Respiratory System
Respiratory System
• Primary Function
– Gas Exchange
• Secondary Functions
– Speech
– pH regulation of internal
environment
• Anatomical Divisions
– Conducting pathways
– Respiratory regions
• sites of gas exchange
• Conducting
Pathways
– Upper
respiratory tract
• Nasal cavity
• Pharynx
• Nasal Cavity
– Functions
• warms air
• humidifies
air
• filters air
–Features of
Nasal Cavity
• Conchae
• Ciliated
epithelial
mucosa
• Nasal cavity
communicates
with nasal
sinuses
• Pharynx
(refer to digestive system notes)
• Pharynx
– Functions
• food and air pathways
• resonating chamber for voice
• swallowing
– 3 divisions
• Nasopharynx
• Oropharynx
• Laryngopharynx
• Structural features of pharynx
– Lined with a stratified squamous
epithelium
– Skeletal muscle in wall
• Additional structural features
– Eustachian tube opening
– uvula
– tonsils
• Lower Respiratory Tract
– Larynx
– Trachea
– Bronchi
– Bronchioles
• Larynx
• Larynx
• Structure of the Larynx
• Structure of the Larynx
– Cartilages
_
Epiglottis
_
Epiglottis
_
Arytenoid
Epiglottis
Corniculate
Arytenoid
_
Epiglottis
Corniculate
Arytenoid
_
Cricoid
Epiglottis
Corniculate
Arytenoid
Thyroid
Cricoid
Epiglottis
Cuneiform
Corniculate
Arytenoid
Thyroid
Cricoid
• Structure of the Larynx
– Cartilages
• Structure of the Larynx
– Cartilages &
• Structure of the Larynx
– Cartilages & ligaments
• Structure of the Larynx
– Cartilages & ligaments
– Muscles
• Structure of the Larynx
– Cartilages & ligaments
– Muscles &
• Structure of the Larynx
– Cartilages & ligaments
– Muscles & bone
• Structure of the Larynx
– Cartilages & ligaments
– Muscles & bone
– Lined with a mucous
membrane
goblet cell cilia mucus
• Other Features of Larynx
• Other Features of Larynx
–Ventricular folds (‘false
vocal folds’)
• Other Features of Larynx
–Ventricular folds (‘false
vocal folds’)
– Vocal folds
• Other Features of Larynx
–Ventricular folds (‘false
vocal folds’)
– Vocal folds
• Other Features of Larynx
–Ventricular folds (‘false
vocal folds’)
– Vocal folds
– Glottis
• Primary Function of the
Larynx
• Primary Function of the
Larynx
– Sound production
-------------------------
• Primary Function of the
Larynx
– Sound production
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Cricothyroid Muscle
Cricothyroid Muscle
• Primary Function of the
Larynx
– Sound production
• Secondary Functions of the
Larynx
– Prevents food & drink from
entering lower respiratory
tract
•ventricular folds and vocal
folds
• Secondary Functions of the
Larynx
– Prevents food & drink from
entering lower respiratory
tract
•ventricular folds and vocal
folds
• Secondary Functions of the
Larynx
– Prevents food & drink from
entering lower respiratory
tract
•ventricular folds and vocal
folds
•epiglottis
• Trachea
(‘Windpipe’)
– General
features
• 1 inch
diameter
• 4-5 inches
long
– 1st inch
in neck
– Composed
of 15-20 “C”
rings
– Rings linked
by annular
ligaments
• Bronchi
• Bronchi (singular: bronchus)
• Bronchi (singular: bronchus)
– Primary
• Bronchi (singular: bronchus)
– Primary
• to lungs
• Bronchi (singular: bronchus)
– Primary
• to lungs
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• to lobes of lungs
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• to lobes of lungs
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• to lobes of lungs
– Tertiary
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• to lobes of lungs
– Tertiary (segmental)
• Bronchi (singular: bronchus)
– Primary
• to lungs
– Secondary (lobar)
• to lobes of lungs
– Tertiary (segmental)
• to bronchopulmonary
segments of lungs
• Bronchioles
• Bronchioles
– Branch off of tertiary
bronchi
• Bronchioles
– Branch off of tertiary
bronchi
– Less than 1 mm in diameter
• Bronchioles
– Branch off of tertiary
bronchi
– Less than 1 mm in diameter
– Smooth muscle in walls
• Bronchioles
– Branch off of tertiary
bronchi
– Less than 1 mm in diameter
– Smooth muscle in walls
• Bronchioles
– Branch off of tertiary
bronchi
– Less than 1 mm in diameter
– Smooth muscle in walls
• exhibit
bronchoconstriction
• Bronchioles
– Branch off of tertiary
bronchi
– Less than 1 mm in diameter
– Smooth muscle in walls
• exhibit
bronchoconstriction &
bronchodilation
• Terminal Bronchioles
• Terminal Bronchiole
– Last bronchioles before
alveoli
• Terminal Bronchioles
– Last bronchioles before
alveoli
– Deliver air to lung lobules
Review:
• Anatomical Divisions of
Respiratory System
– Conducting pathways
– Respiratory regions: sites of
gas exchange
•respiratory bronchioles
•alveoli
• Respiratory Bronchioles
– have alveoli
• Alveoli
• Alveoli (singular: alveolus)
• Alveoli (singular: alveolus)
–Sites of gas exchange
• Alveoli (singular: alveolus)
–Sites of gas exchange
• Alveoli (singular: alveolus)
–Sites of gas exchange
–Form the respiratory
membrane with alveolar
capillaries
• Alveoli (singular: alveolus)
–Sites of gas exchange
–Form the respiratory
membrane with alveolar
capillaries
• Alveoli (singular: alveolus)
–Sites of gas exchange
–Form the respiratory
membrane with alveolar
capillaries
–Secrete surfactant
• Structure of Lungs
–
• Structure of Lungs
– Alveoli
– Bronchi and Bronchioles
– Reticular CT with lots of
elastic fibers
– Blood vessels and nerves
• Pleural Cavities
• Pleural membranes
– Visceral pleura
– Parietal pleura
• Pulmonary Ventilation
– Movement of air into and
out of the alveoli
•
Pulmonary ventilation
can be explained by:
1. Boyle’s law: P ~ 1/V
2. And the basic concept
that a given volume of
air will move from a
region of high air
pressure into a region of
low air pressure
• Ventilation Steps
– Inspiration (quiet or forced)
– Expiration (quiet or
forced)
–Muscles of quiet inspiration
•Diaphragm
•External intercostals
• Why does air enter the lungs
when these muscles contract?
–Muscles of forced
inspiration
–Pect. Minor
– Serratus anterior
– Sternocleidomastoid
–Muscles of quiet expiration
•None!
–Muscles of forced expiration
–Internal intercostals
–Abdominal muscles
• Asthma Video
• Gas Exchange Video
• Bronchoscopy
• Respiration Video