2/27 Vocab Quiz

aorta

a large arterial trunk that arises from the base of the left ventricle and channels blood from the heart into other arteries throughout the body

aortic valve

the semilunar valve between the left ventricle and the aorta that prevents blood from fl owing back into the left ventricle

atrioventricular (AV) valves

the two valves (tricuspid and mitral) situated between the atria and the ventriclesthe amount of blood pumped from the heart per minute

cardiac output

the amount of blood pumped from the heart per minute

diastole

the period of relaxation in the heart when the chambers are fi lling with blood

endocardium

the innermost layer of the heart, which lines the interior of the heart chambers and covers the valves of the heart

epicardium

the outermost layer of the heart and the innermost layer of the pericardial sac

inferior vena cava

largest vein in the human body that returns deoxygenated blood to the right atrium of the heart from body regions below the diaphragm

interatrial septum

the wall that separates the right and left atria in the heart

interventricular septum

thick wall that divides the two ventricles in the heart

mitral valve

the valve that closes the orifi ce between the left atrium and left ventricle of the heart; bicuspid valve

myocardium

the middle layer of the heart, which makes up about 2/3 of the heart muscle

papillary muscle

one of the small muscular bundles attached at one end to the chordae tendineae and at the other to the innermost or endocardial wall of the ventricles; maintains tension on the chordae tendineae as the ventricle contracts

semilunar valves

valves situated at the opening between the heart and the aorta and at the opening between the heart and the pulmonary artery; they prevent backfl ow of blood into the ventricles

stroke volume

the volume of blood pumped from the heart per beat

superior vena cava

second largest vein in the body that returns deoxygenated blood to the right atrium of the heart from the upper half of the body

systole

a period of contraction when the chambers are pumping blood out of the heart

tricuspid valve

the valve that closes the orifi ce between the right atrium and right ventricle of the heart; composed of three cusps

vasoconstriction

narrowing of the blood vessels, which decreases blood fl ow

vasodilation

widening of the blood vessels, which increases blood fl ow

aortic arch

the curved portion of the aorta between the ascending and descending parts of the aorta

arteries

vessels that carry blood away from the heart

arterioles

microscopic arteries that connect with capillaries

brachial artery

the artery located at the fold of the elbow where the brachial pulse is detected

capillaries

small, thin-walled vessels where oxygen and carbon dioxide gas exchange occurs

capillary beds

network of intertwined vessels formed by multiple capillaries

carotid artery

the artery located on the side of the neck, where the carotid pulse is felt

coronary sinus

large venous channel between the left atrium and left ventricle on the posterior side of the heart that empties into the right atrium at the junction of the four chambers

ductus arteriosus

a short, broad vessel in the fetus that connects the left pulmonary artery with the descending aorta, allowing most of the blood to bypass the infant’s lungs

foramen ovale

opening in the septal wall between the atria; normally present only in the fetus

precapillary sphincter

a band of smooth muscle fi bers that encircles the capillaries at the arteriole- capillary junctions and controls blood fl ow to the tissues

pulmonary circulation

circulation of oxygen-poor blood from the right ventricle, through the lungs, and returning to the left atrium with oxygen-rich blood

radial artery

the artery located on the thumb side of the wrist, where the radial pulse is detected

systemic circulation

circulation of oxygenated blood through the arteries, capillaries, and veins of the circulatory system, from the left ventricle to the right atrium

tunica externa

the outermost layer of a blood vessel, composed mostly of fi brous connective tissue that supports and protects the vessel

tunica intima

the innermost layer of a blood vessel, composed of a single layer of squamous epithelial cells over a sheet of connective tissue; its smooth, frictionless surface allows blood to fl ow smoothly through the vessel

tunica media

the thicker middle layer of a blood vessel that contains smooth muscle cells, elastic fi bers, and collagen; its muscle cells are directed by the sympathetic nervous system to increase or decrease blood fl ow to tissues as needed

veins

vessels that carry blood to the heart

venules

the smallest veins; connect the capillaries with the larger systemic veins

vital signs

measurements of pulse and blood pressure