Urinary system Flashcards
what is the function of the kidney in the simplest terms
filter blood and produce urine
what is the function of the ureters in the simplest terms
transport urine to the bladder
what is the function of the bladder in the simplest terms
store urine
what is the function of the urethra in the simplest terms
excrete pee
how many ureters are there
2
what are ureters
muscular tubes
what are ureters lined with
transitional epithelium
what does the bladder do when it gets full
distends/stretches
what is the bladder lined with
transitional epithelium
where is the bladder located
different places for men and women
what are the 3 regions of the urethra in men
prostatic, membranous, spongy
what does the urethra in men do
remove urine and semen
what type of tissue in the urethra is closest to the bladder
transitional
in males, what is the type of tissue that lies in the middle of the urethra
psuedostratified
what type of tissue is towards the end of the urethra
stratified squamous (a urethra would make kat STRATford sqeamous)
why are UTIs more common in women
urethras are shorter, closer to anus, and sexually transmitted
what is the granular superficial part of the kidney called
renal cortex
what are the cone shaped pyramids in the kidney called
renal medulla
how does urine flow because of the medulla
papillae to ureter
where does blood flow come from in the medulla
segmental artery
what is the pathway of blood flow in renal circulation
renal artery –> afferent arteriole –> glomerulus –> efferent arteriole –> peritubular capillaries –> venule –> renal vein
what are the two parts of the nephron
glomerulus and renal tubule
what is the glomerulus
tube of capillaries
what is the renal tubule
cup shaped capsule
what is the renal tubule followed by
proximal convoluted tubule, loop of henle, distal convoluted tubule
what tissue is the renal corpuscle composed of
simple squamous cells
what tissue is the proximal convoluted tubule composed of
simple cuboidal cells
what tissue is the descending limb of the nephron loop composed of
simple squamous cells
what tissue is the ascending limb of the nephron loop composed of
simple cuboidal cells
what tissue is the distal convoluted tubule composed of
simple cuboidal cells
what is main difference between the cuboidal cells in the distal vs proximal convoluted tubules
proximal has microvilli and lots of mitochondria and distal doesn’t
how many types of cells does the collecting duct have
2
what tissue is the papillary duct composed of
simple columnar cells
what is the most abundant type of nephron
cortical nephrons
where are cortical nephrons found
renal cortex
where are juxtamedullary nephrons found
between cortex and medulla
what do juxtamedullary nephrons have
long loops of henle that innvervate the medulla
what do the juxtamedullary nephrons do
concentrate urine
what is glomerular filtration influenced by
hydrostatic pressure
where does glomerular filtration take place
renal corpuscle
what is produced in glomerular filtration
filtrate
what happens in the proximal convoluted tubule
water and nutrients are reabsorbed back into the blood stream
what happens in the descending limb of the nephron loop
reabsorbs water into bloodstream
what happens in the ascending limb of the nephron loop
reabsorbs sodium and chloride into the bloodstream
what happens in the distal convoluted tubule
secretes ions, toxins, etc and reabsorbs water into blood stream
what happens in the collecting duct
water reabsorption and solutes are secreted
what happens in the papillary duct
delivers urine to minor calyx to be eliminated
3 layers of the glomerular filtration membrane
glomerular capillary, basement membrane, podocytes (go be pussies)
what does the glomerular capillary layer contain
fenestra - pores
what connects the capillary layer and podocytes
basement membrane of the glomerular filtration membrane
what are podocytes
filtration slits
which way does filtrate travel in the glomerular filtration membrane
from capillary lumen to the capillary space
what is the glomerular filtration rate
filtrate formed per minute
what is glomerular hydrostatic pressure
pressure in the glomerulus due to BP
what are the 2 forces that oppose GHP
capsular hydrostatic pressure and blood caloidal pressure
what is capsular hydrostatic pressure
force of filtrate against the capsule wall in the glomerulus
how does blood caloidal pressure oppose GHP
blood proteins in the capillaries increase osmotic pressure which causes filtrate to be drawn back into capillaries
what does net filtration pressure cause if it becomes off balance
renal/kidney failure
where does tubular reabsorption occur
proximal convoluted tubule
what is being absorbed in the proximal convoluted tubule
water, inorganic, and organic solutes
where does tubular secretion occur
proximal convoluted tubule, distal convoluted tubule, and collecting duct
where does tubular secretion never occur
nephron loop
what’s being secreted in tubular secretion
inorganic, organic solutes, and drugs/toxins
how does facilitated diffusion work
glucose attaches to carrier protein which moves it into/out of cell
is ATP required for facilitate diffusion
no
why is ATP not required for some carrier-mediated transport mechanism
concentration gradient is what moves the molecules
how does co-transport work
2 molecules follow the same gradient in the same direction
does co-transport require ATP
no
how does active transport work
sodium-potassium pumps move Na+ and K+ against gradient
is ATP required for active transport
yes
how does counter transport work
one molecule enters cell while another exits
are leak channels always open
yes
what enters the cell in in the proximal convoluted tubule
glucose and sodium
what is formed in the cell in the proximal convoluted tubule
H+
what goes in and what goes out in the proximal convoluted tubule
Na+ in, K+ out
how does glucose and sodium enter the cell in the process of transport in the proximal convoluted tubule
co transport
how else can sodium enter the cell in the process of transport in the proximal convoluted tubule
leak channels
how does H+ form in the cell in the process of transport in the proximal convoluted tubule
carbonic anhydrase reaction
how does Na+ leave cell and K+ enter cell in the process of transport in the proximal convoluted tubule
exchange pump
how do carrier proteins become saturated
Na+ and glucose concentrations are too high so sodium glucose transporters can’t transfer them across the membrane, so the solutes are left in the filtrate
how does Na and Cl enter the cell in the transport at the distal convoluted tubule
co transport
how does Cl leave the cell in the transport at the distal convoluted tubule
leak channels
how does Na leave the cell in the transport at the distal convoluted tubule
exchange pump with K+
when Na leaves in the cell in the transport at the distal convoluted tubule, what is it exchanged with
K+
how does K leave the cell in the transport at the distal convoluted tubule
leak channels
how can the Na/K pump be regulated
by aldosterone
what happens after H is moved into the cell in the transport at the distal convoluted tubule
bicarbonate is moved into the blood
what happens to CO2 once it enters the cell in the transport at the distal convoluted tubule
interacts with water to form carbonic acid which then dissociates into H+ and bicarbonate
what happens once H+ and bicarbonate is formed in the transport at the distal convoluted tubule
H+ leaves the cell and Na moves in
how else can Na enter the cell in the second part of the transport at the distal convoluted tubule
counter transport with ammonia
where does ammonia come from in the transport at the distal convoluted tubule
amino acid deamination
what else is formed from amino acid deamination
bicarbonate
how does bicarbonate exit the cell at the end of the transport at the distal convoluted tubule
counter transport with Cl- (chloride shift)
what fluid in the kidneys become urine
tubular fluid
what does tubular transport result in
medulla osmotic gradient
what causes the osmotic gradient in renal
concentration in medulla is greater than the concentration in the cortex
what is osmolarity defined as
how much solute is in a certain amount of water
how is osmotic gradient obtained
changes in tubular fluid, peritubular fluid, and blood
what is the general idea of what happens to fluid as it moves along the nephron loop
filtrate concentration changes
what can pass through the descending loop
only water
what can pass through the ascending loop
only Na and Cl
what happens to osmolarity as fluid moves down the descending limb
increases because water is leaving
what happens to osmolarity as fluid moves up the ascending limb
decreases because Na and Cl are leaving
what is the counter current multiplication defined as
the flow of filtrate in opposite direction in the nephron loop and concentration multiplying
how does transport at the collecting duct change peritubular concentration
urea concentrations increase
why do urea concentrations increase when moving from the nephron loop to collecting duct
because urea can’t pass through ascending or descending limb
what can urea pass through in the renal
papillary duct
where does urea go once it’s passed through the papillary duct
peritubular fluid
what is the main function of the vasa recta
maintain concentration gradient of the medulla
which way does the vasa recta carry blood
opposite direction of filtrate in nephron loop
how does the vasa recta maintain the osmolarity of the blood
absorbs the solutes and water that are in blood to balance it out/bring levels back down
what are 3 ways the body controls glomerular filtration rate
auto regulation, neural regulation, and hormonal regulation
when is auto regulation used
when the body is at rest
when is neural regulation used
when the body is experiencing stress
what type of regulation is short term stress and which is long term
neural - short term, hormonal - long term
how does neural regulation decrease GFR
sympathetic fibers innervate the kidneys which causes afferent arterioles to constrict
what is hormonal regulation initiated by
kidneys - RAAS system
what are juxtaglomerular cells and where are they found
smooth muscles cells in the afferent arterioles
what kind of receptors do juxtaglomerular cells contain
mechanoreceptors
where are macula densa cells found
distal convoluted tubule
what kind of receptors do macula densa cells contain
chemo and osmo receptors
what properties do mesanglial cells have
contractile
what can mesanglial cells be affected by
vasopressin and angiotensin 2
what do auto regulation cells do when homeostasis is disrupted
dilates afferent arterioles, contracts mesanglial cells, and contracts efferent arterioles
what does dilation of afferent arterioles, contraction of mesanglial cells, and contraction of efferent arterioles result in
glomerular BP increases and homeostasis is restored
what two things are released during hormonal regulation
cortisol and aldosteron
what does aldosterone trigger in normal regulation
retention of sodium and water and increase in BP and blood volume
how is renal absorption affected in zona glomerulosa
increased
what is the renal absorbing in zona glomerulosa
Na and H2O
what is renal absorption stimulated by in zona glomerulosa
angiotensin 2
what stimulates the RAAS system in the very beginning
decrease in BP
what is released by the kidneys when low BP is detected
renin
when happens when renin enters the blood
converts angiotensinogen to angiotensin 1
what converts angiotensin 1 to angiotensin 2
ACE enzyme
what can angiotensin 2 do
make you thirsty, constrict blood vessels, act on adrenal cortex
what happens when angiotensin 2 acts on the adrenal cortex
releases aldosterone which leads to Na reabsorption in kidneys
what does the macula densa detect
low Na levels
what happens when macula densa detects low Na levels
releases renin to enter the bloodstream
what organ causes angiotensinogen and convert to angiotensin 1 to enter the blood
liver
what releases ACE to convert angiotensin 1 to angiotensin 2
lungs
what does angiotensin 2 act on
posterior pituitary gland
what happens once angiotensin 2 is acted on posterior pituitary
ADH is released
what do paracellular junctions contain
tight junctions (with pores)
what do transcellular junctions contain
aquaporins
what are aquaporins
transmembrane proteins that are only water permeable
what does ADH express in the DCT and collecting duct
aquaporins
what happens when ADH expresses aquaporins
increased water absorption into blood which decreases urine volumes
what is indicated if urine concentrations are too high
pathology
what does high protein concentrations in urine indicate
hypertension
what does high glucose concentrations in urine indicate
diabetes
what does high bilirubin concentrations in urine indicate
liver problems
what does high leukocytes concentrations in urine indicate
UTI
what are the metabolic functions of the kidney
vitamin D synthesis and forming calcitriol
what does vitamin D impact
metabolism, endocrine, and digestive system
what are some metabolic wastes that are removed in urine
urea, creatine, uric acid
what happens to urea, creatine, and uric acid
either dissolved in blood or eliminated in urine
how do the kidneys play a part in blood homeostasis
regulates volume, composition, and pH
what is gluconeogensis in terms of the kidney functions
energy during fasting
what are the affects of the kidneys on endocrine function
produces renin and erythropoietin
