Phys Blood Pressure

Question 1

___ is the primary mechanism involved in short term regulation of arterial BP.
It is a ____ system. What happens when MAP increases/decreases?

Answer 1

Baroreceptor reflex
Negative feedback
Increase: symp incr, parasymp decr
Decrease: opposite

Question 2

Where are baroreceptors found? What kind of receptors are they?

Answer 2

Carotid sinuses
Aortic arch
Large vessels in the thorax
*stretch receptors

Question 3

The ___ baroreceptors are tonically active. They are the most sensitive and effective baroreceptors, so the ___ are not as sensitive

Answer 3

Carotid sinus

Aortic arch baroreceptors

Question 4

Baroreceptors display both ___ and ___ characteristics. Explain each

Answer 4

1. Tonic: magnitude of BP (MAP)

2. Phasic: rate of change in BP

Question 5

If arterial pressure is elevated for a period of time the baroreceptor output will be ____
*shifts to the ___

Answer 5

Lower

Right

Question 6

Peripheral resistance:

Pressor vs depressor center

Answer 6

1. P: tonically active, controls symp outflow - changes TPR

2. D: not tonically active, modulates activity of pressor center, indirectly affects TPR

Question 7

Cardiac output:

Cardioinhibitory system vs. Cardiostimulatory system

Answer 7

1. I: tonically active, controls parasympathetic output to heart
2. S: tonically active, controls symp output to heart

Question 8

Afferent pathway

Answer 8

Vagus n.

Glossopharyngeal n.

Question 9

Efferent pathway

Answer 9

Sympathetic

Parasympathetic

Question 10

Decreased pressure leads to ____

Increased pressure leads to ____

Answer 10

Increased SNS output

Decreased SNS output

Question 11

Effector organs in the baroreceptor reflex

Answer 11

1. Heart: rate and contractility (output)
2. Arteriolar smooth muscle: resistance
3. Venular smooth muscle: capacitance
4. Adrenal medulla: EPI and NEPI release

Question 12

Low pressure baroreceptors are located where?

Answer 12

Right atrium

Pulmonary a.

Question 13

Changes in central venous pressure are relayed to the ___ and on to the ___ to alter sympathetic and parasympathetic activity

Answer 13

Hypothalamus

Cardioinhibitory/stimulatory centers

Question 14

Receptors involved in sympathetic system

Answer 14

1. Alpha 1 on vascular smooth muscle
2. Beta 1 on myocardium and kidney
3. Beta 2

Question 15

Receptors involved in parasympathetic system

Answer 15

1. M
2. Craniosacral outflow- vasodilation
3. NO

Question 16

Decreased MAP will increase sympathetic activity which will:

Answer 16

+ cardiac function
vasoconstriction (+ Psf)
venoconstriction (+ RVR)
*Results in increased CO and decreased PRA

Question 17

How does G force affect the body?

Answer 17

• increased: pooling of blood in lower extremities, decreased flow to brain
• decreased: perception of hypervolemia, excess volume excreted, when you return to earth you can be hypovolemic