urinary system two Flashcards
functional filtration unit of the kidney
nephron
what is the function of a nephron?
filters blood, then modifies this “filtrate”
how many nephrons does a kidney contain?
over 1 million
what does the nephron consist of?
renal corpuscle, proximal convoluted tubule, nephron loop, and distal convoluted tubule
glomerulus and glomerular capsule
renal corpuscle
what is the visceral layer of the renal corpuscle made of?
podocytes
what is one of the places where capillaries can be controlled?
podocytes
filtrate is squeezed into here and then enters the proximal convoluted tubule
capsular space (in parietal layer of renal corpuscle)
what is the function of the proximal convoluted tubule?
resorb “the good stuff” from the filtrate and secrete some ions back to the tubule
how is resorbed material sent to the blood (proximal convoluted tubule)?
in peritubular capillaries
where does filtrate go after going through proximal convoluted tubules?
nephron loop
what is the function of the nephron loop?
resorb more material and water in the filtrate
how is resorbed material sent to the blood (nephron loop)?
in the vasa recta
where does filtrate travel after the nephron loop?
distal convoluted tubule
what is the function of the distal convoluted tubule?
resorbs more materials and water in the filtrate
where is resorbed material sent to the blood (distal convoluted tubule)?
peritubular capillaries
what is the flow of filtrate/urine?
- filtrate is squeezed out of the glomerulus, enters capsular space
- proximal convoluted tubule
- nephron loop
- distal convoluted tubule
- collecting duct (target of ADH)
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder
- urine exits the body via the urethra
when does filtrate become urine?
after leaving the collecting duct
long, thin, paired muscular tubes
ureters
what is the function of the ureters?
transport urine (via peristalsis) from kidney to urinary bladder
why do the ureters use peristalsis as opposed to relying on gravity to pump urine into the urinary bladder?
because we are not always standing and urine needs to move even when we are sitting/sleeping
what three layers make up the histology of the ureter?
mucosa, muscularis, adventitia
what type of mucosa does the ureter have?
transitional epithelium
how many layers of smooth muscule does the ureter’s muscularis have?
two
what type of adventitia does the ureter have?
areolar connective tissue
what is renal calculi (kidney stones)?
calcifications/crystals
- biggest factor: frequent dehydration
what is the function of the urinary bladder?
urine reservoir (muscular storage sac for urine); it changes shape as it filIs
what does the urinary bladder look like when it’s empty?
upside-down pyramid, in true pelvis (adults)
what does the urinary bladder look like when it’s full?
oval, bulging into abdominal cavity
what is the neck of the bladder?
narrow base of the bladder
what layers make up the histology of the urinary bladder?
mucosa, submucosa, muscularis, adventitia
what type of mucosa does the urinary bladder have?
transitional epithelium
what type of submucosa does the urinary bladder have?
dense irregular connective tissue
how many layers of smooth muscle does the urinary bladder’s muscularis have?
three
what do the three layers of the urinary bladder’s muscularis form?
detrusor muscle
is the internal urethral sphincter involuntary or voluntary?
involuntary (ANS)
where is the internal urethral sphincter located?
in the muscularis of the urinary bladder
what type of adventitia does the urinary bladder have?
areolar connective tissue
singular muscular tube running from bladder to exterior of body
urethra
what is the function of the urethra?
expels urine from the body
a group of skeletal muscles pierced by the urethra
urogenital diaphragm
is the external urethral sphincter under voluntary or involuntary control?
voluntary (pudendal nerve)
where is the external urethral sphincter located?
urethra part of the urogenital diaphragm
components of the female urethra
- carries urine only
- short
- distensible
what does distensible mean?
can be streched
components of the male urethra
- carries both urine and semen
- longer
- not as distensible
why are UTI’s more common in women?
because there is a smaller area for bacteria to travel into
are catheters longer for men or women?
men
