Circulatory System Notes Functions of the circulatory system

Circulatory System Notes

Functions of the circulatory system…

-Carries nutrients, oxygen & other needed materials to cells

-Carries carbon dioxide & other wastes away from cells

-Blood helps fight disease & heal wounds.

-Helps maintain body temperature & homeostasis.

The circulatory system is made up of the Heart Blood & Blood vessels

Heart… muscular organ that pumps blood throughout the body.

right side pumps blood to lungs & left side pumps blood to body… separated by a thick muscular wall called the septum.

Upper two chambers are called the atrium (atria) & receive blood into the heart…

…the lower two chambers are ventricles that have thick muscles to pump blood out of the heart.

Upper & lower chambers are separated by valves that keep blood from flowing backward.

Heartbeat muscle contractions that push blood through the blood vessels.

You hear the valves opening & closing… when the heart muscles relax the valves open & the atria fill with blood LUB… then the ventricles contract & the valves close DUB.

Pulse Throbbing of arteries as heart beats & pumps blood… used to determine heart rate.

Blood pressure force with which the ventricles contract.

Blood vessels… Arteries=> Capillaries=> Veins

Arteries Muscular blood vessels that carry blood with oxygen away from the heart.

Pulmonary artery Carries blood from heart to lungs… only artery that does not carry oxygenated blood.

Aorta largest human artery that carries blood from the heart to the body.

Capillaries smallest blood vessels where substances are exchanged by the process of diffusion

Veins… carry blood with carbon dioxide to the heart from the body.

Pulmonary vein Carries blood from lungs to heart… only vein that not carries oxygenated blood.

Superior vena cava is the largest vein in the human body.

Hypertension (high blood pressure) occurs when the pressure in the blood vessels is too high… above 140/90.

The heart has to work harder.

Can cause damage to the heart, arteries and other organs.

Heart attacks occur when arteries get clogged and stop the flow of blood to the heart muscles.

Strokes occurs when the blood supply to the brain is cut off or when a blood vessel burst causing damage to brain cells.

Atherosclerosis is a condition where artery walls thicken and restrict the flow of blood in the arteries.

Caused by high cholesterol that deposits in the arteries causing them to narrow or harden.

Can lead to heart, disease or strokes.

Irregular heartbeats occur when the heart rhythm is too fast or too slow.