Chapter 22# The Cardiovascular System

Front 1

Facts about the human Heart:

Back 1

- The human heart is a strong muscular pump about three quarters the size of a clinched fist.

- It weighs less than 1 pound (approximately 250-350 grams).

- It lies in the thoracic cavity in the mediastinal space (a mass of tissues and organs lying behind the sternum, between the lungs, and in front of the vertebral column).

- The heart is shaped like an irregular and slightly flattened cone.

Front 2

APEX

Back 2

Lower point of the heart, formed by the tip of the left ventricle. (the apical pulse is counted here)

Front 3

What are the 3 layers of the heart wall?

Back 3

- endocardium

- myocardium

- epicardium

Front 4

ENDOCARDIUM

Back 4

(Inner heart) is a membrane lining the hearts interior wall.

Front 5

MYOCARDIUM

Back 5

middle and thickest layer of the heart wall; the muscular layer.

Front 6

EPICARDIUM

Back 6

The thin, outer layer of the cardiac wall.

Front 7

PERICARDIUM

Back 7

A sac that surrounds and protects the heart.

Front 8

What are the 3 layers of the pericardium?

Back 8

- epicardium

- parietal layer

- fibrous pericardium

Front 9

EPICARDIUM

Back 9

Portion of the heart wall, which also makes up the pericardium's visceral layer, adheres to the heart's surface.

Front 10

PARIETAL LAYER

Back 10

The inner serous pericardium.

Front 11

PERICARDIAL SPACE OR CAVITY

Back 11

The space between the visceral and parietal layers.

Front 12

The Heart

Back 12

Front 13

PERICARDIAL FLUID

Back 13

Acts as an lubricant and reduces friction between the layers ad the heart contracts and relaxes.

Front 14

FIBROUS PERICARDIUM

Back 14

The outermost layer; composed of dense fibrous connective tissue.

Front 15

SEPTUM

Back 15

A complete muscular wall that divides the heart into right and left sides.

Front 16

What are the 4 chambers of the heart?

Back 16

- right atria (atrium)

- left atria (atrium)

- right ventricle

- left ventricle

Front 17

Right and Left atria (atrium)

Back 17

the two upper chambers; thin walled, low-pressure chambers are the receiving centers for blood.

Front 18

Right and Left ventricle

Back 18

the two lower chambers; are high pressure chambers; they pump blood out of the heart.

The left ventricle must contract with sufficient force to send blood to the entire body; therefore its muscle walls are the thickest and its internal pressures the highest.

The right ventricle needs only to pump blood into the low pressure lungs and therefore is a thinner-walled chamber.

Front 19

KEY CONCEPT

Back 19

The left ventricle contains the thickest layer of muscle in the heart. It must pump strongly enough to send blood out to the entire body. The right ventricle also has thick muscles; the muscles in the atria are thinner than those of either ventricle.

The left lung is smaller than the right lung, to make room for the heart.

Front 20

VALVES

Back 20

As each heart chamber contracts, it pushes blood either into a ventricle or out of the heart to the lungs or body. The cardiac valves are one-way flaps of tissue that open and close in response to pressure changes within the chambers. These unidirectional (one-way) valves allow blood to flow in one direction only, preventing backflow.

Front 21

Atrioventricular (AV) Valves

Back 21

valves that lie between the atria and ventricles.

Front 22

Tricuspid Valve

Back 22

valve between the right atrium and the right ventricle.

Front 23

Mitral Valve (bicuspid valve)

Back 23

valve between the left atrium and the left ventricle.

Front 24

chordae tendineae

Back 24

tendon like strands that are anchored to papillary muscles located on the inner surface of the ventricles.

Front 25

SEMILUNAR VALVES

Back 25

Each ventricle empties through a valve with 3 cresent shaped (half-moon) cusps called the SEMILUNAR VALVE.

Front 26

Pulmonary semilunar valve

Back 26

separates the right ventricle from the pulmonary artery (also called the pulmonic valve).

Front 27

Aortic (semilunar) valve

Back 27

separates the left ventricle from the aorta, the body's largest artery.

Front 28

KEY CONCEPT

Back 28

The pulmonary arteries are the only arteries in the body that carry deoxygenated blood. The pulmonary veins are the only veins that carry oxygenated blood. The oxygen saturation of the hemoglobin within the arteries is normally about 95%-100%. Within the veins, it is about %75%.

Front 29

Blood flow through the heart:

Back 29

Front 30

Blood flow through the heart:

Back 30

Front 31

Coronary arteries and cardiac veins:

Back 31

Front 32

Left coronary artery (LCA) also known as Left main coronary artery (LMCA):

Back 32

Passes along the left atrium and divides into two branches: the left anterior descending (LAD) artery and the left circumflex (LCX) artery

Front 33

Left anterior descending (LAD) artery:

Back 33

descends along the anterior intraventricular groove to provide blood to most of the ventricular septum and anterior portion of the left ventricle. The LAD and its branches also supply blood to the anterior papillary muscles, the apex of the left ventricle and the right and left bundle branches.

Front 34

Left circumflex (LCX) artery:

Back 34

Extends around the left side of the heart, along the groove between the left atrium and left ventricle, to supply blood to the left atrium and the lateral and posterior portions of the left ventricle. It supplies blood to the sinoatrial (SA) node in approximately 40% of the population and the AV node in approximately 10% of the population.

Front 35

Right coronary artery (RCA):

Back 35

Branches out along the right AV groove to supply blood to the right atrium and right ventricle. It provides blood to the SA node in approximately 60% of the population and to the AV node in 90% of the population.

Front 36

Marginal Branch

Back 36

the main branch of the RCA that supplies the hearts right side.

Front 37

Ischemia

Back 37

Reversible cell injury due to decreased blood and oxygen supply.

Front 38

Myocardial Infarction (MI)

Back 38

A localized area of dead tissue caused by a lack of blood supply (heart attack).

Front 39

Collateral circulation

Back 39

Circulation that occurs when one blood vessel is plugged and another evolves to take over it's function, usually in the heart.

Front 40

Coronary Sinus

Back 40

returns blood to the right atrium

Front 41

Key Concept

Back 41

Arteries carry blood away from the heart. Veins carry blood toward the heart. Except in the pulmonary circuit, arteries carry oxygenated blood and veins carry deoxygenated blood.

Front 42

AORTA

Back 42

The largest artery in the body.

Front 43

PRINCIPAL SYSTEMIC ARTERIES:

Back 43

Front 44

Microcirculation

Back 44

Blood flow through capillaries

Front 45

Key Concept

Back 45

The capillaries are very important. They are known as "exchange vessels" because it is here that the exchange of nutrients and wastes occurs.

Front 46

Superior vena cava (SVC)

Back 46

Returns blood from the head, neck and arms.

Front 47

Inferior vena cava (IVC)

Back 47

Returns blood from the lower body.

Front 48

KEY CONCEPT

Back 48

When a vein is cut, the muscles in the wall constrict, and blood flows in a steady stream rather than pulsating like arterial blood.

Front 49

Key Concept

Back 49

If placed end-to-end, the blood vessels in an average human body would measure about 100,000 km-twice around the earth.

Some blood vessels are modified to serve specific functions.

Examples include the sinusoids of the liver and spleen, and the choroid plexes within the ventricles of the brain.

Front 50

vasoconstriction

Back 50

contraction of veins.

Front 51

The layers within arteries and veins are?

Back 51

-Tunica adventitia- the outermost layer. This layer is composed of connective tissues and nerve cells, as well as nutrient capillaries in larger vessels. This layer protects the outside of the vessel.

-Tunica media- the middle layer. This layer contains the thickest elastic fibers, as well as connective tissue composed of polysaccharides. This layer is covered by a thick elastic band (the external elastic lamina) and smooth muscle fibers, which control the caliber (size) of the vessel.

-Tunica intima - the innermost layer. This layer is the thinnest-a single layer of simple squamous endothelium held together by an intercellular matrix. This layer is surrounded by connective tissue interlaced with elastic bands (internal elastic lamina).

Front 52

Key Concept

Back 52

The blood vessels do not pump blood, they can regulate their diameter (especially the arteries). This helps to change blood flow to specific organs, regulate blood pressure and regulate

body temperature. (thermoregulation)

Front 53

SA node (sinus node)

Back 53

Is embedded in the wall of the right atrium where it is joined by the superior vena cava (SVC). It is also considered the heart's "pacemaker"

Front 54

Key Concept

Back 54

A syncytium is a merging of cells interconnected by cytoplasmic bundles. This meshwork allows an electrical stimulus in one cell to spread through the network to the other cells. The person with a poorly functioning SA node usually requires the implant of an electronic pacemaker.

Front 55

Special bundles of unique tissue in the heart transmit and coordinate electrical impulses to stimulate the heart to beat are called:

Back 55

- SA node or sinus node

- AV node

- Bundle of His

- Right and left Bundle Branches

- Purkinje Fibers

Front 56

Atrioventricular node (AV node)

Back 56

found in the lower part of the right atrium near the ventricle.

Front 57

Key Concept

Back 57

The electrical activity of the heart must occur before the mechanical, or pumping, activity of the heart can respond with a heartbeat.

Front 58

Key Concept

Back 58

Conduction System of the Heart

- SA (sinoatrial) node (pacemaker)

- AV (atrioventricular) node

- Bundle of His (AV bundle)

- Right and left bundle branches

- Purkinje fibers to muscles of ventricles.

Front 59

Key Concept

Back 59

In less than 1 second, both atria contract as both ventricles relax. Immediately after this, both ventricles contract as both atria relax. This process is considered on cardiac cycle or one heartbeat.

Front 60

SYSTOLE

Back 60

The sequence of dual contractions, the atria followed by the ventricles.

Systole makes up one-third of the cardiac cycle.

Front 61

DIASTOLE

Back 61

Atrial relaxation. followed by ventricular relaxation.

Diastole takes up two thirds of the cardiac cycle.

Front 62

Key Concept

Back 62

The contraction that pumps the blood from the heart is called systole, and the period when the heart relaxes is called diastole. The heart is actually in systole twice, once for the atria (atria systole) and once for the ventricles (ventricular systole).

Front 63

S1

Back 63

The first normal heart sound is called the "lub" and is produced by closure of the AV valves when the ventricles contract.

Front 64

S2

Back 64

Is called the "dub" or "dup" and is produced by the closure of the aortic and pulmonary semilunar valves when the ventricles relax. Thus S1 occurs at the beginning of systole and S2 occurs at the beginning of diastole. The first sound is loudest and longest. It can be heard over all the pericardium, but is usually loudest at the apex of the heart. S2 is more easily heard at the base of the heart.

Front 65

PULSE

Back 65

The heartbeat as felt through the walls of the arteries and the skin or as heard at the apex of the heart with a stethoscope.

Front 66

Pulse assessment locations are named for the artery in each area:

Back 66

radial - wrist

carotid - neck

popliteal - back of knee

femoral - groin

tibial - ankle

pedal - foot

axillary - armpit

temporal - temple

Front 67

Cardiac Output (CO)

Back 67

The amount of blood pumped by the ventricles in 1 minute.

In the resting adult the normal amount is between 4 and 6 L.

Front 68

Stroke Volume (SV)

Back 68

The volume of blood ejected with each heartbeat.

CO is related to SV and BPM. Therefore, changes in the amount of blood leaving the heart or changes in heart rate, will affect cardiac output.

Front 69

What factors can affect cardiac output?

Back 69

-preload - the amount of pressure or "stretching force" against the ventricular wall and end-diastole(maximum relaxation of the heart).

-afterload - the amount of pressure o resistance the ventricles must overcome to empty their contents.

Front 70

Blood Pressure (BP)

Back 70

A function of CO and systemic vascular resistance(resistance in blood vessels), is the force that blood exerts against the walls of blood vessels.

Systolic Blood Pressure (sBP) - the pressure exerted against vessel walls during ventricular systole.

Diastolic Blood Pressure (dBP) - the pressure exerted during ventricular diastole (relaxation).

Front 71

Pulse Pressure

Back 71

The difference between systolic and diastolic pressure

Front 72

Key Concept

Back 72

When you measure blood pressure, you record the systolic (contraction) pressure and the diastolic (relaxation) pressure of the blood within the arteries. Average blood pressure is 120/80 in an adult.

Front 73

Systemic vascular resistance (SVR) or total peripheral resistance

Back 73

The force opposing the movement of blood through the blood vessels.

SVR primarily affects diastolic blood pressure.

SVR is typically thought of as "vasomotor tone."

This means that blood vessels can change (increase or decrease) their diameter (constriction or dilation) depending on the needs of the body.

Front 74

Key Concept

Back 74

Blood flows from high pressure to low pressure.

Continuous capillary flow is a result of :

- Minimal resistance in large vessels

- Large vessels can expand and contract

- Arterioles provide resistance to even out the intermittent pressure caused by heart beats.

Front 75

Key concept

Back 75

Vasoconstriction can be induced by hormones, such as vasopressin and angiotensin, as well as neurotransmitters, such as epinephrine. Vasodilation is caused by antagonists, the most important of which is nitric oxide. Nitric oxide increases the force of blood within the vessel, causing vasodilation.

Front 76

Key Concept

Back 76

As individuals age, systolic blood pressure often rises owing to stiffening of large arteries. This stiffening is the result of calcification of vessel walls (arteriosclerosis or "hardening of the arteries"). Other blood vessels become less elastic.

Front 77

What other problems can blood vessel disorders cause?

Back 77

Occlusion(plugging of a vessel)

Vessel damage or hemmorhage

Atherosclerosis

Vasculitis

Edema

Malfunction of venous valves.

Front 78



cardiac blood flow

Back 78

deoxygenated blood from body > superior vena cava > right atrium > tricuspid valve > right ventricle > pulmonic valve > branches of pulmonary artery > lungs to exchange CO2 for O2 > pulmonary veins > left atrium > bicuspid valve > left ventricle > aortic valve > aorta > to the rest of body (oxygenated blood is diffused into body cells while CO2 is taken up by blood)

Front 79

Disorders of Aging

Back 79

1. plugging of a vessel
2. hemorrhage
3. fats and cholesterol deposited within arteries' wall
4. inflammation of vessels
5. edema
6. malfunction of venous valves

Front 80

factors of CV system

Back 80

1. quality of sleep and rest
2. use of drugs
3. stress
4. fat, cholesterol, and carbohydrate level intake
5. medication compliance