Cardiovascular System: Functions of Heart

thermoreceptors, hypothalamus, and arterioles.

Epicardium, Myocardium, Endocardium

Outer layer of heart, protects, secretes lubricating serous fluid.

Middle layer of heart, muscular, contracts to pump blood.

The innermost layer of heart, lines the chambers and valves.

The tricuspid valve (right AV valve), Pulmonary semilunar valve, Bicuspid valve (left AV valve, or mitral valve), aortic semilunar valve

Blood pressure measures arterial force by the blood on walls of the vessels; systolic over diastolic pressures.

The maximum pressure when the ventricles contract, forcing blood into the aorta and pulmonary trunk; the top number.

The period in which the ventricles relax and blood pressure is at its lowest point; the bottom number.

Longer circuit; blood pressure is higher; blood in arteries carries more oxygen than blood in the veins. When oxygen levels low, VASODILATION to promote blood flow to tissues that need it.

Shorter circuit; low blood oxygen triggers VASOCONSTRICTION, which redirects blood to better ventilated parts of the lung.

The narrowing of blood vessels, reducing blood flow.

The P wave –> the QRS interval ———-> the ST segment —-> T wave ————-> U wave

ECG - Represents atrial depolarization

ECG - Represents ventricular depolarization

ECG - Represents the period between ventricular depolarization and repolarization.

ECG - Represents ventricular repolarization.

Largest arteries (includes the aorta and major branches). Stretch when blood forced out of heart + recoil under low pressure.

Middle layer of blood vessels; smooth muscle and elastic fibers, regulate vessel diameter. More elastin than any other vessels.