Final Exam Flashcards
Three major functions of urinary system
excretion - removal of waste (kidney), elimination - discharge of waste (bladder), Homeostatic regulation of blood volume and solute concentration of blood
Other functions of urinary system
regulating BP by regulating volume and releasing EPO and renin. regulating ion concentration (Na, K, Cl, Ca). Stabilizing pH by elimination of excess H. (Urine pH is 6). Conserving valuable nutrients (kidneys filter blood and reabsorb). Detoxification
Location of kidneys
extend from T12 - L3
Kidneys are surrounded by..
fibrous capsule
Renal Cortex
is the superficial portion of kidney in contact w/ fibrous capsule
Renal medulla
extends from renal cortex to the renal sinus
renal pyramid
conical structure extending from the cortex to a tip called renal papilla
renal papilla
tip of the renal pyramid
Minor calyx
collects urine produced by a single kidney lobe
major calyx
forms through a fusion of 4-5 minor calyces
renal pelvis
large, funnel-shaped structure that collects urine from major calyces. it is continous through ureter
Hilum
blood vessel servicing the kidney enter through the hilum
Nephron - define
Functional unit of kidney, everything happens, all physiology.
How many nephrons in each kidney
2 million
Location of nephron
border/bounday of cortex and medulla
Location of corpuscle, PCT, DCT
located in cortex
loop and collecting duct location
medulla
collecting ducts merge and drain through..
renal papilla in minor calyx
Afferent Arteriole
carries blood into glomerulus
efferent arteriole
carries blood out of glomerulus
glomerulus
capillary - filtration of blood occurs
renal corpuscle
structure of nephron, where filtration of blood occurs, holds glomerulus
PCT (descending)
proximal convulated tubule - wavy/twisty tube behind renal capsule - reabsorbs water, ions, and organic nutrients - recover anything of value to reabsorb to blood stream. permeable to water
Nephron loop
dips down into medulla - hormones work in kidney (aldosterone, anit-diuretic hormone, calcitonin
DCT (ascending)
distal convoluted tubule - after neprhon loop - farther from renal capsule - twisty tube - secretes ione, acids, drugs, toxins, may reabosrb some things possible. . Function depends on presence of hormones (ADH, Aldosterone, Calcitonin)
collecting duct
everything is now urine
blood flow organization
renal artery –> segmental artery –> interlobar artery –> artery turns and forms art –> artcutate arteries –> extend to cortex –> cortical radiate vein –> afferent arteriole
filtration
blood hydrostatic pressure forces water and solutes across the capillary wall
reabsorption
removal of water and useful solutes from filtrate back to body. this occurs by diffusion osmosis, carrier mediated transport
secretion
transport of solutes and wastes into renal tube by diffusion, osmosis, carrier mediated transport, etc.
podocytes in renal capsucle
warps around endothelial cells and litts pods/feet overlap one another and form slits - to maintain integrity by wrapping aroudn endothelial to make usre they don’t break up and also is good filtering slit as blood passes through
glomerular capillaries
longer, leakier, under higher pressure than normal capillaries - only endothelial cells so more brittle - so podocyte helps to not break them
Glomerular Filtration
result of BHP - BCOP = 10mmHg. Blood hydrostitc pressure - blood colloid osmotic pressure - results in filtration - movement of items from blood stream to capsular space
What doesn’t get filtered?
large protein and cells
How much filtrate do nephrons create per day? How much of that is reabsorbed?
48 gallons. 99%
Juxtaglumerular Coplex
endrocrine structure that secretes EPO and Renin
Juxtaglumerule cells
receptors that monitor sodium as it is passing by.
If filtration rate is too slow or too fast..
Slow - correct by restricting efferent arteriole and dilate afferent arteriole to create more filtrate.
too fast - the opposite- dilate efferent - restrict afferentym
mechanisms to control GFR
Autoregulation, hormonal, autonomic regulation
Autoregulation
dilation and contriction of afferent and efferent arterioles by stretch receptors
Hormonal
RAA pathway, ADH, and ANP. Drop in glomerular BP results in increase of renin from JGC - look at picture.
autonomic regulation
sympathetic - filtration rate goes down. parasympathetic speeds up
aldosterone
conserve sodium and water - to increase volume and pressure - comes from adrenal gland
ADH
antidiuretic hormone - comes from posterior pituitary - makes body conserve fluid - conserves water - increases volume nad pressure
ANP
atrial naturitic peptide - protein affects sodium - comes from atrium - when BP is high it exerts force on these cells and causes them to release ANP which works on DCT to prevent you from reabsorpting sodium - may promote body to excrete sodium/water - dropping BP
RAA
increases pressure - ADH increases pressure - ADP increase pressure
PCT - reabsorption
99% of glucose, amino acids, other organic compounds. reabsorbs ions (Na, K, HCO3, Mg, PO4, SO4) Co2 is abosrbed and affects pH. 60% of water is reabsorbed.
Passive Reabsorption of water..
when water leaves descending loop (PCT) the osmotic concentration rises, when the highly concentrated fluid flows through ascending loop (DCT) ions leave by diffusion.
DCT - reabsorption
reabsorb Na, Cl. loss of K. aldosterone, ANP. Ca regulation. precense of PTH and calcitrol. secretion of H in exchange for Na.
Absence of ADH and Presence of ADH
absense - dont absorb water - very dilute urine. presence - water goes out - urine hihgly concentrated
ureters
extend from kidney to bladder. enter bladder through ureteral openings. transitional epithelium lining. peristalsis.
urinary bladder
hollow mscular organ - trigone (ureteral openings and urthera) transitional epithelium. 2 layers of smooth muscle called detrusor muscle
urehtra
bladder to exterior. males 7-8inches, prostatic, membranous, spongy urethra. female 1-2in. urine has internal and external sphincters. stratified squamous epithelium
micturation reflex
like defecation - spinal cord level reflux - stimulus due to stretch of bladder - motor singal back to bladder to contract and relax intenral urthra sphincter
Fluid movement - three compartment - hydration
increasing fluid voluem in blood stream - making blood dilute compared to tissue - by osmosis the fluid will shift to the tissues - tissues then more dilute than cells -so fluid will shift to cells - if you over hydrate cells will burst
fluid movement - 3 comparment - dehydration
sweating. water going out of blood - then blood more concentrated then tissues - so water travels from tissues to blood. tissues then more concentrated then cells- so fluid shifts from cells to tissues. process continues tuntil you take in fluids - if you become very dehydrated your cells will shrinm
hypokalemia
too little K. harder to generate electrical signals. makes nervous system hard to reach resting membrane potential - not enough K in extracellular fluid – sluggish/slurred speech
hyperkalemia
too much K. seizure and death.
EPO
erythropoietin – blood cell formation. low oxygen is when it is release – to stimulate RBC production - which increased capacitiy to carry oxygen – and restore
