3.3 Circulatory System

This system is responsible for delivering nutrients absorbed by the digestive system to each cell in your body.

It is your bodies transportation network.

It also is responsible for delivering the oxygen and wastes created by the respiratory system.

Your circulatory system acts similar to the a highway interchange;

◦ Your body has different routes to take to reach different areas

◦ Oxygen-rich blood flows one way, CO2 rich blood travels the other

◦ There are larger systems closer to the main area than the remote areas of the body

The most important part of the system

The heart is A PUMP, did you know it is actually two pumps?

The right and left side are each a separate pump that work together

The Heart

The right side of the heart pumps blood to your lungs ◦ Here it receives fresh oxygen and gives CO2

The left side of your heart receives this oxygen-rich blood from your lungs and pumps it to all the rest of your body

The blood returns to the right side to begin all over again

The Right and Left Side

There 2 atriums and 2 ventricles in the heart

Atriums Receive blood from veins

◦ Right Atrium – receives blood low in oxygen from the body and pumps it into the right ventricle

◦ Left Atrium – Receives oxygen-rich blood from the lungs and pumps it into the left ventricle

The Heart – Atrium and Ventricles

Ventricles Are the bottom two chambers of the heart

that receive blood from the atriums

Pushes blood out through arteries

◦ Right Ventricle – when it contracts it pumps blood to the lungs

◦ Left Ventricle – When it contracts it pumps blood to the body

The aorta is a three hole artery that carries the blood from the heart to the entire body

This is the major tube that carries all of the bodies blood to the areas that need it

THE AORTA

ARTERIES, VEINS, and CAPILLARIES

Made up of 3 of the 4 types of tissue;

◦ Connective on the outside (Tough)

◦ Muscle in the middle (Very strong and elastic)

◦ Epithelial on the inside

Blood Vessels

Inside the body there is an intricate network of blood vessels

These vessels are about 100,000km in length if completely stretched out

Inside the body the blood vessels that are responsible for carrying blood away from the heart.

These blood vessels are called ARTERIES.

They carry blood from the heart to both the lungs and the rest of the body

Arteries

Have a thick muscular layer in the middle that expands and contracts to help push blood along

When you feel the expansion of the arteries this is commonly known as PULSE

Arteries

Inside the body the blood vessels that are responsible for carrying blood towards the heart.

These blood vessels are called Veins.

They carry blood from rest of the body and the lungs to your heart

Veins

Veins are thinner than arteries, and have valves that stop the blood from flowing backwards

Veins

Are tiny blood vessels whose purpose is the diffusion of nutrients and gases

Are located between arteries and veins

They have two adaptations;◦ 1) Epithelial tissues that are only one cell thick

◦ 2) Are very narrow so that blood cells have to pass through single file

Capillaries

Diffusion -- transports oxygen from your blood into your cells, and carbon dioxide from your cells into your blood

Osmosis – Transports water in and out of the blood cell

Diffusion and Osmosis

The Blood

Is the second largest example of connective tissue◦ (bones are the largest)

Blood is composed of;◦ Red Blood Cells◦ White Blood Cells◦ Platelets (tiny cells)◦ Plasma (liquid portion)

Plasma makes up 55% of blood, everything else makes up 45%

Blood

High specialized in order to perform their function◦ Function is to carry oxygen

RBC’s do not have a nuclei, therefore have more room for oxygen◦ Are extremely flexible – can bend and twist

through the small capillary spaces

Blood Cells

Specialized cells to fight infection

Some are capable or eating bacteria at infection sites such as cuts

White Blood Cells

Are cells that help to stop the bleeding at cuts

PLASMA

The liquid portion of your blood, transports nutrients to your cells and carries wastes, such as carbon dioxide, away

Platelets and PLASMA

http://www.youtube.com/watch?v=gg7FuKqKY4E