ch 17 heart

At what point in the cardiac cycle does the semilunar valve close?

when pressure in the ventricle becomes less than aortic pressure. When pressure in the ventricle drops below aortic pressure, the semilunar valve shuts. This prevents blood from flowing backward through the heart.

At what point in the cardiac cycle does the semilunar valve open?

when ventricular pressure becomes greater than aortic pressure. When pressure in the ventricle exceeds pressure in the aorta, the semilunar valve opens. This allows blood to be ejected from the ventricle.

At what point during the cardiac cycle does the AV valve close?

when ventricular pressure becomes greater than atrial pressure

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

Bicuspid (mitral) valve. The atrioventricular valve on the left is the bicuspid valve. The mitral valve is also called the mitral valve.

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

Bicuspid valve

The moderator band is found on both the right and left side of the heart. (T/F)

FALSE. The moderator band is a cord like structure found in the right ventricle. It contains portions of the cardiac conduction system that help convey the electrical message for the ventricles to contract. It works as a shortcut within the cardiac conduction system.

Epicardium

Inner layer of pericardium (called the visceral layer)

Endocardium

Inner lining of the heart. Glistening white sheet of endothelium lining on the inside of the heart

Oxygenated blood flows through the_____ side of the heart.

LEFT Oxygenated blood returning from the lungs is received by the left atrium, then to the left ventricle before being pumped out to the body. This pathway of blood flow is known as the systemic circulation.

Oxygen Rich blood

Left atrium, pulmonary vins, left ventricle, aorta

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

Left atrium. * The pulmonary veins deliver blood to the left atrium.

Identify the most muscular chamber.

Left ventricle The left ventricle is responsible for pumping blood out to the body. This requires a lot of force. The left ventricle is the most muscular in order to pump the blood with adequate force.

What heart chamber pushes blood through the aortic semilunar valve?

Left ventricle. The aortic valve is located between the left ventricle and the aorta. The left ventricle pumps oxygenated blood out of the heart through the aortic valve to the body.

Myocardium.

Middle layer of the heart, composed mainly of cardiac muscle

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

Pectinate muscles (the pectinate muscles are ridge like elevations of muscle. They are parallel to each other and resemble teeth of a comb. They are easily observed inside the right atrium.)

Aortic semilunar valve.

Prevents backflow of blood into the left ventricle

What is the function of the coronary circulation?

Provide a blood supply to the heart (The coronary circulation provides oxygenated blood to the heart through coronary arteries. Coronary veins return the deoxygenated from the heart to the coronary sinus on the posterior surface of the heart. The coronary sinus empties the deoxygenated blood directly into the right atrium where it joins deoxygenated from the body.)

Which of the following statements is NOT true about the shape, position, and location of the heart?

The heart is enclosed in a double-layered sac called the pleural membrane

What is happening during the "pause" phase when the heart is resting (relaxing)?

Ventricles are filling.

What does the QRS wave of the electrocardiogram (ECG) represent?

Ventricular depolarization is represented by the QRS complex of an ECG.

arrange them, from left to right, in order of blood flow of oxygen-rich blood into the heart.

lung capillaries Pulmonary veins Left atrium Mitral/bicuspid valve Left ventricle Aortic/semilunar valve

The heart is located in a subdivision of the thorax called the

mediastinum

What is the name of the circuit that supplies blood to the brain, heart, and gastrointestinal tract?

systemic circulation

Most of the decrease in ventricular volume takes place during which phase of the cardiac cycle?

ventricular ejection. As the ventricles contract, blood is forced through the semilunar valves and out into the arteries, resulting in a reduction in ventricular blood volume. At the end of this phase, ventricular volume is at a minimum−the "end-systolic volume" (ESV).

Ventricular pressure is greater than aortic pressure during which phase of the cardiac cycle?

ventricular ejection. While pressure in the ventricle is greater than pressure in the aorta, the semilunar valve remains open. This allows blood to be ejected from the ventricle.

Most of the increase in left ventricular volume takes place during what phase of the cardiac cycle?

ventricular filling. During ventricular filling the AV valves remain open, which allows blood to flow from the atria into the ventricles. The passive flow of blood during this phase (before atrial contraction) accounts for roughly 80 percent of the increase in ventricular volume.

At what point in the cardiac cycle does the AV valve open?

when atrial pressure becomes greater than ventricular pressure. Blood flows through the heart in one direction (atria-ventricles-large arteries) and from high to low pressure. When pressure in the atrium becomes greater than ventricular pressure, the AV valve opens; and blood flows from the atrium into the ventricle.

Indicate the valve separating the following areas of the heart: Left atrium and left ventricle.

Bicuspid (mitral) valve

Which of the following is equivalent to the ventricular volume during isovolumetric contraction?

The end diastolic volume (EDV)

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

The left ventricle

The structure that prevents backflow of blood into the left atrium is the

mitral (bicuspid) valve

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

moderator band

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

the mitral, or bicuspid, valve

The endocardium is composed of

- simple squamous epithelium.

How many chambers make up the human heart?

4

ligamentum arteriosum

A remnant of the ductus arteriosus ( ligamentum arteriosum is a remnant of the ductus arteriosus. The ductus arteriosus is a fetal shunt that connects the pulmonary trunk to the aorta.)

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

Aortic semilunar valve

Identify the ear like flaps that are attached to the top chambers of the heart.

Auricle (auricles are flap like extensions of the atria that are observed on the external surface of the heart.)

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

Chordae tendineae. Chordae tendineae are the fibrous cords that attach the atrioventricular valves to papillary muscles. They help anchor the atrioventricular valves in a closed position during ventricular contraction.

Pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium. a vein carrying oxygenated blood from the lungs to the left atrium of the heart.

Name the inner lining of the heart.

Endocardium. Correct. The endocardium is the smooth, slick lining of the chambers of the heart. Endocardium is a continuation of endothelium that lines blood vessels. Both endocardium and endothelium are composed of simple squamous epithelial tissue, which minimizes friction between the wall of the chamber/vessel and the blood.

brachiocephalic artery

In both the sheep and human, the brachiocephalic artery is the first major vessel to exit the arch of the aorta. Further branching of the brachiocephalic artery and the arch of the aorta differs between a sheep and a human.

Which of the following is true during ventricular systole?

The AV valves are closed.

Isovolumetric relaxation is characterized by which of the following?

The semilunar and AV valves are closed. During isovolumetric relaxation, all valves into and out of the ventricles remain closed. This prevents blood from flowing backward through the heart.

During the ventricular ejection phase of the cardiac cycle, which of the following is true?

The semilunar valves are open.

When the atria contract, which of the following is true?

The ventricles are in diastole

How do the highlighted valve cusps function during a ventricular contraction?

They are held closed by the chordae tendineae to prevent blood from flowing back into the right atrium.

Name the needle like ridges of muscle lining the ventricles.

Trabeculae carneae. Trabeculae carneae are the small elevated ridges of muscle arranged in a web type fashion found in both the right and left ventricles.

The vessel that carries oxygen-rich blood to tissues is the

aorta

Blood Flow through the Heart

aorta to smaller systemic arteries to systemic capillaries to systemic veins to right atrium through the tricuspid valve. All systemic veins return oxygen-poor venous flow to the right atrium, through the tricuspid to the right ventricle, and up and out the pulmonary semilunar valve to the pulmonary trunk and pulmonary arteries to the capillaries of the lungs. Returning oxygen-rich blood flowing through pulmonary veins enters the left atrium, passes through the mitral valve to the left ventricle, and flows out through the aortic semilunar valve into the aorta and on to systemic capillaries.

Indicate the valve separating the following areas of the heart: left ventricle and aorta.

aortic semilunar valve

Atrial pressure is greater than ventricular pressure during which phase of the cardiac cycle?

atrial contraction. Blood always flows from high to low pressure. During atrial contraction, blood flows from atria (high pressure) to ventricles (low pressure). Similarly, this same pressure gradient exists during ventricular filling.

Tricuspid valve

atrioventricular valve located on the right side of the heart. It separates the right atrium from the right ventricle.

aortic semilunar

between left ventricle and aorta

What causes the abnormal swishing or whooshing sound that is heard as blood regurgitates back into an atrium from its associated ventricle?

blood turbulence

The major pumping chambers of the heart are

both ventricles

Identify the three branches of the highlighted vessel.

brachiocephalic trunk, left common carotid artery, left subclavian artery

three branches of the aorta arch

brachiocephalic trunk, left common carotid artery, left subclavian artery

The vessels that carry oxygen to the myocardium are called

coronary arteries

Which of the following is equivalent to the ventricular volume during isovolumetric relaxation?

end systolic volume (ESV). Isovolumetric relaxation occurs at the beginning of ventricular diastole when the ventricular volume is at its minimum value−the end systolic volume (ESV). Because no volume changes occur during isovolumetric relaxation, ventricular volume remains at this value throughout the phase.

heart wall layers

epicardium, myocardium, and endocardium

The pericardial sac that encloses the heart is a two-layered structure. The outer layer is the ________.

fibrous pericardium

In what direction does blood flow through the heart?

from a region of high pressure to a region of low pressure. Blood moves through the heart from atria to ventricles and out large arteries, always from areas of high pressure to areas of lower pressure through one-way valves.

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

left atrium; left ventricle

Cardiac muscle tissue ________.

is striated, like skeletal muscle tissue

myocardium

layer of the heart wall contracts and is composed primarily of cardiac muscle tissue. composed of cardiac muscle and a dense network of connective tissue.

Which artery supplies the anterior ventricular walls and laterodorsal part of the left side of the heart?

left coronary artery

The chamber of the heart that takes up the most volume is the is the

left ventricle

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

left ventricle into the left atrium

Which chamber of the heart sends oxygenated blood to the systemic circuit via the aorta?

left ventricle. sends blood to the systemic circuit via the aorta and its branches.

endocardium

lines the inside of the heart. Its surface is composed of simple squamous epithelium.

mitral valve

located between the left atrium and left ventricle

Which of the following is a branch of the right coronary artery?

posterior interventricular artery. posterior interventricular artery is a branch of the right coronary artery, although an anastomosis with the circumflex artery meets with it near its origin.

A blockage in which of these vessels could cause a myocardial infarction in the lateral right side of the heart?

right marginal artery

Which chamber of the heart exits into the pulmonary trunk?

right ventricle

right ventricle (FUNCTION)

right ventricle pumps deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk to be distributed to the lungs.

Oxygen Poor

superior vena cava, right ventricle, right atrium, pulmonary arteries

. The capillaries receiving blood flow from the left side of the heart are the

systemic capillaries

Pulmonary semilunar valve

the valve located at the exit of the right ventricle.

The highlighted structure consists of ___.

three semilunar cusps

What is the main function of heart valves?

to prevent backward flow of blood

The base of the heart is located at the _____

top of the heart

The __________ valve is located between the right atrium and the right ventricle.

tricuspid valve

Blood on the right never mixes with blood on the left, once the heart is fully developed. (T/F)

true. Once fetal modifications (i.e. foramen ovale, ductus arteriosus) close following delivery of the infant, blood on the right side of the heart should not mix with blood on the left side of the heart.

The portion of the pericardium that covers the heart wall is called the ________.

visceral layer (epicardium)

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

aortic semilunar valve

The structure that is located anatomically between the aorta and the left ventricle is the

aortic semilunar valve