Urinary Flashcards
functions of the urinary system
store/excrete urine, regulate blood volume, erythrocyte production, ion levels, and acid-base balance
*retroperitoneal
components of the urinary system
2 kidneys, 2 ureters, urinary bladder and urethra
where is the urinary system located?
anterior of 12th rib, right kidney is lower than left, adrenal glands are on top of the kidneys
describe the kidneys
- surrounded by layers of fascia and fat
- renal fascia= between parietal peritoneum and 1st fascia, there is a layer of paranephric fat. It protects and insulates kidneys from physical damage
gross anatomy of kidneys
surrounded by fibrous capsule
consists of renal cortex, medulla, pyramid, papilla, calyx and column
what is the renal cortex
outer layer, consistent with appearance
what is the renal medulla
inner layer, composed on microscopic filtration units and collection ducts
renal pyramid
triangle that comes together at a point towards center of kidney
renal papilla
where renal pyramid come together and urine drains into minor calyx
*many minor calyx form a major calyx
major calyx
drain into the renal pelvis- where urine drains into the ureter, then goes to the bladder
renal column
extensions of the renal cortex that divides the renal pyramids
blood supply to kidney chain
renal artery– segmental artery– interlobar artery– arcuate artery– interlobular artery– afferent arteriole– glomerulus– efferent arteriole
Peritubular capillaries– interlobular vein– arcuate vein– interlobar vein– renal vein
what is a nephron
- functional unit of the kidney
- composed of a renal corpuscle that surrounds the glomerulus
– from renal corpuscle– proximal convoluted tubule, down the descending limb and up the ascending limb (nephron loop) - empties into collecting duct which drains into the renal papilla and into a minor calyx
glomerulus
carries blood through, waste is filtered out into the renal corpuscle
glomerulus anatomy
- afferent arteriole enters the Bowman’s capsule and splits into several mini arteries to form the glomerulus.
- Bowman’s capsule + glomerulus make up the renal corpuscle.
- As blood passes through the glomerulus, waste is filtered and collected in Bowman’s capsule — then to the proximal convoluted tubule.
- Blood from glomerulus moves into
efferent arteriole that then becomes the renal capillaries before draining into veins.
ureters
collect urine from renal pelvis and transport it to the urinary bladder, peristalsis moves urine down
- has 2 layers of smooth muscle
- adventitia, and two layers of mucosa layer made of lamina propria and transitional epithelia
***same type of layers as digestive system, but different type of epithelium
urinary bladder
- urine enters the bladder at the posterioinferior aspect through ureteral openings
- rugae (allows for expansion) transitional epithelial
- trigone: no rugae in this area, serves as a funnel to move urine towards urethra
what does the trigone do?
formed from distal portion of the ureters that become incorporated into posterior bladder wall during fetal development
*doesn’t expand with filling
* serves as a funnel to move urine towards urethra
adventitia
outer layer of bladder, holds shape
areolar CT in urinary bladder
detrusor muscle
main muscle in wall of bladder that contracts to propel urine out of the body
smooth muscle
submucosa
found between mucosa and muscle layers formed from dense irregular CT to support bladder wall
mucosa
**transitional epithelium- stretches to accommodate urine storage, innermost layer
lamina propria- highly vascularized, supports mucosa
urethral sphincters
Internal urethral sphincter, external urethral sphincter
What is the internal urethral sphincter?
involuntary, relaxes when bladder is full, stimulates the micturition reflex (to urinate)
what is the ‘fancy’ word (official word) for urinating?
micturition
what is the external urethral sphincter?
- voluntary, can be contracted to ‘hold up’ until bladder can be emptied
- located in the pelvic diaphragm
trace the path of blood to kidneys: arteries
renal artery– segmental artery– interlobar artery– arcuate artery– interlobular artery– afferent arteriole– glomerulus– efferent arteriole
trace the path of blood to kidneys: veins
peritubular capillaries– interlobular vein– arcuate vein– interlobar vein– renal vein
