2. breathing

1.

Breathing

2.

Lesson objectives
⚫ To understand mechanisms of breathing.

3.

Put your hand on your chest. Breath
slowly. Why is your hand moving?

4.

Let’s recall.
What was the purpose of
respiration?

5.

What is the purpose of the
respiration?
⚫Living things
extract energy
from food by
respiration.
⚫And use these
energy for life
processes.

6.

What was the air path through the
body?

7.

Air path through the body:
⚫Nasal cavity
⚫Pharynx
⚫Trachea
⚫Bronchus
⚫Lungs (bronchiole -
alveoli)

8.

What are sites of gas exchange in
the body?

9.

⚫Gas exchange occurs between the alveoli
and capillaries.

10.

⚫Gas exchange
take place
between blood
and tissues.

11.

12.

13.

What is breathing?
⚫It is the
process of
taking air in
(inhalation) and
out
(exhalation) of
the lungs.

14.

Two groups of muscles participate
in breathing process:
Intercostal muscles
2. Diaphragm
1.

15.

Inhalation
⚫Intercostal muscles move chest upward.
⚫Diaphragm goes down.
⚫Chest volume increases.
⚫Pressure in chest decreases.
⚫So air pressure becomes larger than in
lungs.
⚫As a result air moves from the area of
high pressure to area of lower pressure
⚫So we breath in.

16.

Exhalation
⚫Intercostal muscles move chest down.
⚫Diaphragm goes upward.
⚫Chest volume decreases.
⚫Pressure in chest increases.
⚫So lungs pressure becomes larger than in
air.
⚫As a result air moves from the area of
high pressure to area of lower pressure
⚫So we breath out.