Chapter 21 Mastering

Part D Which of the following structures can only be seen using a posterior view of the heart?

Coronary sinus

Part A Which of the following contain oxygenated blood?

Left atrium, pulmonary veins, and aorta (The left atrium, pulmonary veins, and aorta all contain oxygenated blood. Remember that the right ventricle and superior vena cava do not contain oxygenated blood.)

Which number represents the structure that allows the atria to complete its contraction prior to initiation of the ventricular contraction?

3 (Conduction through the atrioventricular node is slow; thus, the atria are able to complete contraction before the electrical signal travels to the ventricles.)

In what way does cardiac muscle differ from skeletal muscle?

Cardiac muscle relies heavily on aerobic respiration, whereas skeletal muscle can function for a time in anaerobic conditions.

Part B Which vessel(s) brings blood to the heart?

Pulmonary veins (The pulmonary veins bring oxygenated blood to the heart. Remember that oxygenated blood is ejected away from the heart in the aorta.)

Which of the following statements is true of the myocardium?

The cells of the myocardium are linked by specialized junctions called intercalated discs.

Which layer of the heart is continuous with the parietal pericardium?

epicardium

The sinoatrial and atrioventricular nodes __________.

establish cycles of contraction and relaxation for the myocardium

In comparison, the right atrium and ventricle __________.

generate less pressure for contraction than the left atrium and ventricle

Part A In anatomical position the

heart lies slightly to the left of midline.

The endocardium __________.

is continuous with the inner lining of the aorta

Oxygenated blood returns to the heart from the lungs and enters the __________.

left atrium (The right atrium receives only deoxygenated blood.)

Part C The coronary sulcus

marks the border between the atria and ventricles.

What is the purpose of the chordae tendineae?

to keep the atrioventricular valves shut during ventricular contraction

Part C - Does the Heart Rest? After studying the diagram "The Phases of the Cardiac Cycle," estimate the amount of time between the beginning of one heart beat to the next heart beat for which all heart muscle relaxes.

During ventricular diastole, there is a period of time when both chambers relax for about ½ the complete cardiac cycle.

Part B - Phases of the Cardiac Cycle How are chamber pressure, blood flow, and arterial pressure related to the cardiac phases, systole, and diastole?

Systole: high chamber pressure, blood ejection, high arterial pressure Diastole: low chamber pressure, blood filling chamber, low arterial pressure

Part B Which of the following correctly describes the borders of the heart?

The right ventricle forms the inferior border of the heart.

The most inferior point of the left ventricle can be found at the __________ of the heart.

apex

In the pulmonary circuit, __________.

arteries carry deoxygenated blood

Which of the following is a major component of the conduction system located in the interventricular septum, and extends toward the apex of the heart?

bundle branches

Art-labeling Activity: The autonomic innervation of the heart

https://gyazo.com/06457200168890d85daa91b756130daa

Art-labeling Activity: Coronary Circulation

https://gyazo.com/0c933f96fb540cd8d54677e095bef5c9

Art-labeling Activity: A three-dimensional view of cardiac muscle cells

https://gyazo.com/0ff53b38714fb8578656ff535099e4f7

Part D Match the labels in the diagram of the cardiac conduction system to the descriptions below.

https://gyazo.com/156c543a2fdb05c21748aa0da449ccd6

Art-labeling Activity: Histological organization of muscle tissue in the heart wall

https://gyazo.com/cc157b69da112db86083df96fb19e8ab

Art-labeling Activity: Valves of the heart

https://gyazo.com/ffe43460030a31342af1e7d8c353ed80

When blood leaves the lungs and returns to the heart, it enters the __________.

left atrium

A damaged mitral valve would affect the flow of blood into the __________.

left ventricle

Part A - Components of the Conducting System The two basic components of the cardiac conducting system that cause autorhythmicity is a network of __________, which initiate and pace contractions and the __________, which distribute the electrical impulses to cardiac muscle fibers.

nodal cells; conducting fibers

A blockage in the pulmonary trunk would first affect which heart chamber with a buildup of blood?

right ventricle

Part D Looking at this figure of the heart, it is evident that

the left ventricle has the thickest myocardium of all of the chambers.

Which of the heart's chambers is responsible for sending blood to the lungs to pick up oxygen?

the right ventricle

If a disease were to cause the corrosion of the fibrous skeleton of the heart, which of the following would NOT be affected?

the sizes of the veins in the systemic circuit

Part C The valve found between the right atria and right ventricle is the

tricuspid.

Part E Which of the following correctly identifies the path that blood takes on its way through the heart?

Right atria, right ventricle, pulmonary trunk, and pulmonary arteries

Damage to the internodal pathways would NOT affect the function of the __________.

SA node