10. Anatomy & Physiology - The Cardiovascular System

Front 1

What is the role of lymph nodes?

Back 1

Lymph nodes in the neck, axilla, and groin help filter impurities en route to the heart.

Front 2

Describe the 'all or none' principle.

Back 2

If a single muscle fiber becomes depolarized, the action potential will spread through the whole syncytium.

Front 3

Describe the function of sympathetic nervous enervation of the heart.

Back 3

The chemical neurotransmitter for the sympathetic nervous system, and thus for the cardiac plexus, is norepinephrine. Its release increases heart rate and cardiac contractile force, primarily through its actions on beta receptors.

Front 4

Describe the function of the parasympathetic nervous enervation of the heart.

Back 4

The neurotransmitter for the parasympathetic nervous system, and thus the vagus nerve, is acetylcholine. Its release slows the heart rate and slows atrioventricular conduction. Several maneuvers can stimulate the vagus nerve, including Valsalva maneuver (forced expiration against a closed glottis, which can occur when lifting heavy objects), pressure on the carotid sinus (carotid sinus massage), and distention of the urinary bladder.

Front 5

Describe the relationship between capillaries, venules, veins, and the vena cava.

Back 5

Blood enters the venous system through the capillaries, which drain into the venules. The venules, in turn, drain into the veins, the veins into the venae cavae, and the vanae cavae into the atria.

Front 6

Describe the role of the internodal atrial pathways.

Back 6

Internodal atrial pathways conduct the depolarization impulse to the atrial muscle mass, and through the atria to the AV junction.

Front 7

Describe the structure of the parasympathetic nervous enervation of the heart.

Back 7

Parasympathetic control of the heart occurs through the vagus nerve (the tenth cranial nerve). The vagus nerve descends from the brain to innervate the heart and other organs. Vagal nerve fibers primarily innervate the atria, although some innervate the upper ventricles.

Front 8

Explain how deoxygenated blood returns from the coronary circulation to the general circulation.

Back 8

Blood drains from the left coronary system via the anterior great cardiac vein and the lateral marginal veins. These empty into the coronary sinus. The right coronary artery empties directly into the right atrium via smaller cardiac veins.

Front 9

Explain how the sympathetic and parasympathetic nervous systems regulate the heart.

Back 9

The sympathetic and parasympathetic components of the autonomic nervous system work in direct opposition to one another to regulate the heart. In the heart s normal state the two systems balance. In stressful situations, however, the sympathetic system becomes dominant, while during sleep the parasympathetic system dominates.

Front 10

How big is the adult heart?

Back 10

Closed fist.

Front 11

The pulmonary artery is the only artery in the body to carry which type of blood?

Back 11

The pulmonary artery is the only artery in the body to carry deoxygenated blood.

Front 12

What are intercalated discs and what do they do?

Back 12

Intercalated disks are specialized bands of tissue inserted between myocardial cells that increase the rate in which the action potential is spread from cell to cell.

Front 13

What are the characteristics and alternative name of the left atrioventricular valve?

Back 13

The left atrioventricular valve is also called the mitral valve. It has two leaflets.

Front 14

What are the characteristics and alternative name of the left semilunar valve?

Back 14

The left semilunar valve is also called the aortic valve. It connects the left ventricle to the aorta.

Front 15

What are the characteristics and alternative name of the right atrioventricular valve?

Back 15

The right atrioventricular valve is also called the tricuspid valve because it has three leaflets, or cusps.

Front 16

What are the characteristics and alternative name of the right semilunar valve?

Back 16

Also called the pulmonic valve. It connects the right ventricle to the pulmonary artery.

Front 17

What are the characteristics of the atria?

Back 17

Receive incoming blood. The right and left atria are separated by the interatrial septum.

Front 18

What are the characteristics of the endocardium?

Back 18

It is the innermost layer of the heart. It lines the heart's chambers, and is bathed in blood.

Front 19

What are the characteristics of the myocardium?

Back 19

The thick middle layer of the heart. Its cells are unique in that they physically resemble skeletal muscle but have electrical properties similar to smooth muscle. These cells also contain specialized structures that help to rapidly conduct electrical impulses from one muscle cell to another, enabling the heart to contract.

Front 20

What are the characteristics of the pericardium?

Back 20

A protective sac surrounding the heart. It consists of two layers, visceral and parietal. The visceral pericardium, also called the epicardium, is the inner layer, in contact with the heart muscle itself. The parietal pericardium is the outer, fibrous layer. In the pericardial cavity, between these two layers, is about 25 milliliters of pericardial fluid, a straw-colored lubricant that reduces friction as the heart beats and changes position.

Front 21

What are the characteristics of the ventricles?

Back 21

The ventricles pump blood out of the heart. The ventricles are separated by the interventricular septum.

Front 22

What are the effect of beta blockers?

Back 22

Beta blockers slow the heart rate and lower blood pressure by blocking the beta1 receptors, whose job is to increase heart rate and contractility.

Front 23

What are the roles of the AV node and AV fibers?

Back 23

The impulse passes through the AV junction into the AV node and on to the AV fibers, which conduct the impulse from the atria to the ventricles.

Front 24

What do coronary arteries do?

Back 24

The main coronary arteries lie on the surface of the heart, and small penetrating arterioles supply the myocardial muscle.

Front 25

What does the obturator nerve control?

Back 25

Abductor muscles medial thigh.

Front 26

What does the term anastomosis mean?

Back 26

Communication between two or more vessels.

Front 27

What is action potential?

Back 27

The stimulation of myocardial cells, as evidenced by a change in the membrane electrical charge, that subsequently spreads across the myocardium.

Front 28

What is automaticity?

Back 28

The pacemaker cells capability of self-depolarization.

Front 29

What is cardiac depolarization?

Back 29

A reversal of charges at a cell membrane so that the inside of the cell becomes positive in relation to the outside; the opposite of the cell s resting state in which the inside of the cell is negative in relations to the outside.

Front 30

What is chronotropy?

Back 30

Pertaining to heart rate.

(Chrono = time)

Front 31

What is contractility?

Back 31

The ability of muscle cells to contract, or shorten.

Front 32

What is dromotropy?

Back 32

Pertaining to the speed of impulse transmission.

Front 33

What is inotropy?

Back 33

Pertaining to cardiac contractile force.

Front 34

What is resting potential?

Back 34

Normal electrical state of cardiac cells.

Front 35

What is the function of alpha receptors?

Back 35

Responsible for vasoconstriction.

Front 36

What is the function of beta1 receptors?

Back 36

Increase the heart rate and contractility.

Front 37

What is the function of beta2 receptors?

Back 37

Cause bronchodilation and peripheral vasodilation.

Front 38

What is the function of the chordae tendoneae?

Back 38

Prevent the valves from prolapsing into the atria, preventing backflow during ventricular contraction. They connect the valves, leaflets to the papillary muscles.

Front 39

What is the intrinsic rate of the Purkinje system?

Back 39

15-40 beats/min

Front 40

What is the intrinsic rate of the SA node?

Back 40

60-100 beats/min

Front 41

What is the purpose of the arterial system?

Back 41

Carries oxygenated blood from the heart under high pressure.

Front 42

What is the purpose of the lymphatic system?

Back 42

Drains lymph from body tissues and delivers it to the subclavian vein.

Front 43

What is the role of calcium in cardiac function?

Back 43

Calcium takes part in myocardial depolarization and myocardial contraction. Hypercalcemia can result in increased contractility, whereas hypocalcemia is associated with decreased myocardial contractility and increased electrical irritability.

Front 44

What is the role of potassium in cardiac function?

Back 44

Influences repolarization. Hyperkalemia decreases automaticity and conduction, whereas hypokalemia increases irritability.

Front 45

What is the role of sodium in cardiac function?

Back 45

Major role in depolarizing the myocardium.

Front 46

What is the role of the AV junction?

Back 46

Slows the impulse and allows the ventricles time to fill.

Front 47

What is the role of the Purkinje system?

Back 47

Spreads the impulse across the myocardium

Front 48

What is the role of the bundle of His?

Back 48

Divides into the right and left bundle branches.

Front 49

What is the role of the left bundle branch?

Back 49

Divides into anterior and posterior fascicles that also ultimately terminate in the Purkinje system. The Purkinje system spreads it across the mass of the myocardium.

Front 50

What is the role of the right bundle branch?

Back 50

Delivers the impulse to the apex of the right ventricle.

Front 51

What is the term used to describe a group of cardiac muscle cells that physiologically function as a unit?

Back 51

Syncytium

Front 52

What is the term used to describe a law of physiology stating that blood flow through a vessel is directly proportional to the radius of the vessel to the fourth power?

Back 52

Poiseuille's Law

Front 53

What is the term used to describe the ability of the cells to propagate the electrical impulse from one cell to another?

Back 53

Conductivity

Front 54

What is the term used to describe the ability of the cells to respond to an electrical stimulus?

Back 54

Excitability

Front 55

What is the term used to describe the period of the cardiac cycle when the myocardium is contracting?

Back 55

Systole

Front 56

What is the term used to describe the period of time from the end of the one cardiac contraction to the end of the next?

Back 56

Cardiac Cycle

Front 57

Where are alpha receptors located?

Back 57

Peripheral blood vessels

Front 58

Where are beta1 receptors located?

Back 58

In the heart

Front 59

Where are beta2 receptors located?

Back 59

In the lungs and peripheral blood vessels.

Front 60

Where do coronary arteries originate?

Back 60

In the aorta, just above the leaflets of the aortic valve.

Front 61

Where does blood flowing through the right atrium go next?

Back 61

The right atrium pumps blood through the tricuspid valve and into the right ventricle.

Front 62

Where does oxygenated blood flowing through the left atrium go next?

Back 62

Passes though the mitral valve into the left ventricle.

Front 63

Where does the inferior vena cava receive blood from?

Back 63

From the areas below the heart.

Front 64

Where does the right ventricle pump blood to next?

Back 64

Through the pulmonic valve to the pulmonary artery and on to the lungs.

Front 65

Where does the superior vena cava receive blood from?

Back 65

Head and upper extremities

Front 66

Where is the ascending aorta located?

Back 66

Blood vessel coming directly from the heart.

Front 67

Where is the heart located?

Back 67

The heart is located in the center of the chest in the mediastinum, anterior to the spine and posterior to the sternum. The bottom of the heart, or apex, is just above the diaphragm, left of the midline. The top of the heart, or base, lies at approximately the level of the second rib.

Front 68

Where is the thoracic aorta located?

Back 68

Curves inferiorly and goes through the chest (or thorax).

Front 69

Which veins return oxygenated blood from the lungs back to the left atrium?

Back 69

Return oxygenated blood from the lungs back to the left atrium.

Front 70

What are the three layers of tissue in the heart?

Back 70

Endocardium, myocardium, pericardium

Front 71

Where does the left ventricle send its blood?

Back 71

Through the aortic valve to the aorta, which feeds the oxygenated blood to the rest of the body.

Front 72

Where is the abdominal aorta located?

Back 72

Goes through the diaphragm and enters the abdomen.

Front 73

What is the term used to describe the period of time when the myocardium is relaxed, and cardiac filling and coronary perfusion occur?

Back 73

Diastole

Front 74

Describe the structure of sympathetic nervous enervation of the heart.

Back 74

The sympathetic nerves arise from the thoracic and lumbar regions of the spinal cord, then leave the spinal cord and form the sympathetic chain, which runs along the spinal column. The cardiac plexus arises in turn from ganglia in the sympathetic chain and innervates both the atria and ventricles.

Front 75

List five electrolytes that affect cardiac function.

Back 75

Sodium (Na+), Calcium (Ca++), Potassium (K+), Chloride (Cl-), Magnesium (Mg++).

Front 76

What is the term used to describe the return of a cell to its pre-excitation resting state?

Back 76

Repolarization.

Front 77

What is the purpose of the venous system?

Back 77

Transports blood from the peripheral tissues back to the heart under low pressure.