Cardiology 5: Integration and Regulation Flashcards
the determinants of arterial blood pressure can be ___ or ___
physical or physiological
list 2 physiological factors that influence arterial BP
cardiac output and periperal resistance
list 2 physical factors that influence arterial BP
arterial blood volume and arterial compliance
the body will alter all other factors to maintain ___
arterial blood pressure
arteriole baroreceptors are ___ receptors located in the __ and ___
stretch, carotod sinuses and aortic arch
stretch of the arterial baroreceptors ____ receptor firing and inhibits ____ outflow from the pressor region. This is called the ___ effect
increases; sympathetic; dpressor
which of the arterial barorecptors is most sensitive?
carotid
arterial baroreceptors are the key to ___term adjustment of bp
short
cardiopulmonary baroreceptors are ___ receptors in the __, ___ and ___
atria, ventricles and pulmonary vessels
cardiopulmonary baroreceptors inhibit ____ outflow from the pressor region, but also inhibit release of factors important to ____ (such as angiotensin, aldosterone, vasopressin)
sympathetic; water retention
cardiopulmonary baroreceptors work to ___ BP
increase
peripheral chemoreceptors are ___ bodies in the __ and ___
small; carotid sinuses and aortic arch
peripheral chemoreceptors are stimulated by decreased __ and increased __
PO2 and pH; PCO2 and H+
peripheral chemoreceptors primarily affect __, but also stimulate ___
respiration; pressor region
peripheral chemoreceptors can also be found in the heart and cause ___ in response to low O2
pain (angina)
central chemoreceptors are located in the __ and respond to changes in ___ and __ but not ___
brain; PCO2 and pH; PO2
central chemoreceptors directly stimulate ____ regions of the medulla, causing ____ outflow and arteriole __
chemo-sensitive; sympathetic; constriction
stimulation of the posterior hypothalamus __bP, while syimulation of the anterior hypothalamus ___BP
raises; lowers
the hypothalamus contains ___sensation that controls blood flow to the skin
temperature
stimulation of motor and premotor cortexes results in __-response, while emotional stimuli may result in a ___ response (such as fainting or blushing)
pressor; depressor
painful stimulation of the skin causes a ___ response while distention causes ___ response
pressor; depressor
in the barorecptor reflex, the sudden change in arterial blood pressure causes a(n) ____ change in heart rate
inverse
the baroreceptor reflex is most pronounced ____ range of blood pressure
intermediate
in the bainbridge reflex, stretch o f the right atrium by increased ___ causes a___ in heart rate
venous return ; increase
at a slow heart rate, increased volume causes ___ in bp
increase
at fast heart rate, increased volume casues __ in BP
decrease
during hemorrhage, cardiac output and arterial pressure ___ and arterial pulse becomes __ and __
drops; fast and feeble
during hemorrhage, skin veins ___, making skin __ and __
collapse; moist and blue
during hemorrhage, respiration rate is ___ and the depth may be ___
rapid; shallow or deep
if blood loss is sufficient to decrease mean pressure to 50mmHg, what tends to happen to pressure?
rise over next 30 minutes and continues until normotensive, or pressure falls dramatically until death (hemorrhagic shock)
during hemorrhage, various adjustment occur by ___ feedback loops
negative
during hemorrhage, the baroreceptor resposne is___-, causing a ___ in parasympathetic and a __ in sympathetic tone
decrease; increase
during hemorrhage, arteriole constriction ___, minimizing the fall of arterial bp
increases
arterial pressure drops below __mmHg cannot evoke barorecptor response as they are belowe threshold
60
why can chemoreceptors take over for baroreceptors when arterial bp drops below threshold?
low blood flow leads to hypoxia which stimulates chemo
in response to hemorrhage, chemoreceptors ___ peripheral vasoconstriction and ___ respiration, which increases___
increase; increase; venous return
the cerebral ischemic response occurs when the arterial pressure falls below ___mmHG and ___ and ___ resposnes are recruited
40; sympathetic and adrenal
during cerebral ischemic response the sympathetic discharge is increased several times, increasing __ and __
vasoconstriction and contractility
with more severe ischemia, ____ centres become activated, resulting in bradycardia and reduced blood pressure
parasympathetic
what are 2 endogenous vasoconstrictors released by the adrenal gland during hemorrhage?
Ne and E
when bp drops to 40mmHg there is a __fold increase in NE and E
50
during hemorrhage, vasopressin is secreted by the ___ due to baroreceptors or left atrial stretch receptors
posterior pituitary
in hemorrhage, reduced renal perfusion causes secreation of ___, which results in production of potent vasoconstrictor __
renin; angiotensin 2
during hemorrhage, tissue fluid reabsorption occurs due to __-forces
starling
during hemorrhage, reduce arterial and venous pressure and increased arteriole constriction lowers ___pressure in the capillaries, which promotes net absorption of ___ into vessels
hydrostatic; interstitial fluid
during hemorrhage, there is renal conservation of __ ad __
salt and water
during hemorrhage, ___ and ___ activity promote fluid and electrolyte retention by the kidney s
vasopressin and sympathetci
lower arterial pressure ___ glomerular filtration rate and elevated angiotensin 2 levels stimulates release of ___form the adrenal cortex. Both act to ___ fluid and electrolyte loss
decreases; aldosterone; decrease
t/f bp normally increases with age
true
hypertension is the persistent elevation of bp beyond __
normal range
what are the 2 general forms of hypertension?
- renal hypertension
2. essential hypertension
what is the cause of renal hypertension??
increased activity of renin-angiotensin system
what is the cause of essential hypertension?
cause unknown, but risk fators include genetics, obesity, lifestyle and smoking
what are the 2 common consequences of hypertension?
hypertrophy and atherosclerosis
hypertrophy is the result of the heart pumping against chronically elecated __, which causes the ventricle to become stiff, requiring higher __ and becoming more dependent on atrial contraction
afterload ; preload
atherosclerosis can cause: ___, ___, ___disease and ___disease
MI; stroke; peripheral vascular; renal
what are the 2 principal treatments of hypertension?
- lower cardiac output
2. vasodilation
what are 3 ways to lower cardiac output to treat hypertension?
reduce salt intake; B blockers; diuretics
what are 2 ways to improve vasodilation to treat hypertension?
- calcium channel blocker
2. angiotensin converting enzyme inhibitor
congestive heart failure occurs when the heart is unable to ___
pump enough cardiac output
what are the 2 primary causes of congestive heart failure?
diastolic dysfunction and systolic dysfunction
what are the 2 primary consequences of congestive heart failure?
- reduced cardiac output/bp
2. fluid retention
what are 3 consequences of reduced cardiac output/pressure in CHF?
- increased heart rate
- vasoconstriction
- fluid retention
what are the 4 principal treatments for CHF?
- diuretics
- ionotropic drugs
- vasodilators
- B blockers
what is the role of diuretics in treating CHF?
increase Na and water secretion (reduce fluid retention)
what is the role of ionotropic drugs in treating CHF?
digoxin (increase ca for improved contractility )
what is the role of vasodilators in treating CHF?
ACE inhibitors to reduce afterload
what is the role of B blockers to treat CHF?
reduce sympathetic drive to the heart (suspected to reduce workload)
