Anatomy of the Heart Study Guide Flashcards
pathway of blood through the heart into pulmonary and systemic circulation
SVC/IVC/coronary sinus → right atrium → tricuspid valve → right ventricle → pulmonary SL valve → pulmonary trunk → pulmonary arteries → Lungs ( → capillaries) → pulmonary veins → left atrium → bicuspid valve → left ventricle → aortic SL valve → ascending aorta ( → R&L coronary arteries) → aortic arch →
- Brachiocephalic artery → r upper chest, r upper back, r shoulder, r arm, r neck, r head
- Left common carotid artery → l neck and l heard
- Left subclavian artery → l upper chest, l upper back, l shoulder, l arm
- Descending aorta → remainder of body
oxygenated
pulmonary veins - aortic arch
deoxygenated
SCV/IVC/CS - pulmonary arteries
physical location and orientation of the heart within the mediastinum.
- Between sternum and vertebral column
- Rests on diaphragm
- ⅔ of the heat’s mass is to the left of the midsternal line
- Base: wide and flat, posterior surface, directed to the right shoulder
- Apex: points inferiorly to the left hip
Pericardium
double walled sac that encloses the heart
Fibrous pericardium
loose fitting superficial part of pericardium
- Dense connective tissue
- Protects heart, keeps it from overfilling, anchors it to mediastinum
Serous pericardium
deep to fibrous pericardium, made of 2 thin layers
- Parietal layer: lines the internal surface of fibrous pericardium
- Visceral layer: lines external surface of heart
contents of the pericardial cavity.
Space between the parietal + visceral layers, filled with serous fluid
function of the pericardial cavity.
reduces friction
3 layers of heart wall
epicardium, myocardium, endocardium
epicardium
= visceral pericardium – the most superficial layer
Myocardium
middle, muscle layer
- Composed of contracting cardiac muscle; bulk of heart
- Cardiac muscle cells are arranged in spiral bundles, they are tethered to each other by criss crossing connective tissue fibers
Endocardium
deepest layer, made of endothelium
- Lines the heart’s chambers, contiguous with the lining of the great vessels
functions of the cardiac skeleton.
A reinforcing, dense network formed by the connective tissue fibers; prevents overstretching from continuous stresses + ensures that APs only spread along desired pathways (in myocardium)
Pericarditis
inflammation of the pericardium
- beating heart tubs against the pericardial sac – audible sound is produced, causes pain deep to the sternum, can lead to adhesions; impeded cardiac activity
Cardiac tamponade
compression of the heart by large amounts of inflammatory fluid in the pericardial cavity
- Heart’s ability to pump blood is reduced. Managed by removal of excess fluid by syringe
function of the auricles
Small, wrinkled appendages that sit atop each atrium, that expand the volume capacity of the right and left atria as needed
papillary muscles
muscles that project into ventricular chambers and play a role in valve function
Chordae tendineae
tiny white collagen cords attached to AV valves, they anchor the cusps of the valves to the papillary muscles, prevent valve inversion, and force blood into the great arteries
Atria
small, receiving chambers, generate only minimal contraction to push blood into ventricles
- Fossa ovalis: a depression in the interatrial septum – marks the spot of the former foramen ovale
- Foramen ovale: fetal shunt between the atria – bypasses lungs
Right atrium
anterior wall is covered with bundles of muscles called pectinate muscles , blood enters the right atrium through the IVC, SVC, and coronary sinus
Left atrium
walls are smooth, blood enters the left atrium via the pulmonary veins (4)
Ventricles
the pumping chambers, make up most of the volume of the heart and have much thicker myocardial walls than the atria, have trabeculae carnae (irregular ridges of muscle that line internal walls of ventricles), and contraction of ventricles propels blood out of heart and into circulation
Left ventricle
myocardial wall is 3X thicker than right ventricle, cavity is circular, propels blood through aorta
