Ch. 23

Question 1

Arterial Baroreflexes

Answer 1

Stimulus: increased arterial pressure (stretch)
Pathway: increased BP –> increased stretch –> increased firing rate of carotid sinus nerve
Response to high BP: increased parasympathetic to heart and decreased sympathetic to heart and blood vessels
Effect: decrease HR, contractility and vasodilation

Restore MAP

Question 2

Cardiopulmonary Baroreflexes

Answer 2

Location: Ventricle
Stimulus: increase preload
Activation Response: decrease sympathetic to heart and blood vessels
Activation Effect: Vasodilation

Restore Normal Stroke Volume

Question 3

Peripheral Chemoreceptors

Answer 3

Location: Carotid Body & Aortic Body
Stimulus: decrease o2, increase in co2, and decrease in pH (blood)
Activation response: increase sympathetic and parasympathetic
Activation Effect: Vasoconstriction & Bradycardia

Restore normal blood gasses

Question 4

Central Chemoreceptors

Answer 4

Location: Brain, Medulla
Stimulus: increase co2 and decrease pH (interstitial fluid)
Activation response: increase sympathetic and parasympathetic
Effect: peripheral vasoconstriction and tachycardia

Question 5

Cushing’s Triad (Hypertension, bradycardia, respiratory depression)

Answer 5

increase intracranial pressure constricts arterioles –> cerebral ischemia –> increase co2 and decrease pH –> central chemoreceptors activated –> increase sympathetic –> increase perfusion pressure (hypertension) –> increase stretch in carotid sinus —> peripheral reflex baroreceptor-induced bradycardia

Question 6

Reflexes from lung

Answer 6

Location: Lung
Stimulus: lung inflation
Response: decrease in sympathetic and parasympathetic
Effect: vasodilation and tachycardia

Question 7

Skeletal Muscle during Exercise

Answer 7

Location: Muscle Afferents
Stimulus: K+, H+, Adenosine
Response: increase sympathetic and decrease parasympathetic
Effect: tachycardia, vasodilate active muscle, vasoconstrict inactive