Cardiovascular System - The Heart

Front 1

Location and Surface Projection of the Heart

Back 1

directly under sternum; apex tips toward the left side of the body; about the size of a clenched fist; the "top" is called the base

Front 2

Pericardium (pericardial sac)

Back 2

sac around the heart; lessens friction with other thoracic structures

Front 3

Fibrous pericardium

Back 3

made of dese irregular connective tissue; collagenous fibers; is the outermost layer; minimizes expansion

Front 4

Serous pericardium

Back 4

double layered; smooth and slippery; minimizes friction

Front 5

parietal layer of serous pericardium

Back 5

lines inside of pericardial sac

Front 6

visceral layer of serous pericardium/epicardium

Back 6

innermost layer; directly on the heart; is made of simple squamous epithelium

Front 7

Pericardial Fluid

Back 7

fills pericardial sac/between parietal and visceral layers of the serous pericardium; reduces friction between membranes as the heard pumps

Front 8

Myocardium

Back 8

middle layer of the wall; made of cardiac muscle tissue

Front 9

Intercalated disks

Back 9

thickenings of the sarcolemma where two adjacent cells adjoin

Front 10

desmosomes

Back 10

reinforcing hooks; "spot welds" holding cells together

Front 11

Gap Junctions

Back 11

within the intercalated disks; for fast electrical synapses

Front 12

Endocardium

Back 12

simple squamous epithelium and very thin connective tissue; slippery; continuous throughout the cardiovascular system

Front 13

Atria

Back 13

upper 2 chambers; collect blood (returned from circulation)

Front 14

Auricle

Back 14

sac/flap-like appendage on the side of the atria; increases the volume of blood that the atria can collect

Front 15

Interventricular Sulcus

Back 15

groove dividing the ventricles; protect coronary arteries

Front 16

Coronary Sulcus

Back 16

groove around the exterior of the heart where the atria and ventricles connect (superficial/external); protect coronary arteries

Front 17

Interatrial Septum

Back 17

wall separating the two atria

Front 18

Fossa Ovalis

Back 18

oval depression in the left atrial side of the interatrial septum where there was a hole prior to birth (foramen ovale)

Front 19

Ventricles

Back 19

lower two chambers of the heart; connective tissue separates muscles of the atria from the muscles of the ventricles; muscle layer is thickest in the ventricles, especially the left ventricle (where systemic blood pressure is developed)

Front 20

Interventricular Septum

Back 20

wall between ventricles

Front 21

Size of chambers and myocardial thickness

Back 21

when living, all four chambers have about the same capacity; ventricles are the thickest with the left ventricle being the most thick; amount of thickness reflects the amount of work (workload)

Front 22

Fibrous Skeleton of the Heart

Back 22

four dense connective tissue rings surrounding the 4 valves; interconnect; structural, and is electrical insulation between atria and ventricles

Front 23

Valves of the Heart

Back 23

keep blood flowing in one direction; prevent backflow

Front 24

Atrioventricular Valves

Back 24

there are two of these; between atria and ventricles; Ventricular contraction (systole) tightens the tendons to keep the flaps closed

Front 25

Papillary Muscle

Back 25

extensions of muscle attach to chordae tendineae which attach to valves; tighten valves during force of contraction so they remain sealed

Front 26

Chordae Tendineae

Back 26

tendon-like strips of connective tissue that hold valves in place

Front 27

Right atrioventricular valve

Back 27

tricuspid valve

Front 28

Left Atrioventricular Valve

Back 28

Bicuspid or Mitral Valve

Front 29

Semilunar Valves

Back 29

there are two of these; in the two great arteries that exit the ventricles; each valve is a little pocket; when backflow blood fills them, they close off the opening (lumen) of the vessel

Front 30

Pulmonary Semilunar Valve

Back 30

valve in the pulmonary trunk

Front 31

Aortic Semilunar Valve

Back 31

valve in the ascending aorta

Front 32

Systemic Circulation of Blood

Back 32

from left ventricle to the body and back to the right atrium; delivers oxygen rich blood to tissues and returns oxygen poor blood

Front 33

Pulmonary Circulation of Blood

Back 33

from right ventricle to the lungs and back to the left atrium; delivers oxygen poor blood to the lungs and returns oxygen rich blood to the heart

Front 34

Blood Flow Through the Heart

Back 34

superior and inferior vena cava and coronary sinus to the right atrium to the right AV valve to the right ventricle to the pulmonary semilunar valve to the pulmonary trunk to the right and left pulmonary arteries to the pulmonary capillaries of the lungs to the pulmonary veins to the left atrium to the left AV valve to the left ventricle to the aortic semilunar valve to the aorta to the systemic capillaries of the body to the superior and inferior vena cava and coronary sinus

Front 35

Coronary Circulation/Heart Blood Supply

Back 35

this type of circulation provides continual oxygen supply to the heart (there is a limited supply of reserve oxygen in myoglobin)

Front 36

Coronary Arteries

Back 36

first arteries off the aorta (left and right)

Front 37

collateral circulation

Back 37

branching vessels interconnect between larger vessels so if one artery is blocked, part of the area that was fed will continue getting oxygen via another route

Front 38

Anastomoses

Back 38

interconnecting blood vessels (two ore more arteries usually supply the same region; this term refers to where these connect)

Front 39

Aerobic Exercise

Back 39

increases coronary circulatory branching

Front 40

Coronary Veins

Back 40

blood drains from the tissues of the heart , to the coronary sinus via these veins

Front 41

Coronary Sinus

Back 41

lowers the "back pressure" to facilitate drainage; drains blood from the veins serving the heart itself; located on the posterior surface of the right atrium

Front 42

Myocardial Ischemia

Back 42

insufficient oxygen to an area of the heart wall

Front 43

Hypoxia

Back 43

condition of low oxygen

Front 44

Angina Pectoris

Back 44

ischemia of the heart causes this pain; an area is blocked and therefore not getting enough oxygen; not a heart attack but could precede one; indicates temporary to permanent damage; usually felt during exertion

Front 45

Silent Myocardial Ischemia

Back 45

low oxygen to heart tissues without pain and therefore without awareness

Front 46

Myocardial Infarction

Back 46

blood supply to some heart cells blocked and cells have died; individual survives if area is confined and not within vital portions of the conduction system

Front 47

Intrinsic Conduction System

Back 47

cardiac muscle cells without contractile proteins; instead are for intrinsic regulation of heart rate; with influence via ANS

Front 48

Autorhythmic Cells/Self-excitability

Back 48

need no outside stimulation

Front 49

Sinoatrial (SA) Node

Back 49

"Pacemaker"; beat is normally initiated here and conducts signal to the rest of the heart; on the posterior side of the right atrium; 100 bmp, slowed via parasympathetic to "normal"

Front 50

Ectopic Pacemaker/Focus

Back 50

coordinates contractions of the heart instead of SA node...abnormal location or in addition to SA node; causes arrhythmias

Front 51

Atrioventricular (AV) Node

Back 51

secondary pacemaker if SA node stops; location is in the interatrial septum; gets impulse from the SA node

Front 52

Atrioventricular (AV) Bundle (Bundle of His)

Back 52

signal transfers to here from the AV node, then to bundle branches

Front 53

Right and left bundle branches

Back 53

signal passes through here, then to the Purkinje fibers

Front 54

Conduction Myofibers (Purkinje Fibers)

Back 54

releases impulse to ventricles

Front 55

Electrocardiogram

Back 55

measures heart's electrical activity

Front 56

P Wave

Back 56

atrial depolarization causes this on EKG (contraction of the atria follows)

Front 57

QRS Wave (Complex)

Back 57

ventricular depolarization causes this on EKG (contraction of the ventricles follows); (atrial repolarization is masked)

Front 58

T Wave

Back 58

on EKG - ventricular repolarization (Na, Ca, and K return to "normal")

Front 59

Disorders detected by EKG

Back 59

location of heart attack damage; rhythm disorders; heart blocks; electrolyte imbalance

Front 60

Diastole

Back 60

heart is relaxed, dilated and filling

Front 61

Systole

Back 61

heart is contracting to pump blood out

Front 62

lubb

Back 62

AV valves close (sound)

Front 63

dupp

Back 63

semilunar valves close (sound)

Front 64

Cardiac Output

Back 64

5-6L/min...5.25 L/min average; CO = SV (mL/beat) X HR (beats/min)

Front 65

Stroke Volume

Back 65

volume out per ventricle with each beat; 50-70ml average

Front 66

Heart Rate

Back 66

60-100 bpm; about 70 bpm average

Front 67

Stress, Exercise and high Ca

Back 67

increase HR and SV, thus CO

Front 68

increased cardiac output

Back 68

lowered blood pressure creates CV center sympathetic response

Front 69

decreased cardiac output

Back 69

high blood pressure creates CV center parasympathetic response

Front 70

Cardiac Reserve

Back 70

amount of capable increase in output; about 3-4x (if aerobically active individual - up to 10x)

Front 71

Preload

Back 71

effect of stretching (Frank-Starling Law of the heart) - a greater amount of stretch, due to increase amounts of blood in a chamber in diastole, will cause a greater amount of contraction during systole; will equalize the output to systemic circulation to that of pulmonary circulation; law is in effect to a maximum point

Front 72

Contractility

Back 72

the strength of contraction at any given preload; thus, stretching increases

Front 73

Afterload

Back 73

the amount of pressure to open a semilunar valve (which occurs after ventricular contraction)

Front 74

Congestive Heart Failure

Back 74

heart pumps less efficiently; preload increases beyond what the heart (Frank-Starling Law) compensates for; when over-stretched, the heart actually decreases in contractility; potential life-threatening positive feedback loop

Front 75

Medulla (cardiovascular center)

Back 75

tells heart to speed up or slow down...not when to beat

Front 76

Chemoreceptors, baroreceptors (pressoreceptors) and proprioceptors

Back 76

all feed information into the medulla

Front 77

endocrine glands release epinephrine (adrenal medulla)

Back 77

chemical regulation of heart rate (hormones and ions)

Front 78

age, gender, physical fitness, body temperature

Back 78

factors in heart rate regulation

Front 79

exercise and the heart

Back 79

regulates ratio of lipoproteins 9ncreases HDLs; decreases LDLs and VLDLs); Increases cardiac output and coronary circulation. This increases the chances of surviving a heart attack. It also increases skeletal muscle circulation, so muscle cells have a better oxygen supply

Front 80

Coronary Artery Disease (CAD)

Back 80

condition of inadequate coronary blood supply

Front 81

Atherosclerosis

Back 81

risk factors are smoking, diabetes mellitus, and high blood pressure; fat accumulation in walls of blood vessels - starts in areas of branching; most common sites are cerebra, coronary and renal; increased collateral circulation is protective

Front 82

diagnosis of CAD

Back 82

include cardiac catheterization and cardiac sonography

Front 83

treatment of CAD

Back 83

coronary artery bypass grafting, coronary angioplasty and stent

Front 84

fibrillation (flutter)

Back 84

disorganized contraction

Front 85

heart block

Back 85

action potential doesn't get through all the autorhythmic fibers (skipped beats)

Front 86

premature ventricular contraction

Back 86

ventricles lack filling; can overlap atrial contraction