Chapter 7 - The Breathing System

Chapter 7 - The Breathing System

Larynx: (Voice box) makes sound.Trachea: (windpipe) allows air to pass in and out to lungs.

Rings of cartilage: keep trachea open.

Bronchus: branches off trachea into each lung.

Bronchioles: thin tubes which carry air within the lung.

Alveoli: air sacs covered by tiny blood vessels. Allow air to pass through the blood.

Intercostal muscles: found between the ribs. Allow the ribs to move up and down during breathing.

Diaphragm: sheet of muscle below the lungs that moves down when we breathe in and moves back up when we breath out.The Bell Jar Model

When the tag is pulled down, the balloons fill with air. This is the same as when we breathe in. i.e. our lungs fill with air as our diaphragm moves down.

When the tag is pushed up, the balloons empty. This is the same as when we breathe out. i.e. our lungs empty as our diaphragm moves back up.

Gaseous Exchange at the Alveoli

Gaseous exchange occurs when oxygen from the air is swapped with carbon dioxide from the body.

It occurs at the alveoli.

There are millions of alveoli in each lung. There are found at the ends of the bronchioles.

There is a network of tiny blood vessels wrapped around the alveoli.

The walls of the alveoli are very thin. This allows the exchange of gases to happen very quickly. i.e. the gasses diffuse through the thin walls.

Smoking

Smoking can affect your health in many ways;a) Tar can irritate the bronchioles, leading to a build up of mucus and bronchitis.

b) Nicotine can damage the heart and blood vessels.

c) Carbon monoxide can take the place of oxygen

d) Can cause lung cancer.

Chapter 7 - The Breathing System - Revision Questions

1) Name the gas we breathe in?

Oxygen

2) Name the gas we breathe out?

Carbon Dioxide

3) Give a function for each of the following:a) Larynx: makes sound.b) Rings of cartilage: keeps the trachea open.c) Diaphragm: sheet of muscle under the lungs that moves up and down as we breathe.d) Intercostal muscles: allow ribs to move while breathing.e) Alveoli: allow air to pass through the blood.f) Bronchus: carries air from trachea to lungs.g) Bronchioles: carries air within the lung.h) Trachea: allows air to pass in and out of lungs.4) Name the 4 parts of the Bell Jar Apparatus that represents the parts of the human breathing system.

Glass tube - tracheaY-tube - bronchi

Balloon - lung

Bell jar - rib cage

Rubber sheet - diaphragm

5) Name the two muscles involved in breathing.

Diaphragm and intercostals muscle.6) Explain the term gaseous exchange.

The gaseous exchange occurs when oxygen from the air is swapped with carbon dioxide from the body.

7) Name the 3 gases that we breathe in and give their %.

Nitrogen - 78%Oxygen - 21%

Carbon Dioxide - 0.003%

8) Name the 3 gases that we breathe out and give their %.

Nitrogen - 78%Oxygen - 16%

Carbon dioxide - 4%

9) List 2 reasons why smoking is bad for you.

Can cause lung cancer, can cause damage to blood vessels and heart.10) Give another name for breathing in and out.

Inhaling and exhaling