midterm Flashcards
explain the atrial stretch reflex
- increase blood volume
- increase venous return
- increase atrial pressure (filling)
- stretching baroreceptor of atrial wall
- increase signal firing to medullary control center
- inhibition of SNS
- result in renal vasodilatation, decrease BP (decrease vassopression and increase ANP), increase HR
result of atrial stretch reflex
result in renal vasodilatation, decrease BP (decrease vassopression and increase ANP), increase HR
blood velocity increase or decrease with a higher cross-sectional area
decrease
which blood vessel as the higher velocity and slowest velocity
H: aorta
L: capillaries
blood flow become slower or faster the further away of the heart and why
slower to aid in O2 exchange, allow the O2 to have time to go out of the blood and reach cells
in laminar flow, the greatest velocity is found where and why
in the center of the vessel because there’s less resistance in the center
in laminar flow, the lowest velocity is found where and why
along the vessel wall, because there’s higher resistance along the vessel wall
in turbulent flow, the greater the cross-sectional area, the _ the velocity
lower
in turbulent flow, the greater the blood flow, the _ the velocity
greater
what is laminar flow
linear velocity
less amount of friction, highest velocity is found in the center
if the Reynold number is lower than 2100 which type of flow do we have
laminar
what is turbulent flow
happen if vessel is block by at theroscleritic plaque
if the Reynold number is higher that 4000 which type of flow do I have
continuous turbulent
in anemia you have which type of blood flow and explain
Low hemtocrit = blood less viscous = reynaud number increase = increase CO = turbulent flow
in thrombus which type of blood flow do we have and explain
Decrease diameter = reynaud number increase = turbulent
if velocity increase, Reynaud number increase or decrease
increase
if density increase, Reynold number increase or decrease
increase
if viscosity decrease, Reynold number increase or decrease
increase
if Reynold number is between 2100 and 4000 which type of flow do we have
transient turbulence
what is cardiac contractibility
Instrinsic ability of the myocardium to pump in the absence of change in preload and afterload
cardiac contractibility is altered by and which part of
cns has the more important effect
- Can be altered by: neural, humoral or pharmacological influence
- SNS has MOST importance effect
factor influence vascular resistance
viscosity -> proportional to resistance
blood vessel length -> longer vessel have more resistance than shorter vessel
blood vessel radius -> narrower = more resistance
what happen with blood flow if resistance increase
decrease
what happen with blood in vasoconstriction
decrease vessel radius -> increase resistance = decrease blood flow
what happen with blood flow and resistance in anemia
ischemia reduce red blood cell = decrease blood viscosity = decrease resistance = increase blood flow
what happen if a blood clot or blockage develop in artery
decrease artery radius = increase resistance = decrease blood flow
role of RBC in blood velocity
increase in RBC result in increase viscosity of blood = reduce blood velocity
what happen with blood velocity with polycythemia
increase in RBC = increase viscosity = increase resistance = decrease blood velocity = decrease blood flow
-> increase BP
what happen with blood viscosity in anemia
decrease RBC = decrease viscosity = increase velocity
factor influencing blood velocity
hematocrit
plasma protein
diameter of blood vessel
temperature;
determinant of blood pressure
total peripheral resistance
CO
blood viscosity
blood volume
what happen in blood viscosity if plasma protein decrease
decrease
result of hypoabulminaena
decrease albumin
decrease resistance
increase blood flow
decrease BP (immediate response) but at the end = unchanged
turbulent flow
physiological effect of anemia
increase CO
increase HR
increase contractility (active)
decrease systemic venous return (passive)
increase venous return (passive)
effect on anemia on circulation
decrease blood viscosity = decrease in resistance (added tissue hypoxia-vasodilation) = increase in CO = increased pumping workload on the heart
decrease viscosity -> decrease peripheral resistance -> increase blood flow -> increase venous return -> increase CO -> increase HR
what happen with plasma volume in dehydration
decrease
physiological effect of dehydration - hypovolemia
decrease plasma volume -> increase hematocrit and decrease mean circulation filling pressure -> increase blood viscosity and decrease venous return -> decrease cardiac output -> decrease VO2 max (decrease O2 delivery to tissue) -> increase SVR
abnormal thermoregulation of dehydration
decrease skin blood flow, decrease sweat rate, increase core temperature
what happen physiologically with chronic lung disease
lung impairment -> hypoxia -> low blood O2 -> stimulation of liver and kidney -> erythropoietin release in bloodstream -> stimulation of red bone marrow -> increase red blood cell -> increase O2 carrying capacity
arterial hypoxia -> increase erythropoietin -> increase RBC -> increase blood capacity -> increase blood viscosity -> decompensated erythrocytosis -> poor o2 delivery to muscle-> increase fatigue
explain blood dooping procedure
- athlete donate blood
- blood is centrifuge
- red blood cell are force to the bottom
- liquid part of the blood is draw off the tube and reinfected in athlete
- RBC is stored (or frozen)
- a day before competition, RBC are re-injected in the athlete -> blood can carry more O2 = more endurance
blood dooping advantage and disadvantage
increase O2 level in blood
increase energy availability
risk of bacterial infection
sharing needle increase risk of hepatitis and HIV
blood clot, stroke, heart failure
what is EPO
an hormone produced in kidney that stimulate bone marrow to produce extra RBC -> artificial EPO can’t be differentiate from natural EPO
proven effect of blood doping
increase max oxygen uptake
increase time to exhaustion
increase performance in endurance event
risk of blood doping
increase blood viscosity
blood clotting
heart failure
blood matching error
hepatitis
HIV
what is the difference between the 2 blood doping technique
EPO go to long bone and stimulate RBC production
explain the 4 phase of valsava maneuver
- onset of strain
- increase intrathoracic pressure
- increase SBP
- decrease coronary artery blood flow - continued strain
- decrease SBP
- increase HR - release of strain
- decrease intrathoracic pressure
- decrease SBP - recovery
- increase SBP
- decrease HR
physiological response of valsava maneuver
expire against closed glottis -> increase intrathoracic P -> decrease venous return -> decrease cardiac output -> increase SNS, decrease PNS = increase HR
what happen when valsava is stop
Role of PNS in valsava: increase BP -> increase depolarization of carotid and aortic baroreceptor -> increase stimulation to vagus and glossopharyingeal -> increase PNS -> decrease HR
role of SNS in valsava
Role of SNS in valsava : Decrease BP -> decrease depolarization of carotid aortic receptor -> decrease signal to NTS -> increase SNS -> increase HR
why people can pass out from valsava
if vagus nerve is too munch stimulate = pass out
to munch alteration in BP can decrease amount of O2 to the brain
how munch SBP and DBP increase in cold pressor test
sBP - 20mmhg
DBP- 10
what happen when the body is in contact with a painful cold stimuli
cause massive discharge of the SNS and release epinephrine -> trigger arterial constriction, increase HR and increase cardiac contractility -> increase BP
neural pathway of CPT
cold pressor test trigger peripheral nociceptor -> stimulate hypothalamus -> stimulate RVLM in medulla oblongata -> stimlate SNS -> increase HR and stroke volume -> increase total peripheral resistance and CO -> increase arterial pressure
which nerve is stimulate with diving reflex
trigeminal
what happen with heart rate and BP during diving reflex
slow down drastically (bradycardia), vasoconstriction = increasein BP
three factor include in mammalian diving reflex
bradycardia, peripheral vasoconstriction, blood shift
explain physiology of diving reflex
- Cold water stimulus on face
- Depolarization of opthalmic, maxillary and madibular nerve merge into trigeminal nerve
- Trigeminal nerve (afferent pathway) synapse in the pons (brainstem)
- Sensory nucleus of trigeminal n send signal to vagus nerve (efferent pathway)
- Vagus nerves decrease HR
Initial stimuli = cold to the face region
1.Receptor of the face (3 nerves) merge into trigeminal = inibithed respiratory center
2. Respiratory center inhibit respiratory muscle = apnea
3. Respiratory stimulated CV center in medulla oblongata = stimulated arteriol = vasoconstriction = redirection of blood to brain and heart
4. Medulla oblongata also inhibit para sympathetic system = decrease in HR = bradycardia = help to balance vasoconstriction and reduce energy. Consumption or heart
driving reflex in seal
- Increase in CO2 is the first thing happening = increase in lactic acid due to O2 consumption
- When CO2 reach about 60%, brain receive a stimulus to activate the respiratory center
- Respiratory center send a message to diaphgram to contract
- Inhale/exhale = decrease in CO2
- Vasoconstriction stop = increase in lactic acid
what is myocardial ischemia
relative reduction in blood flow in coronary artery of the heart
Increase plaque in coronary artery = increase arterial resistance = decrease blood flow
O2 demand > O2 supply
what is angina and symptom
cause from insufficient blood flow to heart due to narrowing of coronary artery
Symptom: chest pain/pressure dull or sharp, shortness of breath. Sweating, feeling weak,nause
when does symptom occurs in angina
Symptom occur following physical exertion, heavy meal, cold weather of emotional stress -> because body need more blood and oxygen than when at rest, so heart need to pump harder to meet the demand = people will have chest pain -> pain go away at rest
Sometime pain occurs at rest
what is referred pain
- Due to synapsing of visceral and somatic sensory neuron at the same interneuron as they enter spinal cord
what is angina pectoris
: pain resulting from heart damage, often felt as stimulation of nociceptor in the left arm
what is pulmonary hypertension
Vasoconstriction = thickening of pulmonary arterial walls = increase resistance to blood flow = increase strain of the right ventricule = right ventricule enlargement
- Increase in preload and afterload = increase BP
what is mean pulmonary artery pressure
14
range of pulmonary hypertension at rest and during exercise
rest: > 25
exercise: >30
explain why there’s exercise limitation in pulmonary hypertension
Right vascular dysfunction= afterload mismatch, right ventricule dilatation = functional tricuspid valve regurgitation
Skeletal muscle dysfuncion = decrease capillarization = decrease oxidative enzyme activity = muscle fiber hyperthrophy
how can exercise limitation during pulmonary hypertension can be improve
improve by drug therapy that reduce right ventricular afterload and by exercise training by increasing capillary density and oxidative enzyme activity
what is PAD or PVD
occlusive disease of artery of the lower extremity
most common cause of PAD/PVD
atherothrombosis
arthertis
aneurysm, embolism
pathophysiology of PVD
arterial narrowing -> decrease blood flow = pain
pain result from an imbalance between supply and demand of blood flow that fails satisfy ongoing mechanism requirement
if aorta or iliac artery is obstructed ischemia result in
buttock, hip, thigh
femoral artery result in ischemia where
thigh, calf
popliteal artery occlusion result in ischemia where
calf, ankle foot
how do we calculated ankle brachial index (ABI)
aBI= lower extremity systolic pressure / highest brachial artery systolic pressure
what are the range of PAD severity
normal: 0.95-1.3
mild: 0,75-0.94
moderate: 0,5-0,74
severe: <0,5
what is the most severe peripheral arterial disease
vascular blockade
why is intermittent claudication important
atherosclerosis -> restriction in blood flow -> pain in calf
atherosclerosis -> coronary disease or stroke -> heart attack -> reduced life expectancy
nitroglycerin action
- decrease pain of ischemia
- increase venous dilation
- decrease venous blood return to heart
- decrease preload and cardiac oxygen consumption
- dilates coronary arteries
- increase cardiac collateral flow
-> severe headache can occurs due to lack of blood flow to the brain area
what are the effect of calcium channel blocker
vascular smooth muscle relaxation -> vasodilatation
decrease inonotropic effect (contractility) -> decrease CO
decrease chronotropic effect -> decrease HR
decrease dromotopric effect
-> decrease in BP
effect of beta blocker on the heart
decrease heart rate
decrease afterload
decrease wall stress
decrease heart contractility
result in reduction of myocardial oxygen demand
impact of diuretic
increase NACO3 -> increase H20 secretion -> increase NA excretion -> increase NACl excretion -> increase urine production
