Cardiorespiratory SystemYear 10 PE

Made up of….

• The circulatory system• Heart, blood and vessels

Functions of the heart, blood and vessels

• Circulate blood to all parts of the body

• Transport water, oxygen and nutrients to cells

• Remove wastes, including carbon dioxide, from cells

• Maintain body temperature

The heart

• Composed of four chambers• Two Atria (upper chambers) & two Ventricles (lower

chambers).• The Atria receive blood from the body (and lungs),

the ventricles pump blood back out into the body.

The heart

• Label the various structures of the heart• Color in the heart as to where there would be oxygen rich

blood (red) and oxygen poor (blue) blood

• Think about• How does the blood become ‘oxygen rich?’ • Where does it go after it becomes oxygen rich?• Where does it go after it ‘drops off’ its oxygen?

The heart

Blood Vessels

• Arteries – Carry oxygen rich blood to the working muscles

• Veins – Carry oxygen poor blood back to the heart • Capillaries – site of gas exchange

Blood

• Contains blood cells, fluid, minerals and gases• Each persons has approximately 4-5 L of blood• Blood is made up of• Red Blood Cells (O2 Carrying)• White Blood Cells (immune system)• Platelets (clotting cells)• Plasma (90% water, nutrient carrying)

• Blood Cells (45%)• Blood Plasma (55%)

Blood Vessels

• Arteries – Arterioles – Capillaries – Venules – Veins.

Arteries• The aorta is the largest

artery in the body. The left ventricle pushes the blood into the aorta and onto the rest of the body.

Arteries• The artery walls are

elastic so they are able to expand with each heartbeat to accommodate blood.

• When you take your heart rate, you are feeling the pressure of the blood being pushed into the arterial system.

Arteries

• Arteries further reduce in size to become arterioles as the network of blood vessels work their way into the depths of the body.

• Bleeding from an artery can be recognised by the blood spurting out with each heart beat and by its bright red (oxygen rich) colour.

Arteries

• Coronary Artery – supplies the hearts chambers with oxygen and nutrients.

• Heart attacks are often caused by a blockage of the coronary artery.

• Smoking, drinking, eating fatty foods and lack of exercise contribute to coronary artery blockages.

Capillaries

• The exchange of nutrients and waste between the body and blood cells occurs in the capillaries.

• Heat from cells is also absorbed into blood through the capillaries

Capillaries

• Exchange of materials is easy as capillaries are only one cell thick.

• When you begin to exercise capillaries dilate to allow increased blood flow.

• Other capillaries come into use through the opening of pre-capillary sphincters.

Capillaries

• A long term exercise program may increase the number of capillaries supplying blood to muscles, allowing an increased oxygen supply to muscle and removal of wastes.

Veins

• Veins carry blood back to the heart.• Veins have no pulse, blood flow is steady and constant.• The walls of veins are thin and not as elastic as artery

walls.

Veins.• The return of blood to

the heart depends on contraction of skeletal muscle.

• Veins are squeezed by muscle as they contract.

• One way valves working against gravity and prevent backflow of blood to organs and muscles.