Chapter 18: dynamic mods&hw

Supplies blood to the lateral right side of the myocardium

Right marginal artery.

The normal pacemaker of the heart is the __________.

SA node

Which term describes an area of the heart conduction system with the fastest depolarizing pacemaker cells?

SA node

Choose the correct sequence of current flow through the intrinsic conduction system of the heart.

SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network

Amount of blood ejected by one contraction of the heart

SV

The base of the heart is located at the

top of the heart

Which term describes an area of the heart conduction system where the impulse is delayed for 0.1 sec?

AV node

Prevents backflow of blood into the left ventricle

The aortic semilunar valve

Identify the correct sequence of blood flow through the chambers of the heart.

Right atrium, right ventricle, lungs, left atrium, left ventricle

What is the name of the two receiving chambers of the heart? __________

atria

P wave

atrial depolarization

The ability of some cardiac muscle cells to initiate their own depolarization and cause depolarization of the rest of the heart is called __________.

automaticity

What makes the heart valves open and close?

blood pressure

The major pumping chambers of the heart are ________.

both ventricles

The events associated with blood flow through the heart during one complete heartbeat

cardiac cycle

The lining of the heart chambers is called the __________.

endocardium

Which of the following structures lies on the outside surface of the heart and is an integral part of the heart wall?

epicardium

Match the area of the heart with the "exit" through which the blood leaves: Left atrium.

mitral (bicuspid) valve

Which of the following valves is most often faulty in the heart?

mitral, or bicuspid, valve

The ________ is/are a bundle of cardiac muscle fibers connecting the interventricular septum to anterior papillary muscles.

moderator band

If the SA node is not functioning, an ECG will show ________.

no P waves with a HR between 40-60 bpm

Which of these muscles is particularly associated with anchoring the right and left atrioventricular valves?

papillary muscles

The inner lining of the fibrous pericardium is formed by the

parietal layer of serous pericardium.

The inferior vena cava brings blood from the lower regions of the body and empties into the __________.

right atrium

The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.

vagus

The trabeculae carneae are located in the __________.

ventricles

QRS complex

ventricular depolarization

T wave

ventricular repolarization

The superior chambers of the heart are called the

atria

The coronary arteries receive blood from the _______.

aorta

What is the ligamentum arteriosum?

remnant of ductus arteriosus

Which of the following is a role of the pericardium?

(1) protects the heart, (2) anchors it to surrounding structures, and (3) prevents overfilling of the heart with blood

What is the purpose of the chordae tendineae?

Anchor the AV valves in the closed position

Supplies blood to the interventricular septum and anterior walls of both ventricles

Anterior interventricular artery.

Match the area of the heart with the "exit" through which the blood leaves: Left ventricle.

Aortic semilunar valve

Amount of blood pumped out by each ventricle in 1 minute

Cardiac output (CO)

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

Chordae tendineae

Amount of blood in the ventricle at the end of relaxation

EDV

the amount of blood in the ventricle at the end of contraction.

ESV

Which is the correct sequence of layers in the heart wall, starting with the outer layer?

Epicardium, myocardium, endocardium

The left atrium receives blood from which of the following structure(s)?

Pulmonary veins

A doctor puts his stethoscope on a patient's chest over the location of the heart and hears a swishing sound. Which of the following conditions is the best diagnosis for the patient's condition?

Incompetent cardiac valve

Which of the following factors gives the myocardium its high resistance to fatigue?

Large number of mitochondria in the cytoplasm

Into which chamber of the heart do the pulmonary veins deliver blood?

Left atrium

What muscles prevent the atrioventricular valves from everting during ventricular contraction?

Papillary muscles

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

Pectinate muscles

Prevents backflow of blood into the right ventricle

Pulmonary semilunar valve

The right ventricle sends blood into the _____________

Pulmonary trunk

What part of the heart is considered the systemic circuit pump?

The left ventricle

Name the irregular ridges of muscle lining the ventricles.

Trabeculae carneae

Which of the following is a difference between cardiac muscle and skeletal muscle?

Unlike skeletal muscle cells, cardiac muscle has gap junctions between cells (that allow them to be autorhythmic).

The __________ are attached to the AV valve flaps.

chordae tendineae

Supplies blood to the left atrium and posterior walls of the left ventricle

circumflex artery

The second heart sound (the 'dup' of 'lub-dup') is caused by the __________.

closure of the semilunar valves

Systole is the term for

contraction

The vessels that carry oxygen to the myocardium are called __________.

coronary arteries

The cells of the myocardium behave as a single, coordinated unit called a __________.

functional syncytium

The plateau phase of an action potential in cardiac muscle cells is due to the ________.

influx of Ca2+ through slow Ca2+ channels

Sharply decreased blood volume would

lead to a decrease in heart rate

The interventricular septum forms a dividing wall between the __________.

left and right ventricles

Freshly oxygenated blood is delivered to the __________ and then it passes into the __________ to be pumped to the entire body.

left atrium; left ventricle

The walls of the __________ are thicker than the walls of any other heart chamber.

left ventricle

What heart chamber pushes blood through the aortic semilunar valve?

left ventricle

During systemic circulation, blood leaves the __________.

left ventricle and goes directly to the aorta

When the mitral valve closes, it prevents the backflow of blood from the __________.

left ventricle into the left atrium

Guided by powerful signaling molecules, the human heart develops from __________.

mesoderm

The atrioventricular (AV) heart valves open and close ________.

passively, depending on the pressure of the blood in the atria and ventricles

The heart is enclosed in a double-walled sac called the __________.

pericardium

Runs to the apex of the heart

posterior interventricular artery

The degree to which cardiac muscle cells are stretched just before they contract

preload

Match the area of the heart with the "exit" through which the blood leaves: Right ventricle.

pulmonary semilunar valve

The valve separating the right ventricle and pulmonary trunk is the

pulmonary semilunar valve.

Two from each lung carry blood into the left atrium

pulmonary veins

During pulmonary circulation, blood leaves the __________.

right ventricle and moves to the lungs

The "pacemaker potential" of pacemaker cells is produced by the opening of ________ at the end of an action potential.

slow Na+ channels Submit

The role of the atrioventricular node (AV node) is to __________.

slow down impulses so that the atria can contract to fill the adjacent ventricles with blood

The endocardium is composed of __________.

squamous epithelium

A condition in which the valve flaps of the heart become stiff and constrict the opening is called _________.

stenosis

While auscultating heart sounds during a checkup, Andy's doctor hears a high-pitched sound during ventricular contraction. Which type of valve could cause this?

stenotic aortic semilunar valve

Blood has just been discharged into the pulmonary trunk: from which chamber did it exit?

the right ventricle

Match the area of the heart with the "exit" through which the blood leaves: Right atrium.

tricuspid valve

Blood flows through the heart in one direction—from the atria to the ventricles. t/f

true

Blood on the right never mixes with blood on the left, once the heart is fully developed. t/f

true