Unit 3 Urinary Flashcards
function
- filter metabolic wastes from blood
- maintain acid/base balance
- maintain fluid and electrolyte balance
- hormone production
structures
- paired kidneys
- paired ureters
- bladder
- urethra
kidney structures
hilus cortex medulla medullary rays renal lobe
hilus
a) blood vessels, lymphatics, and nerves enter and exit
b) renal pelvis, major and minor calyces collect urine
cortex
renal corpuscles
medulla
pyramids of tubules separated by cortical columns (of Bertin)
medullary rays
columns of tubules extending into the cortex
renal lobe
medullary pyramid and overlying cortex
renal blood flow
aorta renal artery segmental artery interlobar artery arcuate artery cortical radiate (interlobular) artery afferent arteriole glomerulus efferent arterioles peritubular capillary plexus cortical radiate vein arcuate vein interlobar vein renal vein inferior vena cava
arcuate arteries
coritcomedullary junction
peritubular capillary plexus
surround tubules
vasa recta - juxtamedullary nephrons
filtration flow
glomerulus proximal convoluted tubule thin segment descending loop of Henle ascending loop of Henle thick segment distal convoluted tubule collecting duct
renal corpuscle components
glomerulus
bowman’s capsule
podocytes
mesangial cells
glomerulus
capillary tuft
bowman’s capsule
encloses urinary space
podocytes
visceral layer; pedicels, filtration slits
mesangial cells
support capillary wall and basement membrane; act as phagocytes
renal corpuscle filtration barrier
- endothelium of glomerular capillary
- fused basla lamina
- pedicels
proximal tubule
a) longer than distal tubule
b) convoluted and straight portions
c) simple cuboidal epithelium with brush border
proximal tubule functions
(1) absorb 85% of NaCl and water; glucose, amino acids and small proteins
(2) secrete creatinine
loop of Henle
a) allows the production of hypertonic urine
b) descending limb permeable to water
c) ascending limb impermeable to water
d) thick ascending limb actively transports NaCl out of tubule
distal tubule
a) simple cuboidal epithelium; no brush border
b) smaller cells than proximal tubule
c) macula densa – part of the juxtaglomerular apparatus
d) secretes hydrogen and ammonium ions to maintain acid/base balance
e) responds to aldosterone by resorbing sodium and secreting potassium
collecting tubules and ducts
a) cuboidal epithelium with distinct lateral borders
b) vasopressin (ADH) increases permeability to water allowing it to return to blood
c) delivers urine to renal pelvis
juxtaglomerular apparatus
- afferent arteriole
- distal tubule
- extraglomerular masangial cells
- renin-angiotensin system
afferent arteriole
juxtaglomerular cells
modified smooth muscle cells
secrete renin
distal tubule
macula densa
narrow columnar epithelium
detect sodium ion concentration of filtrate
renin-angiotensin system
a) macula densa monitors ion concentration and communicates with juxtaglomerular cells
b) juxtaglomerular cells release renin
c) renin converts angiotensinogen to angiotensin I (inactive)
d) converting enzyme in lung endothelial cells converts angiotensin I to angiotensin II
e) angiotensin II increases blood pressure; vasoconstriction; stimulates aldosterone release (conserves sodium and chloride)
external passages
calyces renal pelvis ureters bladder urethra
basic structure
- mucosa
- no submucosa
- muscularis
mucosa
- transitional epithelium except in urethra
- lamina propria (loose to dense CT)
- no muscularis mucosa
muscularis
smooth muscle; helical with areas of inner circular and outer longitudinal
bladder
dome cells of epithelium
three layers of smooth muscle
urethra (male)
prostatic (transitional epithelium)
membranous (stratified/pseudo columnar epithelium)
penile (pseudo stratified columnar, some squamous)
urethra (female)
stratified squamous nonkeratinized with some pseudostratified columnar epithelium
urine passage
nephron collecting duct papillary duct minor calyx major calyx renal pelvis ureter urinary bladder
