Unit 3 Exam Lab 10 Flashcards
When taking a blood pressure, the first sound that you hear represents the _____, and is the pressure that is generated during _____.
systolic reading; contraction of the ventricles
As the heart to brain distance becomes greater, the MAP at the level of the heart _____ , while the MAP at brain level _____ when compared with different species.
increases; remains about the same
What are the three equations for MAP?
MAP=COxPR
MAP=HRxSVxPR
MAP=((Ps-Pd)/3)+Pd
Systolic blood pressure is reflected or influenced by _____, whereas diastolic pressure is reflected by _____.
cardiac output; peripheral resistance
You are measuring the blood pressure in a patient using a sphygmomanometer. You could detect an increase in venoconstriction by observing _____________, and you could detect an increase in vasoconstriction of the arterioles by observing ______________.
an increase in systolic pressure; an increase in diastolic pressure
Which of the following factors can affect stroke volume?
-end diastolic volume
-venous return
-heart rate
-ejection fraction
-peripheral resistance
-ventilation
-exercise
-sympathetic stimulation
Everything put peripheral resistance
Which answer about venous valves is false?
prevent blood from pooling in the extremities.
prevent blood from flowing toward the heart.
assist in reducing the effect of hydrostatic pressure on blood returning to the heart.
when impaired are the cause of varicose veins.
prevent blood from flowing toward the heart.
What three mechanisms has the body developed to maintain the return of blood (venous return) to the heart from the extremities?
- skeletal muscle pump
- thoracic pump
- venoconstriction
skeletal muscle pump
muscle contraction squeezes veins which forces blood back to the heart through one way valves
thoracic pump
negative pressure in chest pulls blood to the thorax/heart during each inhalation
venoconstriction
smooth muscle contraction in venous vessels forcing blood back to the heart
What branch of the Autonomic Nervous System innervates the veins?
sympathetic
What autonomic output leads to venoconstriction?
increased sympathetic
What is the effect of venoconstriction on venous return?
increases
What autonomic output leads to venodilation?
decreased sympathetic
What is the effect of venodilation on venous return?
decreases
Increased sympathetic activity stimulates the smooth muscle (effector) in the wall of the veins to ________ and therefore ______ the diameter of the vessel.
contract; decrease
List three factors that can alter peripheral resistance
Length, viscosity, and diameter
Which vessel plays the most important role in altering peripheral resistance?
arterioles
Decreased sympathetic activity stimulates the smooth muscle (effector) in the wall of the veins to ________ and therefore ______ the diameter of the vessel.
relax; increase
Vasoconstriction of arterioles will have what effect on MAP, PR, flow, diameter, Pd, and Ps
MAP, Pd, Ps, PR increases
Diameter/flow decreases
What branch of the Autonomic Nervous System innervates the arterioles?
sympathetic
What is the effect of arteriolar vasoconstriction on peripheral resistance?
increases
What autonomic output leads to arteriolar vasoconstriction?
Increased Sympathetic
