renal system

Question 1

gross anatomy

Answer 1

2 kidneys & ureters, 1 bladder 1 urethra

Question 2

location kidneys

Answer 2

posterior parietal peritoneum
on posterior abdominal wall
lateral to spine
right slightly inferior to left coz liver placement
left kidney inferior to spleen

Question 3

protect kidney

Answer 3

renal capsule - one each
adipose tissue
renal fascia - thin layer connective tissue surround fat, anchor kidney to abdominal wall

Question 4

internal kidney

Answer 4

hilum - concave side renal artery veins nerves
renal sinus (connected to hilum - filled w fat & loose CT)
outer cortex
inner medulla
renal columns in-between renal pyramids
papilla –> minor calyces –> major alyces –> renal pelvis –? ureter

Question 5

nephron

Answer 5

functional unit of kidney
renal corpuscle, proximal convoluted tubule, loop of hence, distal convoluted tubule
juxtamedullary nephron 15% renal corpuscle close medulla, LOH deep
cortical nephron 85% corpuscle near cortex, short LOH

Question 6

renal corpuscle

Answer 6

place filtration
afferent –> efferent arteriole (size difference = pressure diff)

Question 7

bowman capsule

Answer 7

parietal/ outer layer - simple squamous, become cuboidal in PCT
visceral/ inner layer - special cells (podocytes) wrap around glomerular capillaries

Question 8

filtration membrane

Answer 8

fenestrate - lil window/gap in endothelial cell
basement membrane - between cells capillaries and podocytes
filtration slits - gaps between podocytes

Question 9

nephron histology

Answer 9

PCT - simple cuboidal w microvilli (absorption) mitochondria (active reabsorb Na+ K+ Cl-)
loop of henle - thick part (simple cuboidal) thin part (simple squamous) for osmosis/ diffusion
DCT - simple cuboidal, few microvilli, numerous mitochondria - active reabsorption
CD - simple cuboidal

Question 10

urine movement

Answer 10

pressure forces in nephron
smooth muscle forces through ureters - peristalsis
ureters enter bladder obliquely thru trigone. pressure bladder prevent backflow

Question 11

ureters

Answer 11

renal pelvis –> urinary bladder
transitional epithelium, mucosa, muscular, adventitia

Question 12

trigone

Answer 12

triangular area on posterior wall, between entry two ureters and exit urethra
histologically unique

Question 13

urethra sphincter

Answer 13

internal - prevent leakage, elastic CT & smooth muscle
external - skeletal muscle surrounds urethra - voluntary control

Question 14

filtration 1

Answer 14

movement of fluid - water small molecules and ions pass thru membrane
99% reabsorbed
removes toxins from blood

Question 15

renal fraction & glomerular filtration rate

Answer 15

renal fraction - proportion of cardiac output that passes thru kidneys (12-30%)
glomerular filtration rate GFR - amount of filtrate produce each min 125ml/min 180L/day
avg urine output 1-2L

Question 16

filtrate

Answer 16

water, glucose, fructose, amino acids, urea, rate, ions, creatinine
driven by blood pressure

Question 17

juxtaglomerular apparatus

Answer 17

cuff of smooth muscle that surrounds afferent arteriole
macula densa - section specialised cells surround DCT - secrete renin (important regulate filtrate formation & BP regulate)

Question 18

tubular reabsorption

Answer 18

return water small molecules & ions into peritubular capillaries (have low BP)
PCT, active & passive transport
apical surface PCT line nephron
basal surface borders interstitial fluid
filtrate –> apical membrane –> simple cell –> basal membrane –> interstitial space –> capillary

Question 19

tubular secretion

Answer 19

DCT
movement of non filtered or toxic substances intro nephron for excretion

Question 20

urine movement

Answer 20

pressure force
peristalsis
parasympathetic stimulation - increase frequency
sympathetic stimulation - decrease frequency
trigone pressure - prevent backflow urine

Question 21

micturition reflex

Answer 21

ureter to bladder - continuous
bladder to urethra - not continuous
full bladder - stretch receptors –> CNS
voluntary control EUS