Kidney

Question 1

purpose of the kidneys

Answer 1

filtration and maintain osmotic balance

Question 2

what is the functional unit of the kidney

Answer 2

the nephron

Question 3

3 major parts of the nephron

Answer 3

1. renal corpuscle (glomerulus + Bowmans capsule)
2. renal tubule
3. collecting ducts

Question 4

what takes place in the renal corpuscle (glomerulus + Bowmans capsule)

Answer 4

site of filtration

Question 5

what takes place in the renal tubule

Answer 5

site of tubular secretion and absorption
its surrounded by capillaries

Question 6

what takes place in the collecting ducts

Answer 6

site or urine processing (concentration or dilution)

Question 7

where is the glomeruli located

Answer 7

in the cortex

Question 8

where are the renal tubules

Answer 8

they loop through the medulla

Question 9

where are the collecting ducts

Answer 9

start at cortex, pass through medulla, and empty into the ureter

Question 10

how does a longer loop of henle help you

Answer 10

the longer the loop of henle the more concentrated your urine is

Question 11

where does the afferent arteriole lead

Answer 11

afferent arteriole goes in

Question 12

where does efferent arteriole lead

Answer 12

efferent arteriole goes out

Question 13

what are the specialized zones of the renal tubules

Answer 13

proximal convoluted tubule, loop of henle, distal convoluted tubule, collecting ducts

Question 14

which part of the renal tubule creates an osmotic gradient

Answer 14

the loop of henle

Question 15

function of the proximal convoluted tubule

Answer 15

major site of reabsorption of NaCl, and glucose (active transport). water flows by osmosis (passive transport)

ph regulation by secretion of H+, reabsorption of HCO3- (bicarbonate buffer system)

site of secretion of NH3 and assorted poisons

materials removed from tubules returned to venous blood via uptake in per tubular capillaries

Question 16

structure of proximal convoluted tubule

Answer 16

cells have lots of microvilli on lumen face (large survive area for reabsorption)

reabsorption requires active transport, supported by many mitochondria

Question 17

function of the loop of henle

Answer 17

creates concentration gradient in medulla by countercurrent exchange

Question 18

what creates the gradient in the medulla

Answer 18

anti-parallel flow of materials (goes up and down the loop of henle

Question 19

what is the purpose of anti parallel flow

Answer 19

anti parallel flow allows for some of the blood to be oxygenated to 100%. if it were a parallel flow the blood would only have 50% oxygenation

Question 20

what is the purpose of anti parallel flow

Answer 20

anti parallel flow allows for the blood to be oxygenated to 100%. if it were a parallel flow the blood would only have 50% oxygenation

the concentration gradient is maintained throughout the area of exchange

Question 21

function of the loop of henle

Answer 21

establishes external concentration gradient in medulla

Question 22

what is the descending limb permeable to

Answer 22

high permeable to water but not ions

Question 23

what is the thin ascending limb permeable to

Answer 23

permeable to salt (NaCl) passive transport

Question 24

what is the thick ascending permeable to

Answer 24

actively pumps out salt, not permeable to water

Question 25

what is the collecting duct permeable to

Answer 25

permeable to water but not ions, slightly permeable to urea at the bottom

Question 26

how does urine get concentrated

Answer 26

water leaves the collecting duct by osmosis leaving most of the urea in the collecting duct. urine becomes more concentrated because water is leaving

Question 27

summary of proximal convoluted tubule

Answer 27

major site of salt, nutrient and water reabsorption, pH regulation, and secretion of wastes

Question 28

summary of the loop of henle

Answer 28

creates external concentration gradient in medulla by countercurrent exchange

Question 29

summary of distal convoluted tubule

Answer 29

nacl and water reabsorption

Question 30

summary of collecting duct

Answer 30

concentrates urine as water is lost by osmosis, degree of concentration depends on magnitude of gradient

Question 31

which organelles do the cells of the proximal convoluted tubules have a lot of

Answer 31

many microvilli and mitochondria

Question 32

is urine more or less concentrated when it leaves the loop of henle than when it leaves it

Answer 32

urine is more concentrated when it leaves

Question 33

do the cells of the collecting duct conduct a lot or little active transport

Answer 33

conducts little active transport

Question 34

does the descending or ascending limb of the loop of henle transport NaCl

Answer 34

the ascending limb

Question 35

what are aquaporins

Answer 35

h2o selective channels that assist with the movement of water

Question 36

where are aquaporins in the kidney

Answer 36

abundant in structures with high water permeability the proximal convoluted tubule, descending limb of the loop of henle,, collecting ducts

Question 37

what can a mutation of in the aquaporin cause

Answer 37

diabetes insipidus (production of lots of dilute urine) can result from mutation in an aquaporin family member

Question 38

how does kidney regulate renal blood pressure

Answer 38

if systemic pressure decreases, afferent (incoming) renal arterioles dilate to maintain flow through capillaries

Question 39

what are the tissue conditions for systemic regulation of blood pressure

Answer 39

low blood pressure, high osmolarity or high blood pressure in the heart

Question 40

what are the systemic signals for low blood pressure and high osmolarity

Answer 40

renin/angiotensin/aldosterone antidiuretic hormone (ADH)

Question 41

what are the responses for low blood pressure and high osmolarity

Answer 41

constrict efferent arterioles and peripheral vessels, increase salt uptake, thirst, water uptake

Question 42

what are the systemic signals for high blood pressure in the heart

Answer 42

atrial natriuretic peptide (ANP)

Question 43

what are the responses for high blood pressure in heart

Answer 43

decrease salt and water uptake

Question 44

if the afferent arteriole that supplies blood to there glomerulus becomes dilated what happens

Answer 44

the glomerular filtration rate increases