BREATHING

Breathing The primary function of breathing is

to supply the blood with oxygen

Oxygen is needed by every cell in the body to release the energy from glucose in a process called respiration.

Anatomy of Breathing Oxygen enters the respiratory system

through the mouth and the nose.

The oxygen then passes through the larynx (voicebox) and the trachea; which is a tube that enters the chest cavity.

In the chest cavity, the trachea splits into two smaller tubes called the bronchi (singular = bronchus).

Anatomy of Breathing Each bronchus then divides again

forming smaller tubes called bronchioles.

The bronchioles lead directly into the lungs where they lead to tiny sacs called alveoli.

Anatomy of Breathing The inhaled oxygen passes into the

alveoli and then diffuses through the capillaries into the blood.

Carbon dioxide from the veins is released into the alveoli and follows the same path out of the lungs when you exhale.

Anatomy of Breathing

Inhaled Air

• Oxygen (21%)• Carbon Dioxide

(0.4%)

Exhaled Air

• Oxygen (17%)• Carbon Dioxide

(4%)

Alveoli Are important to

increase the surface area of the lungs.

The average adult's lungs contain about 600 million of these spongy, air-filled sacs

Copy the alveoli structure diagram on Pg. 20

Asthma

Emphysema Caused by exposure to toxic

chemicals or long-term exposure to tobacco smoke.

Emphysema

Asthma When the airway becomes inflamed

and is lined with excessive amounts of mucus.

These episodes may be triggered by such things as exposure to an environmental stimulant (or allergen), cold air, warm air, moist air, exercise or exertion.

Asthma