Beckyo - Chapter 20 - The Heart

Front 1

Pulmonary circuit

Back 1

blood vessels that carry blood to an from the gas exchange surfaces of the lung

Front 2

Systemic Circuit

Back 2

blood vessels that carry blood to and from the rest of the body's tissues

Front 3

Arteries

Back 3

efferent vessels

carry blood away from the heart

Front 4

Veins

Back 4

afferent vessels

carry blood toward the heart

Front 5

Capillaries

Back 5

exchange vessels

small, thin-walled vessels between the smallest veins and arteries

Front 6

What allows for the exchange of nutrients, dissolved gasses, and waste products between the blood and the surrounding tissues?

Back 6

The simple squamous cell walls of the capillaries

Front 7

Pericardial cavity

Back 7

cavity that surrounds the heart

Front 8

mediastinum

Back 8

the region of the heart between the two pleural cavities that contains the heart and the great vessels of the heart, thymus, esophagus and trachea.

Front 9

Pericardium (parts of)

Back 9

a. pericardium

b. visceral pericardium

c. parietal pericardium

Front 10

Pericardium (definition)

Back 10

lining of the pericardial cavity

Front 11

Visceral pericardium

Back 11

epicardium

membrane that overs the outer surface fo the heart

serous membrane closest to the heart

Front 12

Parietal Pericardium

Back 12

lines the inner surface of the pericardial sac

serous membrane closest to the body cavity

Front 13

Pericardial sac

Back 13

fibrous pericardium

dense network of collagen fibers that surrounds the heart

stabilizes the position of the heart and the associated vessels of the mediastinum

Front 14

Pericardial fluid

Back 14

10-20 ml of serous fluid inside the pericardial cavity

secreted by the pericardial membranes

acts as a lubricant reducing the friction between opposing surfaces as the heart beats

Front 15

Pericardiatis

Back 15

inflammation of the pericadium due to pathogenic infection

leads to increased friction and irritation of the pericardial membranes

As a result, the pericardium produces more pericardial fluid which restricts the movement of the heart

the rubbing produces a distinct scratching sound

Front 16

Cardiac tamponade

Back 16

restricted movement of the heart due to pericardium inflammation and increased pericardial fluid inside the pericardial cavity or bleeding in the pericardial cavity

Front 17

Atrial Auricle

Back 17

expandable appendage of the atrium

Front 18

Coronary Sulcus

Back 18

deep groove that marks the border between the atria and ventricles

Front 19

Anterior and posterior interventricular sulci

Back 19

mark the boundary between the left and right ventricles

Front 20

Base

Back 20

where the great veins and arteries of the circulatory system are connected to the superior end of the heart

at the level of the third costal cartiliage

Front 21

Apex

Back 21

the inferior pointed tip

points to the left of the anterior side

Front 22

Heart wall consists of

Back 22

a. epicardium

b. myocardium

c. endocardium

Front 23

Epicardium

Back 23

visceral pericardium

serous membrane that covers the heart

Front 24

Myocardium

Back 24

muscular wall of the heart that forms both the atria and the ventricles

contains the cardiac muscle tissue, nerves, and blood vessels

Front 25

Endocardium

Back 25

most inner surface of the heart

comprised of simple squamous epithelium

Front 26

Cardiocytes

Back 26

cardiac muscle cells

connected by intercalated discs

Front 27

intercalated discs

Back 27

coordinate the force of the contraction from cardiocyte to cardiocyte

propogate action potentials

Front 28

Histological differences between cardiac and skeltal muscle cells

Back 28

a. cardiocytes are smaller than skeletal muscle fibers

b. most cardiocytes have a single centrally located nucleus

c. cardiac muscle tissue has branching interconnections, intercalated discs

Front 29

Interaterial septum

Back 29

thin muscular partition dividing the atria

Front 30

Interventricular septum

Back 30

thick muscular partition dividing the ventricles

Front 31

Atrioventricular (AV) valves

Back 31

folds of fibrous tissue that extend into the openings between the atria and ventricles

blood flows through theses vales only one way (from A to V)

AV valves close when ventricles contract and open when ventricles relax

Front 32

Superior Vena Cava and Inferior Vena Cava

Back 32

the two great veins that feed blood into the R atrium from the systemic circuit

SVC carries blood from the tissues of chest, arms and on up

IVC delivers blood to the R Atrium from tissues below the chest

Front 33

Coronary Sinus

Back 33

large, thin walled vein that opens into the R Atrium

Coronary veins feed into the coronary sinus

Front 34

Pectinate muscles

Back 34

prominent muscular ridges that run along the inner surface of the auricle and across the atria wall

Front 35

Foramen ovale

Back 35

an oval opening between the atria that stays open from the 5th week of gestation until birth

allows for the mixing of blood as the lungs develop.

Front 36

Fossa ovalis

Back 36

the shallow remnant of the foramen ovale in the adult

Front 37

Right AV valve (Tricuspid valve)

Back 37

the valve w/ three fibrous cusps between the R Atria & R ventricle

the AV valve closes when the R ventricle contracts.

Front 38

Regurgitation

Back 38

backflow of blood

Front 39

Cusps

Back 39

flaps of valves

Front 40

chordae tentineae

Back 40

tendinous connective tissue that attaches the cusps to papillary muscles of the inner surface of the ventricle.

hold onto the cusps and prevent them from swinging backwards into the atria

Front 41

trabeculae Carneae

Back 41

muscular ridges on the inner surface of the ventricle.

contains a portion of the conducting system -- helps coordinate contractions of muscle cells

Front 42

Pulmonary semilunar valve

Back 42

comprised of 3 semilunar cusps

blood leaves the R ventricle through this valve to enter the pulmonary circuit via the pulmonary trunk

Front 43

The L Atrium receives blood through which blood vessels?

Back 43

R & L Pulmonary veins

Front 44

Left AV Valve or mitral valve

Back 44

valve with two cusps where blood goes through the left atria to the left ventricle

Front 45

Anatomical differences b/t L and R ventricles

Back 45

a. anatomical differences reflect the functional demands placed on them

b. Wall of R Ventricle is relatively thin when compared to the L Ventricle, despite the blood volume is equal

c. left ventricle has a massive muscular wall to pump the blood to all the periphery tissue of the body

Front 46

General bacterial endocarditis

Back 46

oral bacteria gets into the blood stream after dental procedures or dental surgery and causes inflammation of the endocardium

Front 47

Cardiomyopathies - definition

Back 47

shared sign is a progressive, irreversible degeneration of the myocardium. damaged cardiocytes are replaced with fibrous tissue

Front 48

Cardiomyopathies - mechanisms

Back 48

a. muscle walls become thin and weak

b. decrease in heart muscle tone

c. increase in ventricle chamber

d. contractions can not meet cardiac output demand

e. eventually heart failure

f. common causes - alcoholism, coronary artery disease, other infectious agents and muscular dystrophies

Front 49

Hypertrophic cardiomyopathy

Back 49

inherited disorder

L ventricle wall is too thick to pump efficiently

doesn't know until later in life

can cause fatal arrhythmia and sudden death; can control arrhythmia with a pacemaker

Front 50

Rhuematic Fever (definition)

Back 50

Untreated streptococcal infection (strept throat)

inflammatory condition that causes high fever, joint pain, stiffness and distinctive full body rash

Front 51

Rhuematic Fever (mechanisms)

Back 51

a. typically affects children 5-15 years old

b. obvious symptoms last < 6 weeks

c. in severe cases, symptoms last 6 months or more

d. the longer the duration of the inflammation, the more likely the carditis

e. if carditis, then scar tissue gradually forms in the myocardium and the heart valves

f. valves deteriorate over time, may not cause heart problems until 10-20 years after the initial infection

Front 52

Valvular stenosis

Back 52

valves thicken and may calcify

narrow valve orifices

Front 53

Rheumatic Heart disease (RHD)

Back 53

clinical disorder that originated from rheumatic fever

a. valvular stenosis

b. regurgitation due to rough, irregular cusp edges that don't completely close

c. heart more susceptible to infection

e. # of cases of RHD decreased since 1940s due to early detection of strept throat and early treatment w/ antibiotics

Front 54

Fibrous Skeleton of the Heart

Back 54

consists of 4 tough bands of tough elastic tissue that encircle the bases of the pulmonary trunk and aorta

helps to stabilize the heart valves

provides electrical insulation to the heart

Front 55

Coronary arteries

Back 55

originate from the base of the ascending aortic arch

Blood pressure from the coronary arteries is the highest in the systemic circuit to meet the demands of the heart

Front 56

Right Coronary Artery

Back 56

supplies the R atria, portions of both ventricles, and parts of the conducting system

Front 57

Left Coronary Artery

Back 57

supplies blood to the left ventricle, left atria, and the intervenetricular septum

Front 58

Anastomoses

Back 58

arterial interconnections that maintain a constant blood supply to the heart, even as the blood pressure fluctuates

Front 59

What vessels carry blood from the coronary capillaries to the coronary sinus ?

Back 59

great, posterior, small, anterior and middle cardiac veins

Front 60

Coronary Artery Disease

Back 60

partial or complete blockage in areas of the coronary circulation

Front 61

Coronary Ischemia

Back 61

results if coronary arteries are partially or completely blocked depriving the heart of oxygen and nutriends

Front 62

what are some sources for a blockage?

Back 62

Plaques (fatty deposits on the walls of coronary arteries)

thrombus (blood clot on the inner surface of a vessel wall)

Front 63

what are some diagnostic techniques to detect plaques and circulatory conditions of the heart?

Back 63

Angiography and DSA (digial subtraction angiography)

Front 64

Ischemia

Back 64

no oxygen in tissue

tissue initially blanches due to lack of oxygenated blood flow

Front 65

Infarct

Back 65

dead, non-functional tissue

Front 66

Angina pectoris

Back 66

chest pain, early symptom of CAD

Front 67

Nitroglycerin

Back 67

vasodilator

Front 68

Catheter

Back 68

narrow tube that assists the surgical removal of plaque

Front 69

Ballon Angioplasty

Back 69

inflatable balloon at the tip of a catheter to push soft plaques against the vessels wall

Front 70

Coronary Artery Bypass graft

Back 70

place a piece of the patients artery or vein from another region of the body to bridge or bypass the plugged coronary artery

Front 71

Contractile cells

Back 71

produce powerful contractions that push the blood in the correct direction

Front 72

Cells of the conducting System

Back 72

specialized muscle cells that control and coordinate the activities of the contractile cells

Front 73

Sequence of the Conducting System

Back 73

1. SA Node

2. internodal pathway

3. AV node

4. AV bundle

5. Bundle Branches

6. Purkinje cells

Front 74

What cells establish the rate of cardiac contraction?

Back 74

nodal cells

Front 75

SA node

Back 75

cardiac pacemaker; natural pacemaker

embedded in the posterior wall of the R atrium

contains pacemaker cells that establish heart rate

Front 76

How long does the sequence of the conducting system take?

Back 76

225 milliseconds

Front 77

the maximum rate the AV node can conduct impulses

Back 77

230 per minute

heart cannot exceed 230 beats per minute

Front 78

bradycardia

Back 78

HR is below 50bpm

Front 79

tachycardia

Back 79

HR is above 100 bpm

Front 80

Electrocardiogram (ECG or EKG)

Back 80

recording of the electrical activies of the ehart

Front 81

Leads

Back 81

monitoring electrodes placed on the body for an EKG

the placement of the electrodes on the body affects the size and shape of the waves recorded

Front 82

P wave

Back 82

small blip indicating atrial depolarization

voltage-regulated Na+ channels open and get an influx of Na+ inside the cardiocyte

Front 83

QRS complex

Back 83

sharp and tall peak that is indicative of ventricle depolarization.

ventricles begin to contract after the peak of the R wave

Front 84

T wave

Back 84

ventricular repolarization

K+ channels open, cardiocytes lose K+

Front 85

small t wave

Back 85

ventricles are not repolarizting normally

indicates problems with the heart's condition (starvation, low cardiac energy reserves, coronary ischemia, or abnormal concentrations)

Front 86

Extension of the P-R Interval

Back 86

can mean damage to the conducting pathway or the AV node

Front 87

Extension of the Q-R interval

Back 87

conveys conducting problems, coronary ischemia or myocardial damage

Front 88

Cardiac arrythmias

Back 88

can be detected by EKG as abnormal patterns of cardiac electrical activity

momentary are not life threatening, but persistent oens can be

Front 89

Cardiac cycle (molecular)

Back 89

1. Fast voltage gated Na+ channels open to depolarize

2. Slow to close Ca2+ voltage-regulated channels casue an extended plateau/refractory period

3. Slow K+ channels for repolarization

4. Action Potential lasts 30 times longer than skeletal muscle

Front 90

ventricular systole

Back 90

contraction

Front 91

ventricular diastole

Back 91

relaxation

Front 92

End Disastolic Volume (EDV)

Back 92

the amount of blood in each ventricle at the end of ventricular diastole.

EDV is the max amount of blood each ventricle contains for that cardiac cycle

adult @ rest is 130ml

Front 93

Isovolumetric contractrion

Back 93

in the ventricle valves are closed, volume is constant and pressure is rising

Front 94

Ventricular ejection

Back 94

semilumar valves open and blood ejects through the aortic and pulmonary trunks

Front 95

Stroke Volume (SV)

Back 95

the volume of blood pumped out of each ventricle during a single heart beat

roughly 60% of EDV

SV= EDV - ESV

Front 96

End Systolic volume (ESV)

Back 96

the amount of blood remaining in each ventricle when the semilunar vavles close at the end of ventricular systole

40% of EDV

Front 97

Congestive Heart Failure

Back 97

a condition when one or two of the ventricles are damaged

the heart can no longer maintain adequate flow to the rest of the body

Front 98

Auscultation

Back 98

listening to the heart, normally through a stethescope

Front 99

heart sounds (4)

Back 99

s1 - lubb - AV valves close

s2 - dubb - semilunar valves close

s3 - blood flowing through ventricles

s4 - atrial contraction

Front 100

Mitral Valve Prolapse

Back 100

Mitral valves do not close properly

may be due to abnormal length length of chordae tendinae or malfunctioning papillary muscles. As a result, regurgitation occurs during ventricle contraction

Regurtitation of blood makes sounds (heart murmur) of rushing or gurgling. Extreme mitral valve prolapse can be life threatening

Front 101

Heart Attacks

Back 101

myocardial infarction

occurs when coronary arteries are blocked (usually from CAD) and cardiac cells die; the dead or nonfunctional region is an infart

as scar tissue forms in the damaged region, the heartbeat becomes irregular and circulatory problems persists

Front 102

Coronary Thrombosis

Back 102

blood clot forms on a plaque in a coronary wall

Front 103

Cardiodynamics

Back 103

movements and forces generated during cardiac contractions.

Each time the heart beats, the two ventricles eject equal volumes of blood

Front 104

Cardiac Output (CO)

Back 104

the amount of blood pumped by each ventricle in one minute

CO (ml/min) = SV (ml/min) X HR (beats/min)

Front 105

EDV factors affecting Stoke Volume

Back 105

a. Filling Time - amt of time the vent has to fill (dependent on HR)

b. Venous return

c. Preload - degree of stretching during ventricular diastole, directly proportional to EDV. Frank-sterling Principle

Front 106

Frank-Sterling Principle

Back 106

the greater the EDV, the greater the stroke volume

Front 107

ESV factors affecting Stoke volume

Back 107

a. contractibility - the amt of force produced during a contraction.

b. afterload

Front 108

afterload

Back 108

the amount of tension the contracting ventricle must produce to force open the semi-lunar valve to eject the blood (due to back pressue of blood on the other side of the valve)

as afterload increases, the stoke volume decreases