BMS 302 10

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

Mean arterial pressure must be homeostatically maintained..

to insure adequate perfusion of all vascular beds.

 

to insure sufficient pressure so that the forces of gravity can be overcome.

 

to prevent one from passing out if the brain is insufficiently perfused.

 

to allow one to change positions such as going from reclining to standing without feeling faint.

through the baroreceptor reflex.

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

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

If heart rate doubles and stroke volume doubles, cardiac output will:

4X

Which of the following factors can affect stroke volume?

1. End diastolic volume

2. venous return

3. heart rate

4. ejection fraction

5. ventilation

6. exercise

7. SAN simulation

what principle does this graph represent

Starling's Law, which is an intrinsic autoregulation mechanism that matches cardiac output to venous return.

what is responsible for adjusting mean arterial pressure on a moment to moment basis

the baroreceptor reflex

venous valves functions

1. prevents blood from pooling in extemities

2. assist in reducing the effect of hydrostatic pressure on blood returning to the heart

3. when impaired, are the cause of varicose veins

List three mechanisms the body has developed to maintain the return of blood (venous return) to the heart from the extremities.

1. skeletal muscle pump

2. thoracic pump

3. venoconstriction

Which of the following facilitates venous return?

1. increase in venous tone

2. skeletal muscle pump

3. thoracic pump

4. fainting

5. postural changes like lying down w/ feet up

skeletal muscle pump

muscle contraction squeeze veins forcing blood back toward the heart past one way valves

thoracic pump

negative pressure in chest '“pull” blood into the thorax and heart w/ each inhalation

venoconstriction

smooth muscle in the elastic venous vessels contracts forcing blood from the venous system back toward the heart

What branch of the Autonomic Nervous System innervates the veins?

SANS

What autonomic output leads to venoconstriction?

increased SANS

What is the effect of venoconstriction on venous return?

increases

What autonomic output leads to venodilation?

decreased SANS

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.

1. viscosity

2. length

3. diameter

Which of the following vessels play 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

With a generalized vasoconstriction of arterioles..

1. mean arterial blood pressure increases.

2. peripheral resistance increases

3. blood vessels decrease in diameter

4.  blood flow "downstream" from the vasoconstriction decreases

5. diastolic pressure increases

What branch of the Autonomic Nervous System innervates the arterioles?

SANS

What is the effect of arteriolar vasoconstriction on peripheral resistance?

increases

What autonomic output leads to arteriolar vasoconstriction?

increased SANS

What autonomic output leads to arteriolar vasodilation?

decreased SANS

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

Veins and arterioles are in a partially contracted state under rest and repose conditions.

called sympathetic tone

The partially contracted state is the result of a tonic sympathetic stimulation of the smooth muscle in the walls of the vessels.

Under Fight or Flight conditions:

1. Increased Sympathetic Nervous System stimulation causes arterioles controlling blood flow to visceral organs to constrict.

2. Blood flow to visceral organs decreases.

3. Metabolic by-products from contracting skeletal muscle causes a local vasodilation of arterioles in skeletal muscle.

4. Blood flow to active skeletal muscle increases.

Match the component of the baroreflex arc induced when one goes from a reclining to a standing position listed in the left column with the best description in the right column.

1. stimulus- decreased MAP

2. receptor- baroreceptors located in carotid artery and aortic arch

3. afferent pathway- decreased frequency of impulses along sensory neurons

4. integrator- cardiac and vasomotor centers of medulla

5. efferent pathways- sympathetic neurons to heart & vessels and parasympathetic neurons to heart

6. effectors- cardiac muscle and smooth muscle of vessels

7. response- increased MAP

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

hypertension

is diagnosed when blood pressure readings exceed 140/90