chapter 21- cardiovascular system: heart Flashcards
key topics of heart
- vital to survival
- caries oxygen and nutrients to tissues
- carries wastes away from tissues
- closed system
double circuit involves
pulmonary and systemic circuts
heart to lungs and back– oxygenates blood
pulmonary
heart to body and back– delivers oxygen to tissues
systemic
structure of the heart
cone shaped
- inside pericardial cavit
- which is inside the mediastinum
- apex tipped toward the inferior and left
- base superior
membrane of the heart
pericardium
membranes within the pericardium
parietal pericardium, epicardium
double serous membrane with fibrous coat. made up of several levels: parietal pericardium and epicardium
pericardium
outer layer of sac within the pericardium. fibrous and areolar layer
parietal pericardium
also known as visceral pericardium— inner layer of sac. adheres to the heart wall
epicardium
space between the layers of the pericardium. contains serous fluid
pericardial cavity
wall of the heart
epicardium, myocardium, endocardium
also known as visceral pericardium– functions as protective outer layer
epicardium
middle layer– responsible for contractions. made of cardiac muscle
myocardium
inner layer– lines and protects chambers and valves. continuous with endothelium of heart blood vessels
endocardium
components of cardiac muscle tissue
striated aerobic respiration short T-tubules autorhythmic connected mechanically & chemically
known as gap junctions
intercelated discs
4 chambers of the heart
2 atria, 2 ventricles
superior chambers that receive blood from veins. have auricles
atria
flaps in the atria where blood pools
auricles
inferior chambers of the heart. force blood out to arteries. have structural differences between the left and right
ventricles
differences between the left and right ventricles
left = thicker and stronger
right- goes only to the lungs
right- pouch shaped
valves in the heart
tricuspid (right AV valve) and bicuspid (left AV valve)
at right atrioventricular orifice. open when atrial force is greater and close when ventricular force is greater. 3 cusps
tricuspid– right AV valve
at left atrioventricular orifice. 2 cusps
bicuspid– left AV valve
heart strings. hold valves in place. attached to cusps on ventricle side. prevents cusps from collapsing into the atria when valve is closed. prevents back flow
chordae tendonae
components of chordae tendonae
papillary muscles and trabeculae carnae
small bundles of muscle. attach to the chordae tendonae. when valves close, these muscle contract and tighten cords
papillary muscle
scaffolding on interior walls
trabeculae carnae
semilunar valves in the heart
pulmonary and aortic
found between ventricles and artery
semilunar valves– pulmonary and aortic
valve found on the right side of heart. at entrance to pulmonary trunk. open when right ventrical contracts
pulmonary valve
valve on the left side of the heart. at entrance to aorta. open when left ventricle contracts
aortic valve
path of blood
-superior/inferior vena cava/ coronary sinus
- right AV valve
- right ventricle
- pulmonary valve
- pulmonary trunk
- lungs
pulmonary veins
- left atrium
- left AV valve
- left ventricle
- aortic valve
- aorta
- tissues
supplies the heart issues with blood. blockage can result in a heart tissue dying
coronary circulation
branch directly off of the aorta as it emerges. involve left and right coronary arteries
coronary arteries
the coronary arteries
left and right coronary arteries
arteries dealing with left coronary artery
circumflex, anterior interventricular artery
arteries dealing with right coronary artery
posterior interventiruclar artery, marginal artery
drain myocardium. travel with arteries. involve cardiac veins and coronary sinus
cardiac veins
veins involved in the cardiac veins
great, middle, small. coronary sinus
contractile phase; chamber empties
systole
relaxation phase; chambers fill
diastole
heart beat is enabled
nodal cells and conducting fibers
specialized muscle cells that conduct action potentials
nodal cells
distributes stimulus to myocardium
conducting fibers
conducting system of heart
AP moves down heart, causing it to contract unevenly – atria contract before ventricles
tests cardiac output for heart. involves P, QRS, and T waves.
electrocardiogram
P- waves indicate
depoalrization of atria
QRS waves indicate
depolarization of ventricle
T waves indicate
repolarization of ventricles
spontaneous contractions
autorhythmicity
chemical that control autorhythmicity
NE and E
significance of the release of E and NE
increase rate and force of the heart
neural control in medulla deals with
cardioacceleratory centers and cardioinhibitory centers
neural control center in medulla that releases NE and increases HR
cardioacceleratory centers
neural control center in medulla that releases ACh and decrease HR
cardioinhibitory centers
