Blood Pressure & MAP Lab
List the sequence of events initiated by the cardiovascular center, to correct the decrease in mean arterial pressure. Be sure to include: all the ways the sympathetic nervous system acts to raise blood pressure back to normal
Cadiovascular center increases sympathetic stimulation = vasoconstriction (increase in TPR) = 1. Raise in arterial pressure (increase MAP) 2. Fall in pulse pressure (decrease PPP amplitude 3. Increase contractility of the ventricles 4. Increase venous vasocontriction
What is the relationship between total peripheral resistance (TPR) and mean arterial pressure (MAP)
Decrease in TPR (vasodilation) = Decrease in MAP Increase in TPR (vasoconstriction) = Increase in MAP
List the sequence of events during the Valsalva maneuver that result in a drop in blood pressure
Decrease in venous return = decrease EDV = decrease SV = decrease CO = Decrease MAP = decrease stretch of baroreceptors = decrease depolarization rate = info goes to medulla = body's respons = increase sympathetic stimulation = vasonconstriction (increase TPR) = Rise in arterial pressure & fall in PP
What effect does increased sympathetic nervous system stimulation have on the peripheral pulse amplitude (PPP)? Why?
Decreases PPP. Increase in sympathetic stimulation = vasoconstriction ( increase in TPR) = Rise in arterial pressure/increase MAP & decrease in PPP
List the sequence of events beginning with hemorrhage and ending with a decrease in mean arterial pressure
Hemorrhage = decrease in venous return = decrease in EDV = decrease SV = decrease in CO = fall in MAP
How might an increase in blood viscosity affect MAP
Increase viscosity would make blood flow slower/reduces blood flow which would increase TPR and increase MAP
How does a vasoconstriction affect peripheral pulse pressure (PPP) amplitude?
PPP decreases, pulse wave gets shorter if less blood enters the capillary
List all the ways the parasympathetic nervous system acts to raise blood pressure back to normal
Parasympathetic stimulation = vasodilation (decrease TPR) = 1. Decrease in arterial pressure (decrease MAP) 2. Increase in pulse pressure (increase PPP amplitude) 3. Decrease contractility of the ventricles 4. Increase in venous vasodilation
How is laminar blood flow related to the measurement of blood pressure
The walls of the artery stop vibrating and the Korotokoff sounds disappear. The pressure in the artery when the Korotokoff sound first disappears is the diastolic blood pressure
Why does an increase in TPR cause a small amplitude PPP
because it decreases PPP
Why did cold water on the hand result in a small amplitude PPP
because the body tries to reduce heat loss by vasoconstricting the blood vessels. Vasoconstriction causes and increase in MAP which decreases PPP for a smaller amplitude
Why is no sound heard when the sphygmomanometer is not inflated
because there is no pressure on the arterial walls causing any vibrations
Explain why the PPP amplitude became small
because there was a rise in MAP
What causes the sounds of Korotcoff
blood flow is turbulent from the pressure of being stopped by the cuff and makes the walls of the artery vibrate. the vibrations of the walls cause a tapping sound
How is blood pressure measured?
by a sphygmomanometer. Cuff is placed around the person's upper arm, inflated, and then let out slowly. The pressure collapses the brachial artery in the arm
What is the first change in the cardiovascular system that occurs as a result of hemorrhage
decrease in venous return
Predict what happens to PPP when standing up from a sitting position. Be sure to determine 1. the change in MAP cause by standing up 2. the cardiovascular center's corrective response that alters MAP
increase in PPP 1. MAP will decrease because there will be a decrease in venous return. 2. stimulate parasympathetic system to vasodilate blood vessels causing a decrease in MAP and increase in PPP
When a person lies down from a standing position, what is the first change in the cardiovascular system?
increase in venous return
How does vasoconstriction affect TPR
its a small radius of blood vessel and increases TPR, slow blood leaving the arteries
How does vasoconstriction affect MAP
small radius slow blood leaving arteries blood accumulates and backs up in arteries causing MAP to increases
How does the cardiovascular center (baroreceptor reflex) respond to correct this change
vasodilation = decrease in MAP and increase in PP
What is laminar blood flow
when blood flow in the artery is smooth, brachial artery is fully open