Chapter 22 Objectives

Front 1

Describe the three major layers of the heart wall and how they relate to the pericardium

Back 1

Endocardium (inner heart) is the membrane lining the heart's interior wall. Myocardium is the middle, thickest and muscular layer of the heart. Epicardium is the thin outer layer of the cardiac wall and is also called the visceral layer of the serous pericardium and adheres to the hearts surface

Front 2

Identify the chambers of the heart on an anatomical model, including the major vessels that enter and exit each chamber

Back 2

The chambers of the heart are divided by the septum into right and left sides. Upper chambers are the Atria and are the receiving centers for blood. Lower chambers are ventricles which are high-powered chambers because they pump blood out of the heart. The left ventricle is the thickest chamber of the heart. The coronary sinus returns blood from the cardiac vessels and SVC and IVC return blood from the body to the right atrium where it is pumped thru the tricuspid valve to the right ventricle to the pulmonic valve to the pulmonary artery to the lungs where it receives oxygen; then returning to the left atrium via the pulmonary veins dropped into the left ventricle. Aorta is the largest artery and bloods exits via the Aorta from the left ventricle. The four pulmonary veins return blood to the left atrium where it is released to the left ventricle and pumped up to and via the Aorta to the body or for systemic circulation.

Front 3

Define and describe the function of the atrioventricular valves, semilunar valves, chordae tendinease and papillary muscles

Back 3

Atrioventricular valves (AV valves) lie between the atria and ventricles. The tricuspid valve lies beteen the right atrium and right ventricle and has three flaps (cusps) of tissue. The mitral valve/bicuspid lies between the left atrium and left ventricle and has two flaps. The tissue flaps attach to tendon like strands called chordae tendineae. The chordae are anchored to papillary muscles located on the inner surface of the ventricles. Blood flows from the atrium to the ventricles thru open AV valves when pressue is lower in the ventricles while the papillar muscles and chordae tendineae relax. When the ventricles start to contract increased pressure causes these valves to close preventing them from turning inside out not allowing regurgitation.

Semilunar valves: each Ventricle empties thru a semilunar valve with three cusps. The pulmonary semi-lunar valve separates the right ventricle from the pulmonary artery and is the pulmonic valve. The aorti semi-lunar valve separates the left ventricle from t

Front 4

Trace the part of blood through both sides of the heart, using correct terminology

Back 4

The right atrium reveives deoxygenated blood from the SVC and coronary sinus. Blood then passes thru the triscupid valve to the right ventricle. It moves on thru the pulmonic semi-lunar valve during ventricular contraction to enter the pulmonary artery and the to the lungs to receive oxygen.

THEN oxygenated blood travesl thru pulmonary veins into the left atrium. It travels thru the left atrium via the mitral valve to the left ventricle then thru the aortic semi-lunar valve to the aorta to be distributed to the systemic system.

Front 5

Identify the coronary arteries supplying the myocardium, specifing the location of each and the areas supplied: define collateral circulation

Back 5

Two coronary arteries branch off the aorta to provide blood to the heart muscle as the heart has its own blood supply. The coronary arteries are the Left Coronary Artery (LCA) which passes along the left atrium and divides into LAD and LCX.

Right coronary artery (RCA) branches out called the mariginal branch and supplies blood to the right atrium and right ventricle and the SA node.

Collateral circulation is when there is a blockage, the other vessels join together to nourish the damaged area.

Front 6

Compare and contrast the structure and function of arteries, capillaries and veins

Back 6

Arteries are elastic and smooth (involuntary) and carry oxygenated blood away from the heart to the body cells except for the pulmonary artery.

Capillaries are the smallest vessels of all and allows for microcirulation. This is where difussion and filteration takes place or exchange of oxygen, nutrients and carbon dioxide.

At the same time blood is travelling and delivering materials to cells it is picking up waste products from the capillaries and starts back to the heart from the venules. So venules to veins carry deoxygenated blood back to the heart via the vena cave (SVC) except for the pulmonary vein where it can be exchanged in the lungs for oxygenated blood and the process starts again.

Front 7

Describe the party of an electrical impulse through the conduction system of the heart. Describe the purpose of this electrical activity

Back 7

Electrical impulses are transmitted by the SA Node at the general rate of 60 to 100 beats per minute. The normal sinus impulse is transmitted over the heart via specialized fibers know as the conduction system. These impulses stimulate the chambers to contract. The SA node sets the pace and the rest of the heart follows its lead. The swift message is first sent to the muscle tissue of the artria causes it to contract. Then the AV Node in the lower part of the right atrium picks up the message and holds onto it until the atria have contracted and emptied the blood into the ventricles. The AV transmit thru the Bundle of His to the Purkinjie fibers and stimulate the ventricles to contract. The heart rest for a very short period and the process starts again.

Front 8

Explain the events associated with S1 and S2 heart sounds, indicating where each of these sounds is best heard

Back 8

S1 is the first sound heard called the "lub" when the AV valves close and ventricles contract and is best heard at the apex of the heart. S2 is the second sound heard called the "dup/dub" heard at the closure of the semilunar valves (pulomanary semi-lunar and aortic semi-lunar) when the ventricles relax and is more easily heard at the base of the heart.

Front 9

Describe cardiac output, including the factors involved in its regulation

Back 9

Cardiac output is the amount of blood that the ventricles pump out in one minute. In the resting adult the normal amount is between 4 to 6L. The stroke volume (SV) is the volume of blood ejected with each heartbeat. To calculate CO multiply SV by the number of beats per minute of heart rate (HR); this can increase during exercise. CO=SV x HR

Factors that can affect CO are freight, etc. Also, preload and afterload. Preload is the amount of pressure or "stretching force" agains the ventricular wall at the end of diastole

Afterload is the amount of pressure or resistance the ventricles must overcome to empty their contents.

Front 10

Differentiate between systolic and diastolic blood pressure, defining the term

Back 10

Systole is the sequence of dual contractions of the artria followed by the ventricles.

Atrial relazation followed by ventricular relaxation is called diastole. Diastole takes longer allowing the chambers to adequately fill with blood.

One cardiac cycle is made up of systole (contractions) of the atria and ventricles and diastole (relazation) of the atria and ventricles.

Systolic blood pressure determiedn in part by CO is the pressure exerted against the vessel walls during ventricular systole.

Diastolic blood pressure is the pressure exerted during ventricular diastole (relaxation). The difference between the two is called pulse pressure.

Blood flows from high pressure to low pressure.

Front 11

Identify the major factors that affect the regulation of blood pressure.

Back 11

Factors such as the force and rate of the pumping heart help to maintain and regulate blood pressure. Also, the amount and contents of circulating blood, elasticity and ability of smooth muscles in aterial walls to dilate and to constrict, plaque build-up on the arterial walls, kindney fuction and hormones.

Front 12

State four changes in the cardiovascular system caused by aging. Discuss suggested nursing implications for each

Back 12

A change in the blood vessels such as increaed ridigidty from decreased elasticity will increase BP. Nurse suggest decrease fat intake

Dilation in blood vessels due to weakening muscle tone may cause varicose veins. Nurse suggest a diuretic medication

Heart, fibrosis of the heart will show change on ECG. Nurse suggest to pace activities or have rest periods.

Calification of the valves may cause irregular heart beat; Nurse may suggest to know their normal pulse rate

Increased size of the Myocardium may cause fatigue; nurse suggest what to do if dizziness occurs