Circulatory System C3L1
3 parts to system
Blood
-plasma: carry cells waste away from cells, carries food from digestive system to
cells. Light/pale yellow colored. Largest part of blood.
-red blood cells (rbc): carry oxygen. Bright red when they carry oxygen, dark red
when carrying unoxygenated wastes. 2nd largest part of blood.
-white blood cells (wbc): kill germs. Different shapes & sizes depending on what is
needed from them.
-platelets: pieces of cells that float in blood. When blood vessel is cut, they clump
together & stick to edges of cut. Help form clots which stop bleeding.
Blood vessels
-arteries: carry blood Away from heart. Thick, muscular walls that stretch when heart
pushes blood into them. Carry blood with lots of oxygen. Branch into smaller blood
vessels (capillaries).
-capillary: smallest blood vessel. Wall of capillary is one cell thick. Oxygen can move
thru walls to blood cells; waste can move out of cells. Join together to become veins.
-veins: blood vessels take blood back to heart. Have valves.
valves: flaps that act like doors to keep blood flowing in one direction
Heart
-divided into two sides. Right side pumps blood to lungs; left side pumps to body.
-each side has 2 parts: atrium & ventricle
-atrium: upper portion.
-ventricle: lower portion, larger than atrium
-parts pump in repeating pattern: left atrium & right atrium pump first; then 2 ventricles
pump