1 of 18

The Circulatory System

2 of 18

The Circulatory System

By the end of today the goal will be for you:

To understand the movement of blood throughout the body

The relationship between the circulatory and respiratory system

To understand the functions of the circulatory system
To recall the names of the main parts of the circulatory system and to understand their role.

Blood vessels: Arteries, veins, capillaries
Blood and its components

3 of 18

What is the colour of blood?

4 of 18

5 of 18

THE MOVEMENT OF OXYGENATED AND DEOXYGENATED BLOOD

Oxygenated blood means the blood that is rich in oxygen and a lot less carbon dioxide.

Deoxygenated blood means the blood has greater concentration of carbon dioxide as compared to oxygen.

6 of 18

Recap

right side of the heart pumps blood to your lungs
left side of your heart receives this oxygen-rich blood from your lungs and pumps it to other parts of your body.
gas exchange will happen between cells and blood vessels.
deoxygenated blood is going to the heart to be pumped to the lungs.
once at the lungs it will be oxygenated and then sent to the rest of the body

7 of 18

We can now recognize the relationship between the respiratory system and circulatory system.

Gas exchange is occurring between alveoli and capillaries (blood vessels). -through which process?

8 of 18

THE CIRCULATORY SYSTEM

The circulatory system has four (4) major functions:

Circulates blood through the body.

Transports water, oxygen and food to cells and removes wastes from cells.

Helps fight disease.

Maintains correct body temperature.

9 of 18

Main components of the circulatory system

Blood vessels
Blood
The heart

10 of 18

THE BLOOD VESSELS

There are 3 types of blood vessels:

Arteries: carry oxygenated blood away from the heart to the cells of the body

Veins: carry de-oxygenated blood (used up by the cells) back to the heart

Capillaries: join arteries & veins. They are very thin and is where oxygen & nutrients pass into cells.

11 of 18

Arteries	Have no valves	Small lumen to maintain high pressure	Blood is at high pressure	Thick walls with elastic fibres and muscles to withstand high pressure	Carries blood away from heart
Veins	Contains valves to prevent backflow of blood	Large lumen to help blood flow	Blood is at low pressure	Thin walls	Carries blood to the heart
Capillaries	Have no valves	Tiny vessel with narrow lumen so they can ‘fit’ between cells	Blood is at low pressure	Walls a single cell thick (short diffusion path)	Carries blood between cells

12 of 18

13 of 18

Video on Blood

14 of 18

What is the purpose of blood?

Blood is needed to keep us alive.
It brings oxygen and nutrients to all the parts of the body so they can keep working.
Blood carries carbon dioxide and other waste materials to the lungs, kidneys, and digestive system to be removed from the body.
Blood also fights infections, and carries hormones around the body.

15 of 18

THE BLOOD CELLS

The blood consists of:

Plasma: largely consists of water

Red Blood Cells: carry oxygen

White Blood Cells: fight infections

Platelets: responsible for blood clotting

16 of 18

RED BLOOD CELLS

made in the bone marrow
contain hemoglobin: a protein that carries oxygen to the tissues in the body.
Biconcave disc shape

17 of 18

WHITE BLOOD CELL

part of the immune system that protects your body from infection.
WBCs circulate through your bloodstream and tissues to respond to injury or illness by attacking any unknown organisms that enter your body

18 of 18

PLATELET

small, colorless cell fragments in our blood that form clots and stop or prevent bleeding
If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a plug (clot) to fix the damage.