Chapter 21: The Heart Flashcards
functions of the cardiovascular system
transport nutrients, gases, waste products, and hormones around the body
how heavy is the heart
8-10 ounces
what is the apex of the heart
the left ventricle
where is the apex
fifth intercostal space
what is the base of the heart
broad, top end of heart with great vessels of the heart
where is the base of the heart
third intercostal space
where is the heart located
central compartment inside mediastinum
what is the mediastinum
the area within the thoracic cavity, between the lungs
what is the pericardium
the double layered sac surrounding the heart
what does the pericardium do
anchor and protect the heart
what are the two parts of the pericardium
fibrous pericardium and serous pericardium
what is the fibrous pericardium
the outer layer of the pericardium that fuses with the diaphragm and sternum
what are the two layers of the serous pericardium
parietal and viceral pericardial
where is the pericardial cavity
between the parietal and visceral serous pericardium
what is inside the pericardial cavity
pericardial fluid
what does pericardial fluid do
reduce friction
what are the three layers of tissue that make the wall of the heart
epicardium, myocardium, and endocardium
the epicardium is also known as the
visceral pericardium
what type of tissue is the epicardium
epithelium
what is the myocardium
the thickest, middle layer of cardiac muscle tissue in the heart
what type of tissue is endocardium
simple squamous epithelium
what layer lines the inside of the heart chambers and valves
endocardium
characteristics of the cardiac tissue
branched, striated, involuntary
what connects cardiac cells
intercarcalated discs
what are the two types of junctions between cardiac cells
gap junctions and desmosomes
what do gap junctions do
transfer electrical impulses
what do desmosomes do
clamp muscle cells together during contraction
what is the atria
two superior chambers of heart that bring materials inside the heart
what is the ventricles
two inferior chambers of heart that exit materials from heart
what does the right atrium do
receive deoxygenated blood from blood vessels
what are the three blood vessels that transport deoxygenated blood to the heart
superior vena cava, inferior vena cava, and coronary sinus
what does the right ventricle do
receive deoxygenated blood from the right atrium
where does the right ventricle send deoxygenated blood to
the right and left pulmonary trunk
where does the pulmonary trunks send the deoxygenated blood to
the lungs
what does the left atrium do
receive oxygen from the lungs through the pulmonary veins
the left atrium pumps oxygen to
the left ventricle
what does the left ventricle do
receive oxygen from the left atrium
what do valves do
prevent blackflow of blood
what are the two types of valves in the heart
atrioventricular and semilunar
where is the atrioventricular valve
between the atria and ventricles
the tricuspid valve is found in the
right atrioventricular valve
the bicuspid valve is found in the
left atrioventricular valve
what happens when ventricles contract
pressure forces right and left atrioventricular valves to shut
what is chordae tendina
the papillary muscle inside the ventricles that prevent the valves from swinging back into the atria
how many cusps are in the semilunar valves
3
what are the two semilunar valves
pulmonary semilunar and aortic semilunar valves
where is the pulmonary semilunar
between the pulmonary trunk and right ventricle
where is the aortic semilunar valve
between the aorta and left ventricle
pulmonary circulation is
where blood is sent to the lungs to be oxygenated
the systemic circulation is
blood carried to other areas of the body
coronary circulation
carries blood to cells and cardiac tissue of heart
the coronary artieries send ____ blood to the _______
oxygenated, myocardium
what are the two parts of the left coronary artery
left anterior descending arteries/anterior inter-ventricular arteries and the circumflex artery
what are the two divisions of the right coronary artery
posterior interventrical artery and marginal artery
what carries deoxygenated blood from the cardiac tissue
cardiac veins
the right coronary artery merges and empties into the
coronary sinus
where does the coronary sinus empty into
right atrium
what generates the heartbeat
modified cardiac muscles
what is the conduction system that spreads action potentials
syncytial contraction
What are the four regions of the syncytial conduction system
Sinoatrial Node, Atrioventricular Node, Bundle of His, and Purkinje Fibers
what is the pacemaker of the heart
sinoatrial node
where is the sinoatrial node located
right atrium, inferior to medial of SVC entrence
where is the atrioventricular node located
the interatrial septum between left and right atria
what does the atrioventricular node do?
make sure there is a full contraction
what does the AV bundles/bundle of his do
sends action potentials from atria to ventricle
where are the bundles of his located
intraventricular septum between right and left ventricles
where is the purkinje fibers located
the apex
what do purkinje fibers do
spread the action potential superior through myocardium
when does the heart start to develop
2nd week
what develops at the fifth week of developent
atrial and ventricular septums form
what does the atrial septum do
act as a flap valve over the foramen ovale
where does blood flow through the atrial septum
from the right atria to the left atria
what does the ductus arteriosus do
connect the aorta to the pulmonary trunk
what happens when you take your first breath at birth
oxygen increases in blood and umbilical blood flow stops, initiating the start of pulmonary circulation
what is the depression left from the foramen ovale
the fossa ovalis
what is the ligamerrtum arteriosum
fibrous band between the aorta and the pulmonary trunk
what is the average cardiac cycle
.75-1 second
what is the systole
the contraction portion of cardiac cycle
what are the two systole contractions
atrial systole and ventricular systole
what is diastole
the relaxation portion of cardiac cycle
what are the two diastole relatxations
atrial diastole and ventricular diastole
what causes the heart sounds
the pressure from closing of valves and collisions of blood against the valves
when atrial pressure exceeds ventricular pressure what happens
the AV valves open
when ventricular pressure exceeds atrial pressure, what happens
the AV valves close
what is the first heart sound called
S1 or “lub”
what is happening when the one hears the first heart sound
the Av valve closes (tricuspid and mitral)
what is the second heart sound called
S2 or “dub”
where can you hear heart sounds
5th intercostal space on each side of the sternum, 2nd intercostal space on each side of sternum
what is a heart murmur
a embryological defect of heart valves causing unstead blood flow
this is the narrowing of blood valves
stenosis
when can you hear AV stenosis
prior to S1
when can you hear semilunar stenosis
prior to S2
