Heart Anatomy and Physiology Flashcards
Pericardium
A double-walled sac that protects the heart.
Epicardium
The heart muscle lining the external surface of the heart wall.
Myocardium
Middle muscle layer which is the thickest and performs the work of the heart.
Endocardium
The inner muscular lining of the heart, continuous with the endothelium of the blood vessels.
Starling’s Law
The force of the contraction of the heart depends on the length of the muscle fibers of the heart.
More blood volume produces a greater stretch which in turn results in a more forceful contraction.
Right Atria
Receives unoxygenated blood from the superior and inferior vena cava.
Supplies blood to the right ventricle via the “atrial kick.”
Right Ventricle
Pumps deoxygenated blood to the lungs.
Makes up the anterior aspect of the heart.
Left Atria
Receives oxygenated blood from the lungs.
Supplies left ventricle with oxygenated blood via the “atrial kick.”
Left Ventricle
Forms the apex, inferior, and posterior parts of the heart.
Pumps oxygenated blood to the body.
Aortic Valve
Semilunar in shape
Fibrous flaps separating left ventricle from aorta
Three cusps
No muscle function to open/close
Pulmonic Valve
Semilunar in shape
Fibrous flaps that separate right ventricle and pulmonary artery
Three cusps
No muscle function to open/close
Tricuspid Valve
Valve between right atrium and right ventricle
Made up of three fibrous flaps
Has muscles attached that keep it closed during contractions so blood doesn’t flow backwards into the atria
Bicuspid/Mitral Valve
Valve between left atrium and left ventricle.
Two fibrous flaps attached to muscles close when the heart contracts, keeping blood from flowing back into the left atria.
Aorta
Largest vessel in the body
Takes oxygenated blood from the left ventricle and pumps it to body.
Superior Vena Cava
Returns deoxygenated blood from head and arms to the right atria.
Inferior Vena Cava
Returns deoxygenated blood from the trunk and legs to the right atria.
Pulmonary Artery
Transports deoxygenated blood from the right ventricle to the lungs.
Only artery in the body to carry deoxygenated blood.
Pulmonary Veins
Transport blood back from the lungs to the left atria.
Only veins in the body to carry oxygenated blood.
Describe the path of blood through the vessels, valves, and chambers of the cardiac system.
Deoxygenated blood enters the right atria through the superior and inferior vena cava.
Blood passes from right atria to right ventricle via the tricuspid valve.
Blood exits the right ventricle and enters the pulmonary arteries via the pulmonic valve.
Blood circulates the lungs and returns to the heart through the pulmonary veins.
Oxygenated blood enters the left atria from the pulmonary veins.
Blood goes from left atria to left ventricle via the mitral valve.
Blood exits the left ventricle and passes to the aorta and out into the body via the aortic valve.
Systole
Ventricles contract
Atria relax and fill
Increasing blood volume causes increased pressure that makes the ventricles contract.
Diastole
Ventricles are relaxed and filling while the atria contract.
Blood moves passively from the atria to the ventricles.
Atrial Kick
Atrial contraction forcing an additional 15-30% of blood into the ventricles at the end of diastole.
Name the five regions of the heart that correlate with a 12-lead EKG.
Inferior
Posterior
Lateral
Septal
Anterior
Identify the following coronary arteries:
