lecture 29

Question 1

whats a cortical nephron vs juxtamedullary nephron

Answer 1

cortical nephrons are 85% of nephrons which are found entirely within the medulla
juxtamedullary nephrons are 15% of nephrons these extend into the medulla and are important for formation of concentrated urine

Question 2

what are the functions of the nephron

Answer 2

they selectively filter blood, return anything which needs keeping to the blood, carry waste for waste and expulsion,

Question 3

whats the vasa recta

Answer 3

extensions of the peritubular capillaries that follow the nephron loops into the medulla, only found with juxtamedullary nephrons

Question 4

function of the peritubular capillaries

Answer 4

Specialised for absorption, Receives filtered blood from glomerulus via efferent arterioles Receives reabsorbed filtrate from nephron
Some non-filtered solutes that need to be excreted can pass from here into nephron

Question 5

what are the pedicels, whats between them and whats it do

Answer 5

pedicels are the branching of the podocytes, they have the filtration slits between them, filtration slits prevent the larger solutes passing through into the nephron space

Question 6

what are the nephron loops and what do they do

Answer 6

loops of the nephron down into the medulla, length is important in production of urine. as these parts are responsible for the urine production

Question 7

juxtamedullary nephron loops are surrounded by what?

Answer 7

the juxtamedullary nephron loops are surrounded by the vasa recta.

Question 8

function and histology of the distal convoluted tubule

Answer 8

these do fine-tuning of the urine concentrations. they are cuboidal epithelium but thinner than the PCT epithelia.

Question 9

sttructure of the DCT cells

Answer 9

they have less microvilli so no brush boarder, also have fewer mitochondria.

Question 10

reabsorption across the DCT cells are affected by what

Answer 10

aldosterone

Question 11

function and overall structure of the collecting tube

Answer 11

it does fine tuning of concentration. Filtrate from several DCTs drains into one collecting duct, which empty at papilla

Question 12

what hormones influence the collecting tubes

Answer 12

reabsorption is influenced by aldosterone and ADH

Question 13

structure of collecting tube epithelia

Answer 13

wall of simple cuboidal epithelium, with two cell types, principal cells are there for reabsorption and intercalated cells are for acid/base balance