Download THE RESPIRATORY SYSTEM

THE RESPIRATORY SYSTEM
FUNCTIONS OF THE RESPIRATORY
SYSTEM
Transports air into the lungs and facilitates the
diffusion of oxygen into the blood stream
 Receives carbon dioxide from the blood and
exhales it

Organs of the Respiratory system
 Nose
 Pharynx
 Larynx
 Trachea
 Bronchi
 Lungs alveoli
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 13.1
SLIDE 13.1
ORGANIZATION OF THE RESPIRATORY
SYSTEM


Upper Respiratory System – Nose, nasal cavity,
paranasal sinuses, and pharynx
Lower Respiratory System – Larynx, Trachea,
Bronchi, Bronchioles, Alveoli
Upper Respiratory Tract
Figure 13.2
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
SLIDE 13.3B
NOSE, NASAL CAVITY, PARANASAL SINUSES
Primary passageway for air entering the
respiratory system
 The only externally visible part of the respiratory
system
 The maxillary, nasal, frontal, ethmoid, and
sphenoid bones form the lateral and superior
walls of the nasal cavity
 The mucous secretions produced in the paranasal
sinuses keep the nasal cavity moist and clean

PHARYNX (THROAT)
Chamber shared by the digestive and respiratory
systems
 The pharnyx is divided into the nasopharynx,
oropharynx, and laryngopharynx
1. Nasopharynx – superior portion of pharynx
2. Oropharynx – oris/mouth; extends between the
soft palate and the base of the tongue at the
level of the hyoid bone
3. Laryngopharynx – inferior part of pharynx;
entrance to larynx and esophagus

LARYNX (VOICEBOX)
Cartilaginous structure that surrounds and
protects the glottis (narrow opening where
inhaled air leaves the pharynx and enters larynx)
 Epiglottis – superior to the glottis; composed of
elastic cartilage; during swallowing the larynx is
elevated and the epiglottis folds back over the
glottis, preventing the entry of both liquids and
food into the respiratory tract
 Sound production - air passing through the
glottis vibrates the vocal folds and produces
sound waves (phonation)

TRACHEA (WINDPIPE)
Tough, flexible tube
 Transports air between the larynx and primary
bronchi
 Cilia and mucus protect the respiratory tree by
trapping inhaled debris and sweeping it toward
the pharynx, where it is removed through
coughing or swallowing
 Branches within the mediastinum, giving rise to
the right and left primary bronchi
 Right bronchus supplies the right lung, left
bronchus supplies the left lung

LUNGS
Air moves into the lungs through the trachea
(windpipe)
 The trachea branches out into two bronchi (main
airways that reach into each lung)
 Bronchioles (network of tubes) brings air closer to
the site of external respiration
 At the end of each bronchiole are groups of
microscopic structures called alveoli (thin-walled
air sacs covered with capillaries)
 Gas exchange takes place as oxygen and carbon
dioxide spread across the walls of the capillaries
and alveoli

Lungs
Figure 13.4b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
SLIDE 13.12B
RESPIRATION
External respiration – oxygen moves from the
blood into the lungs
 Internal respiration – oxygen moves from the blood
into the cells, and carbon dioxide moves from the
cells into the blood
 Continual exchange of gases in both external and
internal respiration is essential for survival
