Anatomy and Physiology II

Cardiac muscle can use fatty acids, ____ , lactic acid, amino acids, and ___ bodies as fuel sources.

Glucose; ketone

When heart rate and stroke volume increase, cardiac output ______.

Increases

The circumflex artery supplies blood to the ______ ventricle.

Left

The primitive ventricle forms most of the ___ ventricle.

Left

In which two chambers are papillary muscles found?

Left and right ventricles

What heart chamber pushes blood through the aortic semilunar valve?

Left ventricle

By day 19 (middle of week 3), two endocardial tubes form from ______ in the embryo.

Mesoderm

The movement of ______ is responsible for the depolarization phase of the action potential in cardiac muscle cells.

Na+

True or false: Neurons have a pacemaker potential.

Nodal cells have pacemaker potential.

Atrial contraction causes which to occur?

Openings of the great veins are compressed. Blood is pushed into the ventricles.

A common error is to describe arteries as the vessels that always transport ______ blood instead of describing it as a vessel that takes blood ______ from the heart.

Oxygenated; away

The wave of an ECG that reflects the electrical changes of atrial depolarization is the

P wave

Name the ridged bundles of muscle found projecting inside the right atrium.

Pectinate muscles

What is the function of the coronary circulation?

Provides blood and drainage to the heart

Identfiy the valve located at the exit of the right ventricle.

Pulmonary valve

The complex of an ECG that represents the electrical changes that are associated with ventricular depolarization is the

QRS wave

Which chamber of the heart exits into the pulmonary trunk?

Right ventricle

Rank the components of the cardiac conduction system in the order they are involved.

SA Node -> Contractile cells of the Atria -> AV Node -> AV Bundle -> Right and Left Bundle Branches -> Purkinje Fibers -> Contractile cells of the ventricles

Name the irregular ridges of muscle lining the ventricles.

Trabeculae carneae

True or False: Blood on the right never mixes with blood on the left, once the heart is fully developed.

True

True or False: The cells of the cardiac conduction system do not contract.

True; They initiate and conduct electrical signals but they do not contract.

An arterial forms ___ when more than one artery is providing blood to a given tissue.

anastomosis or anastomoses

The anterior interventricular artery (LAD) supplies the ______ wall of the left ventricle and ______ the interventricular septum.

anterior; most of

The fibrous skeleton of the heart is located between the ______.

atria and ventricles

When the ______ contract, blood is forced into the ______ through the open AV valves.

atria; ventricles

During ventricular relaxation, blood is allowed to flow through the right ______ valve into the right ventricle.

atrioventricular

The wrinkled flap-like extensions visible in the anterior view of the heart are the

auricles

The heart is innervated by the ______ nervous system.

autonomic

The atrial reflex is initiated when ___ in the atrial walls are stimulated by an increase in venous return

baroreceptors

Identify the valve found between the left atrium and left ventricle.

bicupsid, or mitral valve

The ___ valves are closed in the isovolumetric phase of the cardiac cycle.

bicuspid tricuspid mitral pulmonary semilunar

contributes to the ability of a cardiac muscle to meet its energy demands.

blood supply numerous mitochondria myoglobin creatine kinase

The time from the start of one heartbeat to the initiation of the next is called a(n)

cardiac cycle

The ______ system is responsible for the transport of blood in the body.

circulatory

Electrical activity is started at the SA node, which causes an action potential to spread through the heart through the ______.

conduction system

The ______ delivers oxygen-rich blood to the thick heart wall while the ______ carries the deoxygenated blood away from the heart wall.

coronary arteries; coronary veins

Nodal cells in the SA initiate a heartbeat by spontaneously ___ to generate an action potential

depolarizing

Name the inner lining of the heart.

endocardium

The outermost heart layer of the heart wall is the ______ and is also known as the ______ layer of the serous pericardium.

epicardium; visceral

Factors that result in an increase in venous return include ___ and a decreased heart rate.

exercise

True or False: The moderator band is found on both the right and left side of the heart.

false - right only

The _____ of the heart is formed from dense irregular connective tissue.

fibrous skeleton

The heart is a relatively small, conical organ approximately the size of a person's ______.

fist

Since it is the right side of the heart that sends blood to the lungs, blood is shunted from the right atrium to the left atrium by traveling through the ______ and pushing the septum primum to the ______.

foramen ovale; left

The ______ lies within the anterior interventricular sulcus.

great cardiac vein

Coronary arteries are considered functional end arteries and not anastomoses because ______.

if one becomes blocked there is insufficient blood flow to the tissue

The right and left ventricles are separated by the ______.

interventricular septum

The position of the interventricular septum is deep to the ______ located on the heart's superficial surface.

interventricular sulci

The contraction phase of the cardiac cycle that includes closure of the AV and semilunar valves even though the Purkinje fibers have initiated ventricular contraction is the

isovolumic phase

The interatrial septum forms a thin wall between the right and

left atria

Identify the most muscular chamber.

left ventricle

As the cardiac cycle begins, the semilunar valves are closed because the pressure exerted by the blood in the ventricles is ___ than the pressure the blood exerts in the great arteries.

lower

The pulmonary circulation includes the movement of blood to and from the ___ for gas exchange.

lungs

The right coronary artery typically branches into the right ______ artery, which supplies the lateral wall of the right ventricle, and the posterior ______ artery, which supplies the posterior surface of both the left and right ventricles.

marginal; interventricular

The cardiac center is within the

medulla oblongata

______ in the SA node are the pacemaker cells that initiate a heartbeat.

nodal cells

The pericardium of the heart includes an ______ fibrous layer and an ______ serous membrane.

outer; inner

Cardiac muscle cells contain Ca2+ pumps that keep more Ca2+ ___ the cell

outside

Which type of blood flows through the left atrium?

oxygenated

The ability to reach threshold without stimulation is called the ___ ____of the SA node.

pacemaker potential

Like the right atrium, the left atrium also has ______ in its auricle.

pectinate muscles

The posterior atrial wall is smooth, but the auricle and anterior wall exhibit obvious muscular ridges, called ______.

pectinate muscles

The heart is surrounded by a visceral and parietal ______.

pericardium

The single heart tube develops into what 4 structures?

primitive atrium bulbus cordis primitive ventricle sinus venosus

The cardiovascular system consists of two circulations: the ______ circulation and the ______ circulation

pulmonary; systemic

During atrial contraction, the atria are contracting and the ventricles are

relaxed (or filling)

What is the ligamentum arteriosum?

remnant of the ductus arteriosus

The____ atrium and ventricle are prominent when viewing the heart from the anterior view.

right

The right atrioventricular opening is covered by the ______ valve.

right atrioventricular tricuspid

The opening for the coronary sinus is located in the wall of the ______.

right atrium

In the heart, action potentials spread across the ______ of cardiac muscle cells, causing them to contract.

sarcolemma

Which of the following are part of the cardiac muscle cells?

sarcolemma myofibrils T tubules

The two categories of heart valves are

semilunar and atrioventricular

The space between the parietal layer and visceral layer of the pericardium contains ______.

serous fluid

In the embryo, since the embryonic lungs are not functional, much of the blood is ______ the lungs and to the ______ of the body.

shunted away from; rest

The heartbeat is initiated by the specialized cardiac muscle cells of the ______, which are located in the posterior wall of the right atrium, adjacent to the entrance of the ______.

sinoatrial node; superior vena cava

The ______ and primitive atrium form parts of the left and right atria.

sinus venosus

The sarcolemma of the cardiac muscle cells has fast voltage-gated ___ channels that participate in the depolarization of the cell membrane.

sodium, or Na+

Identify the three major vessels that empty into the right atrium.

superior vena cava inferior vena cava coronary sinus

The contraction of a heart chamber is called ______.

systole

The purpose for the delay in the conduction of the action potential from the AV node to the bundle branches of the ventricles is to allow ______, before the ventricles contract.

the atria to complete their contraction

Identify the right atrioventricular valve.

tricupsid valve

The right atrioventricular opening is covered by the ______ valve.

tricuspid right atrioventricular

True or false: Healthy individuals can increase their cardiac output to meet the metabolic needs of their tissues when exercising.

true

Cardiac output is defined as the amount of blood pumped by one ___ and is expressed as liters per minute.

ventricle

Heart rate is altered by stimulation of the SA node or the

AV node

The right ___ valve is forced closed when the right ventricle begins to contract, preventing blood from flowing back into the right atrium.

AV, atrioventricular, or tricuspid

The inferior, conical end of the heart is called the

Apex

The two basic types of blood vessels are ______, which carry blood away from the heart, and ______, which carry blood toward the heart.

Arteries; veins

Toward the end of ventricular filling, the left and right ______ contract simultaneously.

Atria

The posterior-superior surface of the heart is called the

Base

Passive filling of the ventricles through the open ___ valves occurs at the beginning of the cardiac cycle while the ventricles are in ___

Blank 1: AV or atrioventricular Blank 2: diastole or relaxation

The common atrium is subdivided into a left and right atrium by an interatrial septum, which consists of two parts: the septum ___ and the septum ___that partially overlap.

Blank 1: primum Blank 2: secundum

The three main components of the cardiovascular system are ___ , blood vessels, and the ___

Blood, Heart

___ shorten as a result of sarcomeres shortening.

Both cardiac and skeletal muscle cells

The volume of blood pumped by one ventricle in one minute is defined as

Cardiac Output

___ is a measure of how effective the cardiovascular system is in fulfilling its function in transporting life supporting substances through the body.

Cardiac Output

______ cells cannot exhibit tetany. (unlike skeletal)

Cardiac muscle

What fibrous structure functions to anchor the atrioventricular valves in a closed position?

Chordae tendineae

A large loss of blood would result in a(n) ___ in the venous return to the heart.

Decrease

Stroke volume(SV) is equal to --- minus ---

EDV - ESV

The amount of blood in the ventricles immediately prior to initiation of contraction is called

End Diastolic Volume

The heart wall consists of three distinctive layers:

Epicardium, myocardium, endocardium

The sarcoplasmic reticulum is more extensive in smooth muscle fibers than in skeletal muscle fibers.

False; Skeletal muscle and cardiac muscle fibers both have more extensive SR than smooth muscle fibers.

events resulting in the action potential for cardiac muscle cells

1) depolarization 2) plateau 3) repolarization

True or false: The heart myocardium is nourished primarily through the diffusion of nutrients from the blood in the heart chambers.

False; The walls do not absorb nutrients or oxygen by diffusion and are dependent on the coronary arteries to deliver them.

The average normal adult heart weighs about ______ grams.

300

During weeks ______, the single heart tube becomes partitioned into four chambers (two atria and two ventricles), and the main vessels entering and leaving the heart form.

5-8

Stroke volume (SV) in a healthy adult is approximately ______.

70mL

Which events occur during the atrial contraction and ventricular filling phase of the cardiac cycle?

SA node initiates atrial contraction. Blood flow into the atria from the veins is restricted. The ventricles have reached their EDV.