The Heart Flashcards
Heart location
In the mediastinum
Middle of the chest, tilted over to left
Pericardium
The heart is enclosed and held in place by the pericardium
Consists of outer fibrous pericardium and an inner serous pericardium
Pericardium: Serous Pericardium
Has two layer
- visceral
- pariteal
Layers of the heart wall
3 layers
Epicardium ( composed of cardiac muscle) , Myocardium- biggest, all muscle
Endocardium- epithelial tissue, lines inside of the heart
Right atrium
Receives blood from the superior and inferior vena cava and the coronary sinus
Blood passes from right to left atrium through the tricuspid valve
Chambers of the heart
Include two upper atria and two lower ventricles
On the surface of the heart are the auricles ( small pouches on the anterior surface that increase the capacity of each atrium ) and sulci ( grooves that contain blood vessels and fat and separate the chambers )
Right ventricle
Receives blood from the right atrium and sends blood to the pulmonary trunk via the pulmonary semilunar valve
Left atrium
Receives blood from the pulmonary veins
Blood passes from the left atrium to the left ventricle through the bicuspid valve
Left ventricle
Forms the apex of the heart
Blood passes from the left ventricle through the aortic semilunar valve into the aorta
Wall is much thicker than that of the right ventricle
Flow of blood
Right Atrium- Left Ventricle-Pulmonary Trunk -Lungs-Pulmonary Veins-LA-down LV-through AV- Atrium - pumped around to body-returns via vena cava
Coronary circulation
The flow of blood through many vessels. Delivers oxygenated blood and nutrients to and removes carbon dioxide and wastes from the myocardium
Coronary veins
Deoxygenated blood returns to the right atrium primarily via the coronary sinus
Removes carbon dioxide and wastes from the myocardium
4 types of electircal activity in the heart
Pacemaker potential
Atrial action potential
Ventricular action potential
Electrocardiogram
Conduction system
- Sino Atrial Node fires aka SA node
- AtrioVentricular node fires
- Excitement spreads down AV bundles
- Right and Left bundle branches
- Purkinje Fibers
Cardiac muscle cells
Self-exitable, therefore autorythmic
- Repeatedly generate spontaneous action potentials that then trigger heart contractions
- They form the conduction system, the route for propagating action potential through the heart muscle