Heart & Heart Disease (Full)

Front 1

Circulation

Back 1

continuous one way circuit of blood through blood vessels propelled by the heart

Front 2

Location of the heart

Back 2

• between lungs in centre
• bit to left of body's midline
• occupies most of mediastinum
• heart's apex (pointed inferior portion) directed towards left

Front 3

Three tissue layers of heart

Back 3

• endocardium
• myocardium
• epicardium

Front 4

Endocardium

Back 4

• thin smooth layer of epithelial cells
• lines heart's interior
• provides smooth surface for easy flow of blood
• extensions of endocardium cover flaps of valves

Front 5

Myocardium

Back 5

• heart muscle
  
• thickest layer
• pumps blood through vessels

Front 6

Epicardium

Back 6

• serous membrane
• outermost layer of heart wall
• also considered visceral layer of pericardium

Front 7

pericardium

Back 7

• sac that encloses heart
• fibrous pericardium (outer layer)
• serous pericardium (inner layer, composed of 2 layers)

Front 8

myocardium special features

Back 8

• lightly striated
• single nucleus cells
• controlled involuntarily
• intercalated disks
• branching muscle fibers

Front 9

Right side of heart

Back 9

receives blood low in oxygen that has passed through body already and pumps it to lungs through pulmonary circuit

Front 10

Pulmonary circuit

Back 10

portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart.

Front 11

Left side of heart

Back 11

receives highly oxygenated blood from lungs and pumps it throughout body via systemic circuit

Front 12

Systemic circuit

Back 12

carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart

Front 13

Left/right heart chambers separated by:

Back 13

partitions called septum

- interatrial septum separates atria

- interventricular septum separated two ventricles

Front 14

interatrial septum

Back 14

partition separating two atria

Front 15

interventricular septum

Back 15

partition separating two ventricles

Front 16

Atria

Back 16

-upper chambers

- mainly blood receiving

Front 17

Ventricles

Back 17

- lower chambers

- forceful pumps

Front 18

vena cava

Back 18

large vein carrying deoxygenated blood into the heart

Front 19

inferior vena cava

Back 19

carries blood from the lower body

Front 20

superior vena cava

Back 20

carries blood from the head, arms, and upper body

Front 21

Right atrium

Back 21

- receives blood from body tissues

- returning blood carried in veins

Front 22

Right ventricle

Back 22

- receives blood from right atrium

- pumps it to lungs

Front 23

Left atrium

Back 23

- receives oxygen rich blood from lungs via pulmonary veins

Front 24

Left ventricle

Back 24

- pumps highly oxygenated blood to all of body

- blood goes into aorta first then into branching systemic arteries that take blood to tissue

Front 25

Valves

Back 25

- direct blood flow through heart

- located at entrance/exit of each ventricle
- 4 in total

Front 26

Atrioventricular valves

Back 26

ENTRNACE valves

Front 27

Semilunar valves

Back 27

EXIT valves

remember lunar/night = end = exit

Front 28

Right atrioventricular (entrance) valve

Back 28

- tricuspid

- 3 flaps that open/close
- when open, blood flows from right atrium to right ventricle

Front 29

Left atrioventricular (entrance) valve

Back 29

- bicuspid/mitral

- permits blood to flow from left atrium to left ventricle

- ensures forward blood flow into aorta

Front 30

chordae tendinae

Back 30

- thin fibrous threads to papillary muscles arising from walls of ventricles

- function is to stabilise valve flaps when ventricles contract to prevent backflow of blood when heart beats

Front 31

Pulmonary valve (exit)

Back 31

- located between right ventricle & pulmonary trunk

- prevents blood from returning to ventricle

Front 32

Aortic valve (exit)

Back 32

- located between left ventricle and aorta

- prevents backflow of blood from aorta into ventricle

Front 33

Back 33

-

Front 34

coronary circulation

Back 34

is the blood supply to myocardium

composed of:

- left coronary artery
- right coronary artery
- coronary sinus

Front 35

left coronary artery

Back 35

branches into circumflex artery and left-anterior descending artery

Front 36

right coronary artery

Back 36

snakes around heart inferior to right atrium
- gives off major branch called posterior descending artery

Front 37

coronary sinus

Back 37

dilated vein that opens into right atrium near inferior vena cava
- blood collect in coronary sinus after passing through capillaries in myocardium

Front 38

cardiac cycle (heartbeat)

Back 38

Heart muscle contraction begins in thin-walled upperchambers, atria, followed by contraction of thick muscle in lower chambers,ventricles.

Front 39

systole

Back 39

active phase, contraction

Front 40

diastole

Back 40

resting phase

Front 41

cardiac output

Back 41

volume of blood pumped by each ventricle in one minute is termed cardiac output (CO)

CO = HR x SV

Front 42

stroke volume

Back 42

volume of blood ejected from ventricle with each beat

Front 43

heart rate

Back 43

number of times heart beats per minute

Front 44

Heart conduction system

Back 44

heart muscle is stimulated to contract by electric energy passing along cells
- this action potential is generated by specialised tissue within heart
- 2 of these structures are tissue masses called nodes
- remainder consists of specialised fibers branching through myocardium

Front 45

Nodes (2 types)

Back 45

sinoatrial node
atrioventricular node

Front 46

sinoatrial node

Back 46

- initiates heartbeats by generating action potential at regular intervals
- also called pacemaker
- located in upper wall of right atrium in small depression describes as sinus

Front 47

atrioventricular node

Back 47

located in interatrial septum at bottom right atrium

Front 48

Specialised fibers (3 types)

Back 48

• Atrioventricular bundle (bundle of His)
  
• Purkinje fibers
• Intercalated disks

Front 49

Atrioventricular bundle (bundle of His)

Back 49

- fibers travel down both sides of interventricular septum in groups called right and left bundle branches
- located top of interventricular septum

Front 50

Conduction pathway (sinus rhythm)

Back 50

• Sinoatrial node
• Atria
• Atrioventricular node
• Internodal pathways
• Bundle of his
• Bundle branches and Purkinje fibers
• Ventricles

Front 51

Sinus rhythm

Back 51

normal heart rhythm originating at sinoatrial node

Front 52

Control of heart rate (3 systems)

Back 52

• autonomic nervous system
• sympathetic nervous system
• parasympathetic nervous system

Front 53

autonomic nervous system influence on heart

Back 53

modifies heart rate according to changing body conditions

Front 54

sympathetic nervous system influence on heart

Back 54

• stressors (excitement) activate SNS
• increase contraction rate by stimulating nodes
  
• increases contraction force

Front 55

parasympathetic nervous system influence on heart

Back 55

• decreases heart rate
  
• cranial nerve x - slows heart by acting on nodes, does not influence stroke volume

Front 56

Bradycardia

Back 56

slow heart rate
less than 60bpm

Front 57

Tachycardia

Back 57

heart rate more than 100bpm

Front 58

sinus arhythmia

Back 58

regular variation in heart rate
caused by changes in rate/depth of breathing

Front 59

premature ventricular contraction (PVC)

Back 59

ventricular contraction initated by Purkinje fibers instead of SA node

Front 60

Lub

Back 60

• first heart sound
  
• longer/lower pitches
• caused by close of AV valves

Front 61

Dub

Back 61

• shorter/sharper than lub
• occurs beginning ventricular relaxation
• caused by sudden closure of semilunar valves

Front 62

Murmur

Back 62

any abnormal sound heard

Front 63

Murmur types (2)

Back 63

• Organic murmur
  
• Functional murmur

Front 64

Organic murmur

Back 64

any abnormal sound caused by structural change in heart or vessels connected with heart

Front 65

functional murmurs

Back 65

normal sounds such as rapid filling of ventricles

Front 66

heart studies (4)

Back 66

• stethoscope
• Electrocardiograph (ECG or EKG)
• Catheterization
• Echocardiography

Front 67

Electrocardiograph

Back 67

• electrodes placed on skin to pick up electrical heart activity

• represents activity as waves

Front 68

catheterization

Back 68

thin tube passed through veins of arm or groin then into right side of heart

Front 69

echocardiography

Back 69

high frequency sound waves sent to heart from small instrument on chest surface

recorded as they return from bouncing off heart

Front 70

Heart inflammation (3 types)

Back 70

• Endocarditis
  
• Myocarditis
  
• Pericarditis
  

Front 71

Endocarditis

Back 71

• inflammation of heart lining
• inflammation of endocardium covering valves
• S&S: fever, systemic infection, murmur, anorexia, malaise, lethargy, cough, diarrhoea

Front 72

Myocarditis

Back 72

• inflammation of heart muscle
• caused by viruses or secondary infection or cocaine
• S&S: flulike symptoms, malaise, tachycardia, low grade fever

Front 73

Pericarditis

Back 73

• inflammation of serous or fibrous membrane surrounding heart
• occur secondary to other systemic or cardiac diseases
• S&S: chest pain abrupt in onset, can only breathe sitting up and leaning forward

Front 74

arrhythmia

Back 74

abnormal rhythm of heartbeat

Front 75

flutter

Back 75

heartbeat up to 300bpm

Front 76

fibrillation

Back 76

300-600bpm

- must be corrected by defibrillator

Front 77

heart block

Back 77

interruption of electrical impulses in heart's conduction system

Front 78

correction of arrhythmias

Back 78

- artificial pacemakers
- implantable cardioverter-defibrillator

Front 79

Congenital heart disease

Back 79

problems with heart's structure that are present at birth

• atrial septal defect
• patent ductus arteriosus
• ventricular septal defect
• coarctation of aorta
• tetraology of fallot

Front 80

Rheumatic heart disease

Back 80

• caused by streptococci release of toxins during infection
• antibodies containing toxins attack heart valves
• heart valves become inflamed
• valve cusps thicken/harden
• pulmonary congestion occurs

Front 81

Coronary artery disease

Back 81

involves walls of blood vessels that supply heart muscle

Front 82

types of coronary artery disease (3)

Back 82

- myocardial infarction
- angina pectoris
- atherosclerosis

Front 83

Myocardial infarction

Back 83

• sudden occlusion of coronary vessel obstructing blood flow to heart muscle
• results in death of muscle (necrosis)

Front 84

Angina pectoris

Back 84

• moderate ischemia causes characteristic discomfort felt in region of heart and left arm/shoulder
  

Front 85

Atherosclerosis

Back 85

• Lumen (space) in blood vessels gradually narrow
  
• causes thickening/hardening of blood vessels with loss of elasticity
  
• Leads to ischemia
  
• Results in blood clot (thrombus) formation
  

Front 86

Heart failure

Back 86

• heart unable to pump sufficient blood
• heart chambers enlarge
• blood backs up into lungs
• ventricular muscles have decreased ability
• fluid accumulates in lungs, liver abdomen and legs
  S&S: fluid retention, oedema, shortness of breath, fatigue, malnutrition, cyanosis, tachycardia