Baroreceptors

Question 1

Calculation of Flow

Answer 1

Flow = ^ Pressure / Resistance

Question 2

Calculation fo Arterial Blood Pressure

Answer 2

Arterial Blood Pressure = Cardiac Output x Total Peripheral resistance

Question 3

Feedback Loop baroreceptor reflex

Answer 3

Stretch-sensitive baroreceptors acting as the sensors (afferents)
Cardiovascular control centre in the Medulla Oblongata acting as the integrator
Autonomic neurons acting as the effectors (efferents)

Question 4

What are A fibres

Answer 4

A fibres deal with normal range blood pressure changes

Question 5

what are C fibres

Answer 5

C fibres deal with high level blood pressure changes

Question 6

Not all baroreceptors are created equal

Answer 6

carotid sinus baroreceptors are more sensitive that cause greater changes in blood pressure that aortic arch baroreceptors

Question 7

Long term control differs

Answer 7

Longer term control differs : relies on control of blood volume think control of cardiac output by starling’s law of the heart and involves kidneys

Question 8

calculation of pulse pressure

Answer 8

Pulse Pressure = systolic blood pressure - diastolic blood pressure

Question 9

mean arterial blood pressure

Answer 9

mean arterial blood pressure = DBP + 1/3 (Pulse Pressure)

Question 10

what is pulse pressure determined

Answer 10

Determined by the volume of blood ejected and the compliance of the arterial vasculature

Question 11

what causes an increase in pulse pressure

Answer 11

increase in volume of blood ejected by ventricles during exercise with relative compliance of vessels will cause an increase in pulse pressure

Question 12

what is stroke volume

Answer 12

Stroke volume - is volume of blood ejected

Question 13

what is compliance

Answer 13

compliance is arterial distensibility

Question 14

reltaionship between low complaince and workload

Answer 14

low compliance means greater cardiac workload

Question 15

How effectors alter heart increasing blood pressure

Answer 15

increased sympathetic drive
Increased noradrenaline release from post synaptic neurons
Binds to β1 adrenoreceptors expressed on the myocardium Increased chronotropy, dromotropy, inotropy and decreased lusitropy
Results increased cardiac output(CO)

Question 16

how effectors alter vascualture increasing blood pressure

Answer 16

Increased sympathetic drive
Increased noradrenaline release from post synaptic neurons
Binds to α1 adrenoreceptors expressed on the vasculature Increased vasoconstriction
Results in increased total peripheral resistance(TPR)

Question 17

how effectors alter the heart decreasing blood pressure

Answer 17

Increased parasympathetic drive
Increased acetylcholine (Ach) release from post synaptic neurons
Binds to muscarinic M2 receptorsexpressed on the myocardium Decreasedchronotropy, dromotropy, inotropy and increased lusitropy
Results in decreased cardiac output (CO)

Question 18

how effectors alter the vasculature decreasing blood pressure

Answer 18

Increased parasympathetic drive
Increased acetylcholine (Ach)release from post synapticneurons
Binds to muscarinic M3 receptors expressed on the vasculature
Increased vasodilation by endothelium dependentmechanismResults indecreasedtotal peripheral resistance(TPR)

Question 19

Anaphylaxis

Answer 19

Anaphylaxis is a hypersensitivity reaction involving mast cell degranulationwhich then causes release of vasoactive compounds, which amongst otherthings cause circulatory collapse due to severe hypotension

Question 20

plasma volume is altered by

Answer 20

Plasma volume is altered by salt exretion by RAAS , antidiuretic hormone and atrial natiruretic peptide

Question 21

RAAS

Answer 21

Decreased renal perfusion pressure aka a decrease in effective circulating volume→ Rise in sympathetic nervous system activity to kidneys→ Decreased NaCl concentration in the macula densa

Question 22

Anigotensin II stimualtes

Answer 22

Angiotensin II stimulates aldosterone , vasoconstriction and thirst