Physiology: Short Term Control Of Blood Pressure

Question 1

Auto regulation with respect to blood

Answer 1

Despite increasing/ decreasing blood pressure, the body is able to control blood flow naturally and automatically to vital areas.

Usually the auto regulation zone is between 60-160

Question 2

Baraorecptor reflex

Answer 2

Located along the carotid sinus and monitor dilation/constrictions first blood vessels.

Decrease in stretch on baroreceptors causes:

• decrease in carotid sinus nerve activity
• increases sympathetic activity
• decreases parasympathetic activity
• increases heart rate, contractility
• increases venous return

Increase in stretch on baroreceptors causes:

• increases carotid sinus nerve activity
• increases parasympathetic activity
• decreases sympathetic activity
• decreases heart rate, contractility
• decreases venous return

Question 3

Parasympathetic effects from baroreceptors

Answer 3

Focus only on decelerating the heart rate by decrease activity in the SA node

Question 4

Sympathetic effects from baroreceptors

Answer 4

Decreases cardiac acceleration, contractility, and vasoconstriction of arterioles/veins

Question 5

Valsalva maneuver with respect to baroreceptors reflex

Answer 5

Increases intrathroacic pressure which decreases venous return to the heart

• causes decrease in preload and cardiac output
• causes decrease in arterial presssure

This causes the baroreceptor reflex to increase sympathetics and decrease parasympathetics
- increases heart rate

Question 6

Factors that DECREASE overall blood pressure

Answer 6

Decrease in afterload pressure

Increase in parasympathetic effects

Increase in ventricular thickness

B2 receptor activation (increase diameter)

Question 7

Factors that INCREASE blood pressure

Answer 7

Increased preload

Increased contractility

Increase in blood volume
- both venous return and tone

Increase in ventricular pressure and radius

A1 receptor Activation (decrease in diameter)

Increase in renin production