THE
RESPIRATORY
SYSTEM
C16L1

• What does the respiratory system do?
• How do the parts of the respiratory system work together?
• How does the respiratory system interact with other body systems?

Functions of the respiratory system breathing gas exchange between the atmosphere and the blood (supply oxygen & removes carbon dioxide and other waste gases) preventing foreign substances from entering during breathing phonation (speaking)

Breathing is the movement of air into and out of the lungs.
Breathing enables your respiratory system to take in oxygen and to eliminate carbon dioxide.

Respiratory System
Every cell in your body needs oxygen for a series of chemical reactions called cellular respiration.
During cellular respiration, oxygen and sugars react, releasing energy a cell can use.
Your respiratory system removes carbon dioxide and other waste gases from your body, so that cells can function.

breathe in

breathe out

STRUCTURES OF THE
RESPIRATORY SYSTEM nose and nasal cavities pharynx larynx trachea bronchi bronchioles alveoli

nose and nasal cavities nasal
septum: separate the two nasal cavities

ciliated mucous membranes
Cilia line the nose and most other airways in the respiratory system.

Wavelike motions of the cilia carry trapped particles away from your lungs.
The cilia help prevent harmful particles from getting very far into your respiratory system.

Functions of the ciliated mucous membranes filters bacteria, smoke, and dust particles from the air warms and moistens air
If anything irritates nasal membranes, it stimulates sneezing.

a thick, sticky substance that filters the air entering the body mucous

The pharynx is a tube-like passageway at the top of the throat that receives air, food, and liquids from the mouth or nose.

pharynx muscular tube lined with a ciliated mucous membrane about 5 inches long extends from the back of the nose to the esophagus sometimes called the "control center" for incoming substances, since it serves both the respiratory and digestive systems

7 openings into or out of the pharynx
2 openings of nasal cavities
2 passageways to middle earspace (Eustachian tubes) opening of mouth esophagus (passageway to stomach) larynx (passageway to lungs)

larynx
(voice box) short passageway from the pharynx to the trachea

larynx walls consist of cartilage pieces held together by several muscles and ligaments

vocal chords (or folds) a pair of membrane folds in the larynx

vocal cords produces the voice.

vocal chords (or folds) vocal chords in females are thinner and shorter
(they vibrate more rapidly)

vocal chords (or folds) vocal chords in males are thicker and longer (they vibrate more slowly)

glottis the space between the folds

epiglottis a thin, flexible flap in front of the larynx; folds over and blocks the glottis during swallowing
It keeps food and liquids from entering the rest of the respiratory system.

Trachea (windpipe) the tube that carries air between the pharynx and the bronchi

It is held open by
C-shaped rings of cartilage.
lined by the ciliated mucous membrane which traps matter such as dust, pollen, and smoke ends behind the heart, where it divides into 2 bronchi

(singular, bronchus) the 2 branches off of the trachea leading into the lungs

bronchi function: carrying air to and from the lungs

Lungs are the main organs of the respiratory system.
Inside the lungs, the bronchi continue to branch into smaller and narrower tubes called bronchioles.

bronchi branch and rebranch to form bronchioles

bronchioles carries air to and from the alveoli within the lungs

alveoli
(singular, alveolus) the microscopic sacs in which the exchange of gases takes place in the lungs

alveoli walls only 1 cell thick surrounded by capillaries

How does this gas exchange take place? by diffusion

breathing the process of inhaling and exhaling air

Below the lungs is a large muscle called the diaphragm that contracts and relaxes and moves air in and out of your lungs.

breathing
diaphragm: main muscle used in breathing
Secondary muscles are the intercostals