Cardiology
is the study of the heart of normal heart and related disease.
the heart has 4 muscular chambers ____ that pump blood into vessels
right and left atria
right and left ventricles
the vessels is divided into two circuts
1. Pulmonary circuit
carries rich carbon dioxide-rich blood from the
heart to the gas exchange surface of the lungs and
returns oxygen-rich blod to the heart
2. systemic
circuit- transports oxygen-rich blood from the
heart to the rest of the body and returns oxygen rich blood
to the heart
arteries
blood away from the heart
veins
return blood to the heart
capillaries aka
exchange vessels
they exchange nutrients, dissolved gases and wastes
are small, thin walled vessels connecting veins and capillaries
The heart sits within the mediastinum, located between the
twopleural cavities. The pericardium, which surrounds the heart,
is composed of afibrous pericardium and a serous pericardium.
pericardium
surrounds the heart and has two parts
fibrous pericardium and serous pericardium
the fiberous pericardium is composed of
dense network of collagen fibers that stabilize the position of the heart
the lining of the pericardium is the serous periardium and has two layers
1. visceral layer aka epicardium (inner layr)
2.Parietal layer- (outer layer)
the pericardia fluid
acts as a lubricant, reducing friction between the opposing visceral
and parietal surfaces as the heart beats
layers of the heart from superficial to deep
outer epicardium
middle myocardium
inner endocardium
base of the heart
is a broad, superior portion of the heart, where it is attached to
the major arteries and veins of the systemic and pulmonary circuits
Apex of the heart
inferior, pointed tip and mainly formed by the left ventricle
the heart is slightly located
left
intercalated discs
cell-to-cell junction
The plasma membranes of two cardiac muscle cells are bound
together bydesmosomes. This locks the cells together and
prevents them from separating during contractions.
gap junction
action potential
pericarditis
infection of inflammation of the pericardium surrounding the heart
viral infection
myocarditis
inflammation of the myocardium
viral infection
blood clots, stroke
may require heart transplant
endocarditis
inflammation in the endocardium
always the result of bacterial infection, or fungal infection
fossa ovalis
vestige of former foramen oval ( a shunt from right atrium to left
atrium, allowing fetal blood to bypass non-ventilated lungs
the right ventricle
oxygen- poor blood flows from the right atrium through theright
AV valve and into the right ventricle. Blood flows from the right
ventricleinto the pulmonary trunk to enter the pulmonary circuit.
the left ventricle
has the thickest wall of any heart chamber. Its extra-thick
myocardium enables the left ventricle to develop enough pressure to
force blood around the entire systemic circuit.
the left atrium
The left and right pulmonary veins carry oxygen-rich blood
fromthe lungs to the left atrium. Blood flows from the left
atrium through the left AV valve into the left ventricle.
the structure and function of heart valves
The atrioventricular valves and the pulmonary and aortic
valvesprevent regurgitation of blood into the atria and
ventricles. The valves open andclose due to pressure changes as
the heart pumps blood.
coronary artery disease
the leading cause if death for women and men in the unites states
it occurs when arteries become hardened and narrowed due to the
build up of cholesterol, calcium, and plaque
the coronary veins
The heart is drained by the coronary sinus and the anterior cardiac
veins. The coronary sinus and the anterior cardiac veins empty into
the rightatrium
the pump function is to
1. develop pressure
2. move volume of fluid in a specific direction at an acceptable speed
the heart works in cycles of
systole (contraction)
and
diastole ( relaxation)
nodal cells establish
the rate of cardiac muscle do not contract
conducting cells
distribute the contractile stimulus to the myocardium
sinoatrial (SA) node
contains pacemaker cells that initiate the electrical impulse that
results in a heart beat
internodal pathways
are conducting fibers in the atrial wall that conduct the impulse to
the AV node while simultaneously stimulating cardiac muscle cells of
both atria
atrioventicular AV node
slows the electrical impulse when it arrives from the internodal pathways
AV bundle
cnducts the impulse from the AV to the bundle branches
left bundle branch
extends toward the apex of the heart and then radiates across the
inner surface of the left ventricle
right bundle branch
extends toward the apex of the heart and then radiatesacross
the inner surface of the right ventricle
moderator band
relays the stimulus through the ventricle to the
papillarymuscles, which tense the chordae tendineae before
theventricles contract
purkinje fibers
convey the impulses very rapidly to the contractilecells of the
ventricular myocardium
cardiac cycle complete heart beat consists of the systole and
diastole of both atria and both ventricles
0.8 seconds to complete
electrocardiogram (EKG)
recording of electrical changes that accompany cardiac cycle, useful
in diagnosing abnormal rhythms
at what age does a embryo develop his heart
5 weeks, lungs are nonfunctional
forman ovale in the fossa ovalis
between left and right atria