Circulatory System
Key Concepts
What are blood’s components and their functions?
What is blood pressure and why is it important?
How is heart rate affected by exercise?
Key Terms
Circulatory system
Blood
Red blood cell
Artery
Vein
Capillary
THE CIRCULATORY SYSTEM WORKS WITH OTHER BODY SYSTEMS
The circulatory system transports materials from the digestive system and the respiratory system to cells of the body.
It works with the respiratory system to transport oxygen to cells of the body and remove carbon dioxide and other
wastes.
The circulatory system supplies blood, a fluid that carries materials and wastes, to all parts of the body.
STRUCTURES IN THE CIRCULATORY SYSTEM FUNCTION TOGETHER
The heart and blood vessels make up the circulatory system.
The heart
The heart pushes blood throughout the circulatory system and is divided into four chambers.
The right atrium receives oxygen-poor blood from the rest of the body.
The right ventricle pumps the oxygen-poor blood to the lungs.
The left atrium receives oxygen-rich blood from the lungs.
The left ventricle pumps oxygen-rich blood to the rest of the body.
Blood
Blood is a tissue made up of four components.
Plasma contains proteins, sugar, hormones and gases and makes up most of the blood. 60% of blood
White blood cells help your body fight infection.
Red blood cells carry oxygen to other cells of the body.
Platelets are large cell fragments that help form blood clots.
Wrap your head around this
In one cubic millimeter of blood, the size of a grain of rice, you have about 5 million red blood cells (life span about 120
days)
In the same amount you have about 5-10 thousand white blood cells (from a few days to many months)
In that same amount you have about 400,000 platelets (from five to nine days)
Blood Vessels
Blood vessels are structures that blood flows through.
Arteries are vessels that take blood away from the heart.
Veins are blood vessels that carry blood back to the heart.
Capillaries connect arteries with veins and are the sites where materials are exchanged between blood and tissues.
Try this
Hold one hand above your head and the other at your side for one minute
The fingertips of the hand held down will be redder, indicating that blood flowed down.
Blood Exerts Pressure on Blood Vessels
Blood pressure is the force that blood exerts on blood vessels.
Low blood pressure can keep oxygen and other materials from other cells.
High blood pressure causes strain on arteries and veins and can cause the heart to work harder than it should.
There Are Four Different Blood Types
Each red blood cell contains proteins that determine blood type.
People with type A protein have type A blood.
Type B proteins produce type B blood.
People without either protein have type O blood.
Some people have both A and B proteins, resulting in AB type blood.
Blood Type
Cardiovascular Problems
Atherosclerosis- when cholesterol builds up inside of blood vessels causing narrowing and blockage
Hypertension- abnormally high blood pressure which can lead to heart attack, kidney disease, and stroke.
Stroke- when a blood vessel in the brain becomes clogged or ruptures. Brain receives no oxygen, brain dies.