Ch 40 urinary system overview

ajv09c's version from 2015-05-01 01:14

Section 1

Question Answer
urinary system consits ofkidneys, urinary bladder, ureters, urethra, trigone
kidneysmajor homeostatic organ of body
kidneys function toremove nitrogenous wastes from blood stream,

maintain fluid balances,

maintain electrolyte balance,

maintain acid base balance
urinary bladderreservoir for urine
ureterstransports waste fluids from kidneys to urinary bladder
urethraconnects bladder to external environment
trigonetriangular area delineated by the openings of ureters and urethra

Section 2

Question Answer
kidneys fiter blood toremove metabolic wastes, toxins, excess ions
kidneys 2 major regionsrenal cortex- outer portion of kidney renal medulla-innter portion of kidney
renal medulla containsrenal pyramids papilla/apex faces calyx.
renal pyramids are separated byrenal columns
blood flow to, through, from kidneysdescending aorta, renal arteries, segmental arteries, interlobal arteries, arcuate arteries, cortical radiate arteries, afferent arterioles, cortical radiate veins, arcuate veins, interlobal veins, renal vein
what artery enters blood into kidneysegmental

Section 3

Question Answer
each kidney contains aprx how many nephronsone million
functional unit of the kidneynephron
nephron usually foundwithin cortex (cortical nephrons) but some have parts in loop of hence in medulla
nephron in the medullajuxtamedullary nephron
2 major structures of the nephronglomerulus and renal tubule
glomeruluscapillary knot formed by the afferent arteriole where blood is filtered
renal tubuleforms the glomerular capsule, proximal and distal convoluted tubules and loop of henle
bowmans capsulesurrounds glomerulus, visceral inner wall composed of podocytes
podocytes forma porous membrane so fluid can pass through
fluids/ ions not reabsorbed from the renal tubule passes tocollecting duct
collecting duct serves multiple nephrons which then dumps urine into the calyces and pelvis of kidneys

Section 4

Question Answer
nephron function depends on features of the renal circulation
nephrons 2 distinct capillary bedsglomerulus and peritubular
glomerulus fluid filtration occurs becauseafferent arteriole has high pressure/resistance and large diameter efferent arteriole draining glomerulus also has high resistance but smaller diameter
net result of glomerulus fluid filtrationhigh hydrostatic pressure forces fluid and small proteins out of afferent arteriole/glomerulus into glomerular capsule called filtrate
juxtaglomerular apparatus functionsto concentrate urine
juxtaglomerular apparatus is composed ofjuxtaglomerular cells and macula dense
juxtaglomerular cellsin arteriole walls sense blood pressure
macula densa area of specialized columnar chemoreceptors cells in distal convoluted tubule
urine formation results from filtration, reabsorption (tubular), secretion
filtrationpassive process in glomerulus
reabsorption (tubular) active and passive (by osmosis) process----- 75-80% occurring in proximal convoluted tubule-----highly selective----- filtrate components reabsorbed through tubule wall and into peritubular capillaries
what is selectively reabsorbed glucose, amino acids and some ions
secretionsubstances not filtered in glomerulus (left in the blood) are secreted from peritubular capillaries and absorbed into tubules

Section 5

Question Answer
urinary bladder functionreservoir for urine until micturition
micturition controlled byinternal urethral sphincter and external urethral sphincter
internal urethral sphincter involuntary---- composed of smooth muscle
external urethral sphinctervoluntary----- composed of skeletal muscles----located at the urogenital diaphragm
urinary bladder containsrugae so bladder can stretch as it fills with urine

Section 6

Question Answer
urine characteristicscolor, odor, ph, specific gravity
urine colorclear/pale yellow to amber
yellow color due to urochrome pigment from hemoglobin destruction
order due tofoods and drugs
ph due todiet---- diabetes mellitus, makes urine smell fruity acetone like
specific gravity due to1.001-1.030 depends on solutes dissolved in urine
specific gravity increases with concentration caused by fever, limited fluid intake, kidney inflammation
kidney inflammation medical termpyelonephritis
high specific gravity can causekidney stones
kidney stone medical termrenal calculi
majority of solutes found in urine in decreasing concentration orderurea (break down of proteins), sodium, potassium, phosphate, sulfate ions, creatinine (from skeletal muscles), and uric acid (from nucleic acid breakdown
abnormal components of urineglucose, albumin, ketone bodies, bile pigments, white blood cells, nitrites, red blood cells, hemoglobin

Section 7

Question Answer
glucose in urineglycosuria, cause: diabetes mellitus
albumin in urinealbuminuria, cause: damage to glomerular membrane (kidney trauma, poisons/ heavy metals) toxins, hypertension, pregnancy, excessive protein intake
ketone bodies in urineketonuria, cause: low carb diet, starvation
bile pigments in urinebilirubinuria, cause: liver disease (hepatitis, cirrhosis)
nitrites in urinebladder infection, bacterial infection
red blood cells in urinehematuria, cause: urinary tracct irritation by kidney stones, urinary tract infection
hemoglobin in urinehemoglobinuria cause: hemolytic anemia, poisonous snake bites, renal disease