The Circulatory System

arteries function

carry blood away from the heart

veins function

Carry blood back to the heart

capillaries function

exchange substances with body tissues

describe arteries structure

blood vessel with thick, elastic, muscular walls

describe veins structure

thin walls, valve to stop backflow

describe capillaries structure

thin walls that allow substances to pass through, one cell thick

pulmonary artery function

carries deoxygentated blood from the heart to the lungs

most arteries carry

oxygenated blood, except for the pulmonary artery

deoxygenated blood

large amount of carbon dioxide, small amount of oxygen

oxygenated blood

large amount of oxygen, small amount of carbon dioxide

blood is under ____ pressure in the arteries

high pressure because of the thick, muscular, elastic walls

blood is under ___ pressure in veins

low because its lumen is wide

lumen

space in the middle of arteries and veins where blood flows

functions of blood

carries oxygen, carbon dioxide and water vapour around the body, transports food, waste and hormones, transports heat, defends against disease

composition of blood

55% plasma, 45% cells

plasma contains...

90% water and 10% dissolved substances

cells contain...

red blood cells, white blood cells, platelets

what type of muscle is the heart made from?

cardiac muscle

what is special about a cardiac muscle?

it never gets tired

average heart rate for a healthy person

72 BPM

factors that affect someone's average BPM

age, fitness level, general health

factors that affect someone's short term heart rate

exercise, temperature, emotions and shock increase heart rate, relaxation and sleeping decreases it

blood pressure

amount of work the heart has to do to push blood through arteries

five factors that cause high blood pressure

smoking, old age, lack of physical activity, genetics, too much salt in the diet

circulatory system functions

carries nutrients, oxygen, heat, removes waste, white blood cells fight diseases

aorta

carries oxygen around the body

valves

stops the backflow of blood to the ventricles

pulmonary vein

carries oxygenated blood from the lungs to the heart

left atrium

receives oxygenated blood

bicuspid valve

stops backflow of blood from the lungs to the heart

septum

divides right and left sides of the heart

right ventricle

receives blood from the right atrium

tricuspid valve

stops the backflow of blood to the right atrium

vena cava

carries deoxygenated blood from the body to the heart

right atrium

receives deoxygenated blood from the body

pulmonary artery

carries blood to the lungs

red blood cells function

transports oxygen

white blood cells

protection, makes antibodies

platelets

clot blood