Anatomy Urine Test
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- kidney functions
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-regulate blood composition (Na, K, Ca, Cl)
-regulate pH (H and bicarb), osmolarity, glucose
-regulate blood volume (conserve/eliminate water)
-regulate blood pressure (secrete renin)
-excrete wastes - renal capsule
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-surrounds kidney, gives structure
-need because kidney is retroperitoneal - renal fascia
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-goes around kidney and adrenal gland
-anchors to wall - adipose tissue
- -used for shock absorption and insulation
- quadratus lumborum
- -refered kidney pain goes to the back muscles
- urinary system organs
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-kidneys, bladder, ureter, urethra
-kidneys located under floating ribs
-ureters come out of kidneys (lead to bladder, which stores urine)
-urethra leaves bladder and exits body - structure of kidney
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-lobes consist of cortex, medulla, and sinuses
-cortex contains nephron and blood vessels
-medulla is divided into pyramids (contain blood vessels and some nephron) - urine dumps into sinuses
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-minor calyces
-major calyces
-renal pelvis
-ureter - blood flow to kidney
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-renal artery goes in, divides to afferent arterioles
-lead to glomerular capillary bed
-come out through efferent arteriole, lead to peritubular capillary bed (or vasa recta)
-merge and come out renal vein - parts of a nephron
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-glomerular capsule
-proximal convoluted tube
-loop of Henle (first part of nephron that enters medulla, descending and ascending limb)
-distal convoluted tubule (drains into collecting duct) - mesangial cells
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-wrap around entire capillary bed
-have muscle cells that contract, help regulate how much you filter - podocytes
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-wrap around one capillary
-prevent too much stuff from leaving - cortical nephrons
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-main type of nephron
-almost completely in cortex
-filter and reabsorb - juxtamedullary nephrons
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-starts close to junction, loop of Henle is deep into medulla
-does alot more concentrating of urine - intercalated cells
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-in collecting duct
-help to regulate pH (bicarb and H+ - principal cells
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-in collecting duct
-mostly for Na+(aldosterone) and H2O(ADH) - renal tubules
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-filter almost everything out
-proximal convoluted tubes reabsorb things into blood stream
-anything left in tubes goes down loop of Henle
-descending limb reabsorbs H2O
-ascending limb reabsorbs Na+ (both go into vaso rectum)
-anything you don't reabsorb goes to distal convoluted tube and collecting duct (fine tune urine based on hormones, empties into minor caluces) - juxtaglomerular apparatus
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-as loop of Henle comes back up, passes by afferent and efferent neurons
-cells in between are the JG apparatus
-composed of macula densa and JG cells - macula densa cells
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-sensory cells, tell JG to constrict or dialate afferent or efferent neurons
-sense osmolality and GFR in distal convoluted tubule - ureters
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-begins at renal pelvic travels to urinary bladder
-enter bladder posterior and interior
-mucous coat, muscular coat, and fibrous coat
-flap at end to prevent urine from going backwards - detrusor muscle
- -major muscle in urinary bladder, contracts to push urine out
- trigone
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-in bladder, triangle shape
-composed of 2 ureters and 1 urethra - urinary bladder
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-mucous layer, submucous layer, muscular coat, serous coat
-urine fills in from bottom, can hold about 800 mL
-stretch receptors - micturition reflex
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-stretch receptors in bladder
-parasympathetic stimulation (spine sends signal back causing contraction of muscle)
-internal urethral sphincter (can't control)
-external urethral sphincter (skeletal muscle, can control)
-you pee - urethra
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-urine from bladder to outside
-lined with mucous membrane and urethral glands which secrete mucous - urinary incontinence
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-loss of urine control
-may be temporary from and underlying medical condition - resorption (from-to)
- -from tubes back to peritubular capillaries
- secretion (from-to)
- -peritubular capillaries into tubes
- excretion (from-to)
- -anything left in tubes is put into urine
- excretion formula
- -excretion = filter - reabsorption + secretion
- filtration (from-to)
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-from glomerulus to bowman's capsule
-driven by pressure - filtration
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-collect filtrate
-filter 180 L per day
-anything you filter out goes into bowman's capsule (glomerular filtrate)
-goes out proximal convoluted tube - filtration membrane
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1)pores don't allow formed elements (RBC, platelets, WBC) out of blood stream
2)basil lamina doesn't let large proteins through
3)podocytes wrap around and create slits, don't let medium molecultes out - glomerular blood hydrostatic pressure
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-pressure of blood inside glomerular capillaries (55 mm/Hg)
-in favor of filtration - blood colod osmotic pressure
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-proteins inside blood drawing water towards it (30 mm/Hg)
-against filtration - capsular hydrostatic prssure
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-15 mm/Hg
-against filtration - net filtration pressure
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-total pressure that promotes filtration
-NFP = GBHP - (CHP + BCOP) = 10 mm/Hg - high pressure system
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-afferent is a large arteriol and is dialated: allows lots of blood into glomerular capillaries (raise pressure)
-efferent are small and restricted (blood is forced to stay in capillaries) - constrict afferent
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-decr. pressure
-decr. GFR
-incr. reabsorption - dialate afferent
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-incr. pressure
-incr. GFR
-decr. reabsorption - constrict efferent
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-incr. pressure
-incr. GFR
-incr. reabsorption
*always constricted, keeps a gradient between tubes and peritubular capillaries (allow yourself to reabsorb more at a higher GFR) - dialate efferent
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-decr. pressure
-decr. GFR
-decr. reabsorption - glomerular filtration rate (GFR)
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-amount of filtrate filtered per unit of time
-directly proportional to pressure
-indirectly proportional to reabsorption - regulation of GFR
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-adjust blood flow in and out of glomerular capillaries (constrict or dialate efferents or afferents)
-change surface area you are filtering off (mesengial cells :smooth muscle, constrict, decr. surface area, decr. GFR) - myogenic mechanism
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-autoregulates
-designed not to change GFR should blood pressure go up (excercise)
-incr. bp, incr. pressure of afferent arterioles, they constrict (doesn't affect system, just redirects blood to muscles that need it) - using JG apparatus to autoregulate
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-macula densa senses osmolality and flow rate (using pressure receptors)
-if either one goes up, means you didn't reabsorb (adjust by constricting afferent arterioles, decr. GFR)
-if decr. osmolality, dialate afferent, incr. pressure, incr. GFR, decr. reabsorption, stimulate jg cells to secrete renin - neural regulation
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-sympathetic NS
-vasoconstrict arterioles, incr. bp
-constrict afferent and efferent (to lesser degree): slight decr. GFR, slight incr. reabsorption
-overrides autoregulation - atrial natriuretic peptide (ANP)
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-released from heart due to high bp/bv
-inside kidney
-relaxes mesengial cells (incr. surface area, incr. GFR)
-inhibit Na/K pumps in collecting duct (Na stays in urine, water follows, bring bv down) - Angiotensinogen
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-inactive, made in liver
-renin from kidneys converts it to angiotensin I - angiotensin converting enzyme (ACE)
- -converts angiotensin I to angiotensin II
- hormonal regulation
- -contracts efferent and afferent (to a lesser extent): incr. GFR
- angiotensin II
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-targets adrenal cortex to release aldosterone
-goal is to get GFR back to normal
-constrict efferent arterioles, reabsorption goes up, incr. GFR
-contracts mesengial cells - aldosterone
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-stimulates collecting ducts to reabsorb Na+
-good if Na+ or bp is low - renin release by JG cells
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-stimulation by macula densa (senses low osmolality in distal convoluted tubes, dialate afferent arterioles, release renin)
-reduce stretch in afferent arterioles (if bp was down)
-stimulation by angiotensin II (more you make, more renin you release)
-stimulation by sympathetic nerves - tubular reabsorption
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-go from tubes back into peritubular capillaries
-proximal convoluted does most of the reabsorption
-loop of henle only does Na+ and H2O
-distal convoluted and collecting duct fine tune and regulate hormones - secondary active transport
- -one substance goes down concentration gradient, 2nd substance is pulled against its gradient using energy from first using symporter
- primary active transport
- -2 substances going against gradients using ATP
- symporter
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-protein that can harness energy
-can only work so fast - glucosuria
- -glucose is reabsorbed during secondary active transport. glucose levels are too high in blood, symporter only works so fast to reabsorb, so glucose ends up in urine
- reabsorption of Na+
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-high concentration outside cell
-diffuses inside cell (primary active transport)
-goes in symporter, pulls in glucose, vitamins, etc against gradient - Cl, fat soluble things, and water reabsorption
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-Cl and other negativly charged stuff diffuses out following electrical gradient
-fat soluble things diffuse right through (absorb urea)
-water in tubes moves from dilute to concentrated area - labor of proximal convoluted tubule
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-reabsorb most of filtered water and solutes
-major site of solute secretion - labor of loop of henle
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-reabsorb large quantities of major ions and some water
-adjust osmolarity in blood - labor of distal convoluted tubule
- -fine tuning for most substances (pH, water balance0
- why we secrete
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-reabsorb something we don't want, secrete it
-regulation (vitamins, Na+, K+, electrolytes)
-if you didn't filter something (too big) but you don't want it
-regulate pH (H+ and bicarb) - functions of electrolytes
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-control osmosis of water between compartments
-help maintain acid base balance
-carry electrical current
-serve as cofactors for enzyme activity - water intoxication
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-blodd becomes dilute, water into cells, cell swells
-need to drink something with electrolytes (gatorade) - cotransport
- -diffuse in with something else
- countertransport
- -diffuse in and push something else out (ie. H+)
- water diuresis
- -increase urine flow but not solutes (don't have aquaporins) diabetes insipidus
- osmotic diuresis
- -increase urine flow as result of increase solute excretion (pulls water with it) diabetes melatus
- coupling Na+ and H2O
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-take Na+ out, lower osmolality, water follows
-can only follow if there are aquaporins
-in prox. conv. tubes, lots of pores, can absorb water
-in distal conv. tubes and collecting ducts, based on ADH (puts pores there) - countercurrent mechanism
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-in loop of henle, sets up osmotic gradient in interstitial fluid
-collecting ducts then reab. or not reab. water based on ADH levels
-if reab. urine is concentrated, high ADH - diuretics
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-substances that slow renal reab. of water and cause diuresis (incr. urine flow rate)
-caffeine, alcohol, meds - measuring Na+
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-indirectly measure by blood volume/pressure
-bv high, Na+ must be high: Na+ is hyperosmotic, pulls water out of cells, raise bv - sodium regulation via GFR
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-lose Na+ and water, lose volume and pressure (sense by baroreceptors)
-decr. bp, decr. baroreceptors, symp NS fires more: contricts afferent arterioles, which decr. GFR, incr. reab. (all Na+ and water end up in blood, less is excreted) incr. bv/bp - ANP
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-from heart
-occurs if Na+ levels or bp are high, targets collecting ducts to inhibit Na+ reab, incr. secretion - renin
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-sense decr. pressure in afferent arterioles, stimulated by symp.NS and decr.osmolality in distal conv. tubes
-makes angiotensin II which stimulates release of aldosterone - thirst
- -stimulated by angiotensin, decr. bp, incr osmolality, dry mouth
- potassium regulation
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-aldosterone regulates K+ (targets Na+/K+ pump)
-secrete K+, reabsorb all of it, secrete based on needs of body
-K+ levels are high, release aldosterone, targets kidneys to secrete K+, put in urine