41 terms

A&P II quiz 8

function of urinary system
to maintain the volume and composition of body fluids within normal limits
- removal of nitrogenous waste products including urea, uric acid, creatinine
- maintaining electrolyte and fluid balance
-helps maintina acid/base balance
-regulates the production of RBCs (EPO)
-partial regulation of blood pressure (juxtaglomerular apparatus--renin)
end product of the metabolism of amino acids this is formed in the liver and released into the blood. some will be filtered out by the kidneys and become part of urine, blood test called a BUN blood urea nitrogen is used to evaluate these processes
kidney malfunction that results in too much urea in the blood
uric acid
an end product of nucleic acid metabolism
a waste product of muscle metabolism(results from the breakdown of creatinine phosphate )
creatinine clearance test
measure the amount of creatinine that is filtered out of the blood in a given amount of time
parathormone, cuases kidneys to conserve calcium
from the adrenal cortex, causes kidneys to conserve sodium; affects the osmotic pressure of fluids and thus the movement of water, therefore impacts blood volume and blood pressure
antidiuretic hormone from the hypothalamus, reduces the amount of water that goes out as urine; and influence of blood volume
stimulates the formation of RBCs in the red bone marrow
juxtaglomerular apparatus
contain chemoreceptors and baroreceptors that respond to changing conditions by producing the enzyme renin; RENIN from the kidneys initiates a biochemical pathway that results in the formation of angiotensin II,
angiotensin II
a potent vasoconstrictor; responds to a decrease in blood pressure
lie between T12 and L3 are retroperitoneal; only partially protected by the rib cage; each has a hilus which opens to a renal sinus
urine carrying structures that pass through the hilus
renal fascia
outermost layer DFCT surrounds the kidneys and the adrenal glands and anchors them to their surroundings
adipose capsule
middle cushioning layer; thickness of this helps keep kidneys in place; decreased fat here can cause kidney to drop down and create kinks in the ureters resulting in the backup of urine into the kidneys causing a condition called HYDRONEPHROSIS
renal capsule
transparent, shiny layer that lies directly on the surface of each kidney and also lines the renal sinus; acts as a barrier to prevent infections from entering kidney tissues
renal cortex
thinner outer layer; contains the majority of the microscopic, urine forming structures called NEPHRONS which are complex and have long tubules that dip into the interior region and ultimately drain into collecting ducts
renal medulla
interior to the cortex; contains renal pyramids which are separated by renal columns (portions of cortex that extend into the medulla); the apex of the pyramids from projections called papilla. each papillae is enclosed by a cup shaped end of a hollow tub called a minor calyx (calyces = plural); minor calyces collect urine that drains continuously from the papillae
major calyces
formed by merged minor calyces; carry urine into a funnel shaped hollow region called the renal pelvis which turns into the ureter which carries the urine on into the urinary bladder
**walls of the calyces, renal pelvis, and ureters contain smooth muscle which contract to propel the urine along to the bladder
an infection of just the renal pelvis and clyces
infection or inflammation of the entire kidney
normal healthy kidney
medical conditions involving the kidney
arterial blood supply
renal arteries arise from the aorta they branch to form the interlobular arteries; small lateral branches of the interlobular arteries carry the blood into the nephrons and are referred to as the afferent arterioles which supply the glomerulus and blood then exits via the efferent arterioles
renal veins
how blood exits the kidneys; they exit the kidneys at the hilus and empty into the inferior vena cava
nerve supply to the kidneys
vasomotor neurons of the autonomic nervous system (form the renal plexuses) impact the rate of filtration by altering the diameters of the afferent and efferent arterioles of the glomerulus
the functional units of the kidneys; control what ends up in the urine and what remains in the blood, each kidney has about a million nephrons
renal corpuscle
the filtering unit of nephron contains :
-glomerulus: ball of capillaries that have lots of fenestrations which facilitate filtration of big things
-bowmans capsule: double layered cup like structure that surrounds the glomerulus- inner layer has modified epithelial cells called podocytes that have slits in between the individual cells
filtrations membrane
formed by the combination of the fenestrated capillaries of the glomerulus and the modified visceral layer of the bowmans capsule--water and dissolved solutes are known as filtrate after passing the bowmans capsule
renal tubule
complex microscopic tubular structure that consists of three distinct sections which are different histologically
proximal convoluted tubule PCT
highly coiled, cells are adapted for reabsorption via active transport; cuboidal epithelial cells w/ lots of mitochondria and microvili
loop of henle, nephron loop
narrowed segment has a descending limb that extends into the medulla and makes a sharp U turn and then has an ascending limb that returns toward the cortex
distal convoluted tubule DCT
highly coiled; most cells are adapted for secretion of substances rather than absorption; actually touches the afferet arteriole
--empty their contents into the collecting ducts that form the striations in the pyramids of the medulla
[collecting tubules-renal papillae-minor calyces-major calyces-renal pelvis-ureters]
juxtaglomerular apparatus JG apparatus
composed of specialized cells from different parts of the nephron that make contact w/ each other where the DCT passes b/w the afferent and efferent arterioles
macula densa* think DCT
chemoreceptor cells of the distal convoluted tubules these cells detect the concentration of sodium, potassium and chloride in the filtrate of the DCT
juxtaglomerular cells
in the afferent arteriole they produce an enzyme called renin; cells called renal baroreceoptors respond to changes in pressure of the blood coming in to the glomerulus
function of JG apparatus
to help regulate the blood pressure and the rate blood is filtered by the kidneys by the way of the renin angiotensin II pathway
fluids and solutes from the blood are filtered out of the glomerulus into the Bowman's capsule about 20% of the plasma and it's solutes enters the capsule; this is the filtrate; consists of water, small proteins, urea, glucose, amino acids
about 90% of the water and some of the solutes in the filtrate are returned to the blood stream by passing from the renal tubule into the peritubular capillaries
the reverse of reabsorption; some substances from the blood will end up in the filtrate by passing from the peritubular capillaries into the renal tubules