Download 1-Chapter 33 3 presentation (respiratory system).

Lesson Overview
The Respiratory System
Lesson Overview
33.3 The Respiratory
System
Lesson Overview
The Respiratory System
Functions of the Respiratory System
• picks up oxygen from the air [inhale]
• releases carbon dioxide into the air [exhale]
• respiration = process of gas exchange
between body and environment
Lesson Overview
The Respiratory System
Structures of Respiratory System:
Nose & Nasal Cavity
• To keep lung tissue healthy:
o Hairs lining the nasal cavity trapping large
particles
o Incoming air is warmed in the inner nasal
cavity and sinuses
o These areas also produce mucus that
moistens the air and catches even more
dust particles.
Lesson Overview
The Respiratory System
Pharynx, Larynx, and Trachea
• From the nasal cavity, air moves down into the:
o pharynx = (throat) passageway for both air & food
o Only air moves from the pharynx into the larynx =
(voicebox) contains elastic folds of tissue known
as vocal cords
 When muscles pull the vocal cords together, the
air moving between them causes the cords to
vibrate and produce sounds
Lesson Overview
The Respiratory System
Pharynx, Larynx, and Trachea
o From the larynx, air moves into the trachea= windpipe
 When you swallow food or liquid, a flap of tissue
called the epiglottis covers the entrance to the
larynx, ensuring that the food or liquid goes into
the esophagus
 Mucus produced in the trachea continues to trap
inhaled particles
 Cilia lining the trachea sweep both mucus and
trapped particles away from the lungs toward the
pharynx, where they can be swallowed or spit out
Lesson Overview
The Respiratory System
Lesson Overview
The Respiratory System
Bronchi and Bronchioles
• From the trachea, air moves
into two large tubes in the chest
cavity called bronchi. Each
bronchus leads to one lung.
• Within each lung, the large
bronchus divides into smaller
bronchi, which lead to even
smaller passageways called
bronchioles.
Lesson Overview
The Respiratory System
Alveoli (Lungs)
o The bronchioles continue to
branch until they end in tiny air
sacs called alveoli
 Alveoli make up lung tissue
o Alveoli are grouped in clusters,
like bunches of grapes. A
network of capillaries
surrounds the alveoli in order
for gas exchange to occur
Lesson Overview
The Respiratory System
Gas Exchange
• When air enters the lungs,
oxygen dissolves in the moisture
in alveoli and then diffuses across
capillary walls into the blood
o Oxygen diffuses in this
direction because the oxygen
concentration is greater in the
alveoli than it is in the blood
• Carbon dioxide diffuses from blood into the alveoli
because its concentration is greater in the blood than
it is in the alveoli
Lesson Overview
The Respiratory System
Inhalation [breathing in]
• When you inhale, the diaphragm
muscle contracts and flattens.
Muscles between the ribs also
contract, raising the rib cage
• These actions increase the
volume of the chest cavity and
create a partial vacuum inside the
cavity, which draws air into the
lungs
Lesson Overview
The Respiratory System
Exhalation [breathing out]
• During exhalation, both the
rib cage and the diaphragm
relax, decreasing the
volume of the chest cavity
• Air rushes out of the lungs
Lesson Overview
The Respiratory System
Exhalation
• Exhalation is usually a passive
process, but to blow out a
candle, speak, sing, or yell, you
need more force provided by
muscles between the ribs
Lesson Overview
The Respiratory System
Smoking and the Respiratory System
Lesson Overview
The Respiratory System