Neurohumeral Influences Flashcards
Parasympathetic stimulation (CHOLINERGIC) - control located in
medulla oblongata
carioinhibitory center
Parasympathetic stimulation (CHOLINERGIC) - via what
vagus nerve, cardiac plexus
Innervates SA node, AV node and myocardium
Releases Ach
Parasympathetic stimulation (CHOLINERGIC) - does what
slows rate and force of myocardial contraction
decreases myocardial metabolism
causes coronary artery VC
Sympathetic stimulation (ADRENERGIC) - control located in
medulla oblongata
cardioacceleratory center
Sympathetic stimulation (ADRENERGIC) - via what
cord segments T1-T4, upper thoracic to superior cervical chain ganglia
Innervates SA node, AV node, conduction pathways and myocytes
Releases epinephrine and NE
Sympathetic stimulation (ADRENERGIC) - does what
Causes increase in rate and force of myocardial metabolism
Causes coronary artery VD
Sympathetic stimulation (ADRENERGIC) - the skin and peripheral vasculature receive
ONLY postganglionic sympathetic innervation
Causes VC of cutaneous arteries, sympathetic inhibition must occur for VD
Drugs that increase sympathetic function
sympathomimetics
Drugs that decrease sympathetic function
sympatholytics
Baroreceptors (pressoreceptors)
main mechanism controlling heart rate
Baroreceptors (pressoreceptors) located where
in walls of aortic arch and carotid sinus via vasomotor center
Baroreceptors (pressoreceptors) - Circulatory reflex: responds to changes in
blood pressure
Baroreceptors (pressoreceptors) - Circulatory reflex: Increased BP results in
parasympathetic stimulation
decreased rate and force of cardiac contraction
sympathetic inhibition, decreased peripheral resistance
Baroreceptors (pressoreceptors) - Circulatory reflex: Decreased BP results in
sympathetic stimulation
increased HR and BP and VC of peripheral BVs
Baroreceptors (pressoreceptors) - Circulatory reflex: Increased right atrial pressure causes
reflex acceleration of HR