the heart and blood vessels Flashcards
what does the blood carry
oxygen and nutrients
what is the circulatory systems purpose
transport oxygen and nutrients to tissues
what does the heart do
pump blood to the body
how many chambers does the heart have
4
what are the top two chambers called
right and left atrium
what are the bottom chambers called
right and left ventricles
what are the purpose of veins
carry deoxygenated blood to the heart
what is the purpose of arteries
carry oxygenated blood away from the heart
what is the purpose of capillaries
carry nutrients to tissues and remove waste products
what are the features of arteries
have thick muscular walls to pump blood
narrow to maintain pressure
no vavles
wide walls to assist blood flow
what are the features of veins
thin walls
wide lumen to maintain pressure as blood flows away from the heart
vavles to prevent backflow
what are the features of capillaries
small lumen only lets one cell through at a time
no muscle
no vavles
single cell thick for short diffusion distance
how does deoxygenated enter the heart
through the vena cava
how does oxygenated blood enter the heart
pulmonary vein
what are the walls of the heart made mostly of
muscular tissue
what are the purpose of vavles in the heart
make sure blood flows in the right direction
what do the atria do
contract pushing blood into ventricles
what do ventricles do
contract, forcing blood into the pulmonary artery and aorta, and out of the heart
what is a pacemaker
a group of cells wich control your resting heart rate. found in the right atrium wall
what do pacemaker cells do
produce small electric impulse wich spreads to the surrounding muscle cells causing them to contract
what is an artificial pacemaker
device wich is implanted under the skin and has a wire going to the heart. produces an electrical current to keep the heart beating
describe the double circulatory system
the right ventricle pumps deoxygenated blood to the lungs to take on oxygen and the blood then returns to the heart
the left ventricle pumps oxygenated blood around the other organs of the body. the blood gives up it’s oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
