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
What autonomic output leads to arteriolar vasodilation?
Decreased Sympathetic
What is the effect of arteriolar vasodilation on peripheral resistance?
decreases
Increased sympathetic activity stimulates the smooth muscle (effector) in the wall of the arterioles to ________ and therefore ______ the diameter of the vessel.
contract; decrease
Decreased sympathetic activity stimulates the smooth muscle (effector) in the wall of the arterioles to ________ and therefore ______ the diameter of the vessel.
relax; increase
Under Fight or Flight conditions:
Blood flow to visceral organs decreases
Blood flow to active skeletal muscle increases
During moderate exercise, systolic pressure increases because cardiac output _____ and diastolic pressure is maintained close to resting levels or decreases as blood flow to exercising skeletal muscle _____, and blood flow to the digestive tract _____.
increases; increases; decreases
Starling’s Law
Intrinsic autoregulation mechanism that matches cardiac output to venous return
Sympathetic tone
Veins and arterioles are in a partially contracted state under rest and repose conditions.
The partially contracted state is the result of a tonic sympathetic stimulation of the smooth muscle in the walls of the vessels.
Baroreflex arc stimulus
Decreased MAP
Baroreflex arc receptor
Baroreceptors
Baroreflex arc afferent pathway
Decreased sensory neuron impulses
Baroreflex arc integrator
Medulla
Baroreflex arc efferent pathway
Sympathetic neurons: heart/vessels
Parasympathetic neurons: heart
Baroreflex arc effectors
Cardiac and smooth muscle of the vessels
Baroreflex arc response
Increases MAP
