Urinary System Flashcards
urinary system consists of…
2 kidneys
2 ureters
1 urinary bladder
1 urethra
urinary system functions
- regulate blood volume, blood pressure, pH + ion concentration
- eliminate urea, uric acid, drugs etc.
kidney characteristics
- retroperitoneal located behind peritoneum b/w dorsal body + parietal peritoneum
- hilus is medial indentation
- contains renal artery, renal vein + ureter
- right kidney is slightly lower due to liver
- protected by renal capsule (adipose tissue + renal fascia)
kidney: internal gross anatomy
1) renal cortex
2) renal medulla: contains renal pyramids
renal medulla: renal pyramids
- separated by renal columns (downward extensions of cortical tissue)
- 6 renal columns per kidney
- narrow end call apex of renal papilla
kidney characteristics
- retroperitoneal
- contains renal artery, renal vein + ureter
- protected by renal capsule
renal capsule is made of…
adipose tissue + renal fascia
kidney location
behind peritoneum b/w dorsal body + parietal peritoneum
KIDNEY: internal gross anatomy
1) renal cortex
2) renal medulla: renal pyramids
renal pyramids
- separated by renal columns
- narrow end = apex
- collecting ducts exit at renal papillary
flow of collecting ducts in renal medulla
material > 4-5 minor calyces > 2-3 major calyces > renal pelvis > ureter
KIDNEY: microscopic anatomy
1) nephron
2) renal corpuscle
nephrons: cortical nephron
- 85% of nephrons
- renal corpuscle located near surface in cortex
- loop of henle is shorter & located in outer medulla
- composed of peritubular capillaries
nephrons: juxtamedullary nephrons
- 15% of nephrons
- renal corpuscles in cortex are close to medulla
- very long loops of henle penetrate deep into medulla
- contain peritubular capillaries + vasa recta
- allow concentration + dilution of urine
blood supply to kidney
renal arteries > segmental arteries > interlobular artery (delivers blood up columns) > arcuate artery (junction of medulla + cortex) > cortical arteries
blood supply to nephrons
cortical radiate artery > afferent arteriole > glomerulus > efferent arteriole > peritubular capillaries (cortical nephrons + vasa recta in juxtamedullary nephrons) > cortical radiate vein > arcuate vein > interlobular vein > renal vein
juxtamedullary apparatus
- located at point of contact b/w distal convoluted tubule + afferent arteriole
- function: regulate blood pressure, ion concentration of blood + formation of filtrate
juxtamedullary apparatus: tubular portion
- macula densa
- composed of modified cells of distal convoluted tubule
- cells are taller + narrower
juxtamedullary apparatus: arteriolar portion
- composed of afferent + efferent arteriole
- juxtaglomerular cells (modified smooth muscle cells contain granules)
- produce hormonal enzyme - renin
ureters
- retroperitoneal
- function: transport new formed urine from kidneys
- mucosa: transitional epithelium (allows stretching)
- muscularis externa: smooth muscle
- serosa/advetitia
urinary bladder
- mainly retroperitoneal
- mucosa: transitional + rugae (folds of epithelium)
- muscularis externa: smooth muscle - detrusor muscle
- adventitia: posterior + inferior surfaces, superior surface is serosa
urinary bladder: internal structure
trigone: triangle from opening of 2 ureters + urethra
- lacks rugae
- openings are fixed
urethra basic charateristics
- connects bladder to outside
- male: longer and transports urine + semen
- female: short and only urine
urethra: sphincters
- internal is thickening of detrusor muscle at base of bladder (smooth muscle)
- external surrounds urethra passing thru urogenital diaphragm (skeletal muscle)
- both sphincters surround proximal opening
wall of urethra
- smooth muscle lined by mucosa (transitional proximal to bladder)
- stratified squamous near end of urethra
MICROSCOPIC ANATOMY: nephron
functional unit made of renal corpuscle + renal tubule
MICROSCOPIC ANATOMY: renal corpuscle
- in renal cortex
- site for blood filtration
- made of glomerulus (capillary bed) + bowman’s capsule (encases + drains filtrate into proximal convoluted tubule)
KIDNEY: filtration membrane
- consists of Bowman’s capsule + glomerulus
- filters into Bowman’s capsule
- consists of: glomerular endothelium, basement membranes, podocyte of Bowman’s capsule
glomerular endothelium
porous epithelial layer of simple squamous cells
basement membrane
attach glomerular endothelium to podocytes
podocytes of Bowman’s capsule
- simple epithelium (allows filtrate to pass)
- made of podocytes w/ filtration slits
KIDNEY: renal tubule consists of
1) proximal convoluted tubule
2) loop of henle
3) distal convoluted tubule
proximal convoluted tubule (PCT)
in cortex of kidney
loop of henle
descending > ascending look of henle in medulla
distal convoluted tubule (DCT)
in cortex of kidney
