Page 160 - 84 human physiolofy part-1

Chapter 8

Fibrous Pericardium: a dense connective tissue that protects the heart, anchoring it to the surrounding
walls, and preventing it from overfilling with blood
Heart Rate: term used to describe the frequency of the cardiac cycle
Hepatic Veins: blood vessels that drain de-oxygenated blood from the liver and blood cleaned by the
liver (from the stomach, pancreas, small intestine and colon) into the inferior vena cava
Hypertension or High Blood Pressure: medical condition wherein the blood pressure is chronically
elevated
Inferior Vena Cava (or IVC): a large vein that carries de-oxygenated blood from the lower half of the
body into the heart
Intraventricular Septum: the stout wall separating the lower chambers (the ventricles) of the heart
from one another
Left Atrium:receives oxygenated blood from the left and right pulmonary veins
Lub-Dub: first heart tone, or S1; caused by the closure of the atrioventricular valves, mitral and
tricuspid, at the beginning of ventricular contraction, or systole
Lumen: hollow internal cavity in which the blood flows
Lymph: originates as blood plasma that leaks from the capillaries of the circulatory system, becoming
interstitial fluid, filling the space between individual cells of tissue
Mitral valve: also known as the bicuspid valve; prevents blood flowing from the left ventricle into the
left atrium
Myocardium: the muscular tissue of the heart.
Norepinephrine: Produced in the adrenal medulla of the adrenal glands, major function is a strong
vasoconstrictor that will in turn increase respiratory rate.
Pacemaker Cells: cells that create these rhythmical impulses of the heart
Plaque: an abnormal inflammatory accumulation of macrophage white blood cells within the
walls of arteries
Pulmonary Valve: lies between the right ventricle and the pulmonary artery; prevents back-flow of
blood into the ventricle
Pulse: the number of heartbeats per minute
Purkinje Fibers (or Purkinje tissue): located in the inner ventricular walls of the heart, just beneath
the endocardium; specialized myocardial fibers that conduct an electrical stimulus or impulse that
enables the heart to contract in a coordinated fashion
Renin-Angiotension system:
Right Atrium: receives de-oxygenated blood from the superior vena cava and inferior vena cava
Serous Pericardium: functions in lubricating the heart to prevent friction from occurring during heart
activity
Semilunar Valves: positioned on the pulmonary artery and the aorta
Sinoatrial Node: (abbreviated SA node or SAN, also called the sinus node): the impulse generating
(pacemaker) tissue located in the right atrium of the heart
Sinusoidal Capillaries: special forms of fenestrated capillaries that have larger opening allowing
RBCs and serum proteins to enter
Systole: contraction of the heart
Systolic Pressure:' the highest point in blood pressure when the blood is being pumped out of the left
ventricle into the aorta during ventricular systole
Superior Vena Cava (SVC): a large but short vein that carries de-oxygenated blood from the upper
half of the body to the heart's right atrium
Thrombus: a blood clot in an intact blood vessel
Tricuspid Valve: on the right side of the heart, between the right atrium and the right ventricle; allows
blood to flow from the right atrium into the right ventricle when the heart is relaxed during diastole
Vasoconstriction: the constriction of blood vessels
Vasodilation: the dilation of blood vessels

160 | Human Physiology