Ch 20 Heart

What is the ability to rhythmically depolarize without outside stimulation called?

Autorhythmic

The ions that affect cardiac muscle function are ----- ----- ----

Calcium Ca, Sodium Na, and Potassium K

The ------ refractory period is the time when the muscle cell cannot be further stimulated, no matter the strength of the stimulus..

absolute

atrial systole and ventricular diastole

atrial myocardium contract, pushing blood into the ventricles

The amount of blood reaching the right atrium from systemic circulation is referred to as ____

venous return *Reason: Cardiac output is the amount of blood pumped out of the ventricles per minute. Reason: Stroke volume is the volume of blood ejected by the left ventricle each contraction.

The chambers of the human heart include _

2 atria and 2 ventricles

The typical cardiac output in a resting healthy adult is ------ liters

5

Which is a typical cardiac output in a resting healthy adult?

5 liters

Under resting conditions, the normal stroke volume is approximately _____

70 ml

baroreceptor reflex in chronological order

A decrease in blood pressure within the aorta stimulates a decrease in frequency of action potential within the baroreceptors. Afferent signals sent to the medulla oblongata. Sympathetic response increases and parasympathetic response decreases. Herat rate and stroke volume increase. Response is an increase in blood pressure.

The group of autorhythmic cells in the interatrial septum of the heart that relays excitation from the atria to the ventricles is known as the

AV or Atrioventricular node

Period of isovolumetric contraction

As contraction proceeds, ventricular pressures continue to rise, but no blood flows from the ventricles because all the valves are closed. because the volume of the blood in the ventricles doesn't change, even though the ventricles are contracting.

Why does blood flow through the systemic circulation from the aorta ultimately to the right atrium?

Blood flows from high pressure to low pressure

Which autonomic system(s) innervate(s) the heart?

Both sympathetic and parasympathetic nerves

What is the difference (as in subtraction) between the maximum and resting cardiac output? Multiple choice question.

Cardiac Reserve

Identify the functional changes in the heart that occur with the normal aging process.

Cardiac arrhythmias Elevated pressures in chambers/arteries Decreased aerobic metabolism

Identify the cardiac measurements that will increase during exercise.

Cardiac output Stroke volume End-diastolic volume

Mean arterial pressure changes proportionally with changes in which variables?

Cardiac output Stroke volume Peripheral resistance

The blood vessels that supply nutrients and oxygen only to the heart muscle make up the specific type of circulation called the ______ circulation.

Coronary circulation

------- is a composite recording of all cardiac action potentials.

EKG or Electrocardiogram

True or false: The coronary circulation is made up of all of the systemic blood vessels.

F Reason: The coronary circulation pertains to the heart, so it consists of the blood vessels within the heart tissue.

True or false: The coronary circulation is made up of all of the systemic blood vessels.

FALSE: Reason: The coronary circulation pertains to the heart, so it consists of the blood vessels within the heart tissue.

True or false: A typical resting stroke volume is 5 liters per heartbeat.

False Reason: Five liters would be a typical cardiac output, whereas a typical stroke volume would be 70 milliliters.

True or false: The pumping activity of the heart rarely changes over the course of one's life.

False Reason: The heart is actually actively regulated to deal with changes in the metabolic activity of the tissues.

Place the events of the baroreceptor reflex their correct order. Start with an increase in blood pressure

Increase in blood pressure within aorta stimulates an increase in frequency of action potentials within the baroreceptors. Afferent signals are then sent to the medulla oblongata. Sympathetic responses decrease and parasympathetic increase. Heart rate and stroke volume decrease. Response is a decrease in blood pressure.

What is the double-layered sac that surrounds the heart called?

Pericardium

What must be overcome as blood travels through the vessels?

Peripheral resistance

Mean arterial pressure changes proportionally with changes in which variables?

Peripheral resistance Stroke volume Cardiac output

Define the Pulmonary Circulation vs Systemic circulation

Pulmonary Circulation: matches Choice, Transports blood from the right ventricle of the heart to the lungs for exchange of gases Transports blood from the right ventricle of the heart to the lungs for exchange of gases Systemic Circulation: Choice, Transports blood from the left ventricle to the body tissues to supply the tissues with oxygen and nutrients Transports blood from the left ventricle to the body tissues to supply the tissues with oxygen and nutrients

Diastole

Relaxation of the heart

Cardiac output is equal to which of the following?

SV x HR (stroke volume x heart rate)

ventricular repolarization

T wave represents, leads to ventricular diastole

In maintaining homeostasis, regulation of the pumping action of the heart ensures ______

The metabolic demands of tissues are maintained Reason: The pumping action of the heart is not altered to alter deliver of hormones.It is altered as metabolic demands of tissues is altered.

period of ejection

The semilunar valves are pushed open, and blood flows from the ventricles into the pulmonary trunk and aorta.

True or false: Normal aging does not substantially change the heart's ability to function at rest.

True,Reason: Age-related changes are easily compensated for under resting conditions

The strongest stimulus will not cause muscle contraction during the ______ refractory period.

absolute

A direct connection between multiple arteries that provides an alternate route of blood flow if blockage occurs is an arterial __

anastomosis

When blood pressure is measured in the brachial artery, it reflects blood pressure in the ___

aorta

When blood pressure is measured in the brachial artery, it reflects blood pressure in the ______.

aorta

What valves close at the time indicated by the circle?

atrioventricular (semilunar or tricuspid would be above

The structure that relays excitation from the atria to the ventricles is known as the ___

atrioventricular node

The chambers of the human heart are the right and left ------ ant the right and left ------

atrium ; ventricles

The cardiac muscle cells are described as ______ because individual cells can depolarize on their own without outside stimulation.

autorhythmic

beginning of cardiac cycle

av valves are open and semilunar valves are closed

Mean arterial pressure is defined as the _____.

average pressure in the aorta

The ------ valve and the ---- valve close at the same time of low pressure

bicuspid/mitral/AV/ Right atrioventricular and the tricuspid/Left atrioventricular

Period of isovolumetric relaxation

blood begins to flow back toward the ventricles, causing the semilunar valves to close. With closure of the semilunar valves, all the heart valves are closed, and no blood flows into the relaxing ventricle during this period.

At a given point in time, blood flows in the heart from ___

both atria to both ventricles (CO2 blood from R atrium to R ventricle then to lungs back into heart via left atrium then into the left ventricle then O2 blood to body ; the blood enters the heart from both atriums then the ventricle chambers take it in, close and push with their muscle to go out to the lungs or out the body

the difference between the maximum cardiac output and resting cardiac output is known as the ------- reserve

cardiac

The __ is a repeating series of contraction and relaxation events that move blood through the heart.

cardiac cycle

The sequence of events that begins with heart muscle contraction and ends with the beginning of the next contraction is called the ----- -------

cardiac cycle

What is the volume of blood ejected by the ventricles per minute called?

cardiac output

Mean arterial pressure is equal to _____

cardiac output times peripheral resistance

Mean arterial pressure is equal to ______.

cardiac output times peripheral resistance

t is important to know the location of the heart for ____

cardiopulmonary resuscitation applying leads for ECG listening to heart sounds

An organ or cell specialized to detect chemicals is classified as a

chemoreceptor

The input for the reflex response to blood pH comes from the ______ in the large arteries, which detect changes in blood chemicals.

chemoreceptors

Systole means

contraction

Colder body temperatures will result in a(n) ______ in heart rate.

decrease

During surgical procedures, the body temperature can be ______ to minimize blood flow.

decreased

Cardiac output is the volume of blood ______.

ejected by the ventricles per minute

What controls the opening of the ion channels in cardiac muscle cells during phases of the action potential?

electrical changes

Venous return increases the _____

end-diastolic volume

The three layers of the heart wall from deep to superficial are the

endocardium, myocardium, and epicardium

True or false: During one heartbeat, blood flows from the right atrium to the right ventricle, and during the next heartbeat, blood flows from left atrium to left ventricle.

false, Blood flows from both atria to both ventricles during each heartbeat.

at rest most pressure changes occur due to passive pressure changes resulting from opening and closing of

heart chambers

Regular aerobic exercise improves the heart's functional capacity ____

in all ages

An increase in venous return to the heart leads to a(n) ______ in preload and therefore a(n) ______ in stroke volume.

increase, increase

Increasing exercise will cause ____

increased heart rate increased stroke volume increased cardiac output

When mechanisms within the heart regulate cardiac output, it is referred to as _____ regulation.

intrinsic

The average pressure in the arteries is the _____.

mean arterial pressure

The electrical charge difference between the inside and outside of the plasma membrane in excitable cells is referred to as the resting membrane-----------potential.

membrane

The membrane potential when a cardiac muscle cell is relaxed is the resting __

membrane potential

An increase in stimulation by what branch of the nervous system lowers the heart rate?

parasympathetic

time period when blood is passively moving into ventricles is called

passive ventricular filling

The ------ is a doubled-walled sac enclosing the heart

pericardium

The mean arterial pressure is dependent on two factors: cardiac output and the force against which blood must be pumped or

peripheral resistance

Blood is transported from the right ventricle to the lungs for gas exchange and returned it to the left atrium of the heart by the--------- circuit, while blood is transported from the left ventricle to supply the tissues of the body with oxygen and nutrients by the--------circuit.

pulmonary ; systemic

atrial diastole

relaxation of the atrial myocardium

The amount of blood pumped during each heartbeat is called the------ -----

stroke volume

___ is the volume of blood ejected from the heart with each beat.

stroke volume

when systole and diastole are used alone

they refer to the ventricular myocardium

Cardiac output is equal to stroke volume ______ heart rate.

times

True or false: Systolic and diastolic blood pressures reflect pressure changes in the aorta.

true, Reason: Systolic and diastolic blood pressures measured in the brachial artery clinically reflect blood pressure in the aorta.

The heart sounds are made by the action of which of the following?

valves

Electrical changes across the membrane cause the opening and closing of -------gated ion channels..

voltage

Intrinsic regulation of cardiac output results from mechanisms ______ the heart

within