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PowerPoint® Lecture Slides
prepared by
Barbara Heard,
Atlantic Cape Community
College
CHAPTER
22
The Respiratory
System:
Part A
© Annie Leibovitz/Contact Press Images
© 2013 Pearson Education, Inc.
The Respiratory System
• Major function-respiration
– Supply body with O2 for cellular respiration;
dispose of CO2, a waste product of cellular
respiration
– Its four processes involve both respiratory and
circulatory systems
• Also functions in olfaction and speech
© 2013 Pearson Education, Inc.
Processes of Respiration
• Pulmonary ventilation (breathing)movement of air into and out
of lungs
• External respiration-O2 and CO2
exchange between lungs and blood
• Transport-O2 and CO2 in blood
• Internal respiration-O2 and CO2
exchange between systemic blood
vessels and tissues
© 2013 Pearson Education, Inc.
Respiratory
system
Circulatory
system
Respiratory System: Functional Anatomy
• Major organs
– Nose, nasal cavity, and paranasal sinuses
– Pharynx
– Larynx
– Trachea
– Bronchi and their branches
– Lungs and alveoli
© 2013 Pearson Education, Inc.
Figure 22.1 The major respiratory organs in relation to surrounding structures.
Nasal cavity
Oral cavity
Nostril
Pharynx
Larynx
Trachea
Carina of
trachea
Right main
(primary)
bronchus
Right
lung
Left main
(primary)
bronchus
Left lung
Diaphragm
© 2013 Pearson Education, Inc.
Functional Anatomy
• Respiratory zone-site of gas exchange
– Microscopic structures-respiratory
bronchioles, alveolar ducts, and alveoli
• Conducting zone-transit area to gas
exchange sites: throat, trachea etc
– Includes all other respiratory structures;
cleanses, warms, humidifies air
• Diaphragm and other respiratory muscles
promote ventilation
PLAY
Animation: Rotating face
© 2013 Pearson Education, Inc.
The Nose
• Functions
– Provides an airway for respiration
– Moistens and warms entering air
– Filters and cleans inspired air
– Serves as resonating chamber for speech
– Houses olfactory receptors
© 2013 Pearson Education, Inc.
The Nose
• Two regions-external nose and nasal
cavity
• External nose-root, bridge, dorsum nasi,
and apex
– Philtrum-shallow vertical groove inferior to
apex
– Nostrils (nares)-bounded laterally by alae
© 2013 Pearson Education, Inc.
Figure 22.2a The external nose.
Epicranius,
frontal belly
Root and
bridge of nose
Dorsum nasi
Ala of nose
Apex of nose
Naris (nostril)
Surface anatomy
© 2013 Pearson Education, Inc.
Figure 22.2b The external nose.
Frontal bone
Nasal bone
Septal cartilage
Maxillary bone
(frontal process)
Lateral process of
septal cartilage
Minor alar
cartilages
Dense fibrous
connective tissue
Major alar
cartilages
External skeletal framework
© 2013 Pearson Education, Inc.
The Nose
• Nasal cavity-within and posterior to
external nose
– Divided by midline nasal septum
– Posterior nasal apertures (choanae) open
into nasal pharynx
– Roof-ethmoid and sphenoid bones
– Floor–hard (bone) and soft palates (muscle)
© 2013 Pearson Education, Inc.
Nasal Cavity
• Nasal vestibule-nasal cavity superior to
nostrils
– Vibrissae (hairs) filter coarse particles from
inspired air
• Rest of nasal cavity lined with mucous
membranes
– Olfactory mucosa
– Respiratory mucosa
© 2013 Pearson Education, Inc.
Nasal Cavity
• Olfactory mucosa contains olfactory
epithelium
• Respiratory mucosa
– Pseudostratified ciliated columnar epithelium
– Mucous and serous secretions contain
lysozyme and defensins
– Cilia move contaminated mucus posteriorly to
throat
– Inspired air warmed by plexuses of capillaries
and veins
– Sensory nerve endings trigger sneezing
© 2013 Pearson Education, Inc.
Figure 22.3b The upper respiratory tract.
Cribriform plate
of ethmoid bone
Sphenoid sinus
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic tube
Uvula
Nostril
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Hard palate
Soft palate
Tongue
Lingual tonsil
Laryngopharynx
Esophagus
Larynx
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Trachea
Thyroid gland
Illustration
© 2013 Pearson Education, Inc.
Hyoid bone
Figure 22.3a The upper respiratory tract.
Olfactory nerves
Olfactory
epithelium
Superior nasal concha
and superior nasal meatus
Mucosa
of pharynx
Middle nasal concha
and middle nasal meatus
Tubal
tonsil
Inferior nasal concha
and inferior nasal meatus
Pharyngotympanic
(auditory) tube
Nasopharynx
Hard palate
Soft palate
Uvula
Photograph
© 2013 Pearson Education, Inc.
Nasal Cavity
• Nasal conchae-superior, middle, and
inferior
– During inhalation, conchae and nasal mucosa
• Filter, heat, and moisten air
– During exhalation these structures
• Reclaim heat and moisture
© 2013 Pearson Education, Inc.
Homeostatic Imbalance
• Rhinitis
– Inflammation of nasal mucosa
– Nasal mucosa continuous with mucosa of
respiratory tract  spreads from nose 
throat  chest
– Spreads to tear ducts and paranasal sinuses
causing
• Blocked sinus passageways  air absorbed 
vacuum  sinus headache
© 2013 Pearson Education, Inc.
Pharynx
• Muscular tube from base of skull to C6
– Connects nasal cavity and mouth to larynx
and esophagus
– Composed of skeletal muscle
• Three regions
– Nasopharynx
– Oropharynx
– Laryngopharynx
© 2013 Pearson Education, Inc.
Figure 22.3c The upper respiratory tract.
Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Regions of the pharynx
© 2013 Pearson Education, Inc.
Nasopharynx
• Air passageway posterior to nasal cavity
• Soft palate and uvula close nasopharynx
during swallowing
• Pharyngeal tonsil (adenoids) on posterior
wall
• Pharyngotympanic (auditory) tubes drain
and equalize pressure in middle ear; open
into lateral walls
© 2013 Pearson Education, Inc.
Oropharynx
• Passageway for food and air from level of
soft palate to epiglottis
© 2013 Pearson Education, Inc.
Laryngopharynx
• Passageway for food and air
• Posterior to upright epiglottis
© 2013 Pearson Education, Inc.
Figure 22.3b The upper respiratory tract.
Cribriform plate
of ethmoid bone
Sphenoid sinus
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic tube
Uvula
Nostril
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Hard palate
Soft palate
Tongue
Lingual tonsil
Laryngopharynx
Esophagus
Larynx
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Trachea
Thyroid gland
Illustration
© 2013 Pearson Education, Inc.
Hyoid bone
Larynx
• Attaches to hyoid bone; opens into
laryngopharynx; continuous with trachea
• Functions
– Provides patent airway
– Routes air and food into proper channels
– Voice production
• Houses vocal folds
© 2013 Pearson Education, Inc.
Larynx
• Nine cartilages of larynx
– All hyaline cartilage except epiglottis
– Thyroid cartilage with laryngeal
prominence (Adam's apple)
– Epiglottis-elastic cartilage; covers laryngeal
inlet during swallowing; covered in taste budcontaining mucosa
© 2013 Pearson Education, Inc.
Figure 22.4a The larynx.
Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
Cricothyroid ligament
Cricoid cartilage
Cricotracheal ligament
Tracheal cartilages
Anterior superficial view
© 2013 Pearson Education, Inc.
Figure 22.4b The larynx.
Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyrohyoid membrane
Cuneiform cartilage
Fatty pad
Corniculate cartilage
Vestibular fold
(false vocal cord)
Arytenoid cartilage
Thyroid cartilage
Arytenoid muscles
Vocal fold
(true vocal cord)
Cricoid cartilage
Cricothyroid ligament
Cricotracheal ligament
Tracheal cartilages
Sagittal view; anterior surface to the right
© 2013 Pearson Education, Inc.
Figure 22.4c The larynx.
Epiglottis
Hyoid bone
Thyroid
cartilage
Lateral
thyrohyoid
membrane
Corniculate
cartilage
Arytenoid
cartilage
Glottis
Cricoid
cartilage
Tracheal
cartilages
Photograph of cartilaginous framework
of the larynx, posterior view
© 2013 Pearson Education, Inc.
Figure 22.4d The larynx.
Epiglottis
Laryngeal
inlet
Corniculate
cartilage
Posterior
cricoarytenoid
muscle on
cricoid
cartilage
Trachea
(d) Photograph of posterior aspect
© 2013 Pearson Education, Inc.
Larynx
• Vocal ligaments-deep to laryngeal
mucosa
– Contain elastic fibers
– Folds vibrate to produce sound as air rushes
up from lungs
© 2013 Pearson Education, Inc.
Larynx
• Vestibular folds (false vocal cords)
– Superior to vocal folds
– No part in sound production
– Help to close glottis during swallowing
© 2013 Pearson Education, Inc.
Figure 22.5 Movements of the vocal folds.
Base of tongue
Epiglottis
Vestibular fold (false vocal cord)
Vocal fold (true vocal cord)
Glottis
Inner lining of trachea
Cuneiform cartilage
Corniculate cartilage
Vocal folds in closed position; closed glottis
© 2013 Pearson Education, Inc.
Vocal folds in open position; open glottis
Voice Production
• Speech-intermittent release of expired air while
opening and closing glottis
• Pitch determined by length and tension of vocal
cords
• Loudness depends upon force of air
• Chambers of pharynx, oral, nasal, and sinus
cavities amplify and enhance sound quality
• Sound is "shaped" into language by muscles of
pharynx, tongue, soft palate, and lips
© 2013 Pearson Education, Inc.
Larynx
• Vocal folds may act as sphincter to
prevent air passage
• Example-Valsalva's maneuver
– Glottis closes to prevent exhalation
– Abdominal muscles contract
– Intra-abdominal pressure rises
– Helps to empty rectum or stabilizes trunk
during heavy lifting
© 2013 Pearson Education, Inc.
Trachea
• Windpipe–from larynx into mediastinum
© 2013 Pearson Education, Inc.
Trachea
• Trachealis muscle
– Connects posterior parts of cartilage rings
– Contracts during coughing to expel mucus
© 2013 Pearson Education, Inc.
Figure 22.6a Tissue composition of the tracheal wall.
Posterior
Mucosa
Esophagus
Trachealis
muscle
Submucosa
Lumen of
trachea
Seromucous gland
in submucosa
Hyaline cartilage
Adventitia
Anterior
Cross section of the trachea
and esophagus
© 2013 Pearson Education, Inc.
Figure 22.6b Tissue composition of the tracheal wall.
Goblet cell
Mucosa
• Pseudostratified
ciliated columnar
epithelium
• Lamina propria
(connective tissue)
Submucosa
Seromucous gland
In submucosa
Hyaline cartilage
Photomicrograph of the tracheal
wall (320x)
© 2013 Pearson Education, Inc.
Figure 22.6c Tissue composition of the tracheal wall.
Scanning electron micrograph of cilia in the
trachea (2500x)
© 2013 Pearson Education, Inc.
Bronchi
• Tubes coming off each side of the bottom
of the trachea
© 2013 Pearson Education, Inc.
Conducting Zone Structures
• Trachea  right and left main (primary)
bronchi
• Each main bronchus enters hilum of one
lung
– Right main bronchus wider, shorter, more
vertical than left
• Each main bronchus branches into lobar
(secondary) bronchi (three on right, two
on left)
– Each lobar bronchus supplies one lobe
© 2013 Pearson Education, Inc.
Conducting Zone Structures
• Each lobar bronchus branches into
segmental (tertiary) bronchi
– Segmental bronchi divide repeatedly
• Branches become smaller and smaller 
– Bronchioles-less than 1 mm in diameter
– Terminal bronchioles-smallest-less than
0.5 mm diameter
© 2013 Pearson Education, Inc.
Figure 22.7 Conducting zone passages.
Trachea
Superior lobe
of left lung
Left main
(primary)
bronchus
Superior lobe
of right lung
Lobar (secondary)
bronchus
Segmental (tertiary)
bronchus
Middle lobe
of right lung
Inferior lobe
of right lung
© 2013 Pearson Education, Inc.
Inferior lobe
of left lung
Conducting Zone Structures
• From bronchi through bronchioles,
structural changes occur
– Cartilage rings become irregular plates; in
bronchioles elastic fibers replace cartilage
– Epithelium changes from pseudostratified
columnar to cuboidal; cilia and goblet cells
become sparse
– Relative amount of smooth muscle increases
• Allows constriction
© 2013 Pearson Education, Inc.
Respiratory Zone
• Begins as terminal bronchioles 
respiratory bronchioles  alveolar
ducts  alveolar sacs
– Alveolar sacs contain clusters of alveoli
• ~300 million alveoli make up most of lung volume
• Sites of gas exchange
© 2013 Pearson Education, Inc.
Figure 22.8a Respiratory zone structures.
Alveoli
Alveolar duct
Respiratory bronchioles
Terminal
bronchiole
© 2013 Pearson Education, Inc.
Alveolar duct
Alveolar
sac
Figure 22.8b Respiratory zone structures.
Respiratory
bronchiole
Alveolar
duct
Alveoli
Alveolar
sac
© 2013 Pearson Education, Inc.
Alveolar
pores
Respiratory Membrane
• Alveolar and capillary walls and their fused
basement membranes
– ~0.5- m-thick; gas exchange across
membrane by simple diffusion
• Alveolar walls
– Single layer of squamous epithelium (type I
alveolar cells)
• Scattered cuboidal type II alveolar cells
secrete surfactant and antimicrobial
proteins
© 2013 Pearson Education, Inc.
Figure 22.9a Alveoli and the respiratory membrane.
Terminal bronchiole
Respiratory bronchiole
Smooth
muscle
Elastic
fibers
Alveolus
Capillaries
Diagrammatic view of capillary-alveoli relationships
© 2013 Pearson Education, Inc.
Figure 22.9b Alveoli and the respiratory membrane.
Scanning electron micrograph of pulmonary capillary
casts (70x)
© 2013 Pearson Education, Inc.
Alveoli
• Surrounded by fine elastic fibers and
pulmonary capillaries
• Alveolar pores connect adjacent alveoli
• Equalize air pressure throughout lung
• Alveolar macrophages keep alveolar
surfaces sterile
– 2 million dead macrophages/hour carried by
cilia  throat  swallowed
© 2013 Pearson Education, Inc.
Figure 22.9c Alveoli and the respiratory membrane.
Red blood
cell
Nucleus of type I
alveolar cell
Alveolar pores
Capillary
Capillary
Macrophage
Endothelial cell
nucleus
Alveolus
Respiratory
membrane
Alveoli
(gas-filled
air spaces)
Red blood
cell in
capillary
Type II
alveolar
cell
Type I
alveolar
cell
Detailed anatomy of the respiratory membrane
© 2013 Pearson Education, Inc.
Alveolus
Alveolar
epithelium
Fused basement
membranes of
alveolar
epithelium and
capillary
endothelium
Capillary
endothelium
Lungs
• Occupy all thoracic cavity except
mediastinum
• Composed primarily of alveoli
© 2013 Pearson Education, Inc.
Figure 22.10c Anatomical relationships of organs in the thoracic cavity.
Vertebra
Right lung
Parietal pleura
Visceral pleura
Pleural cavity
Posterior
Esophagus
(in mediastinum)
Root of lung
at hilum
• Left main
bronchus
• Left pulmonary
artery
• Left pulmonary
vein
Left lung
Thoracic wall
Pulmonary trunk
Pericardial
membranes
Sternum
Heart (in mediastinum)
Anterior mediastinum
Anterior
Transverse section through the thorax, viewed from above. Lungs, pleural
membranes, and major organs in the mediastinum are shown.
© 2013 Pearson Education, Inc.
Lungs
• Apex-superior tip; deep to clavicle
• Base-inferior surface; rests on diaphragm
• Hilum-on mediastinal surface; site for
entry/exit of blood vessels, bronchi,
lymphatic vessels, and nerves
• Left lung smaller than right
– Cardiac notch-concavity for heart
– Separated into superior and inferior lobes by
oblique fissure
© 2013 Pearson Education, Inc.
Lungs
• Right lung
– Superior, middle, inferior lobes separated by
oblique and horizontal fissures
• Bronchopulmonary segments (10 right,
8–10 left) separated by connective tissue
septa
– If diseased can be individually removed
• Lobules-smallest subdivisions visible to
naked eye; served by bronchioles and
their branches
© 2013 Pearson Education, Inc.
Figure 22.10a Anatomical relationships of organs in the thoracic cavity.
Intercostal
muscle
Rib
Lung
Parietal pleura
Pleural cavity
Visceral pleura
Trachea
Thymus
Apex of lung
Left
superior lobe
Right superior lobe
Horizontal fissure
Right middle lobe
Oblique fissure
Oblique
fissure
Left inferior
lobe
Right inferior lobe
Heart
(in mediastinum)
Diaphragm
Cardiac notch
Base of lung
Anterior view. The lungs flank mediastinal structures laterally.
© 2013 Pearson Education, Inc.
Figure 22.10b Anatomical relationships of organs in the thoracic cavity.
Apex of lung
Pulmonary
artery
Left
superior lobe
Oblique
fissure
Pulmonary
vein
Left inferior
lobe
Cardiac
impression
Hilum of lung
Oblique
fissure
Aortic
impression
© 2013 Pearson Education, Inc.
Left main
bronchus
Lobules
Photograph of medial view of the
left lung.
Figure 22.11 A cast of the bronchial tree.
Right lung
Right
superior
lobe (3
segments)
Left lung
Left superior
lobe
(4 segments)
Right
middle
lobe (2
segments)
Right
inferior lobe
(5 segments)
© 2013 Pearson Education, Inc.
Left inferior
lobe
(5 segments)
Blood Supply
• Pulmonary circulation (low pressure,
high volume)
– Pulmonary arteries deliver systemic venous
blood to lungs for oxygenation
• Branch profusely; feed into pulmonary capillary
networks
– Pulmonary veins carry oxygenated blood
from respiratory zones to heart
© 2013 Pearson Education, Inc.
Blood Supply
– Lung capillary endothelium contains enzymes
that act on substances in blood
• E.g., angiotensin-converting enzyme–activates
blood pressure hormone
© 2013 Pearson Education, Inc.
Blood Supply
• Bronchial arteries provide oxygenated
blood to lung tissue
– Arise from aorta and enter lungs at hilum
– Part of systemic circulation (high pressure,
low volume)
– Supply all lung tissue except alveoli
– Bronchial veins anastomose with pulmonary
veins
• Pulmonary veins carry most venous blood back to
heart
© 2013 Pearson Education, Inc.
Mechanics of Breathing
• Pulmonary ventilation consists of two
phases
– Inspiration-gases flow into lungs
– Expiration-gases exit lungs
© 2013 Pearson Education, Inc.
Homeostatic Imbalance
• Atelectasis (lung collapse) due to
– Plugged bronchioles  collapse of alveoli
– Pneumothorax-air in pleural cavity
• From either wound in parietal or rupture of visceral
pleura
• Treated by removing air with chest tubes; pleurae
heal  lung reinflates
© 2013 Pearson Education, Inc.
Pulmonary Ventilation
• Inspiration and expiration
• Mechanical processes that depend on
volume changes in thoracic cavity
– Volume changes  pressure changes
– Pressure changes  gases flow to equalize
pressure
© 2013 Pearson Education, Inc.
Inspiration
• Active process
– Inspiratory muscles (diaphragm and external
intercostals) contract
– Thoracic volume increases  intrapulmonary
pressure drops (to 1 mm Hg)
– Lungs stretched and intrapulmonary volume
increases
– Air flows into lungs, down its pressure
gradient, until Ppul = Patm
© 2013 Pearson Education, Inc.
Expiration
• Quiet expiration normally passive process
– Inspiratory muscles relax
– Thoracic cavity volume decreases
– Elastic lungs recoil and intrapulmonary
volume decreases  pressure increases (Ppul
rises to +1 mm Hg) 
– Air flows out of lungs down its pressure
gradient until Ppul = 0
• Note: forced expiration-active process;
uses abdominal (oblique and transverse)
and internal intercostal muscles
© 2013 Pearson Education, Inc.