Circulatory and Respritory

Myocardium

muscular, middle layer of the heart

atrium

Each of the two upper chambers of the heart that receives blood that comes into the heart

ventricle

one of two lower chambers of the heart

Valves

Flaps of tissue that open and close to allow the flow of blood in one direction only. The heart's are located at the entrances and exits of its chambers.

pulmonary circulation

The passage of venous blood from the right atrium of the heart through the right ventricle and pulmonary arteries to the lungs where it is oxygenated and its return via the pulmonary veins to enter the left atrium and participate in systemic circulation.

systemic circulation

flow of blood from body tissue to the heart and then from the heart back to body tissues

pacemaker

A group of cells located in the right atrium that sends out signals that make the heart muscle contract and that regulates heart rate.

Arteries

carry blood away from the heart

capilaries

microscopic blood vessels that connect arteries and veins

veins

Blood vessels that carry blood back to the heart

Plasma

Liquid part of blood

red blood cells

Blood cells that carry oxygen from the lungs to the body cells.

Hemoglobin

An iron-containing protein in red blood cells that reversibly binds oxygen.

white blood cells

Blood cells that perform the function of destroying disease-causing microorganisms

Platelets

blood clotting

lymph

watery fluid

Atherosclerosis

condition in which fatty deposits called plaque build up on the inner walls of the arteries

Pharynx

throat; passageway for food to the esophagus and air to the larynx

Trachea

Allows air to pass to and from lungs

Larynx

voice box; passageway for air moving from pharynx to trachea; contains vocal cords

Bronchi

The passages that direct air into the lungs

Alveoli

tiny sacs of lung tissue specialized for the movement of gases between air and blood

Diaphragm

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