renal - lecture 1

Question 1

describe 4 functions of kidney

Answer 1

regulation of water, inorganic ion balance and acid base balance = sodium, potassium, hydrogen, chloride, bicarbonate ion, water
removal of metabolic waste products and their excretion in urine
removal of foreign chemicals from blood and excretion in urine - drugs like antibiotics, some metabolized in liver
production of hormones/enzymes

Question 2

name and describe 3 hormones/enzymes kidney produces

Answer 2

epo = most important, hormone that controls erythrocyte production in bone marrow
renin = enzyme that controls formation of angiotensin and influences bp and sodium balance
1,25-dihydroxy vit d = active vitamine that influences calcium balance - needs to be hydroxylated at 1 in kidney

Question 3

describe gross anatomy of kidney

Answer 3

paired organs = 150g each
behind peritoneum on either side of vertebral column against posterior abdominal wall = small of back
renal = pertaining to kidneys

Question 4

name parts of kidney

Answer 4

renal cortex
renal medulla = pyramid shaped
renal pelvis = cortex and medulla make urine and urine sits in renal pelvis and then goes to ureter to bladder
ureter = connects kidney to bladder
urethra = bladder to outside of body

Question 5

describe blood supply of kidneys

Answer 5

renal artery = direct branch of descending aorta = in
renal vein = directly back to inferior vena cava = out

renal artery = between medulla –> interlobar artery –> arcuate artery (in arch between medulla and cortex, branches out perpendicular towards surface of kidney) –> interlobular artery –> afferent arteriole (blood supply to nephron)
venous = arterial system going backwards

Question 6

what is a nephron

Answer 6

each kidney has ~ 1mil subunits called nephrons

Question 7

what does nephron consist of

Answer 7

renal corpuscle = glomerulus (capillary loops), continuation of afferent arteriole and bowmans capsule
tubule

Question 8

describe parts and structures of kidney - all

Answer 8

proximal tubule
loop of henle
distal convoluted tubule
collecting duct system
hollow tube surrounded by monolayer epithelial cells from here down
(cortex) efferent arteriole –> pct –> (medulla) descending thin limb of henles loop –> descending thick limb of henles loop –> ascending thin limb of henles loop –> ascending thick limb of henles loop –> (cortex) dct – cortical collecting down –> (medulla) medullary collecting duct –> medullary collecting ducts from other nephrons

Question 9

describe renal corpuscle

Answer 9

entangled capillary loops around glomerulus surrounded by bowmans space
Bowman space = lined by monolayer epithelial cells
bownmans capsule = parietal layer not touching glomerulus, visceral layer = podocytes and middle = bowmans space

Question 10

describe glomerulus

Answer 10

distal tubule = end of ascending limb of loop of henle
begining of macula densa

Question 11

describe glomerular capillary wall

Answer 11

filtration barrier
foot processed interdigitate with other podocytes = v tightly surround capillary

Question 12

describe glomerular capillary wall - filtration barrier

Answer 12

3 layers =
visceral glomerular epithelial cells - podocytes =
glomerular basement membrane
endothelial cells
things go through fenestration except cells and large proteins
connected by membrane = filtration slit
some size selection by foot processes = glomerular filtration

Question 13

what is function of glomerulus

Answer 13

filters blood to make urine

Question 14

describe vascular supply of nephron

Answer 14

peritubular capillaries provide blood to rest of system
blood composition becomes venous and then merges with vein

Question 15

name and describe the 3 processes of urine formation

Answer 15

glomerular filtration
tubular secretion
tubular reabsorption

Question 16

describe glomerular filtration

Answer 16

urine formation begins with filtration of plasma from glomerular capillaries into bowmans space

Question 17

describe glomerular filtrate

Answer 17

fluid in bowmans space = cell free (no rbcs/wbcs) and except for proteins (albumins, iggs) contains all same substances and same concentrations as plasma

Question 18

describe tubular secretion/reabsorption

Answer 18

as glomerular filtrate passes through tubules composition altered by movements of substances

Question 19

what is difference between reabsorption and secretion

Answer 19

Reabsorption = filtered into bowmans space and get reabsorbed back to peritubular cap = tubules –> peritubular cap
secretion = from peritubular cap to tubular lumen = peritubular cap –> tubules

Question 20

describe formation of urine

Answer 20

Movement of something from glomerulus to bowmans space then tubular secretion and reabsorption

Question 21

describe how to find amount excreted

Answer 21

amount excreted = amount filtered + amount secreted - amount reabsorbed
differs from substance = amount and location

Question 22

describe PAH excretion

Answer 22

para amino hippurate
bulk remains then all goes to urine
chemical

Question 23

describe sodium and water excretion

Answer 23

lot reabsorbed but small amount excreted
99% kept

Question 24

describe glucose excretion

Answer 24

body need all of it so takes everything back
if sick = like high blood sugar = not perfect and urine has glucose in it

Question 25

describe rate of filtration, reabsorption or secretion

Answer 25

subject to physiological control

Question 26

describe physiological control

Answer 26

when body content of substance goes above or below normal = homeostatic mechanisms can regulate substances bodily balance by changes these rates

Question 27

what is juxtaglomerular apparatus

Answer 27

macula densa = tall columnar shaped cells
juxtagolmerular cells fill space and secrete renin

Question 28

describe physiological control- ex

Answer 28

normal person drinks lots of water = reasborption of water decreased and excess water excreted in urine
drink a lot so pee alot