physio E5L2 ch 17 pulmonary circulation/acid-base blood, ch 18 urinary system and renal function

1. within systemic arterial blood, O2 and CO2 levels ______

   1. O2 direction / rate

   2. CO2 direction / rate

2. respiratory quotient =

   1. what’s normal

   2. how vary

3. where does deoxygenated blood and oxygenated blood begin in pulmonary circuit

1. O2 and CO2 levels remain constant

   1. O2 moves alveoli → blood at same rate O2 consumed by cells

   2. CO2 moves blood → alveoli at same rate CO2 produced by cells

2. respiratory quotient = ratio CO2 consumed/O2 consumed

   1. at rest = 200mLCo2/150mLO2 = .8

   2. varies w/ diet

3. dox v ox

   1. oxygenated begins in pulmonary capillaries after diffusion

   2. deoxygenated begins in systemic capillaries after diffusion

respiratory membrane:

1. thickness/surface area?

2. structure

   1. Type 1 epithelial cells =

   2. fused basement membranes of the 2 cells

   3. endothelial cells =

1. thick, large SA

2. type 1 epi cells = gas exchange, alveolar side

3. fused basement membranes of the 2 cells

4. endothelial cells = blood vessel side

gas exchange/diffusion:

1. what does diffusion in capillaries depend on

   1. presence of other gases?

2. speed of diffusion

3. where does gas exchange happen/why

   1. at rest v exercise

4. Dalton’s law

   1. 4 things pressure of gas (P) depends on

1. gases diffuse down partial pressure gradients high to low PP

   1. presence of other gases irrelevant as gases diffuse down their own PP gradient

2. diffusion is rapid

3. location

   1. first 1/3 of capillary = for at rest h

   2. other 2/3 = needed during exercise

4. Dalton’s Law = PV = nRT, P depends on

   1. V volume, n number of gas mCs, R universal rate constant, T temp

1. Total pressure of a gas mixture =

   1. equation

2. Partial pressure of specific gas =

   1. equation

3. partial pressures atmosphere v lungs

   1. affect of humidity

4. why does gas exchange in lungs happen

1. Total pressure of a gas mixture = sum of pressures of all individual gasses

   1. Total = P1 + P2…

2. Partial pressure of specific gas = proportion of Total that is due to an individual gas

   1. Pgas = %gas x Ptotal

3. partial pressures atm v lungs =

   1. Patm = PN2 + PO2 (CO2 neglible)

   2. Lungs = PN2 + PO2 + PH2O

4. why does gas exchange in lungs happen

   1. difference in gas partial pressures (higher in atmosphere) bc humidity in lungs lowers lung partial pressure, moves high to low

O2 and CO2 solubility:

1. at equilibrium, partial pressures of a gas in the air v. in solution =

   1. mols?

2. comparing solubility of 2 diff gasses… which is more soluble?

1. partial pressure of gas in atm (vaporized) equals partial pressure of the same gas dissolved in solution

   1. mols differ based on solubility

2. at equilibrium, gas w/ more mols in solution at the same partial pressure = more soluble

2 places gas exchange of O2 and CO2 happens:

1. lungs

   1. what affects diffusion b/t alveoli and blood? when?

2. respiring tissues =

   1. direction

1. what does amount of O2 and CO2 exchanged in a capillary bed depend on?

2. mixed veinous blood=

1. lungs

   1. thickening of the thin respiratory membrane (pulmonary edema) slows diffusion

2. respiring tissues = in the cells

   1. still high to low PP

1. amount of exchange depends on metabolic activity of cells

   1. high metabolic activity = more active cells = more O2 and CO2

2. mixed veinous blood = systemic venous and pulmonary artery have same partial pressures

1. why is PP higher in air than in lungs?

2. 2 groups of same PP

3. partial pressures in cells/systemic tissue vary based on?

1. presence of water lowers PP of other gases

2. no difference in PP = no gas exchange

   1. alveolar air, pulmonary veins, systemic arteries = same PP

   2. systemic veins and pulmonary arteries = same PP

3. vary based on metabolic activity

1. 3 factors affect alveolar partial pressures

2. rate of alveolar ventilation = _____

1. 3 factors affect alveolar partial pressures

   1. PO2 and PCO2 of inspired air

   2. minute alveolar ventilation

   3. rate of metabolism

2. rate of alveolar ventilation = rate of metabolism

1. eupnea =

   1. what PP changes

   2. when

2. hyperpnea =

3. hypoventilation =

4. hyperventilation =

1. eupnea = normal ventilation matches cellular demand

2. hyperpnea = increased ventilation due to increased cellular demand (exercise)

   1. minimal change in arterial PO2 and PCO2

3. hypoventilation = ventilation doesn’t meet cellular demands

   1. arterial PO2 decrease, PCO2 increase

4. hyperventilation (panic) = ventilation exceeds cellular demands

   1. arterial PO2 increases, PCO2 decreases

1. 2 forms of O2 transport in blood = what %

2. oxyhemoglobin v deoxyhemoglobin

   1. path from air

   2. path from

1. total O2 in blood = 1.5% O2 dissolved, 98.5% O2 transported by hemoglobin

2. oxyhemoglobin (Hb-O2) v deoxyhemoglobin (Hb + O2) = whether bonded to O2 or not

   1. alveoli: alveolar air → plasma → RBC → Hb + O2 → Hb-O2

   2. systemic capillaries: Hb-O2 → Hb + O2 (RBC) → plasma → tissue

1. what binds

   1. heme =

   2. globin =

2. Hb saturation =

   1. relationship to PP

   2. arterial v. mixed venous blood

3. how O2 bind Hb =

   1. law of ___

1. what binds

   1. heme = 4 O2, CO

   2. globin = CO2

2. Hb saturation = 4 O2 on 1 Hb

   1. higher PP = more % at saturation

   2. arterial = 99% saturation

   3. mixed venous = 75% saturated

3. O2 bind Hb = nonlinear + cooperativity

   1. more O2 → more O2 binding. easier for to bind 2nd than 1st, easier to bind 3rd than 2nd, etc..

   2. law of mass action

1. why doe knowing Hb amount (hematocrit) matter?

2. calculate O2 carrying capacity

1. Hb determines O2 carrying capacity

2. calculate

   1. multiply amount of O2 1g of 100% saturated Hb carries (1.34mL O2) by hemoglobin levels

1. shows what

2. moving right vs. left affect on affinity

3. at rest systemic arterial blood v. systemic venous

1. Hb affinity for O2

2. move

   1. left = high affinity, association (holding onto O2)

   2. right = low affinity, dissociaiton (easily give O2)

3. at rest

   1. systemic arterial blood Hb: 98.5% saturated, less affinity (more unloading)

   2. systemic venous blood Hb: 75% saturated, higher affinity (more loading)

Hb-Oxygen association/dissociation curve:

1. how curve shift

   1. high Temp = shift right

      1. why high

   2. low pH = shift right

      1. Bohr affect =

   3. high CO2 = shift right

      1. carb amino affect =

   4. high 2,3-BPG =

      1. what is it

   5. CO =

      1. asphyxiation v. suffocation

         
         

1. high Temp = shift right

   1. high bc of metabolic activity

2. low pH = (Bohr affect) shift right

   1. metabolic acids from high activity

3. high CO2 = shift right

   1. carb amino affect = carbaminohemoglobin has lower O2 affinity

4. high 2,3-BPG = shift right

   1. produced in RBC during hypoxia

5. CO = shift left

   1. binds tighter to heme than O2 = lack of O2 = asphyxiation

   2. suffocation = preventing ventilation

1. 3 forms CO2 transported in blood

   1. carbaminohemoglobin =

   2. why?

2. carbonic anhydrase reaction =

3. law of mass action =

1. CO2

   1. 5% dissolved in plasma

   2. 5% on globin portion of hemoglobin

      1. “carbaminohemoglobin” when binded

   3. 90% dissolved in plasma as bicarbonate HCO3-

      1. mainly as bicarbonate bc RBC has carbonic anhydrase enzyme

2. CO2 + H20 ←(carbonic anhydrase)→ H2CO3 (carbonic acid) ←> H+ + HCO3- (bicarbonate)

3. law of mass action = increase in CO2 causes increase of bicarbonate and H+

CO2 exchange in blood:

1. steps

2. free H+ v. bound H+

1. tissue to blood

   1. cells → plasma (5% CO2 stays)→ RBC: carbonic anhydrase and H20 = HCO3- + H+

      1. H+ binds hemoglobin

      2. HCO3- moves out of RBC (90% CO2 stays) in exchange for Cl-

   2. remaining CO2 binds hemoglobin (5%)

2. blood to alveoli

   1. pic (reverse)

3. free h+ lowers pH, bound H+ doesn’t

1. Haldane effect =

   1. tissue capillaries v. lung capillaries

2. Bohr affect =

3. carb amino affect =

1. systemic tissue v alveoli = O2/CO2 loading/unloading

1. Haldane effect = inverse relationship, high PO2 → low CO2

   1. tissue cap = high Hb CO2 affinity (low PO2)

   2. lung = low Hb CO2 affinity (high Po2)

2. Bohr affect = low pH (high Co2/H+) → low O2 affinity

3. carb amino affect = CO2 direct bind Hb into carbaminohemoglobin

1. systemic tissue = O2 unloading, CO2 loading

2. alveoli = O2 loading, CO2 unloading

acid-base disturbances in blood

1. what blood do you normally test for this

2. normal pH

   1. lethal range

3. what systems regulate pH/how

4. affect small changes of pH/why

1. arterial blood

2. normal = 7.4 (7.35-7.45)

3. below 6.8 or above 8 are lethal

4. respiratory and renal system regulate pH

   1. lungs = CO2

   2. renal = HCO3

5. small change = big affects bc alter protein activity

acid-base disturbances in blood:

1. how calculate pH

   1. normal pH, HCO3, CO2 levels

2. pH disturbances = which is faster

   1. metabolic vs respiratory

   2. hyper v hypoventilating

3. alkalosis/alkalemia =

   1. 2 cause

   2. effect

4. acidosis/acidemia =

   1. 2 cause

   2. effect

1. pH = HCO3-/CO2

   1. pH 7.35-7.45, HCO3 22-26, CO2 35-45

2. pH disturbances

   1. metabolic = HCO3 is the problem (kidney)

   2. respiratory = CO2 is the problem (lungs)

      1. faster

      2. respiratory alkalosis = hyperventilation

      3. respiratory acidosis = hypoventeniation

3. alkalosis/alkalemia = above 7.45

   1. cause = HCO3- increase or CO2 decrease

4. acidosis/acidemia = below 7.35

   1. cause = HCO3- dec or CO2 inc

acid-base disturbances in blood:

1. 5 steps to figure out which type of acidosis/alkilosis

1. steps

   1. alkalosis or acidoses = pH high or low

      1. example = given high pH, alkalosis

   2. determine 2 possible causes of the pH

      1. example alkalosis = high HCO3 or low CO2

   3. determine if actual HCO3 and CO2 values are high low or normal

   4. compare possible cause to actual value. if match = that’s the reason for the pH

   5. determine compensation if applicable = following the problem to fix it

acid-base disturbances in blood:

1. what type is…

   1. PH 7.2, CO2 50, HCO3 24

   2. PH 7.6, CO2 40, HCO3 30

   3. PH 7.2, CO2 50, HCO3 20

   4. PH 7.6, CO2 30, HOC3 20

   5. PH 7.2, HCO3 20, CO2 30

      1. is subject hyper or hypoventilating

1. PH 7.2, CO2 50, HCO3 24

   1. resp acidosis

2. PH 7.6, CO2 40, HCO3 30

   1. met alkalosis

3. PH 7.2, CO2 50, HCO3 20

   1. resp met acidosis

4. PH 7.6, CO2 30, HOC3 20

   1. resp alkalosis w/ met compensation

5. PH 7.2, HCO3 20, CO2 30

   1. met acidosis w/ resp compensation

   2. hyperventilating (getting rid of CO2)

1. 4 urinary system structures

2. macro kidney anatomy

   1. renal capsule

   2. renal cortex

   3. renal medulla =

   4. renal pelvis =

   5. renal hilus =

1. 4 urinary system structures

   1. 2 kidneys, 2 ureters, bladder, urethra

2. macro kidney anatomy

   1. renal medulla = nephrons and collecting ducts

   2. renal pelvis = cavity

   3. renal hilus = where BVs exit kidney (afferent and efferent arterioles)

nephrons:

1. 2 types

   1. cortical

   2. juxtamedullary renal corpuscle =

2. parts

   1. renal corpuscle =

      1. glomerulus = afferent arteriole, efferent arteriole, filtrate

      2. bowman’s capsule

   2. nephron tubules =

      1. proximal tubule

      2. loop of Henle =

      3. distal convoluted tubule =

   3. collecting duct =

1. 2 types

   1. cortical = most common, short loop of Henle

   2. juxtamedullary = long loop of Henle

2. nephron parts

   1. renal corpuscle = 1st, receives filtrate gives it to proximal tubule

      1. glomerulus = afferent arteriole, efferent arteriole, filtrate

      2. bowman’s capsule

   2. nephron tubules =

      1. proximal tubule

      2. loop of Henle = reabsorb water (concentrate urine)

      3. distal convoluted tubule =

   3. collecting duct = not part of nephron

juxtaglomerular apparatus:

1. where

2. macula densa =

3. granular cell =

1. juxtaglomerular apparatus = b/t afferent arteriole (entrance) and efferent arteriole (exit)

2. macula densa = cells that screen filtrate in distal tubule

3. granular cells = secrete renin when low BP or low flow to kidney

5 steps blood flow in nephron

1. before (BV) =

2. nephron

   1. mowman’s capsule =

   2. PCT =

   3. loop of Henle =

   4. DCT =

3. collecting duct =

1. before =

   1. new blood (filtrate) enters via afferent arteriole → diffuses into Bowmans capsule → filtered blood exits through efferent arteriole

1. nephron

   1. Bowmans capsule = 1st part, engulf capillaries

   2. PCT = reabsorb H2O

   3. loop of Henle = reabsorb water

      1. descending then ascending

   4. DCT = where filtrate is monitored by macula dense in b/t afferent and efferent arterioles

2. collecting duct = hormones work (ADH)

1. filtration =

   1. how increase/dec?

2. reabsorption =

   1. tubule v. plasma?

   2. blood osmolarity?

3. secretion =

4. excretion =

1. difference b/t filtration and excretion tell us____

   1. if filtered 80 units and excreted 120, ____

   2. if filtered 80 and excreted 60, ____

1. filtration = bulk flow glomerular capillaries (glomerulus) → bowman’s capsule

   1. increase = dilate afferent, constrict efferent

2. reabsorption = nephron (tubule)→ blood (plasma)

3. secretion = blood (plasma→ back to nephron (tubule)

4. excretion = what exits outside body

1. tells us how much was secreted v reabsorbed

   1. 40 units secreted

   2. 20 units reabsorbed

nephron:

1. osmolarity vs. specific gravity

2. plasma v tubule

3. reabsorption v secretion

reabsorption = tubule (nephron) → plasma (blood)

secretion = plasma → tubule

osmolarity = concentration of solute in blood plasma

specific gravity = concentration of solute in urine

glomerular filtration:

1. what can be filtered

2. glomerular filtration rate GFR =

   1. why don’t we pee that much

   2. total plasma volume filtered every

3. 3 layers glomerular filtration membrane:

   1. 
      

1. protein-free plasma (proteins too large to be filtered)

2. GFR 100 mL/min but 99% is reabsorbed so we aren’t peeing all the time

   1. total plasma volume filtered ever 22 minutes

3. 3 layers

   1. capillary endothelial layer

   2. basement membrane connecting 2 layers

   3. capsule epithelial layer

glomerular starling forces:

1. hydrostatic pressures

   1. Pgc (glomerular capillaries)

   2. Pbc (bowman’s capsule)

2. oncotic pressures

   1. piGC

   2. piBC

1. which is normally 0, why?

2. which 2 are filtering forces?

3. what is the net starling force across nephron

1. piBC = 0 bc proteins can’t be filtered

2. Pgc and piBC are filtering forces, other 2 are against filtration

3. 60 (filtering) - 44 (against filtering) = 16 mm Hg favoring filtration

1. filtration fraction =

   1. equation

   2. what does it mean

2. filtered load =

   1. equation

   2. concentration in plasma = ____

1. filtration fraction = how much blood to kidney is filtered

   1. filtration fraction = GFR/renal plasma flow = 125mL/625 = 20%

2. filtered load = quantity of solute filtered per unit time

   1. filtered load = GFR x Px

      1. Px = concentration of filtrate in plasma

   2. concentration in plasma = concentration in filtrate

Regulation of GFR:

1. dilattion of aff/constriction of off = ____

2. GFR depends on _____

1. MAP v. GFR plot:

   1. MAP range where GFR is maintained

   2. what happens above/below

1. = higher Pgc = more filtration = higher GFR

2. higher MAP = higher Pgc = higher GFR

   1. MAP → GFR, maintain MAP to maintain GFR

1. MAP v. GFR plot

   1. GFR constant (125mL) when MAP b/t 80-180

   2. MAP > 180, GFR raises

   3. MAP < 180, GFR decreases

intrinsic control of GFR:

1. when

2. 3 types

   1. myogenic regulation = triggered by what

      1. what happens

   2. tuboglomerular feedback =

   3. mesangial cells =

1. intrinsic regulation of GFR = maintain GFR

2. 3 types

   1. myogenic regulation = triggered by high MAP stretching afferent arteriole

      1. vasoconstrict afferent arteriole to lower MAP/GFR

   2. tuboglomerular feedback = triggered by macula dense detecting high Na+ in DCT (high Na+ = high water volume)

      1. vasoconstrict afferent arteriole to lower MAP/GFR

   3. mesangial cells = triggered by stretching capillaries

      1. mesangial cells act like precapillary sphincter that constrict around glomerular capillaries to decrease their surface area

extrinsic control of GFR:

1. via what/when

2. detected by what

3. neural pathway

4. what happens when:

   1. high MAP

   2. low map

5. if bleeding

1. extrinsic control = via sympathetic nervous system when intrinsic mech can’t correct

2. baroreceptors detect stretch in aorta/carotid

3. baroreceptors -CN 9→ CNS -CN10→ heart

4. high map = baroreceptors in aorta/carotid fire → decrease sympathetic activity

5. low map = baroreceptors in aorta/carotid fire → increase sympathetic activity (constrict afferent arteriole) → lower GFR

6. bleeding = increase sympathetic → lower GFR to maintain flow to other places

1. ADH/vasopressin =

   1. where is ADH secreted from

   2. what receptors/do what

   3. when secreted

2. aldosterone =

   1. where is aldosterone secreted from

3. ANP = stop reabsorbing Na+, lowering blood volume and BP

   1. secreted by atrium when walls stretch due to high BP

1. ADH = maintain water balance (kidneys reabsorb water)

   1. made by hypothalamus, stored/realesed from posterior pituitary

   2. osmoreceptors = detect osmolarity of plasma

   3. secreted when osmoreceptors detect thick blood (concentrated plasma)

2. aldosterone = raises Na+, lowers K+

   1. made by zona glomerulosa of adrenal cortex

reabsorption:

1. what / how move

2. mostly happens where

   1. 2 reasons

3. how much glucose

4. path

1. water/solutes (protein free plasma)

   1. mostly move high to low concentration gradient, some bc of hormonal control

2. mostly proximal convoluted tubule (PCT), some DCT

3. 100% glucose reabsorbed (should not be in urine)

4. pathway:

   1. lumen of tubule → epithelial cells → basement membrane → peritubular space (renal interstitial fluid) → basement membrane → endothelial cells of capillaries → plasma of capillary

      1. tubule → epi, mem → p-space → mem,endo,→ plasma

mechanisms of solute reabsorption:

1. how water move =

   1. effect on concentration of filtrate/plasma?

2. active solute reabsorption =

   1. primary active =

   2. secondary active =

3. passive solute reabsorption =

4. reabsorbing sodium only,

1. water moves low to high osmolarity (follows solute)

   1. . if high Na+ outside, H2o goes out

   2. reabsorption concentrates filtrate (water leaves tubule), and dilutes plasma (water enters plasma)

2. active solute reabsorption = uses transporters

   1. primary active = direct use of ATP against gradient

   2. secondary active = facilitated diffusion down ATP established gradient

3. passive solute reabsorption = high to low concentration

1. transport maximum (Tm) =

   1. what happens at Tm?

2. renal threshold =

   1. applies to what solute

   2. glucose =

3. glucose has a ____ and ___

   1. normally filtered/absorbed?

4. glucose normally ___ filtered/ ____ reabsorbed where?

5. what does glucose in urine mean?

   1. is glucose actually 100% reabsorbed?

1. transport maximum = rate of transport when carriers are saturated

   1. if carrier saturated, excess solute is excreted (urine)

2. renal threshold = solute concentration in plasma that causes Tm

   1. glucose = 180 mg/dL ( for solutes normally 100% absorbed)

3. glucose has both transport maximum and renal threshold

4. glucose normally freely filtered at glom and 100% reabsorbed at PCT

5. glucose in urine means transporters are saturated bc blood glucose is high (above 180

   1. glucose 100% reabsorbed up to 180

Reabsportion:

1. apical membrane =

2. basolateral membrane =

3. solutes

   1. glucose = transport across apical/basolateral membranes

1. apical membrane = b/t tubule and epithelial cells

2. basolateral membrane = b/t epithelial cells and peritubule space

3. glucose

   1. apical = 2ndry active w/ Na+ (symported)

   2. baso = facilitated diffusion

regional specialization of renal tubules:

1. PCT (majority) = what type of reabsorption

   1. what does it reabsorb/secrete

2. DCT =

3. loop of Henle =

4. CD =

1. PCT (majority) = non regulated absorption

   1. reab everything, secrete H+

2. DCT = regulated absorption

   1. reab water (in descending)

3. loop of Henle = water conservation

   1. reab Na+ and water, secrete H+ and K+

4. CD = regulated absorption

   1. reab Na+ and water, secrete H+ and K+

1. non regulated reabsorption = where

   1. mass reabsorber =

      1. 3 reasons why

      2. brush border?

      3. tight junctions?

2. regulated reabsorption =

   1. tight junctions?

   2. transport via

   3. transport how?

3. water conservation =

   1. purpose

   2. juxtamedullary nephron =

   3. CD?

1. non regulated reabsorption = PCT

   1. mass reabsorber = PCT bc

      1. non regulated = no need for hormone

      2. has brush borders = large SA

      3. leaky tight junctions

2. regulated reabsorption = DCT and CD

   1. transport through cells

   2. tight junctions = limit paracellular transport (b/t adjacent cells)

   3. transport = specific and directed reab/secretion

3. water conservation = loop of henle and CD

   1. concentrate urine

   2. juxtamedullary nephron = bc longer loop of henle

excretion:

1. what is it

2. equation

   1. 3 factors that determine

3. what excretion rate is less than filtered load? (E<F)

   1. what if F>E

1. excretion = how much of substance released in urine

2. E = F + S - R

   1. amount filtered + amount sec - amount reab

   2. 3 factors = filtered load, secretion rate, reabsopriotn rate

3. E < F. solute reabsorbed. E>F, solute secreted

clearance:

1. what is it

2. equation

   1. Ux , V , Px

1. clearance = volume of plasma from which a substance has been removed by kidneys per unit time

2. clearance = (Ux x V) / Px = excretion rate / plasma concentration

   1. Ux = [solute] in urine

   2. V = volume of urine

   3. Px = [solute] in plasma

3. to estimate GFR

clearance:

1. clinical use

2. how does it work?

   1. inulin?

   2. what’s the problem w/ inulin

   3. what do we use instead now?

1. estimate GFR

2. inulin allows GFR estimation bc it is freely filtered substance (inulin) that isn’t secreted or reabsorbed

   1. that means inulin F = inulin E, which makes clearance = GFR

   2. inulin problem = body doesn’t make it

   3. we use creatinine instead but it a small amount is secreted, so estimated value is slightly higher than GFR

clearance:

1. if C < GFR, ____

2. if C > GFR, ____

3. glucose clearance (freely filtered/completely reabsorbed) =

4. PAH clearance (freely filtered/not reabsorbed/fully secreted) =

   1. why

1. if C < GFR, must have reabsorbed

2. if C > GFR, must have secreted

3. glucose clearance = 0 mL/min

4. PAH clearance = renal plasma flow

   1. bc filtered, not reabsorbed, and fully secreted

   2. whatever kidneys get will be excreted

1. inulin

   1. freely filtered?

   2. reabsorbed?

   3. secreted?

   4. excretion (E)?

2. creatinine

3. glucose

4. PAH

   1. estimate for ___

5. K+

6. Cl-

7. Na+

1. inulin = FF yes, S no, E = F

2. creatinine = FF yes, R no, S a little, E a little > F

3. glucose = FF yes, R 100% up to 180, S no, E = 0

4. PAH = FF yes, R no, S 100%, E > GFR and E = renal plasma flow

   1. PAH = renal plasma flow

micturition:

1. urine pathway

   1. detrusor muscle?

   2. internal v. external urethral sphincter

1. formed in nephrons, ends up in CD

   1. 1 CD collects from multiple nephrons

2. drains into renal pelvis → ureter → bladder

   1. bladder has detrusor muscle = smooth muscle (ANS control)

3. bladder → urethra → internal urethral sphincter → external ureth sphinct

   1. internal = smooth muscle (ANS control)

   2. external = skeletal muscle (SNS)

1. how to tell if any sphincter is smooth muscle or skeletal?

1. ask “is it closer to the inside or outside of my body”

   1. closer to inside = always smooth

   2. closer to outside = always skeletal

micturition reflex:

1. what is it =

   1. override?

2. what kind of reflex =

3. involuntary control

   1. detrusor muscle = how innervated

   2. internal urethral sphincter = how innervated

4. voluntary control

   1. external urethral sphincter = how innervated

1. micturition reflex = urination

2. spinal reflex w/ voluntary override

   1. override = have control up to a certain point and then autonomic takes over and urination happen

3. involuntary control

   1. detrusor muscle = parasympathetic innervation

   2. internal urethral sphincter = sympathetic innerv

4. voluntary control

   1. external urethral sphincter = somatic motor control

micturition reflex:

1. what do you have voluntary control over?

2. valsava maneuver

1. have control over stopping micturition

2. valsava maneuver = abdominal cavity compression helps stimulate micturition