hydrostatic pressure

Question 12

Glomerular hydrostatic pressure

Answer 12

pressure pushing plasma proteins out of the capillaries into the Bowman’s space

Question 13

Colloid osmotic pressure

Answer 13

plasma proteins excrete pressure to retain water

Question 14

Capsular hydrostatic pressure

Answer 14

pressure from Bowman’s capsule pushing fluid back roughly 0

Question 15

glomerular filtration rate

Answer 15

blood passing through the glomerulus each minute, roughly 125ml/min

Question 16

net filtration pressure

Answer 16

net is out

pressures out – pressures in