A&P 18: The Cardiovascular System - The Heart Flashcards
Pulmonary circuit
the blood vessels that carry blood to and from the lungs
Heart
transport system pump (actually 2 pumps side by side)
Systemic circuit
the blood vessels that carry blood to and from all body tissues
Mediastinum
the medial cavity of the thorax
Base
posterior surface of the heart
Apex
pointed part of the heart; points inferiorly toward the left hip
Apical impulse
pressing your fingers between the 5th and 6th ribs just below the left nipple, you can easily feel this, caused by your beating heart’s apex where it touches the chest wall
Pericardium
the heart is enclosed by this double-walled sac
Fibrous pericardium
the loosely fitting superficial part of the pericardial sac; tough, dense connective tissue layer; protects the heart, anchors it to surrounding structures, and prevents overfilling of the heart with blood
Serous pericardium
deep to the fibrous pericardium; thin, slippery, 2-layer serous membrane that forms a closed sac around the heart
Parietal layer
lines the internal surface of the fibrous pericardium
Visceral layer
AKA epicardium; integral part of the heart wall
Pericardial cavity
between the parietal and visceral layers is this slitlike cavity containing a film of serous fluid
Epicardium
visceral layer of the serous pericardium; often infiltrated with fat, especially in older people
Myocardium
middle layer, composed mainly of cardiac muscle; forms the bulk of the heart; this is the layer that contracts
Cardiac skeleton
connective tissue fibers form this dense network that reinforces the myocardium internally and anchors the cardiac muscle fibers
Endocardium
3rd layer of the heart wall, a glistening white sheet of endothelium (squamous) resting on a thin connective tissue layer
Atria
2 superior chambers of the heart
Ventricles
2 inferior chambers of the heart
Intraatrial septum
internal partition that divides the heart longitudinally (where it separates the atria)
Interventricular septum
internal partition that divides the heart longitudinally (where it separates the ventricles)
Coronary sulcus
AKA atrioventricular groove; encircles the junction of the atria and ventricles like a crown
Anterior interventricular sulcus
cradles the anterior interventricular artery; marks the anterior position of the septum separating the right and left ventricles
Posterior interventricular sulcus
provides a landmark for the posterior interventricular artery on the heart’s posteroinferior surface
Auricles
small, wrinkled, protruding appendages which increase the atrial volume somewhat
Pectinate muscles
muscle bundles forming ridges in the walls of the atria; look like the teeth of a comb; found in the right atrium and only the auricle of the left atrium
Fossa ovalis
shallow depression in the interatrial septum that marks the spot where an opening (foramen ovale) existed in the fetal heart
Superior vena cava
blood enters the right atrium through this vein, which returns blood from body regions superior to the diaphragm
Inferior vena cava
blood enters the right atrium through this vein, which returns blood from body areas below the diaphragm
Coronary sinus
blood enters the right atrium through this vein, which collects blood draining from the myocardium
Pulmonary veins
veins entering the left atrium, which makes up most of the heart’s base; transport blood from the lungs back to the heart; best seen in a posterior view
Trabeculae carnae
irregular ridges of muscle that mark the internal walls of the ventricular chambers
Papillary muscles
conelike muscle bundles that play a role in valve function and project into the ventricular cavity
Pulmonary trunk
the right ventricle pumps blood into this, which routes blood to the lungs where gas exchange occurs
Aorta
largest artery in the body; the left ventricle ejects blood into this vessel
Atrioventricular (AV) valves
2 valves, one located at each arial-ventricular junction, prevent backflow into the atria when the ventricles contract
Tricuspid valve
right AV valve; has 3 flexible cusps (flaps of endocardium reinforced by connective tissue cores)
Mitral valve
left AV valve; 2 cusps; AKA bicuspid valve
Chordae tendinae
attached to each AV valve flap are these tiny white collagen cords; “heart strings;” anchor the cusps to the papillary muscles protruding from the ventricular walls
Aortic & pulmonary (semilunar, SL)) valves
valves which guard the bases of the large arteries issuing from the ventricles (aorta & pulmonary trunk) and prevent backflow into the associated ventricles
Coronary circulation
the functional blood supply of the heart; shortest circulation in the body
Left coronary artery
artery running toward the left side of the heart, then dividing into 2 major branches - anterior interventricular artery & circumflex artery
Anterior Interventricular artery
AKA the left anterior descending artery; follows the anterior interventricular sulcus and supplies blood to the interventricular septum and anterior walls of both ventricles
Circumflex artery
supplies the left atrium and the posterior walls of the left ventricle
Right coronary artery
artery coursing to the right side of the heart; gives rise to 2 branches - the right marginal artery and the posterior interventricular artery
Right marginal artery
serves the myocardium of the lateral right side of the heart
Posterior interventricular artery
artery running to the heart apex, supplies the posterior ventricular walls; merges (anastomoses) with the anterior interventricular artery