EXAM 4 MUST KNOW Flashcards
renal corpuscle is comprised of…
glomerulus (glomerular capillaries)
Bowman’s capsule
plasma filtration flow at renal corpuscle
from glomerular capillaries into Bowman’s capsule
blood flows into the __________ within the renal corpuscle
afferent arteriole
blood is filtered at the ________ within the renal corpuscle and leaves via the _______
glomerulus; efferent arteriole
________ is the site of glomerular filtration
________ is the site of reabsorption and secretion
renal corpuscle;
the tubule
purpose of vasa recta
surrounds loop of Henle
permeable to Na+ and water (reabsorbs)
makes sure blood is hypoosmotic
doesn’t wash away medullary osmotic gradient
glomerular filtration substance movement
blood -> tubule
tubular secretion substance movement
blood -> tubule
tubular reabsorption substance movement
tubule -> blood (peritubular capillaries)
Na+ tubular reabsorption is an example of…
active transport
movement down concentration gradient
does not require energy
example: lipid-soluble substances
diffusion
example:
Na+/K+ -ATPase moves Na+ uphill across the basolateral membrane
primary active transport
*requires energy to move uphill against gradient
example:
glucose is transported across luminal membrane uphill and coupled to Na+ transport downhill then diffuses across basolateral membrane by facilitated diffusion
secondary active transport
transport maximum
the amount of material that can be transported per unit time
occurs when binding sites on transport protein are saturated
the amount of fluid filtered
glomerular filtration rate (GFR)
the amount of substance filtered
filtered load
if a substance is freely filtered,
not reabsorbed,
not secreted,
we can measure…
GFR
GFR value in normally functioning kidneys
125mL/min
if a substance is freely filtered,
100% secreted,
we can measure…
renal plasma flow
total plasma volume value in normally functioning kidneys
3 L
if clearance of substance < GFR (125mL/min) then…
less of substance in urine than filtered load (net reabsorption)
if clearance of substance > GFR (125mL/min) then…
more of substance in urine than filtered load (net secretion)
substance that is filtered and completely secreted
para-aminohippurate (PAH)
total renal plasma flow is determined by measuring the…
clearance of para-aminohippurate
2/3 of Na+ and water reabsorption occurs in the…
proximal tubule
in Na+ reabsorption, Na+ moves downhill into…
proximal tubule
ascending loop of Henle
cortical collecting duct
if high vasopressin, urine is…
concentrated (hyperosmotic)
if low vasopressin, urine is…
dilute (hypoosmotic)
*collecting ducts are impermeable to water
constriction of afferent arterioles causes decreased GFR by…
decreasing glomerular capillary hydrostatic pressure
hormone responsible for the formation of angiotensin I
renin
hormone responsible for the conversion of angiotensin I to angiotensin II
angiotensin converting enzyme (ACE)
directly alters aldosterone secretion
angiotensin II
key factor necessary for generation of hyperosmotic urine by the countercurrent multiplier system
active transport of Na+ in the ascending loop of Henle
(impermeable to water)
water is not reabsorbed in…
the ascending loop of Henle (impermeable to water)
increase in Na+, increase in extracellular volume ->
if extracellular volume changes, so does plasma volume ->
plasma volume size helps determine…
blood pressure
basic renal processes of Na+
freely filtered
reabsorbed
not secreted
long term regulation of Na+ reabsorption is controlled by…
aldosterone
renin secretion is stimulated by…
increased renal sympathetic activation
decreased stretch of infrarenal baroreceptors
decreased Na+ sensed by macula densa
*all effects occur with decreased plasma volume leading to decreased blood pressure
if there’s low sodium, then there’s _____ renin to increase Na+ reabsorption, increase plasma volume, and increase blood pressure back to normal
high
if there’s high sodium, then there’s ____ renin to decrease Na+ reabsorption, decrease plasma volume, and decrease blood pressure back to normal
low
if plasma volume is too high,
atria stretches and releases atrial natriuretic peptide (ANP),
decreases plasma aldosterone,
afferent dilation and efferent constriction of arterioles,
increased GFR,
decreased Na+ reabsorption in tubules,
result in…
increased Na+ excretion to reduce blood volume and pressure
if plasma volume is too low,
atria does not stretch or release atrial natriuretic peptide (ANP),
increases plasma aldosterone,
afferent constriction and efferent dilation of arterioles,
decreased GFR,
increased Na+ reabsorption in tubules,
result in…
decrease Na+ excretion, plasma volume increases
basic renal processes of water
freely filtered
reabsorbed
not secreted
water regulation occurs in ________
controlled by ________
collecting ducts
vasopressin
regulation of vasopressin secretion
- baroreceptor pathway (severe response)
- osmoreceptor pathway (minute to minute)
- central nervous system
water diuresis results from…
and produces…
*decreased water reabsorption
low vasopressin
no change in solute excretion
produces dilute hypoosmotic urine
osmotic diuresis results from…
and produces…
*decreased solute reabsorption
decreased water reabsorption
increased solute excretion
produces concentrated hyperosmotic urine
pharmacological agents that increase urine volume by increasing excretion of Na+ and/or water
decrease volume of extracellular fluid
diuretics
basic renal processes of K+
freely filtered
reabsorbed
secreted
K+ is secreted in the _________ but not the _________
cortical collecting duct; proximal tubule
factors influencing high K+ excretion
high K+ in plasma activation of Na+/K+ pump
high K+ in plasma stimulates aldosterone secretion
aldosterone release from adrenal cortex is stimulated by…
angiotensin II
increased plasma K+
aldosterone release from adrenal cortex is inhibited by…
ANP
Ca2+ regulation depends on…
bone distribution in body
kidney excretion
gastrointestinal tract absorption
Ca2+ balance is regulated by…
the parathyroid hormone (PTH)
the HCO3- buffering system is highly effective because…
it eliminates CO2 in the lungs
increased H+ stimulates ventilation,
causing decreased arterial ______ to decrease H+ again
PCO2
respiratory control of CO2 equation
H + HCO3 <-> H2CO3 <-> CO2 + H2O
renal control of HCO3-
(kidneys three main functions in H+ regulation)
reabsorb filtered HCO3-
secrete H+
replenish HCO3-
increased plasma H+, pH < 7.4
acidosis
decreased plasma H+, pH > 7.4
alkalosis
blood pH is largely determined by…
the ratio of HCO3- to PCO2
metabolic acidosis
primary disturbance: decrease HCO3-, diarrhea
compensation: respiratory hyperventilation, decrease CO2
respiratory acidosis
primary disturbance: increase PCO2, hypoventilation
compensation: renal increase HCO3- recovery
metabolic alkalosis
primary disturbance: increase HCO3-, vomiting
compensation: respiratory hypoventilation, increase CO2
respiratory alkalosis
primary disturbance: decrease PCO2, hyperventilation
compensation: renal decrease HCO3- recovery
smooth muscle that surrounds bladder
parasympathetic (contracts)
urination from STIMULATION
detrusor muscle
smooth muscle at base of bladder
sympathetic (relaxes)
urination from INHIBITION
internal urethral sphincter
skeletal muscle
somatic (relaxes)
urination from INHIBITION
external urethral sphincter
function of proximal tubule parts:
proximal tubule is major site of _________
loop of Henle establishes the ________
solute reabsorption;
medullary hyperosmotic gradient
four functions of the digestive system
- digestion
- secretion
- absorption
- motility
structure of GI tract wall
(by lumen)
mucosa
submucosa
muscular externa
serosa
(by abdominal cavity)
circular folds, villi, and microvilli increase…
surface area for absorption
amphipathic cholesterol derivatives for the emulsification (breaking down) of hydrophobic fats
bile salts
fatty acids are held as ____ and then released
micelles
HCl secretion
gastrin (+ hormone)
acetylcholine (+ neurotransmitter)
histamine (+ paracrine)
somatostatin (- paracrine)
digestive enzymes for carb absorption:
salivary:
pancreatic:
both amylase
digestive enzymes for protein absorption:
gastric:
pancreatic:
pepsin;
trypsin/chymotrypsin/carboxypeptidase
digestive enzymes for fat absorption:
pancreatic:
lipase
amount of fluid ingested by a person per day
1200mL/day
amount of fluid secreted into the GI tract per day
7000 mL/day
amount of fluid excreted in feces per day
100 mL/day
most of the fluid that enters the GI tract by ingestion or secretion is…
absorbed
absorption includes net movement of Na+ from lumen to interstitial fluid and water follows by…
osmosis
secretes many digestive enzymes
secretes fluid rich in bicarbonate to neutralize stomach acid, which would inactivate the enzymes
pancreas
synthesizes and secretes bile salts, which are needed for fat digestion
secretes bicarbonate
liver
stores and concentrates bile from the liver
when needed, it contracts and releases bile into small intestine
gallbladder
release is stimulated by amino and fatty acids
works with secretin to inhibit acid production
stimulates gallbladder to secrete concentrated bile salts
relaxes sphincter of Oddi to release bile from the liver and gallbladder to complete fat digestion
CCK (Cholecystokinin)
temporarily stores undigested material
concentrates it by absorbing salt and water
when the rectum contracts, the feces are expelled
large intestine
fast
local gut responses
controlled by enteric nervous system
short reflexes
controlled by CNS
whole-body digestion responses
long reflexes
exocrine cells in gastric glands
mucus cells - opening of glands
parietal cells - walls of glands
chief cells - secrete pepsinogen
endocrine cells in gastric glands
enteroendocrine cells - secrete gastrin
enterochromaffin-like cells - release histamine
D cells - secrete somatostatin
cause of ulcers
H. pylori
causes of vomiting
distention of stomach
substances acting on chemoreceptors
cause of cystic fibrosis
mutation
cause of gallstones
concentration of bile in gallbladder is too high
*cause of jaundice
buildup of high pressure in a blocked common bile duct feedbacks to the liver and prevents further secretion of bile
*bilirubin accumulates in the blood and diffuses into tissues producing yellowish coloration
cause of lactose intolerance
mutation in lactase regulation
cause of constipation
decreased motility in large intestine
cause of diarrhea
decreased fluid absorption, increased fluid secretion, or both
lamina propria,
muscularis mucosa,
and myenteric plexus are made of…
connective tissue,
smooth muscle,
neurons
bile is required for digestion of…
fat
gastric hormone that stimulates acid secretion in the stomach
gastrin
osmosis leads to the absorption of…
water
2 L of hydrochloric acid is secreted by the stomach every…
day
