renal phys

Question 1

fxns of the kidneys

Answer 1

1. Regulation of extracellular fluid volume and blood pressure
2. Regulation of osmolarity
3. Maintenance of ion balance
4. Homeostatic regulation of pH
5. Excretion of wastes
6. Production of hormones

Question 2

retroperitoneal cavity

Answer 2

• behind peritoneal cavity

Question 3

three sections of the kidneys

Answer 3

• renal pelvis (pyramids aligned w/ the nephron), medulla (deep), and cortex (superficial)

Question 4

what supplies blood to the kidneys?

Answer 4

• the renal artery
• 25% of cardiac output goes to the kidneys

Question 5

nephron

Answer 5

• filtration unit, contains glomerulus and renal tubules
  – Blood filtered by glomerulus –> removal of waste (urea and nitrogen-containing compounds ) and regulation of extracellular electrolytes and intravascular volume
  – Produces urine

Question 6

majority of reabsorption happens where?

Answer 6

• proximal convoluted tubule

Question 7

bowman’s capsule

Answer 7

• site of plasma filtration with the glomerulus

Question 8

glomerulus

Answer 8

• first capillary bed, a ball-like network
• goes from afferent arteriole to this

Question 9

proximal convoluted tubule

Answer 9

• filtered fluid flows from bowman’s capsule to this

Question 10

loop of henle

Answer 10

• fluid goes from the PCT to this structure
• descending limb: osmolarity decreases
• ascending limb: osmolarity increases

Question 11

distal convoluted tubule

Answer 11

• fluid goes from the loop of henle to this

Question 12

collecting ducts

Answer 12

• receives fluid from the DCT
• converge and drain into the renal pelvis

Question 13

Collecting ducts pass from the ___ through the ____ and drain into the _____

Answer 13

• cortex
• medulla
• renal pelvis

Question 14

what kind of ions do we want to pass thru

Answer 14

• small ions w/ a pos charge
• ex: Na+ – also most common

Question 15

what do kidneys do?

Answer 15

• filter
• reabsorb
• secrete

Question 16

filtration

Answer 16

• getting stuff in the kidneys
  – Fluid from blood into the lumen of the nephron (Bowman’s capsule)
  – Filtered plasma is called filtrate

Question 17

reabsorption

Answer 17

• mostly happens in proximal convoluted tubule
  – Materials in the filtrate are passed back into the blood
  – Peritubular capillaries

Question 18

secretion

Answer 18

– Active transport from peritubular capillaries
- removes molecules from the blood and adds them to the filtrate in the tubule lumen n

Question 19

increase in BP and BV increases what? What about decrease in BP and BV

Answer 19

• filtration

Question 20

filtrate is protein-free plasma

Answer 20

– Endothelial cells of glomerular capillaries –> Bowman’s capsule
▪ Filtration slits in glomerular capillaries
▪ Hydrostatic pressure (capillary blood pressure)

Question 21

how much water and ions is reabsorbed in the PCT

Answer 21

• about 70%

Question 22

filtrate in the loop of henle

Answer 22

– More ions (Na+, K+, Mg2+, Ca2+) reabsorbed than water, dilute filtrate in lumen

Question 23

distal tubule

Answer 23

– Resorption of ions and water, secretion of some substances
– Depending on hydration status

Question 24

where things go in the nephron

Answer 24

1. In bowman’s capsule water, sodium, potassium, glucose, and urea go out of blood into capsule
2. PCT - some water, sodium, potassium, all glucose gets reabsorbed
3. Loop of henle - descending loop = the rest of the water exits the tubule. Ascending loop = salt exits
4. No water in DCT but we reabsorb sodium and chloride
5. Collecting duct = receives filtrate from the DCT and delivers urine

Question 25

what happens in the loop of henle?

Answer 25

• Na+, Cl- enters the artery from the ascending limb of the loop of Henle, so the blood becomes more concentrated, which is bad because then we cannot maintain homeostasis
• So, water from the descending limb of the loop of Henle leaves and enters the artery to maintain the normal blood concentration
• the result is blood that maintains good concentration and urine that adjusts to make sure blood maintains that good concentration

Question 26

ppl who can’t absorb all their glucose excrete it out. this is a sign of what

Answer 26

• diabetes

Question 27

aquaporin 1 and 2 are found where?

Answer 27

• 1 = loop of henle
• 2 = found in collecting duct

Question 28

what needs to be present in order to reabsorb water?

Answer 28

• ADH

Question 29

what 4 things determine filtration?

Answer 29

• BP
• BV
• Size
• Charge of ion

Question 30

what do we not want in the kidneys?

Answer 30

• calcium
• kidney stones
• also proteins like albumin

Question 31

sodium going into the blood is what transport?

Answer 31

• active

Question 32

what two things hitch a ride with Na+ in the PCT?

Answer 32

• glucose and H2O

Question 33

aldosterone in the kidneys

Answer 33

• takes out sodium back into the blood (water will follow)
• brings K+ and acid into the kidney