The Heart

Front 1

Cardiac output

Back 1

The volume of blood ejected from the ventricles to the aorta or pulmonary trunk each minute.

CO = SV × HR

Front 2

stenosis

Back 2

Valve doesn't open all the way

Front 3

Incompetence

Back 3

Valve closes improperly (leaky)

Front 4

Stroke Volume

Back 4

Volume of blood ejected by ventricle per beat. Should be 70-140 ml usually. SV = EDV - ESV

Front 5

Preload

Back 5

Amount of stretch of ventricle just before contraction.

Front 6

Frank-Starling Law

Back 6

Stretching a rubber band comparison. The more the heart fills with blood during diastole, the greater the force of contraction during systole.

Front 7

Contractility

Back 7

Increase contraction- increase SV

Decrease contraction- decrease SV

Front 8

Positive inotropic agents

Back 8

Substances that increase contractility. Calcium, epinephrine, norepinephrine and drug digitalis.

Front 9

Negative inotropic agents

Back 9

Substances that decrease contractility. Anoxia, acidosis, Beta blockers, calcium channel blockers, and increased potassium level.

Front 10

Afterload

Back 10

Pressure that must be exceeded for ejection of blood to occur from the ventricles. Conditions that increase afterload include:

High blood pressure

Stenosis

Coarctation

Front 11

End diastolic volume

Back 11

Volume of ventricles after relaxation

Front 12

End systolic volume

Back 12

Volume remaining in ventricle at the end of systole.

Front 13

Causes of hyper dynamic circulation

Back 13

Pregnancy

High fever

Hypothyroidism

Severe anemia

Hyper dynamic circulation is an innocent and functional murmur

Front 14

systole

Back 14

contraction

Front 15

diastole

Back 15

relaxation

Front 16

P wave

Back 16

Atrial depolarization. Which spreads through the SA node through contractility fibers in both atria.

Front 17

T wave

Back 17

Indicates ventricular repolarization. Occurs just as the ventricles are starting to relax.

Front 18

R wave

Back 18

Ventricular depolarization. Followed by ventricular contraction.

Front 19

P-Q or P-R interval

Back 19

Represents the conduction time from atrium to ventricle.

Front 20

S-T segment

Back 20

Ventricle depolarized after plateau phase

Front 21

Q-T interval

Back 21

Time from beginning of ventricular depolarization to the end of ventricular repolarization.

Front 22

EKG measuring squares

Back 22

Small square = .04 seconds

Big square = .2 seconds

5 big squares = 1 second

Front 23

Heart Rate

Back 23

Number of beats per minute

60× r waves/ seconds.

Ex: 20 big squares = 4seconds.

Front 24

Cardomegaly

Back 24

Enlargement of the heart

Front 25

Pericardium

Back 25

Membrane that Surrounds and protects the heart. Consists of the layers:

Fibrous pericardium/ outermost layer

Perietal pericardium/layer of serous

Visceral layer/ inner layer of serous

Pericardial cavity contains pericardial fluid

Front 26

Myocardium

Back 26

Responsible for the pumping action of the heart. Composed of cardiac muscle tissue.

Front 27

Layers of heart

Back 27

Epicardium/visceral

Myocardium/muscle

Endocardium/thin layer provides smooth lining for chambers.

Front 28

Myocarditis

Back 28

Inflammation of myocardium.

Front 29

Endocarditis

Back 29

Inflammation of Endocardium

Front 30

Atria

Back 30

Two superior receiving chambers

Front 31

Ventricles

Back 31

Two inferior pumping chambers

Front 32

Coronary sulcus

Back 32

Encircles most of the heart. Marks boundary between the atria an ND ventricles.

Front 33

Anterior interventricular sulcus

Back 33

Shallow groove on the anterior surface of the heart that marks the external bounty between the right and left ventricles on anterior aspect of heart.

Front 34

Posterior interventricular sulcus

Back 34

Marks the external boundary between the ventricles on the posterior aspect of heart.

Front 35

Right atrium

Back 35

Forms right surface of heart and receives blood from three veins:

Superior vena cava

Inferior vena cava

Coronary sinus

Front 36

Pectinate muscles

Back 36

Inside anterior walls rough muscular ridges

Front 37

Fossa ovalis

Back 37

Oval depression in right atrium.

The remnant of the foreman ovale, an opening in interatrial septum of the fetal heart that closes soon after birth. If not closed it is called patent foramen ovale (PFO).

Front 38

Tricuspid valve

Back 38

Blood passes from the right atrium into the right ventricle via tricuspid valve. Three cusps.

Front 39

Right ventricle

Back 39

Forms most of the anterior surface of the heart.

Front 40

Trabeculae careae

Back 40

Series of ridges in ventricles formed by raised bundles of cardiac muscle fibers.

Front 41

Chordae tendineae

Back 41

Cusps of valves ( tricuspid and mitral) are connected to tendonlike cords, the chordae tendineae. Which in turn are connected to cone-shaped papillary muscles.

Front 42

Interventricular septum

Back 42

Partition separating the right and left ventricles.

Front 43

Pulmonary valve

Back 43

Blood passes from the right ventricle to the pulmonary valve then into the large artery, the pulmonary trunk.

Front 44

Pulmonary trunk

Back 44

Divides into right and left pulmonary arteries and carries blood to the lungs to become oxygenated.

Front 45

Left atrium

Back 45

Forms most of the base of the heart. Receives blood from the lungs through the four pulmonary veins.

Front 46

Bicuspid (mitral) valve

Back 46

Blood passes from the left atrium into the left ventricle through the bicuspid valve.

Front 47

Left ventricle

Back 47

Thickest chamber of the heart. Forms the Apex of the heart. Like right ventricle it contains trabeculae carneae and chordae tendineae.

Front 48

Aortic valve

Back 48

Blood passes through the aortic valve from the left ventricle. Then into the ascending aorta. Blood goes into body.

Front 49

Ligamentum arteriosum

Back 49

The ductus arteriosum normally closes sleekly shortly after birth, leaving a remnant known as the ligamentum arteriosum, which connects the arch of the aorta and the pulmonary trunk.

If not closed is called patent ductus arteriosum. (PDA)

Front 50

Fibrous skeleton of the heart

Back 50

Dense connective tissue.

Prevents overstretching of the valves as blood Passes through them.

Also serves as point of insertion for bundles of cardiac muscle fibers and acts as an electrical insulator between the atria and ventricles.

Front 51

Systemic circulation

Back 51

The routes through which oxygenated blood flows from the left ventricle through the aorta to all the organs of the body and deoxygenated blood returns to the right atrium.

Front 52

Pulmonary circulation

Back 52

The flow of deoxygenated blood from the right ventricle to the lungs and the return of oxygenated blood from the lungs to the left atrium.

Hint 52

Front 53

Coronary circulation

Back 53

The myocardium ' s network of blood vessels.

The pathway followed by the blood from the ascending aorta through the blood vessels supplying the heart and returning to the right atrium.

Front 54

Left coronary artery

Back 54

Passes inferior to the left auricle and divides into the anterior interventricular branch or (LAD) left anterior descending in the anterior interventricular sulcus and supplies oxygenated blood to the walls of both ventricles.

Front 55

Circumflex branch

Back 55

Lies in the coronary sulcus and distributes oxygenated blood to the walls of the left ventricle and left atrium.

Front 56

Right coronary artery

Back 56

Supplies small branches to the right atrium.

Continues inferior to the right auricle and divides into the posterior interventricular and marginal branches.

Front 57

Posterior interventricular branch

Back 57

Follows the posterior interventricular sulcus and supplies the walls of the two ventricles with oxygenated blood.

Front 58

Marginal branch

Back 58

Beyond, or under, the coronary sulcus runs along the right margin of the heart and transports oxygenated blood to wall of right ventricle.

Front 59

Autorythmic fibers

Back 59

Cells that repeatedly and rhythmically generate action potentials.

Trigger heart contractions.

Front 60

The conduction system

Back 60

A network of specialized cardiac muscle fibers that provide a path of each cycle of cardiac excitation to progress through the heart.

Front 61

Sinoatrial (SA) node

Back 61

-The pacemaker

-Rate of firing- 60-100 a min.

-Located on right atrium .

-Each action potential from SA node propagates throughout both atria and causes the two atria to contact.

Front 62

Atrioventricular (AV) node

Back 62

- Located in interatrial septum anterior to opening of coronary sinus.

- Rate of firing- 40-60 a min.

- action potential slows. The delay provides time for the atria to empty their blood into the ventricles.

- from AV node action potential enters the AV bundle.

Front 63

Atrioventricular (AV) bundle

Back 63

- bundle of his

- where action potentials can conduct from the atria to the ventricles.

- extends through the interventricular septum, left and right bundle branches, towards apex of the heart.

Front 64

Purkinje fibers

Back 64

- specialized autorythmic fibers

- Rate of firing - 25-40 a min.

- beginning at apex of the heart upward to the remainder of the ventricular myocardium.

- causes ventricles to contract, pushing blood upward towards the semilunar valves.

Front 65

Action potential in a ventricular contractile fiber

Back 65

Depolarization, plateau, repolarization

Front 66

Cardiac conduction system

Back 66

Depolarization ➡ contraction ➡ repolarization ➡ relaxation.

Front 67

Depolarization

Back 67

Ventricles relax, volume increases, pressure increases

- as the sodium rushes back into the cell the positive sodium ions raise the charge inside of the cell from negative to positive. Once the interior of the cell becomes positively charged, depolarization is compete.

Front 68

Plataeu

Back 68

- actual physical contraction

- period of maintained depolarization.

- calcium (+) goes in. Na (+) goes out. Positive charge remains the same.

Front 69

Repolarization

Back 69

- recovery of resting membrane.

- potassium (k+) moves out of cell.

- restores negative resting membrane potential (-90 mV)

Front 70

Refraction period

Back 70

- during this time a second contraction cannot be triggered. Muscle will not respond. Refractory period lasts longer than the contraction itself, another contraction cannot begin until relaxation is well under way.