Physiology E4 Circulatory
describe the brain ischemic reflex/ Cushing reflex
- concussion causes cerebral edema - extra fluid causes compression of the blood vessels= hypoxia - diameter goes down= resistance goes up - decrease of oxygen and increase of carbon dioxide (main regulator for the brain)- message sent to the pons to increase sympathetic response - increase HR- increase TPR- increase BP for blood to go back to the brain - increase BHP= more filtration= more edema= more hypoxia positive feedback loop with negative consequences
flow is the same thing as what?
CO- cardiac output
does slowing down the HR have a direct or indirect effect of contractility?
INDIRECT via negative Bowditch effect
if a patient has left ventricular failure, what type of edema occurs and why?
PULMONARY EDMEA blood is backed up BEHIND the left ventricle- increased BHP behind in the pulmonary= now pulmonary is favoring filtration instead of reabsorption= lungs are no longer dry anymore
what would happen if veins were NOT unidirectional for muscle pumps?
blood would travel in both directions- decrease venous return
how does exercise effect venous return?
both INCREASES venous return
myogenic vs. local metabolites
both are a way of local level (within the tissue) of tissue perfusion regulation 1. myogenic- smooth muscle cells via stretch ion sensitive channels - no mediators - increase pressure= increase stretch= vasoconstriction - decrease pressure= decrease stretch= vasodilation 2. local metabolites - decrease of blood flow/ accumulation of local metabolites= vasodilation (one of the metabolites will be a vasodilator- bradykinin, nitric oxide, prostaglandin or histamine) - increased blood flow/ increase oxygen= vasodilation (send blood to where there is no oxygen) - decrease oxygen= vasodilation
what is an example of a positive feedback loop with negative consequences?
brain ischemic reflex/ Cushing reflex
why is the blood flow to the capillaries described as intermittent?
can be on/ off due to precapillary sphincter based off of metabolic needs
if CENTRAL blood pressure deals with large arteries; what does PERIPHERAL blood pressure deal with?
capillaries
where does exchange of nutrients occur? what happens in other locations?
capillaries- other locations is just transportation
capillary transit time vs. pulmonary transmit time
capillary= 0.75 second pulmonary= 6 seconds
does carbon dioxide or oxygen diffuse more easily through the respiratory membrane? what happens if you increase the thickness of the respiratory membrane/ add more water?
carbon dioxide passes easier than oxygen increasing thickness/ water= slows down diffusion of oxygen even more
capillary fluid shift with counteracting hypovolemic shock
causes vasoconstriction= decrease BHP= switches from filtration to reabsorption to increase blood volume
how does sympathetic tone effect venous return? arterial vs. venous
causes venoconstriction and vasoconstriction increases VENOUS return decreases on ARTERIAL side (more blood stays inside large arteries)
what is the effect of chronic stress on diastolic pressure?
chronic stress= increase diastolic pressure - release of adrenaline= activation B1= vasoconstriction= increase TPR= increase diastolic pressure
chronotropy vs. ionotrophy
chronotropy- HR ionotropy- contractility
how does sweating affect venous return?
decrease
what does arteriosclerosis do to arterial elasticity? what is the effect on systolic pressure?
decrease arterial elasticity- will increase systolic pressure
what causes the transition point between filtration and reabsorption of capillaries? is the transition point constant or variable?
decrease of BHP as it goes from arterial to venous end VARIABLE transition point- depending on the situation
what is the first sign in change of pressures of anemic patients?
decrease of diastolic pressure
kwashiorkor
decrease of protein plasma concentration- leading to edema (decrease of BOP)
less length of a system does what to resistance and sympathetic tone?
decrease of resistance and sympathetic tone
what happens to pulmonary transit time with increased CO?
decrease of transit time- increase of flow rate
what is renin stimulated by?
decrease salt, blood volume and BP
what stimulates vasopressin secretion by posterior pituitary?
decreased atrial stretch
what stimulates renin secretion?
decreased renal BP
how does tachycardia effect on SV? (if there are no compensatory mechanisms) why? how does this effect venous return?
decreases SV cause you're decreasing filling time will DECREASE venous return
what happens to venous return with positive pressure ventilation? starling effect?
decreases venous return to both sides of the heart= further decrease in BP negative starling effect- decrease EDV and decrease SV
how does deep inspiration and deep exhalation affect venous return?
deep inspiration- increase venous return to the RIGHT side of the heart but decreases to the left side of the heart - due to increasing capacity of your lungs will stretch your capillaries= small diameter= more resistance= slow down return deep exhalation- increase venous return to the LEFT side of the heart
what must the blood cells do to pass through the narrow capillaries
deform
what can be administered for brain ischemic reflex?
dextran, mannitol or maltose-insoluble to favor resorption of fluid or do a spinal fluid tap
what are the special cases of hypovolemic shock that is not due to external loss of blood volume
distributive shock- anaphylactoid shock and septic shock
how do cellular elements transport across capillaries?
do not go across- they remain in the capillary
if there is high glucose in the plasma than in the cells, what way does it go?
down its concentration gradient- from plasma into cells
high- end- failure
due to not vasoconstriction to organs that are not needed under sympathetic stimulation not enough blood for circulation- not enough oxygen for some tissues- not enough pressure for circulation- heart has nothing to pump
early sign of arteriosclerosis vs. late 1. systolic pressure 2. diastolic pressure 3. pulse pressure
early 1. increase 2. decrease 3. increase late 1. increase 2. increase due to loss of compliance= arteries will empty faster
accumulation of fluid in interstitial space due to obstruction of lymphatic system
edema
extreme emotional stress vs. mild stress for sympathetic and parasympathetic tone
extreme emotional stress - decrease sympathetic - increase parasympathetic mild stress - increase sympathetic - decrease parasympathetic
syncope
fainting
pulmonary circulation speed vs. systemic circulation speed
faster for pulmonary cause same amount of blood but less distance
do capillaries typically filter more or reabsorb? what does this help create?
filter- to create instill fluid
during edema, are capillaries filtering or reabsorbing more?
filtering
does increased blood pressure tend to favor filtration or reabsorption?
filtration
with Kwashiorkor- how much of the capillary length if favoring filtration? what protein is mainly being effected?
filtration along the ENTIRE LENGTH of the capillary albumin mainly being chewed up
filtration pressure vs. reabsorption pressure at ARTERIAL end; is there filtration or absorption?
filtration- 36 mmHg reabsorption- 30 mmHg filtration
does vasodilation favor filtration or reabsorption?
filtration- increasing the size of the pores/ clefts so more can leave
graphs of pressure vs. volume/ flow for filtration vs. reabsorption
filtration- linear reabsorption- NOT linear
in hypoxic conditions, where does blood get shifted to in the lungs?
goes from base (zone 1) to apex (zone 3) low ventilation to high ventilation
the heart and the brain is controlled by what local metabolites?
heart- oxygen brain- carbon dioxide
main regulator within the brain and the heart
heart= oxygen - high oxygen induces vasoconstriction - low oxygen induces vasodilation brain= carbon dioxide - low carbon dioxide= vasoconstriction - high carbon dioxide (hypercapnia)= vasodilation
how does CAROTID SINUS SYNCOPE affect venous return and syncope?
high BP= overstimulation of carotid sinus due to compression= causing fainting increased firing of baroreceptors= causing drop in HR (vasoinhibitory), decrease CO and BP
how does a high lung volume effect pulmonary resistance and venous return back to the left side of the heart?
high lung volume= stretching capillaries= increasing pulmonary resistance= deceasing venous return back to the left side of the heart
high pressure side vs. low pressure side of systemic circulation
high= arterial low= venous
what zone/ area of the lungs has the highest amount of ventilation?
highest amount of ventilation= highest amount of air= zone 3 (apex)= lowest amount of blood
what paracrine mediator is being described? - released from mast cells in response to injury - vasoDILATOR - response for local edema in inflammation
histamine
which is worse: horizontal or vertical cuts in the gingiva?
horizontal cause blood flow is parallel to the roots
pressure imparted by water
hydrostatic pressure
what happens if you have very high cardiac output to oxygen saturation in pulmonary circulation?
hypoxemia- don't saturate the blood with oxygen cause it's so fast
what happens if you don't match ventilation and perfusion of the lungs?
hypoxic conditions
in what situation is arterial hypotension a good thing?
if you were to get into an accident and you're losing a lot of blood decrease of arterial blood pressure shifts blood from filtration to REABSORPTION- trying to reconstitute your blood volume
what happens to diastolic pressure for increase and decrease of HR?
increase HR= increase diastolic pressure decrease HR= decrease diastolic pressure
hypercapnia
increase carbon dioxide= vasodilation
an increase of compliance does what to pressure?
increase compliance= decrease of pressure
increasing blood volume 1. how does this affect blood pressure? 2. how does this affect venous return?
increase of both
what does pregnancy do to venous pressure? what can this cause?
increase of venous pressure= more filtration than reabsoprtion= edema
how does blood viscosity/ hematocrit affect peripheral resistance?
increase of viscosity (increase of RBC)= increase of peripheral resistance
hyperemia
increased blood flow= engorgement
what do most prostaglandins do?
induce VASODILATION
what is the effect of inhalation and exhalation on SV and BP?
inhalation= decrease SV to left side of the heart= decease BP exhalation= increase SV to left side of the heart= increase BP
what is the blood flow through the capillaries?
intermittent
what organ's blood flow is most influences by alpha 1 constriction?
kidney- can stop urine production completely
- accumulation of abdominal fluid - decreased BOP - body is chewing up ALBUMIN due to malnutrition - favoring filtration along entire length of capillary
kwashiorkor
pressure difference between arterioles and the arterial side of the capillary bed
large drop arterioles- 90 mmHg arterial side of capillary bed- 35 mmHg
failure of what ventricle leads to pulmonary edema
left ventricle
which ventricle is more susceptible to ischemia and why?
left ventricle - more blood supply to the left ventricle - during ventricular systole you will have a compression of the blood vessel= increased flow during diastole - sometimes cannot bring blood supply cause vessels are compressed
what ventricle has a larger supply of blood and why? what are the arteries that provide the blood?
left ventricle cause it's larger left coronary artery (off of ascending aorta) into: 1. circumflex branch 2. anterior inter ventricular branch
what substances go through the endothelial cells?
lipid soluble substances (oxygen, carbon dioxide)
what kind of drugs can pass through BBB?
lipophilic
how much epinephrine needs to be released to stimulate alpha 1 vs. beta 2?
little- beta 2 (greater affinity) more- alpha 1 (less affinity)
which organ received more blood supply than needed for survival? what does it mean about its correlated vein?
liver- hepatic vein has higher oxygen levels than other veins of other organs
since pores/ clefts can be varying diameters... where is there the largest diameter in the body?
liver/ kidneys where there is a lot of filtration/ exchange
if sympathetic tone doesn't control constriction/ dilation of blood vessels in the lungs, then what does?
local anoxia
bradykinin, prostaglandins, histamine and nitric oxide control what level of the arterial and venous tone?
local level- for perfusion WITHIN each tissue
what is a muscle pump? how does this effect venous return?
muscles compressing the veins to INCREASE venous return veins are UNIDIRECTIONAL- blood is forced back to the heart
does pressure in the venous side ever become zero? why or why not?
no cause you still need pressure to bring blood back to the vena cava
where does blood flow when precapillary sphincters are constricted?
no more blood through capillary bed= flows through met arterioles
why is there little/ no autonomic regulation to the brain?
no- done by baroreceptors already
under normal conditions, do plasma proteins leave capillaries? what about abnormal conditions?
no- too big to leave but under allergic conditions they will leave
what does the lymphatic system do?
picks up extra fluid filtered by the capillaries (capillaries typically filter more than reabsorb)
how do medium proteins transport across capillary wall?
pinocytosis- endocytosis on one side and exocytosis on the other
how does things enter or leave the capillaries?
pores/ clefts BETWEEN the cells in different diameters
prehypertension BP vs. hypertension BP
prehypertension: 120/80- 140/90 hypertension: over 140/90
what do valves in the vein do?
prevents backflow- allows for UNIDIRECTIONAL flow
NPY co-neurotransmitter helps stimulate what?
prolonged sympathetic action- prolonged VASOCONSTRICTION
what affects vasoconstriction/ dilation in pulmonary vs. systemic?
pulmomnary= local anoxia systemic- reflex control/ baroreceptors
is pulmonary or circulatory more compliant?
pulmonary
what is the difference in resistance between pulmonary and systemic systems and why?
pulmonary= 0.1 PRU systemic= 1 PRU pulmonary is lower based off of Poiseuille's law- less length
blood volume/ velocity in pulmonary vs. systemic
pulmonary= 10% blood vL= faster velocity cause it's the same amount of blood flow systemic= 90% blood vL= blood circulates slowly
local anoxia in pulmonary vs. systemic
pulmonary= constriction (trying to send blood to where there actually is oxygen) systemic= dilation
mean capillary hydrostatic pressure for pulmonary vs. systemic
pulmonary= lower systemic= higher
tendency to filer in pulmonary vs. systemic
pulmonary= zero (do not want to filter, want to reabsorb to keep lungs try) systemic- slight
does the nephron reabsorb or secrete more?
reabsorb
is reabsorption or filtration happening at venous end?
reabsorption
in pulmonary circulation, is there filtration or reabsorption and why? is there vasodilation or vasoconstriction?
reabsorption along the entire length- trying to keep lungs try reabsorption= vasoCONSTRICTION
main clinical sign of shock
reduction of blood pressure
what happens to the baroreceptor reflex with age
reflex becomes slower
what is used for LONG TERM regulation of blood pressure?
renin-angiotension- aldosterone system via regulating water volume inside your body
what 2 arteries come off of the ASCENDING aorta
right and left coronary arteries
describe the rate of change of flow with the right and left ventricle
right ventricle- constant left ventricle- not constant cause it is more susceptible to ischemia
failure of what ventricle leads to systemic edema
right ventricleo
how does pulmonary artery flow compare to systemic circulation artery flow? what about the autonomic regulation?
same flow but less autonomic regulation of flow to pulmonary cause just going gas exchange
how many layers of endothelial cells of capillaries?
single layer
scalloping effect
small changes in blood pressure due to respiratory activity inhalation= decrease SV= decrease BP exhalation= increase SV= increase BP
what substances can leave between pores?
small water- soluble substances and water
what type of autonomic responses for somatic pain vs. visceral pain?
somatic= sympathetic visceral= parasympathetic
what does stroke volume mainly effect? diastolic pressure?
stroke volume mainly effects pulse pressure diastolic pressure mainly affects TPR- total peripheral resistance cardiac output and TPR both affect MAP (arterial)
blood flow to superficial face vs. deep face
superficial- facial artery deep face- maxillary artery
1. pallor 2. diaphoresis- sweating 3. glazed appearance 4. reduced awareness
syncope symptoms
systemic edema vs. pulmonary edema
systemic edema- right ventricular failure pulmonary edema- left ventricular failure
an increase in blood volume and decreased arterial compliance means what?
systolic hypertension
what happens to systolic pressure and diastolic pressure during exercise? PP? SV? MAP?
systolic- slightly elevate - increase SV and increase ejection rate diastolic pressure- doesn't change much cause depends on body composition increase PP= increase SV= increase MAP
internal carotid arteries and vertebral arteries supply blood to what?
the brain
Why must RBCs be flexible?
they're larger than capillary size
how does oxygen and carbon dioxide transport across capillary cells?
through endothelial cell (through lipid bilayer)
what are the 2 locations where there are no pores/ clefts between cells for no exchange? what is there instead?
tight junctions in BBB and placenta
why is increase of contractility needed with an increase of HR?
to compensate for increase HR if you increase HR without any compensatory mechanisms- decrease of SV overtime
if you are sitting for a long period of time on an airplane, why is it a good idea to squeeze your calves once in a while?
trying to increase venous return back to the heart to reduce swelling (capillary BHP is higher than the venous side of capillaries to increase filtration)
clefts in liver and kidneys
typically larger than other organs
what is the counter- current flow of vasa recta and what is its purpose?
urine going left to right while blood supply is going from right to left used for concentrating urine
exhale against a closed glottis
valsalva maneavur
what could cause decreased effective cardiac output?
valve incompetency
what is valve incompetency? what valves are these typically seen with? how does this effect effective CO? what is the effect on venous return?
valve regurgitation- with semilunar valves will decrease CO- less blood return to the other side of the heart DECREASE of venous return
what is the effect of vasoconstriction vs. venoconstriction?
vasoconstriction- increase peripheral resistance= increase BP venoconstriction- increase venous return= increase SV= increase CO= increase BP
when is blood pulsatile? when does it become continuous? intermittent?
when it is first leaving the heart and becomes more continuous as it gets further away from the heart and becomes intermittent when it reaches the capillaries
common value of TOP and THP at arterial end?
TOP- 1 mmHg THP- 5 mmHg
active hyperemia vs. reactive hyperemia
active- due to local metabolic changes/ local metabolites diffusing through tissue - increase blood flow (more than what you need) - can turn red - boner reactive- post occlusion increase in blood flow - local metabolites are being built up= keeps blood vessel dilated for a long period of time trying to drain the local metabolites away
what is secreted from the adrenal cortex vs. the adrenal medulla?
adrenal cortex- aldolesterone (long term effect for blood pressure) adrenal medulla- epinephrine and norepinephrine (short term effect for blood pressure)
describe the affinity for epinephrine for alpha 1 vs. beta 2?
alpha 1= less affinity beta 2= greater affinity
what is the effect of epinephrine to alpha vs beta 2
alpha- vasoconstriction beta 2- vasodilation
where is the only location in the body where hypoxic conditions will induce VASOCONSTRICTION? why?
alveolar hypoxia- trying to shift blood to areas in the body/ lung where oxygen is more available
what glia cell creates the BBB?
astrocytes
according to starling's hypothesis, how does bulk flow move throughout the body?
balance of hydrostatic and oncotic pressures across capillary endothelium
what receptors are located on the cells towards the lumen on a blood vessel?
beta 2
how does urea, glucose, lactate, ADH/ vasopressin and insular transport across capillaries?
between endothelial cells
elephantiasis
blockage of lymph- example of edema in low extremities and genitalia
what is the bulk flow a day through capillaries? how much FILTERED out of capillaries? how much REABSORBED by capillaries? how much collected by lymphatic system?
7200 L/day 20 L/day FILTERED out 17 L/day REABSORBED 3 L/day collected by lymphatic system
how much % of the blood is stored in the veins?
60%- blood reservoir
2 types of distributive shock and does it cause vasodilation or vasoconstriction
1. anaphylactoid shock 2. septic shock both causing vasodilation
Valsalva maneuver - what is the effect on venous return - what is the effect on HR
- forcible exhalation against a closed glottis, resulting in increased intrathoracic pressure - REDUCE venous return - REDUCE heart rate cause increase thoracic pressure= increase baroreceptor
describe the hearts oxygen extraction rate? why is this a good and a bad thing? what type of metabolism does the heart need in order to survive?
- high oxygen extraction rate (good thing) - it can also be a bad thing cause it cannot extract anymore oxygen if needed (on the verge of aerobic and anaerobic metabolism) - heart needs AEROBIC metabolism to survive
Bowditch effect
- homeometric autoregulation - increasing HR traps more calcium inside= increase of contractility with an increase of HR
vasovagal syncope (what happens to the autonomic regulation) (what is the effect on the heart)
- increase parasympathetic (goes to nodal tissue to slow down HR) - decrease sympathetic
what do blisters and hives do to capillary permeability? what does this cause?
- increases membrane permeability= more proteins leaving= higher TOP= favoring more filtration - vasodilation= pores/ clefts are larger= more leaving - also more blood is rushing through cause of inflammation= higher BHP= more filtration
how does viagra work?
- inhibits the breakdown of cGMP - nitric oxide causes the formation of cGMP which causes the removal of calcium in smooth muscles- causes VASODILATION - thus, viagra keeps vasodilation
what is the effect of alcohol and caffeine on renin- angiotensin- aldosterone system?
- prevents breakdown of cAMP - reduces release of ADH/ vasopressin - no fluid uptake= more urine excretion
polycythemia
- too many RBC - increase viscosity - decrease flow - more resistance - more time for large arteries to empty - increase of DP
ACE inhibitors
- used to treat high blood pressure - prevents ACE within the lungs to work - prevents conversion of angiotensin I to angiotensin II so there is no fluid uptake/ increase of blood pressure
what is the change in oncotic pressure? 1. 0.9% saline 2. lactate ringer 3. 5% albumin in saline 4. 6% heastarch in saline 5. dextran 70 in saline
1. 0 2. 0 3. 20 mmHg 4. 30 mmHg 5. 60 mmHg
2 locations of absent clefts
1. BBB 2. placenta
filtration pressures
1. BHP- blood hydrostatic pressure 1. TOP- tissue oncotic pressure
what 2 pressures increase during blisters, hives, allergic reactions? what does this cause?
1. BHP- due to inflammatory cells migrating causing increased pressure= more filtration 2. TOP- increased membrane permeability and vasodilation allows proteins to leave and increasing TOP= favoring filtration causing edema
absorption pressures
1. BOP- blood oncotic pressures 2. THP- tissue hydrostatic pressures
2 ways to induce vasodilation of sweat glands and blood vessels to skeletal muscle
1. beta 2 via epinephrine 2. M3 muscarinic for special case sympathetics
what 2 factors affect peripheral resistance? which plays a bigger role and why?
1. blood viscosity- not going to affect that much cause blood viscosity/ hematocrit should stay pretty constant 2. arteriole diameter- can vary= thus plays a larger role in peripheral resistance
what happens to cardiac output and arterial pressure if: (hypovolemic shock) 1. 10% of blood is loss 2. 20% of blood is loss 3. 45% of blood is loss
1. both are maintained 2. CO decreased; arterial pressure maintained due to increase of peripheral resistance 3. PHP- both cannot be maintained any longer
central vs. local levels for arteriole and venous tone
1. central level: regulated by AUTONOMIC control to each regional area (arm, GI, kidneys) 2. local level: regulated by LOCAL FACTORS to within each tissue (bradykinin, prostaglandins, histamine and nitric oxide)
where do these capillaries reabsorb filtrate from? 1. peritubular capillaries 2. vasa recta capillaries
1. cortical tubules 2. renal pyramid tubules
what is the effect of DP for: 1. anemia 2. polycythemia 3. aging 4. arteriosclerosis
1. decrease 2. increase 3. increase 4. early stage- decrease but later will rise
anemic patients 1. DP 2. SV 3. CO
1. decrease 2. increase- via increase venous return 3. increase low # RBC= less viscosity= increase flow
4 causes of edema
1. decrease of BOP (e.g. kwashiorkor) 2. increased permeability of capillary walls (e.g. blister/ hives) 3. increased venous pressure (e.g. pregnancy) 4. blockage of lymph (e.g. elephantiasis)
how does ORTHOSTATIC HYPOTENSION affect venous return and syncope?
1. decrease venous return (due to gravity pulling down the blood) 2. most people will not faint from just standing
NO- nitric oxide 1. produced by what cells? 2. what is the stimulator? 3. what is the action? 4. mode of action
1. endothelial cells 2. acetylcholine produced relaxation of vascular smooth muscle 3. vasodilation 4. paracrine
what hormones does the adrenal medulla release? what receptors do they go to?
1. epinephrine (90%)- alpha 1 and 2 (less affinity) vasoconstriction and beta 2 vasodilation (greater affinity) 2. NE (10%)- alpha 1 vasoconstriction
what is happening at these nephron locations? 1. glomerular 2. peritubular capillaries 3. vasa recta
1. filtration 2. secretion and reabsorption 3. concentration of urine
how can ADH be stimulated for release?
1. hypothalamus can sense change in osmolarity 2. angiotensin II
what are the 3 locations in the brain without BBB? what is the purpose of this?
1. hypothalamus- used to detect different substances for regulation 2. pituitary gland- releasing substances into circulation 3. respiratory control area- detecting pH levels and carbon dioxide levels
what happens to these factors during exercise? 1. MAP 2. TPR 3. CO 4. HR 5. skeletal muscle blood flow 6. muscle arteries via what receptor 7. visceral arteries via what receptor 8. systolic pressure 9. diastolic pressure
1. increase 2. decrease- via beta 2 or special case sympathetic M3 so you can send blood throughout your body faster 3. increase 4. increase 5. increase 6. vasodilation via beta2 7. vasoconstriction via alpha1 (do not want to send blood to organs where it is not needed during sympathetics) 8. slightly elevated 9. normal to low
determine whether an increase or decrease of these LOCAL METABOLITES will cause vasodilation or vasoconstriction? 1. myogenic activity 2. oxygen 3. carbon dioxide/ other metabolites 4. metabolites from renin- angiotensin- aldosterone system 5. sympathetic activity 6. histamine 7. heat 8. cold
1. increase= vasoconstriction; decrease= vasodilation 2. increase= vasoconstriction; decrease= vasodilation 3. increase= vasodilation; decrease= vasoconstriction 4. increase= vasoconstriction; decrease= vasodilation 5. increase= vasoconstriction; decrease= vasodilation 6. increase= vasodilation; decrease= vasoconstriction 7. increase= vasodilation 8. increase= vasoconstriction
what happens to blood flow to a tissue with increased metabolic needs? what happens if all the tissues in the body have an increased metabolic demand?
1. increased blood flow 2. increased CO and heart work= goes from 5L/min to 25L/min so the blood is circulating faster
what organ produces these hormones and what are their functions: 1. renin 2. angiotensinogen 3. aldolesterone 4. ADH/ vasopressin
1. kidney- converts angiotensinogen to angiotensin I 2. liver 3. adrenal CORTEX- goes to the KIDNEY to cause reabsorption of sodium and water and VASOCONSTRICTION 4. made by hypothalamus but secreted by posterior pituitary gland- increase water reabsorption from kidney tubules
autoregulation 1. what are the 2 types? 2. does this fall under central or local level for REGULATION OF TISSUE PERFUSION?
1. myogenic and local metabolites 2. local level
Bradykinin is released from what types of stimulation? what is its target and what is the effect?
1. parasympathetic stimulation to salivary glands 2. sympathetic cholinergic stimulation to sweat glands causes vasodilation and increase of filtration
3 vasodilator agents- what does this mean about filtration or reabsorption?
1. prostaglandins 2. histamine- injured tissue and mast cells (arterioles, met arterioles and capillaries) 3. bradykinin- glands favors FILTRATION
ANP (atrial natriuretic peptide) 1. where is it secreted from? 2. what are the 3 stimulators? 3. what are its 4 actions? 4. what is its overall goal?
1. secreted from atria 2. in response to stretch of the atria from increase sodium, increase ECF, or increased atrial BP 3. all INHIBITION of: - Na reabsorption by kidneys= increase of sodium excretion (followed by water) - renin- angiotension- aldosterone system= increase of sodium excretion (followed by water) - afferent arteriole vasoconstriction= causing vasodilation= increase GFR= increase water and sodium excretion - sympathetic nervous system= decrease CO and TPR= decrease atrial BP 4. overall goal= increase urine production and decrease of atrial BP
what is orthostatic hypotension? what is the greatest factor that causes this? what happens to venous return, SV and BP? what is the difference between the capillary blood pressure vs. venous pressure? what does this do to feet and ankles?
1. standing position and not moving 2. gravity 3. decrease venous return= decrease SV= decrease BP (hypotension) 4. capillary blood pressure is GREATER than venous end of capillaries (15 mmHg) due to gravity 5. causes greater BHP= greater filtration= swollen feet and ankles
what happens to the blood supply to these areas during exercise? why? 1. heart 2. skeletal muscle 3. GI 4. kidneys
1. still receiving 4% 2. more 3. less 4. less trying to send blood elsewhere where it is needed during exercise
in a fight or flight response- what 2 things work together for vasoconstriction?
1. sympathetic response 2. adrenaline (aka norepinephrine)
when are people in TEMPORARY horizontal position? and why? what happens to blood pressure? venous return? CO?
1. syncope- fainting 2. due to not enough blood flow to the brain 3. decrease of blood pressure 4. increasing venous return- increase CO- bring back normal circulation to the brain
stimulation of these Endothelin receptors cause what? 1. EdnrA 2. EndrB
1. vasoconstriction 2. vasodilation
what is being favored here? be specific on the changes in filtration/ absorption pressures 1. vasoconstriction 2. arterial hypotension 3. venous hypotension 4. dehydration 5. hemorrhage
1. vasoconstriction- decreased BHP 2. arterial hypotension- decreased BHP (reabsorption forces are now more powerful) 3. venous hypotension- decreased BHP (reabsorption forces are being reinforced) 4. dehydration- decrease of blood vL= decrease BHP 5. hemorrhage- decrease blood vL= decrease BHP REABSOPRTION
what is being favored here? be specific on the changes in the filtration/ absorption pressures 1. vasodilation 2. arterial hypertension 3. venous hypertension 4. increased plasma leakage 5. plasma protein deficiency
1. vasodilation- increased BHP 2. arterial hypertension- increased BHP 3. venous hypertension- increased BHP (overpowering the normal reabsorption forces) 4. increased plasma leakage- decreased BOP and increased TOP 5. plasma protein deficiency- decreased BOP (Kwashiorkor) FILTRATION/ edema
what is the venous end of capillary pressure on avg?
15 mmHg
at REST, what percentage of the capillary beds are open?
20-25%
if a specific capillary bed were to be vasoconstricted/ precapillary sphincter is shut off- describe the flow of blood for the capillary beds ABOVE/OPEN and BELOW/CLOSED this constricted capillary bed what is happening at that specific capillary bed once the precapillary sphincter is open?
ABOVE/OPEN= filtration (increase of BHP) due to backup blood flow BELOW/ CLOSED= reabsorption (decrease of BHP) no blood flow coming in specific capillary bed- increased of filtration cause inflow of more blood due to backpack behind the precapillary sphincter
chest pain indicates what?
ANAEROBIC metabolism in your heart
what are the 2 places where there are no pores/ clefts between cells? tight junctions only
BBB and placenta
what limits the fluid movement in the brain?
BBB- due to astrocytes
common value of BHP at arterial end? BOP? does this mean that there is more filtration or reabsorption at the arterial end?
BHP- 35 mmHg BOP- 25 mmHg more FILTRATION at arterial end
what is the ONLY pressure (out of the 4 of starling's hypothesis) that changes? how does it change?
BHP- blood hydrostatic pressure higher at ARTERIAL end and decreases as it reaches towards VENOUS end- reason why there is more filtration at arterial than venous
blood pressure inside capillary, what happens if you increase this?
BHP- blood hydrostatic pressure increase will cause filtration
what paracrine mediator is being described? - parasympathetic stimulated aids in its release from salivary glands - cholinergic sympathetic fibers aids in release from sweat glands - causes vasodilation- increase BHP- more filtration- more secretion
Bradykinin
what is the flow from the heart vs. the capillaries?
FLOW IS THE SAME
nitric oxide is derived from what AA? what enzyme?
L- arginine with nitric oxide synthetase
what is typically dominate in the heart, M2 or B1?
M2- parasympathetic is more dominate than sympathetic
(CO)(TPR)=?
MAP
does epinephrine or NE have a better effect for increasing venous return?
NE cause it has a higher affinity for alpha receptors (vasoconstriction) than epinephrine
is the adrenal medulla hormones for long term or short term regulation of blood pressure?
SHORT TERM
what type of autonomic control is to blood vessels? via what receptors?
SYMPATHETIC only alpha 1- vasoconstriction beta 2- vasodilation
at rest, are blood vessels under sympathetic constrictor tone or parasympathetic constrictor tone?
SYMPATHETIC- no parasympathetic to blood vessels
if a patient has right ventricular failure, what type of edema occurs and why?
SYSTEMIC EDEMA- swollen joints, fingers, everywhere blood is backed up BEHIND the right ventricle- increased of BHP behind
is more resistance on the arterial side or venous side? why?
arterial side arterioles= resistance vessels
low volume/ high pressure network vs. high volume/ low pressure network
arterial system vs. venous system
pressure at arterial end of capillaries vs. venous end of capillaries
arterial- 35 mmHg venous- 15 mmHg
what happens to BP if you increase volume inside arterial blood vessels vs. venous side?
arterial- will raise blood pressure MORE venous- will raise blood pressure LESS due to the idea that veins have more compliance/ distensibility than arteries
resistance vessels to bring blood towards/ away from capillary bed
arterioles
low BP vs. high BP for reflex control
low BP 1. decrease stimulation of cardio inhibitory (trying to activate sympathetic) 2. decrease inhibition of cardioacceleatory and vasomotor (trying to activate sympathetic) high BP 1. increase stimulation on cardio inhibitory (trying to lower HR) 2. increase inhibition of cardioacceletory and vasomotor (causing dilation and trying to activate parasympathetic)
what is the difference between pulmonary and systemic for mean pressure, SP and DP and pulse pressure?
lower for pulmonary than systemic
where does extra water from interstitial fluid go?
lymphatic system- 3L/day
main function of baroreceptors
maintaining blood flow to heart and brain
bypass channel and regulate flow into capillary beds
metaarterioles
what determines if the precapillary sphincter is open or closed? what are the factors?
metabolic needs- oxygen and CO2
sympathetic tone for pulmonary vs. systemic
minimal for pulmonary and marked for systemic
what is the effect on cardiac output and heart work by controlling tissue percussion so each tissue recieves just enough blood?
minimizing CO and heart work
capillaries inside the liver vs other locations
more leaky- need to uptake a lot of substances from the blood
does epinephrine or norepinephrine cause a greater increase in central blood pressure and why?
norepinephrine cause norepinephrine only does vasoconstriction (and has a higher affinity for alpha- vasoconstriction) while epinephrine does vasodilation and vasoconstriction (and has a higher affinity for vasodilation with a higher affinity with beta 2 receptor)
what do these 3 have in common? 1. hypothalamus 2. pituitary gland 3. respiratory control area
not a lot of BBB for detection and secretion
vasal motion
on/ off circulation in the capillary beds via precapillary dilation or constriction
pressure provided by proteins to hold onto water
oncotic pressure
where is there parasympathetic innervation to the heart? what is the receptor? how does this effect the Bowditch effect?
only to nodal tissue M2 receptor- inhibits adenyl cyclase activity; activated phosphodiesterase increases K+ conductance= hyperpolarization= takes longer to reach T-tubules= slows down HR has a negative Bowditch effect- decreases HR so SLIGHTLY decreases contractility
aldolesterone is secreted from what? where is its target?
origin- adrenal cortex target- peripheral arterioles for vasoconstriction and kidney for uptake of salt and water
How does the Valsalva maneuver affect blood pressure?
originally increases your BP= large baroreceptor activation to reduce BP
opening and closing of precapillary sphincter is determined by what needs?
oxygen and carbon dioxide
even though the heart has dual autonomic innervation, what is normally dominate? how will the normality be overcome?
parasympathetic (M2) typically dominates but an increase in epinephrine to beta1 will cause an increase in heart rate
does epinephrine typically want to vasodilate or vasoconstrict? how does it have the other effect? how does t effect peripheral resistance?
vasodilate cause epinephrine has a higher affinity for beta than it does for alpha small dose= beta 2= vasodilation= decrease peripheral resistance large dose= alpha 1= vasoconstriction= increase peripheral resistance
does cGMP do vasoconstriction or vasodilation?
vasodilation
what will happen under these conditions? - high adenosine (from broken down ATP) - high co2 - low oxygen - high H+ - high K+
vasodilation
in reference to SPECIFIC capillaries- what happens under vasodilation? vasoconstriction? and why?
vasodilation- filtration along the entire length (more blood coming in= higher BHP) vasoconstriction- reabsorption along the entire length (less blood coming in= higher BHP)
how does VASOVAGAL SYNCOPE affect venous return and syncope? what is the overall effect on BP?
vasovagal syncope- amplified PARASYMPATHETIC response via inhibiting sympathetic responses 1. increase parasympathetic- HR decreasing- CO decreases- BP decreases 2. decrease sympathetic- dilation of vessels- dropping BP increases venous return cause they will FAINT/ syncope
what is lowest pressure in your body blood vessels?
vena cava- end of venous circuit
is alpha 2 receptor mostly for vasoconstriction or venoconstriction?
venoconstriction- but alpha1 is still more dominant than alpha2
what is the most useful method to counteract hypovolemic shock?
venoconstriction- increases venous return cause veins are a blood reservoir
what happens if you have an increased venous pressure?
venous end typically favors REABSORPTION but with increased venous pressure you will favor FILTRATION= edema
does arterial or venous side have more distensibility/compliance? why?
venous side- veins are the blood reservoir
reflex control for pulmonary vs. systemic and why?
via BARORECEPTORS pulmonary- minimal cause no reason to regulate blood flow cause all it is doing is gas exchange= thus minimal sympathetic tone systemic- marked effect on the veins
describe the 3 pulmonary vascular zones - how much air - how much blood - how much resistance
zone 1= base - least amount of air - most amount of blood - least amount of resistance zone 2= right above the heart - middle of each - intermittent blood flow zone 3= apex - least amount of blood - most amount of air - most resistance