circulatory system
DESCRIPTION
A breif overview of the circulatory systemTRANSCRIPT
The Circulatory System
the heart, veins and arteries
The Heart
The Heart is a muscle
It’s about the size of your fist
It should beat about 60 -80 times per minute...generally, the lower the better.
The Parts of the Heart
The Path of the Blood
From the lungs into the top left chamber of the heart, the left atrium
Then through a valve to the bottom left chamber, the left ventricle
The heart pumps blood out of the left ventricle and into the aorta, which then carries the oxygen rich blood to all of the parts of the body
Path of the Blood
After the blood travels through the body, then it returns through two large veins. The superior vena cava collects blood from the head and arms and the inferior vena cava collects blood from the legs, abdomen and chest.
Both the superior vena cava and the superior vena cava return blood to the top right side of the heart which is the right atrium.
Path of the Blood
The blood then travels through a valve to the right ventricle and is pumped back to the lungs. Here the blood goes back to the left atrium to start the process again.
Path of the Blood
Blood Vessels
Vessel is another word for pathway.
Arteries are blood vessels that carry blood away from the heart.
Arteries carry oxygen rich blood from the heart throughout the body.
The aorta is the largest artery.
Smaller and smaller arteries branch off and finally reach capillaries, the tiniest blood vessels.
Blood Vessels
Capillaries are the smallest blood vessels.
Capillaries have very thin walls.
The walls of the capillaries allow oxygen and nutrients from the blood to enter cells.
Blood Vessels
Veins are the blood vessels that carry oxygen poor blood back to the heart.
At the cells, capillaries transport the oxygen poor blood to small veins.
Small veins join together to form large veins like streams join together to form rivers.
Finally the blood flows back to the heart through the superior vena cava, if coming from the head or arms or the inferior vena cava, if the blood is coming from the legs, abdomen, or chest.