Lab exam 2 Flashcards
describe the position of the kidney-
retroperitoneal, posterior abdominal wall between T12 to L3. right kidney lower than left because of the liver, rib 12 crosses over middle of left kidney. all of its connecting vessels and organs are retroperitoneal as well
Three protective connective tissue coverings of kidney
Renal fascia
Perirenal fat capsule
Fibrous capsule
Renal fascia of kidney
immediately deep to parietal peritoneum. Binds it to abdominal wall anterior and fused w/ lumbar muscles posteriorly
Perirenal fat capsule of kidney
layer of adipose tissue cushions kidney holding in place
Lateral surface is convex, and medial is concave with a slit, called the hilum
Receives renal nerves, blood cushions kidney and holds it into place
Fibrous capsule of kidney
(tissue paper) encloses kidney protecting it from trauma and infection anchoring at hilum
Collagen fibers extend from fibrous capsule to renal fascia
Still drop about 3 cm when going from lying down to standing up
Renal parenchyma
glandular tissue that forms urine
Appears C-shaped in frontal section
Encircles renal sinus: cavity that contains blood and lymphatic vessels, nerves, and urine-collecting structures. Adipose fills the remaining cavity and holds structures in place
Two zones of renal parenchyma
Outer renal cortex- band of tissue
Inner renal medulla facing sinus
Two major Structures in renal medulla
Renal columns—extensions of the cortex in between triangles that project inward toward sinus
Renal pyramids—triangular shaped darker portions, 6 to 10 conical shaped w/ broad base facing cortex and renal papilla facing sinus
Lobe of kidney:
one pyramid and its overlying cortex
Renal Minor calyx:
cup that nestles the papilla of each pyramid; collects its urine
Renal Major calyces:
formed by convergence of 2 or 3 minor calyces
Renal pelvis
: formed by convergence of 2 or 3 major calyces
Ureter:
a tubular continuation of the pelvis that drains urine down to the urinary bladder
Renal Sinus
is the hilum of the kidney w/blood supplies to kidney coming into hilum w/ major blood supplies to it. Also has nerve innervation in order to function w/ renal nerve coming into hilum of kidney like renal artery and vein. Kidney has smooth muscle that is involuntary working regardless of nerves.
General Renal Circulation
Kidneys are only 0.4% of body weight, but receive about 21% of cardiac output (renal fraction) for waste removal not metabolic demands
Describe the pathway from artery to glomerulus
Renal artery from aorta dividing into segmental arteries that give rise to:
Interlobar arteries: up renal columns, between pyramids towards corticomedullary junction (boundary between cortex and medulla)
Arcuate arteries: over pyramids
Cortical radiate arteries: up into cortex
Branch into afferent arterioles: each supplying one nephron. Afferent lead to glomerulus (ball of capillaries)
Describe pathway from glomerulus to the heart.
Blood is drained from the glomerulus by efferent arterioles
Most efferent arterioles lead to peritubular capillaries
Some efferents lead to vasa recta—a network of blood vessels within renal medulla
Capillaries then lead to cortical radiate veins or directly into arcuate veins
Arcuate veins lead to interlobar veins which lead to the renal vein
Renal vein empties into inferior vena cava
the cortex, peritubular capillaries branch off of the efferent arterioles supplying the tissue near the glomerulus, the proximal and distal convoluted tubules
In the medulla, the efferent arterioles give rise to the vasa recta, supplying the nephron loop portion of the nephron
Flow of fluid from the point where the glomerular filtrate is formed to the point where urine leaves the body:
glomerular capsule → proximal convoluted tubule → nephron loop → distal convoluted tubule → collecting duct → papillary duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra
First half microscopic filtration of urine second half macroscopic parts of system
Ureter-
retroperitoneal, muscular tubes that extend from each kidney to the urinary bladder
About 25 cm long
Pass posterior to bladder and enter it from below
Flap of mucosa at entrance of each ureter acts as a valve into bladder
Keeps urine from backing up into ureter when bladder contracts
Ureters layers
Adventitia—connective tissue layer that connects ureter to surrounding structures
Muscularis—two layers of smooth muscle with third layer in lower ureter
Urine enters, it stretches and contracts in peristaltic wave
Mucosa—transitional epithelium
Begins at minor calyces and extends through the bladder helps blocking once passes so it doesnt flow back up into ureters
Lumen very narrow, easily obstructed by kidney stones
Three layers of urinary bladder
Covered by parietal peritoneum, superiorly, and by fibrous adventitia elsewhere
Muscularis: detrusor: three layers of smooth muscle covered by transitional epithleium as well.
Mucosa: transitional epithelium
Umbrella cells on surface of epithelium protect it from the hypertonic, acidic urine
Rugae—conspicuous wrinkles in empty bladder allowing for more room in urine.
Trigone—smooth-surfaced triangular area on bladder floor that is marked with openings of ureters and urethra
Capacity of bladder
—moderate fullness is 500 mL, maximum fullness is 700 to 800 mL
Highly distensible
As it fills, it expands superiorly
Rugae flatten
Epithelium thins from five or six layers to two or three
Urinary bladder—
muscular sac located on floor of the pelvic cavity.
Inferior to peritoneum and superior to pubic symphysis
Urethra
is tube that conveys urine out of body