Transcript Chapter 30 notes: The Respiratory System

Chapter 30
Respiratory System
23-1
Respiration
• Ventilation: Movement of air into and out
of lungs
• External respiration: Gas exchange
between air in lungs and blood
• Transport of oxygen and carbon dioxide in
the blood
• Internal respiration: Gas exchange between
the blood and tissues
23-2
Respiratory System Functions
• Gas exchange: Oxygen enters blood and carbon
dioxide leaves
• Regulation of blood pH: Altered by changing
blood carbon dioxide levels
• Voice production: Movement of air past vocal
folds makes sound and speech
• Olfaction: Smell occurs when airborne
molecules drawn into nasal cavity
• Protection: Against microorganisms by
preventing entry and removing them
23-3
Respiratory System Divisions
• Upper tract
– Nose, pharynx
and associated
structures
• Lower tract
– Larynx,
trachea,
bronchi, lungs
23-4
• Nose
Nose and Pharynx
– External nose
• Pharynx
– Nasal cavity
– Common opening
• Functions
for digestive and
respiratory systems
–Passageway for air
– Three regions
–Cleans the air
–Humidifies, warms air • Nasopharynx
• Oropharynx
–Smell
–Along with paranasal • Laryngopharynx
sinuses are resonating
chambers for speech
23-5
Larynx
• Functions
– Maintain an open passageway for air
movement
– Epiglottis and vestibular folds prevent
swallowed material from moving into
larynx
– Vocal folds are primary source of sound
production
23-6
Vocal Folds
23-7
Trachea
Insert Fig 23.5 all but b
• Windpipe
• Divides to
form
–Primary
bronchi
23-8
Tracheobronchial Tree
• Conducting zone
– Trachea to terminal bronchioles which is
ciliated for removal of debris
– Passageway for air movement
– Cartilage holds tube system open and
smooth muscle controls tube diameter
• Respiratory zone
– Respiratory bronchioles to alveoli
– Site for gas exchange
23-9
Tracheobronchial Tree
23-10
Bronchioles and Alveoli
23-11
Lungs
• Two lungs: Principal
organs of respiration
– Right lung: Three lobes
– Left lung: Two lobes
• Divisions
– Lobes,
bronchopulmonary
segments, lobules
23-12
Ventilation
• Movement of air into and out of
lungs
• Air moves from area of higher
pressure to area of lower pressure
• Pressure is inversely related to
volume
23-13
Alveolar Pressure Changes
23-14
Changing Alveolar Volume
• Lung recoil
– Causes alveoli to collapse resulting from
• Elastic recoil and surface tension
– Surfactant: Reduces tendency of lungs to collapse
• Pleural pressure
– Negative pressure can cause alveoli to expand
– Pneumothorax is an opening between pleural
cavity and air that causes a loss of pleural
pressure
23-15