neurohumoral control Flashcards
(34 cards)
Which sympathetic nerve receptor predominantly causes vasoconstriction?
alpha
Which sympathetic nerve receptor predominantly causes increased contractility?
beta 1
Which sympathetic nerve receptor predominantly causes bronchodilation?
beta 2
Chronotrophy
HR
inotropy
contractility
dromotropy
conduction velocity
lusitropy
relaxation
What is the “second messenger” that is involved with sympathetic stimulation of a cardiac muscle cell?
cyclic AMP
Which catecholamine does the adrenal gland predominantly release with sympathetic stimulation?
Mostly epinephrine (80%), lesser amount norepinephrine (20%)
What is the Baroreceptor Reflex
Sensor of change in BP, increases or decreases HR due to change. Located in carotid sinus and aortic arch
Where are the receptors for the baroreceptor reflex located?
Located in carotid sinus and aortic arch
How does the Baroreceptor Reflex help with blood pressure regulation?
Sense and buffers change in BP. Reduces the daily variation in BP by ½ to 1/3 from that which would occur if this system were not present. excites vagal - vasodilation of veins and dec HR and contractility
During what surgery does Baroreceptor Reflex activation frequently cause hemodynamic changes?
Carotid endarectomy
What is the Bainbridge Reflex?
Low pressure receptors that respond to stretch, sense CV system volume
Where are the receptors for bainbridge reflex located?
Vena cava – right atrial junction – pulmonary vein – left atrial junction
In addition to receptor activation what also contributes to the heart rate changes seen with the Bainbridge Reflex?
Stretch of heart and stretch of SA node
The Baroreceptor Reflex responds to changes in arterial blood pressure or to changes in blood volume?
pressure
The Bainbridge Reflex responds to changes in arterial blood pressure or to changes in blood volume?
volume
What are some of the effects of Atrial Stretch Receptor activation?
Decreased sympathetic activity to kidney (increased urine output), decerased vasopressin (increased urine output & decreased water reabsorption, decreased BP), increased atrial natriuretic peptide (increased natriuresis, increased UO, decreased BP)
What is the Bezold-Jarisch Reflex?
responds to noxious ventricular stimuli sensed by chemoreceptors and mechanoreceptors within the LV wall by inducing the triad of hypotension, bradycardia, and coronary artery dilatation. strong contraction of an undefiled ventricle elicits this reflex. it plays a role in BP regulation.
What is the CNS ischemic response?
Atrial pressure elevation in response to cerebral ischemia
What is the Cushing Response?
Increased ICP causes increased BP until blood flows once again in the vessels of the brain
What is Cushing’s Triad?
Irregular respirations (caused by impaired brainstem function), bradycardia, and widening pulse pressure (caused by systolic hypertension).
Under what circumstances can Peripheral Chemoreceptors cause hemodynamic changes
They are sensitive to low oxygen, carbon dioxcide exvess and hydrogen ion excess. When arterial pressure falls below a critical level (80).
