How can we help?
You can also find more resources in our
Select a category
Something is confusing
Something is broken
I have a suggestion
What is your email?
What is 1 + 3?
Circulation and Respiration
consists of the heart, blood vessels and blood
A hollow muscular organ that pumps blood throughout the body.
receives blood that comes into the heart
Sends out signals that make the heart muscle contract (beat)
Pumps blood out of the heart.
A flap of tissue that prevents blood from flowing backward.
Blood vessels that carry blood away from the heart.
Tiny, narrow vessels that blood flows into after passing through the arteries
The largest artery in the body
An artery that supplies blood to the heart itself
Alternating expansion and relaxation of an artery wall
The process by which molecules move from an area of higher concentration to lower concentration.
Is force per unit area
The pressure that is exerted by the blood against the walls of blood vessels
The liquid part of blood
Red blood cells
Take up oxygen in the lungs and deliver it to cells elsewhere in the body.
An iron-containing protein that binds chemically to oxygen molecules
White blood cells
The body's disease fighters
Cell fragments that play an important role in forming blood clots.
Failure of the circulatory system to provide an adequate supply of oxygen-rich blood to all parts of the body.
a network of veinlike vessels that returns the fluid to the bloodstream
The fluid that is inside the lymphatic system
Filter lymph, trapping bacteria and other disease-causing microorganisms in the fluid.
the process by which oxygen and glucose undergo a complex series of chemical reactions inside cells.
a thick sticky liquid that moistens the air and keeps the lining from drying out. `
tiny hairlike extensions that move together in a sweeping motion.
The passages that direct air into the lungs
The main organ of the respiratory system
Ting sacs of lung tissue specialized for the movement of gasses between air and blood
A large dome shaped muscle that plays an important role in breathing
Voicebox, located in the top part of the trachea underneath the epiglottis
Folds of connective tissue that produce your voice, stretch across the opening of the larynx
A condition in which an artery wall thickens as a result of buildup of fatty materials
Occurs when part of the heart muscle is blocked
A disorder when your blood pressure is consistently high
Death of brain tissue that can result when a blood vessel in the brain is either blocked by a clot or bursts.
A serious disease that destroys lung tissue and causes breathing difficulties
An irritation if the breathing passages in the small passages become narrower and may be clogged with mucus.
Disease when Airways in the lungs narrow significantly
Infection that causes fluid to collect in the alveoli. Causes difficulty taking in oxygen and getting CO2 out.