A&P Chapter 18 & 19 The Heart
chordae tendineae
"heart strings" which anchor the cusps to the papillary muscles protruding from the ventricular walls
myocardium infarction
HEART ATTACK
cardiac pacemaker
SA node
titanic contractions
__ cannot occur in cardiac muscles
fibrillation
a condition of rapid and irregular or out of phase contractions in which control of heart rythm is taken away from the SA node by rapid activity in other heart regions
serous pericardium
a thin slippery two- layer serous membrane that forms a closed sac around the heart
visceral layer
also called the epicardium, which is an integral part of the heart wall
ectopic focus
an abnormal pacemaker
LAD
another name for the anterior ventricular artery
functional synctium
because gap junctions electrically couple cardiac muscles, the myocardium behaves as a single coordinated unit called a ___
high to low
blood flows through the heart from atria to ventricular which is ___ to ___
pectinate muscles
bundles of muscle that resemble the teeth of a comp
apical impulse
caused by your beating hearts apex where it touches the chest wall
automaticity
cells that spontaneously depolarize
coronary sinus
collects blood draining for the myocardium
purkinjie fibers
completes the pathway through the inter ventricular septum penetrates into eh heart apex and then turns superiorly into the ventricular walls
intercalated discs
connect cardiac muscle fibers into a functional synctium
intrinsic conduction system
consists of noncontractile cardiac cells specialized to initiate and distribute impulses throughout the heart
pericardial cavity
contains a film of serous fluid
bundle branches
course along the inter ventricular septum toward the heart apex
right coronary artery
courses to the right side of the heart, where it also gives rise to two branches
anterior interventricular sulcus
cradles the anterior inter ventricular artery
vagus nerve
decreases heart rate
potassium
element that repolarizes
coronary sinus
empties the blood into the right atrium
coronary sulcus
encircles the junction of the atria and ventricles like a crown
pulmonary veins
enter the left atrium after blood is loaded with oxygen
tricuspid valve
has 3 flexible cusps (flaps of endocardium reinforced by connective tissue cores)
cardiac pacemaker cells
have the special ability to depolarize spontaneously and pace the heart
auricles
increase the atrial volume somewhat, the right and left atria are remarkably free of disgusting surface features
arrhythmias
irregular heart rythms
mitral valve
it resembles the two sided bishops miter found in the left AV valve
systemic
left side of the heart is the ___ circuit
parietal layer
lines the internal surface of the fibrous pericardium
trabeculae craneae
mark the internal walls of the ventricular chamber
fossa ovalis
marks the spot of an opening existed in the fetal heart
total heart block
no impulses get through and the ventricles beat at their intrinsic rate
AV valves
one located on each atrial ventricular junction that prevent back flow into the atria when the ventricles contracts
papillary muscles
play a role in valve function projected into the ventricular cavity
extrasystole
premature contraction before the SA node initiates the next contraction
aortic and pulmonary semi-lunar valves
prevent back flow into the atria
cardiac skeleton
reinforces the myocardium internally and anchors the cardiac muscle fibers
inferior vena cava
returns blood from body areas below the diaphragm
superior vena cava
returns blood from body regions superior to the diaphragm
pulmonary
right side of the heart is the ___ circuit
pulmonary trunk
routes the blood to the lungs where gas exchange occurs
posterior inter ventricular artery
runs tot he heart apex and supplies the posterior ventricular walls
left coronary artery
runs toward the left side of the heart and then divides into two major branches
left coronary artery
runs towards the left side of the heart and then divides into two major branches
right marginal artery
serves the myocardium of the lateral right side of the heart
SA node
sets the pace for the heart because o other region of the conduction system the myocardium has a faster depolarization rate
self excitable
some cardiac muscles are__
AV node
spreads via gap junctions throughout the atria and via internal pathways
cardiac muscle
striated and contracts by the sliding filament mechanism
circumflex artery
supplies the left atrium and the posterior walls of the left ventricle
base
the __ of the heart is directed towards the right shoulder
apex
the __ of the heart points inferiorly down towards the left hip
systemic circuit
the blood vessels that carry blood to and from all body tissues
pulmonary circuit
the blood vessels that carry blood to and from the lungs
pericardium
the double walle sac that the heart is enclosed in
mechanical valve
the faulty valve can be replaced with a__
coronary circulation
the functional blood supply of the heart and the shortest circulation in the body
unit
the heart contracts as a single __
aerobic respiration
the heart relies almost exclusively
less
the heart weighs__ than a pound
ventricles
the inferior chambers of the heart
intertribal septum
the internal partition of the heart that divides the heart longitudinally and separate the atria
inter ventricular septum
the internal partition of the heart that divides the heart longitudinally and separates the ventricles
aorta
the largest artery in the body
fibrous pericardium
the loosely fitting superficial part of the pericardium
mediastium
the medial cavity of the thorax
myocardium
the middle layer of the heart that is composed mainly of cardiac muscle and forms the bulk of the heart
low
the pulmonary circuit is a __ pressure circuit
great cardiac vein, middle cardiac vein, small cardiac vein
the sinus has 3 large tributaries
atria
the superior chambers of the heart
AV budle
the superior part of the interventricular septum
high
the systemic circuit is a __ pressure circuit
endocardium
the third layer of the heart wall that is a glistening white sheet of endothelium resting on a thin connective tissue layer
heart
the transport system pump, and blood vessels that deliver
right ventricle and left ventricle
the two pumping champers of the heart
right atrium and left atrium
the two receiving chambers of the heart
valvular stenosis
the valve flaps become stiff and constrict the opening
epicqrdium
the visceral layer of the serous pericardium and it often infiltrates with fat especially in older people
cardiac veins
their path roughly follow those of the coronary arteries
angina pectoris
thoracic pain caused by a fleeting deficiency on blood delivery to the myocardium
pacemaker cells
trigger action potentials throughout the heart
pressure
valves open and close due to__
relax
when the ventricles__ and the blood flows backwards towards the heart, it feels the cusps and closes the valves