Ch 15 Lecture

Complete each sentence, and then place them in the correct order to describe blood flow through the heart, beginning with blood entering the right side of the heart.

1. Beginning with the return from the systemic circulation, blood enters the right atrium. 2. Blood then travels through the tricuspid valve and into the right ventricle. 3. The right ventricle contracts, which forces blood up through the pulmonary valve and into the pulmonary trunk. 4. After circulating through the pulmonary circulation, blood returns to the heart at the left atrium. 5. Then the blood moves through the left atrioventricular valve, which is also referred to as the bicuspid valve. 6. The left ventricle then contracts and pumps blood through the aortic valve into the aorta, which transports blood to the body.

Complete each sentence discussing the cardiac conduction system. Then place the sentences in the correct order to follow the path of impulses through the heart.

1. The contraction of the heart begins with an autorhythmic impulse of the sinoatrial node located in the superior portion of the right atrial wall. 2. From the pacemaker , the impulse disperses through the myocardium of the atria. 3. The impulse then arrives at the atrioventricular node located in the inferior interatrial septum. 4. The AV node fires, causing the signal to travel into the AV bundle and AV bundle branches which pass through the interventricular septum. 5. Making a U-turn at the apex of the heart, the signals are then carried by the Purkinje fibers through the exterior walls of the ventricles.

Complete the sentences describing the vessels of the cardiovascular system. Then put the sentences in order of blood flow through the body.

1. The function of the cardiovascular system is to transport fluids. The heart provides pressure to pump the fluids into the largest systemic artery, called the aorta, and out to the body. 2. After the leaving the heart, the vessel will branch to become progressively smaller arteries, which are strong vessels adapted for carrying blood away from the heart. 3. These vessels will continue to branch into thinner microscopic tubes called the arterioles. 4. The smallest vessels, the capillaries, are the sites of gas, nutrient, and waste exchange. 5. The exchange vessels become larger vessels known as venules, which converge into even larger vessels known as veins. 6. The largest veins in the body, the venae cavae, drain blood back into the heart.

Complete the sentences describing the coverings of the heart. Then place the structures in order from superficial to deep.

1. The outer layer of the pericardium is called the fibrous pericardium and is composed of dense connective tissue. 2. The parietal pericardium lines the previous layer and secretes serous fluid. 3. The fluid is contained within the pericardial cavity. 4. Covering the outer surface of the wall of the heart is the visceral pericardium, which is also called the epicardium.

Complete the following sentences describing the location of the valves in relationship to the chambers of the heart. Then place the sentences in order of blood flow, starting with oxygen-poor blood returning to the the heart.

1. The tricuspid valve is located between the right atrium and right ventricle. 2. The pulmonary valve is located between the right ventricle and pulmonary trunk. 3. The bicuspid valve is located between the left atrium and left ventricle. 4. The aortic valve is located between the left ventricle and aorta.

What factor can increase blood pressure?

An increase in heart rate

The left ventricle pushes blood into what vessel(s)?

Aorta

What is the equation that correctly depicts the relationship between blood pressure (BP), peripheral resistance (PR), and cardiac output (CO)?

BP = CO x PR

In the cardiovascular system, what vessels are the site of nutrient, gas, and waste exchange?

Capillaries

What is the deepest layer in the wall of the heart?

Endocardium

The ventricles and atria can be in systole at the same time.

False

What is a mass of cells that act as a unit in the heart called?

Functional syncytium

What is the function of chordae tendineae?

Prevent the cusps of the AV valves from moving up into the atria

What site is commonly used to feel a pulse?

Radial artery on the wrist

What vessel is located in the atrioventricular sulcus between the right atrium and right ventricle?

Right coronary artery

What structure is also known as the pacemaker of the heart?

SA node

What wave in an ECG tracing depicts ventricular repolarization?

T wave

When the first heart sound is heard, what is occuring with the heart valves?

The AV valves are closing.

Complete the following sentences describing the location of the heart.

The heart is located in the thoracic cavity. The heart is situated with the lungs to either side, in front of the vertebral column, and behind the sternum. The base of the heart, which is more superior, is the point of attachment for the major vessels. The apex of the heart points inferiorly and to the left, and sits at the level of the fifth intercostal space.

Complete the following sentences describing the basics of the cardiac cycle.

The heart works in a coordinated fashion to pump blood throughout the body. When the atria contract (a phase called atrial systole), the ventricles are relaxed (ventricular diastole). When the ventricles contract (ventricular systole), the atria are relaxed (atrial diastole). At one point during the cardiac cycle, both atria and ventricles are relaxed. The cardiac cycle consists of all the events that take place during one heartbeat, as described above.

Complete each sentence describing blood pressure and its measurement. Labels can be used more than once.

The highest pressure exerted on the arterial walls during the heart cycle is referred to as systolic blood pressure. The diastolic blood pressure is measured when the heart is relaxing and represents the lowest pressure exerted in the walls of the arteries during the heart cycle. A sphygmomanometer is used to measure arterial blood pressure. A normal blood pressure is 120/80 mmHg. The top number (120) is the systolic blood pressure and the bottom number (80) is the diastolic blood pressure.

What is systolic pressure?

The maximum pressure achieved during ventricular contraction

The cardiovascular system pumps blood through two separate circuits.

The pulmonary circuit sends oxygen-poor blood to the lungs. The systemic circuit sends oxygen-rich blood and nutrients to the body.

Complete the following sentences about the functioning of the valves.

The tricuspid valve, associated with the right ventricle, and the bicuspid valve, associated with the left ventricle, are also called atrioventricular valves. Attached to these valves are fibrous strings called chordae tendineae, which in turn are attached to the papillary muscles. The papillary muscles contract with the ventricles, which makes the chordae tendineae taut. As a result, the chordae tendineae prevent the valves from pushing up into the atria.

What valve is located between the right atrium and right ventricle?

Tricuspid valve

What causes the semilunar valves to open during the cardiac cycle?

Ventricular pressure is greater than arterial pressure

As a result of a sudden increase in the blood pressure, signals from baroreceptors lead to a(n) __________ in sympathetic outflow from the vasomotor center, which results in a(n) __________ in peripheral resistance and return of blood pressure to normal.

decrease; decrease