ch. 33: circulatory & respiratory systems // honors biology 9

myocardium

thick middle muscle layer of the heart

atrium

upper chamber of the heart that receives blood from the rest of the body

ventricle

lower chamber of the heart that pumps blood out of the heart to the rest of the body

valve

flap of connective tissue located between an atrium and a ventricle, or in a vein, that prevents backflow of blood

pulmonary circulation

path of circulation between the heart and lungs

systemic circulation

path of circulation between the heart and the rest of the body

pacemaker

small group of cardiac muscle fibers that maintains the heart's pumping rhythm by setting the rate at which the heart contracts; the sinoatrial (SA) node

artery

large blood vessel that carries blood away from the heart to the tissues of the body

capillary

smallest blood vessel; brings nutrients and oxygen to the tissues and absorbs carbon dioxide and waste products

vein

blood vessel that carries blood from the body back to the heart

aorta

carries oxygen-rich blood from the left ventricle to the body

superior vena cava

brings oxygen-poor blood from the upper body to the right atrium

right pulmonary veins

bring oxygen-rich blood from the right lung to the left atrium

right atrium

accepts oxygen-poor blood from the body

right ventricle

pumps oxygen-poor blood to the lungs

inferior vena cava

brings oxygen-poor blood from the lower body to the right atrium

tricuspid valve

valve between the right atrium and right ventricle

left ventricle

pumps oxygen-rich blood to the body

septum

divides the left and right ventricles

aortic valve

valve between the left ventricle and aorta

pulmonary valve

valve between the right ventricle and pulmonary artery

mitral valve

valve between the left atrium and left ventricle

left pulmonary veins

bring oxygen-rich blood from the left lung to the left atrium

left atrium

accepts oxygen-rich blood from the lungs

pulmonary arteries

carry oxygen-poor blood to the lungs

steps of a heartbeat

atria contract and ventricles contract

plasma

straw-colored liquid portion of the blood

red blood cell

blood cell containing hemoglobin that carries oxygen

hemoglobin

iron-containing protein in red blood cells that binds oxygen and transports it to the body

white blood cell

type of blood cell that guards against infection, fights parasites, and attacks bacteria

platelet

cell fragment released by bone marrow that helps in blood clotting

lymph

fluid that is filtered out of the blood

atherosclerosis

condition in which fatty deposits called plaque build up inside artery walls and eventually cause the arteries to stiffen

stroke

sudden death of brain cells when their blood supply is interrupted

pharynx

tube at the back of the mouth that serves as a passageway for both air and food; also called the throat

trachea

tube that connects the larynx to the bronchi; also called the windpipe

larynx

structure in the throat that contains the vocal cords

bronchus

one of the two large tubes in the chest cavity that leads from the trachea to the lungs

alveolus

one of many tiny air sacs at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur

diaphragm

large flat muscle at the bottom of the chest cavity that helps with breathing

epiglottis

flap of tissue that covers the entrance to the trachea

inhalation

rib cage rises and the diaphragm contracts

exhalation

rib cage lowers and the diaphragm relaxes

chronic bronchitis

the bronchi become inflamed and clogged with mucus

emphysema

the loss of elasticity and eventual breakdown of lung tissue