Unit 2Structures of Living Things

Lesson 2How do the circulatory and respiratory systems work

together?

Circulatory System

•The circulatory system is a group of organs that transports needed materials throughout the body.

Respiratory System

• The respiratory system is a group of organs and tissues that exchanges oxygen and carbon dioxide between your body and the environment.

• http://www.youtube.com/watch?v=h9xxIFzuTo8 (0:26)

The Heart• The heart is one of the most

important organs in the body. It is the pumping organ which is made up of a double pump with four chambers. It normally beats at a steady rate.

• Before your heart beats, two of the chambers fill with blood.

• Then, the heart contracts and squeezes blood into large tubes, or blood vessels.

The path of blood

• Blood from the body returns to the heart and then pumps it to the lungs

• Carbon dioxide is then exchanged from for oxygen.

• http://www.metacafe.com/watch/4189102/blood_circulation_in_the_human_body/ (1:07)

The four steps of blood flow through the heart:

• Pulmonary arteries carry blood away from the heart to the lungs.

• Oxygen rich blood from the lungs returns to the heart.

• The heart pumps blood to all parts of the body through arteries.

• Veins carry blood from the body back to the heart.

The Circulatory system

• The circulatory system transports blood loaded with oxygen and nutrients to each cell of the body.

• It takes away wastes from the cell• It is made up of the heart, blood

vessels, and blood.

Blood

• The liquid part of blood is called plasma and is mostly water.– It carries nutrients to the body’s cells.

• The solid part of blood includes red blood cells, white blood cells, and platelets.

• http://www.youtube.com/watch?v=CRh_dAzXuoU (2:24)

• Blood leaves the heart through blood vessels called arteries.

• They lead to small vessels called capillaries.

• They have thin walls and come into direct contact with every body cell. Nutrients, oxygen, and wastes move from areas of high concentration to areas of low concentration, meaning they move to where they are needed.

The Respiratory System

• The respiratory system is a group of organs and tissues that exchanges oxygen and carbon dioxide between your body and the environment.

• A muscle called the diaphragm helps pull air into your body. That air contains oxygen that you need.

The Path of Air In• Nose or mouth• Trachea• Smaller and smaller tubes• Lungs (the main organ)

Working Together• The oxygen in the air that you inhale moves

from the respiratory system into the blood.• Carbon dioxide moves from the blood into

the respiratory system.• Carbon dioxide leaves the body when you

exhale.• The exchange of gases takes place in air

sacs in the lungs.• The thin walls of the capillaries and air sacs

allow gases to move through them.

How does oxygen from the air get into your blood?

• Air is breathed in through nose or mouth.

• It travels through the trachea and smaller branching tubes into the lungs.

• There, oxygen moves into the tiny blood vessels surrounding the air sacs.

• Oxygen-rich blood then travels to the heart and is pumped to all cells in the body.

• http://www.metacafe.com/watch/yt-bwXvqSqAgKc/respiratory_system/ (1:31)

• http://www.youtube.com/watch?v=kX0hQNIjQ-8 (0:26)