renal system

Question 1

nephron

Answer 1

functional unit of the kidney

>1 million nephrons per kidney

Question 2

renal corpuscle consist of

Answer 2

glomerulus
bowman’s capsule
plasma filtration
double walled epithelial cup surrounding glomerulus (podocytes and epithelial cells)

Question 3

juxtamedullary nephrons

Answer 3

(15-20%) 
originate from inner third of cortex) 
longer loop 
A thin descending limb
Thick ascending limb
Allow kidney to excrete very dilute or very concentrated urine

Question 4

cortical nephron

Answer 4

(80-85%)
originate from outer 2/3 of cortex
shorter loops

Question 5

proximal convoluted tubule

Answer 5

simple cuboidal epithelium with micro villi

increased surface are for reabsorption

Question 6

distal convoluted tubule

Answer 6

shorter than proximal

simple cuboidal epithelium, very few microvilli

Question 7

what are the functions of renal tubule ?

Answer 7

fluid balance 
metabolic waste and toxin excretion 
electrolyte homeostasis 
acid/ base homeostesis 
hormone production 
-erythropoetin 
renin 
part of vitamine D processing

Question 8

the rate of filtration is dependent on

Answer 8

hydrostatic pressure of blood

Question 9

glomerular filtration

Answer 9

glomerular capillaries are 100-400 times more permeable than skeletal muscle capillaries (they have tiny holes that allows for a.a, ions etc to pass) .blood doesnt pass or proteins, too big. basement membrane is semipermeable and visceral layer of capsule are podocytes

Question 10

what is the minimum acceptable urine output

Answer 10

30ml/hr

Question 11

what is the avg output for and asult

Answer 11

60ml/hr or 1.44L/ day

Question 12

most important substances secreted

Answer 12

K+ and H+ ions

Question 13

sodium

Answer 13

[Na+] regulated by amount of water in body
When sodium too high, amount of water in body increases by:
Secretion of ADH, causing kidney to retain water
Stimulation of thirst, making you drink liquid

Question 14

potassium

Answer 14

Levels critical for normal nerve and muscle function
High K+:
Direct effect of K+ on epithelial cells of renal tubules to cause increased transport out of peritubular capillaries, subsequently passed in urine
Stimulating effect of K+ on adrenal cortex, increasing Aldosterone, allowing K+ to be passed in urine

Question 15

ca++, mg+, PO4-

Answer 15

When increased levels, causes decreased reabsorption, passing these into urine

Regulated by Parathyroid hormone

Question 16

ca++, mg+, PO4-

Answer 16

When increased levels, causes decreased reabsorption, passing these into urine

Regulated by Parathyroid hormone

Question 17

factors affecting urine production

Answer 17

-BP/ blood volume
-tonicity
-aldosterone
-ADH
PTH