HA - Heart

heart

primary pump for the human body

about 2/3rds of the heart is located to

the left of the midsternal line

the base of the heart is located at the

top of the heart

the apex of the heart points toward the

left hip

Pericardium

double-walled sac that encloses and keeps the heart in place

the pericardium is composed of

the fibrous pericardium and the serous pericardium

fibrous pericardium

outer membrane

dense connective tissue

encloses and anchors the heart

layers of the serous pericardium

parietal layer and visceral layer

Serous pericardium

inner membrane

parietal layer

lines internal surface of the fibrous pericardium

visceral layer (epicardium)

attaches to the heart muscle (myocardium)

pericardial cavity

space between parietal and visceral layers

filled with serous fluid

helps decrease friction as the heart moves

cardiac tamponade

excess fluid accumulation, puts pressure on the heart which limits contraction and reducing blood flow

pericarditis

inflammation of the pericardium

epicardium

thin, protective outer visceral layer of the serous pericardium

myocardium

middle layer, composed of cardiac muscle tissue and bulk of heart wall

endocardium

lines the inside of the heart and covers the heart valves

endothelium

epithelial membrane covering the endothelium

atria

small thin walled upper chambers

atria primary function

receive incoming blood from the body

auricles

small earlike extensions of the atria that increases the chamber surface area

interatrial septum

separates the 2 atria from each other

pectinate muscle

protective muscle covering the inner wall of the atria

fossa ovalis

scar that remains in the adult heart from the foramen ovale

foramen ovale

blood bypass for the pulmonary circuit in a fetal heart

coronary sulcus

external groove on the heart that separates the atria from the ventricles

ventricles

lower heart chambers making up the bulk of the heart

interventricular septum

wall separating the ventricles

ventricles function

pumping blood to the body

trabeculae carneae

ridges on the internal surface of each ventricle, prevents the walls of the ventricles from sticking together

anterior and posterior interventricular sulci

separates the ventricles in the external surface of the heart

ductus arteriosus

a bypass between the pulmonary artery and the aorta, allows blood to bypass the pulmonary circuit

heart valves function

ensure blood flows in one direction through the heart

tricuspid valve

consists of 3 flaps or cusps and is located between the right atrium and ventricle

valve flaps are made of 

connective tissue

bicuspid (mitral) valve

consists of only 2 cusps and is located between the left atrium and ventricle

chordae tendinae

attach the cusps to the papillary muscles

papillary muscles

muscles lining the inside of ventricles and control the AV valves

AV valves when the heart is relaxed

hang down into the ventricular chamber

AV valves when the heart is contracted

shut tight disallowing blood flow

semilunar valves

between ventricles and major arteries and prevent back flow of blood into the ventricles

incompetent valve

does not open or close, very inefficient

valvular stenosis

valve flaps become stiff and constrict the opening

mitral valve prolaps

in 1% of the population, most common in young women, valve flaps become incompetent

pulmonary circulation

carried out by the right side of the heart

blood pumped into the lungs and back to the left side of the body

systemic circulation

carried out by the left side of the heart

blood is pumped to and from the body

coronary circulation

blood flow to and from the heart muscle

left coronary artery carries blood to the

wall of the heart

the left coronary artery branches into the

anterior interventricular branch and the circumflex branch

anterior interventricular branch carries blood to the

apex of the heart

circumflex branch carries blood to the

atrium and posterior part of the heart wall

right coronary artery carries blood to the

wall of the right atrium and to the SA node

angina pectoris

inadequate blood supply to the myocardium

ischemia

reduced oxygen supply to the heart

myocardial infarction

heart attack or coronary

infarction

death of tissue due to interrupted blood supply

streptokinase

treats clot blockages by dissolving them

cardiac muscles are _____ and _____ and contract via the sliding filament theory

striated; involuntary

intercalated discs

only found in cardiac muscles, provide support and strength to contractions

autorhythmicity

muscle fibers contracting in a coordinated fashion

cardiac muscle has limited ability to

repair and regenerate

cardiac conduction system

sinoatrial (SA) node

atrioventricular (AV) node

atrioventricular bundle (bundle of his)

R and L bundle branches

purkinje fibers

Sinoatrial Node (SA Node)

located in the right atrial wall

produces impulse that begin heart muscle contraction

SA Node is the

pacemaker of the heart

Atrioventricular Node (AV Node)

located in the lower portion of the interatrial septum

pulses delayed briefly to allow for complete contraction of the atria

Atrioventricular Bundle (Bundle of His)

located in the inferior portion of the interatrial septum

the only connection between the atria and ventricles

Purkinje fibers

carry impulses completely throughout the interventricular septum and to the apex of the heart

arrythmias

irregular heart rhythem

tachycardia

abnormally fast heart rate

>100 BMP

bradycardia

slow heart rate

<60 BPM

fibrillation

rapid, irregular and uncoordinated heart contractions

interrupt blood flow out of the heart

ectopic focus

abnormal pacemaker

medulla oblongata

controls and regulates much of the hearts activity

cardiac cycles

events that occur during 1 complete heartbeat

systole

contraction and emptying of the heart chambers

diastole

relaxing and filling of heart chambers

Lubb

produced by the closing of the AV valves during ventricular systole

Dubb

2nd heart sound occurs at the end of ventricular systole as the semilunar valves close

heart murmers

abnormal heart sound caused by incomplete closing of the valves

stenosis

change in valve shape

electrocardiogram (EKG or ECG)

measurement of the electrical impulses though the heart

waves of an EKG

P Wave

QRS Complex

T Wave

P wave

1st wave

very small

result of atrial depolarization

QRS Complex

2nd waves

large

results from ventricular depolarization

T Wave

3rd wave

representative of ventricular repolarization

cardiac output (CO)

amount of blood pumped out by each ventricle in 1 min

Autonomic Nervous System (ANS)

runs to the SA and AV node

divisions of the ANS

sympathetic and parasympathetic

sympathetic division

under stress or fear nerves force the release of norepinephrine and epinephrin from the adrenal gland

parasympathetic division

reduced heart rate following stress

baroreceptors

can respond to BP changes

hormones regulating the heart

norepinephrine, epinephrine, and thyroxine

ions regulating the heart

calcium ion, sodium ion, and potassium ion

endocardial tube

appear 19 days after conception

fuse together over 10 days to develop the fetal heart

congestive heart failure

pumping efficiency of the heart is so low that blood circulation of inadequate to meet tissue demands

circulatory shock

cardiac output is reduced so that body tissue does not recieve an adwquate blood supply

catheterization

catheter is introduced into the bloof vessel and worked up into the heart

echocardiology

use of ultrasound to take pictures of the heart

risk factors in heart disease

high cholesterol

high BP

smoking

obesity

lack of Ex

age

genetics

gender

diabetes