Download The Respiratory System

22
PART 1
The Respiratory
System
Pages 645-665
PowerPoint® Lecture Presentations prepared by
Leslie Hendon
University of Alabama, Birmingham
© 2014 Pearson Education, Inc.
The Respiratory System
• Basic functions of the respiratory system
• Supplies body with oxygen
• Disposes of carbon dioxide
• Four processes involved in respiration
• Pulmonary ventilation
• External respiration
• Transport of respiratory gases
• Internal respiration
© 2014 Pearson Education, Inc.
Functional Anatomy of the Respiratory
System
• Respiratory organs
• Nose, nasal cavity, and paranasal sinuses
• Pharynx, larynx, and trachea
• Bronchi and smaller branches
• Lungs and alveoli
© 2014 Pearson Education, Inc.
Organs of the Respiratory System
Nasal cavity
Nostril
Larynx
Trachea
Carina of
trachea
Right main
(primary)
bronchus
Right lung
Parietal
pleura
© 2014 Pearson Education, Inc.
Oral cavity
Pharynx
Left main
(primary)
bronchus
Bronchi
Alveoli
Left lung
Diaphragm
Figure 22.1
Organs of the Respiratory System
• Divided into
• Conducting zone
• Respiratory zone
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The Nose
• Provides an airway for respiration
• Moistens and warms air
• Filters inhaled air
• Resonating chamber for speech
• Houses olfactory receptors
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The Nose
• Size variation due to differences in nasal
cartilages
• Skin is thin—contains many sebaceous glands
Frontal bone
Epicranius,
frontal belly
Root and bridge
of nose
Dorsum nasi
Ala of nose
Apex of nose
Naris (nostril)
Philtrum
(a) Surface anatomy
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Nasal bone
Septal cartilage
Maxillary bone
(frontal process)
Lateral process of
septal cartilage
Minor alar
cartilages
Dense fibrous
connective tissue
Major alar
cartilages
(b) External skeletal framework
Figure 22.2
The Nasal Cavity
• External nares—nostrils
• Divided by nasal septum
• Continuous with nasopharynx
• Posterior nasal apertures—choanae
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Nasal Cavity
• Two types of mucous membrane
• Olfactory mucosa
• Near roof of nasal cavity
• Houses olfactory (smell) receptors
• Respiratory mucosa
• Lines nasal cavity
• Epithelium is pseudostratified ciliated columnar
© 2014 Pearson Education, Inc.
The Upper Respiratory Tract
Cribriform plate
of ethmoid bone
Sphenoid sinus
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic
tube
Uvula
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Laryngopharynx
Esophagus
Trachea
(c) Illustration
© 2014 Pearson Education, Inc.
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Nostril
Hard palate
Soft palate
Tongue
Larynx
Lingual tonsil
Hyoid bone
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Thyroid gland
Figure 22.3
Nasal Conchae
• Superior and middle nasal conchae
• Part of the ethmoid bone
• Inferior nasal conchae
• Separate bone
• Project medially from the lateral wall of the
nasal cavity
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The Pharynx
• Funnel-shaped passageway
• Connects nasal cavity and mouth
• Divided into three sections by location
• Nasopharynx
• Oropharynx
• Laryngopharynx
• Type of mucosal lining changes along its length
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
The Upper Respiratory Tract
Cribriform plate
of ethmoid bone
Sphenoid sinus
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic
tube
Uvula
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Laryngopharynx
Esophagus
Trachea
(c) Illustration
© 2014 Pearson Education, Inc.
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Nostril
Hard palate
Soft palate
Tongue
Larynx
Lingual tonsil
Hyoid bone
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Thyroid gland
Figure 22.3
The Nasopharynx
• Superior to the point where food enters
• Only an air passageway
• Closed off during swallowing
• Pharyngeal tonsil (adenoids)
• Located on posterior wall
• Destroys entering pathogens
• Contains the opening to the
pharyngotympanic tube (auditory tube)
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The Oropharynx
• Arch-like entranceway—fauces
• Extends from soft palate to the epiglottis
• Epithelium
• Stratified squamous epithelium
• Two types of tonsils in the oropharynx
• Palatine tonsils—in the lateral walls of the
fauces
• Lingual tonsils—covers the posterior surface of
the tongue
© 2014 Pearson Education, Inc.
The Upper Respiratory Tract
Cribriform plate
of ethmoid bone
Sphenoid sinus
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic
tube
Uvula
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Laryngopharynx
Esophagus
Trachea
(c) Illustration
© 2014 Pearson Education, Inc.
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Nostril
Hard palate
Soft palate
Tongue
Larynx
Lingual tonsil
Hyoid bone
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Thyroid gland
Figure 22.3
The Laryngopharynx
• Passageway for both food and air
• Epithelium
• Stratified squamous epithelium
• Continuous with the esophagus and larynx
© 2014 Pearson Education, Inc.
The Larynx
• Three functions
• Voice production
• Provides an open airway
• Routes air and food into the proper channels
• Superior opening is
• Closed during swallowing
• Open during breathing
© 2014 Pearson Education, Inc.
The Upper Respiratory Tract
Cribriform plate
of ethmoid bone
Sphenoid sinus
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic
tube
Uvula
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Laryngopharynx
Esophagus
Trachea
(c) Illustration
© 2014 Pearson Education, Inc.
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior)
Nasal vestibule
Nostril
Hard palate
Soft palate
Tongue
Larynx
Lingual tonsil
Hyoid bone
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Thyroid gland
Figure 22.3
Nine Cartilages of the Larynx
• Thyroid cartilage
• Shield-shaped, forms laryngeal prominence
(Adam’s apple)
• Three pairs of small cartilages
• Arytenoid cartilages
• Corniculate cartilages
• Cuneiform cartilages
• Epiglottis
• Tips inferiorly during swallowing
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Anatomy of the Larynx
Body of hyoid bone
Laryngeal prominence
(Adam’s apple)
Cricoid cartilage
Sternal head
Clavicular head
Sternocleidomastoid
Clavicle
Jugular notch
(a) Surface view
Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
Cricothyroid ligament
Cricoid cartilage
Cricotracheal ligament
Tracheal
cartilages
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(b) Anterior view
Figure 22.5a, b
Anatomy of the Larynx
Epiglottis
Thyrohyoid
membrane
Hyoid bone
Corniculate cartilage
Arytenoid cartilage
Thyroid
cartilage
Cricoid cartilage
Glottis
Tracheal cartilages
(c) Photograph of cartilaginous framework of the larynx, posterior view
Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyrohyoid membrane
Cuneiform cartilage
Corniculate cartilage
Arytenoid cartilage
Arytenoid muscle
Cricoid cartilage
Fatty pad
Vestibular fold
(false vocal cord)
Thyroid cartilage
Vocal fold
(true vocal cord)
Cricothyroid ligament
Cricotracheal ligament
Tracheal cartilages
© 2014 Pearson Education, Inc.
(d) Sagittal section (anterior on the right)
Figure 22.5c, d
The Larynx
• Vocal ligaments of the larynx
• Vocal folds (true vocal cords)
• Act in sound production
• Vestibular folds (false vocal cords)
• No role in sound production
• Epithelium of the larynx
• Stratified squamous—superior portion
• Pseudostratified ciliated columnar—inferior
portion
© 2014 Pearson Education, Inc.
Movements of the Vocal Folds
Anterior
Thyroid cartilage
Cricoid cartilage
Vocal ligaments
of vocal cords
Glottis
Lateral
cricoarytenoid muscle
Arytenoid cartilage
Corniculate cartilage
Posterior
cricoarytenoid muscle
Posterior
Base of tongue
Epiglottis
Vestibular fold
(false vocal cord)
Vocal fold
(true vocal cord)
Glottis
Inner lining of trachea
Cuneiform cartilage
Corniculate cartilage
(a) Vocal folds in closed position; closed glottis
© 2014 Pearson Education, Inc.
(b) Vocal folds in open position; open glottis
Figure 22.6
The Trachea
• Descends into the mediastinum
• C-shaped cartilage rings keep airway open
• Carina
• Marks where trachea divides into two primary
bronchi
• Epithelium
• Pseudostratified ciliated columnar
© 2014 Pearson Education, Inc.
Organs of the Respiratory System
Nasal cavity
Nostril
Larynx
Trachea
Carina of
trachea
Right main
(primary)
bronchus
Right lung
Parietal
pleura
© 2014 Pearson Education, Inc.
Oral cavity
Pharynx
Left main
(primary)
bronchus
Bronchi
Alveoli
Left lung
Diaphragm
Figure 22.1
The Trachea
Mucosa
Pseudostratified
ciliated columnar
epithelium
Lamina propria
(connective tissue)
Submucosa
Seromucous gland
in submucosa
Posterior
Hyaline cartilage
Mucosa
Esophagus
Submucosa
Trachealis
muscle
Lumen of
trachea
(b) Photomicrograph of the tracheal wall (250)
Seromucous gland
in submucosa
Hyaline cartilage
Adventitia
Anterior
(a) Cross section of the trachea and esophagus
© 2014 Pearson Education, Inc.
Figure 22.7
Bronchi in the Conducting Zone
• Bronchial tree
• Extensively branching respiratory passageways
• Primary bronchi (main bronchi)
• Largest bronchi
• Right main bronchi
• Wider and shorter than the left
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Bronchi in the Conducting Zone
Superior lobe
of right lung
Trachea
Superior lobe
of left lung
Left main
(primary)
bronchus
Lobar
(secondary)
bronchus
Segmental
(tertiary)
bronchus
Inferior lobe
of left lung
Middle lobe
Inferior lobe
of right lung
of right lung
(a) The branching of the bronchial tree
© 2014 Pearson Education, Inc.
Figure 22.8a
Bronchi in the Conducting Zone
• Secondary (lobar) bronchi
• Three on the right
• Two on the left
• Tertiary (segmental) bronchi
• Branch into each lung segment
• Bronchioles
• Little bronchi, less than 1 mm in diameter
• Terminal bronchioles
• Less than 0.5 mm in diameter
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Figure 22.12 Bronchopulmonary segments.
Apicoposterior
Apical
Superior
Posterior
Anterior
Anterior
Superior
Lateral
Medial
Inferior
Superior
Lingular
Middle
Inferior
Superior
Anterior basal
Superior
Anterior basal
Medial basal
Lateral basal
Posterior basal
Medial basal
Inferior
Lateral basal
Posterior basal
Segmental bronchi
Superior lobe
Apical
Superior lobe
Posterior
Apical
Posterior
Anterior
Anterior
Superior
lingular
Middle lobe
Inferior
lingular
Lateral
Medial
Lingular
division
Inferior lobe
Superior
Inferior lobe
Anterior basal
Superior
Lateral
basal
Anterior
basal
Lateral
basal
Right lung
Left lung
Distribution of bronchiopulmonary segments on lateral surface of lungs
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Superior
division
Changes in Tissue Composition along
Conducting Pathways
• Supportive connective tissues change
• C-shaped rings replaced by cartilage plates
• Epithelium changes
• First, pseudostratified ciliated columnar
• Replaced by simple columnar, then simple
cuboidal epithelium
• Smooth muscle becomes important
• Airways widen with sympathetic stimulation
• Airways constrict under parasympathetic
direction
© 2014 Pearson Education, Inc.
Figure 22.8b The bronchi in the conducting zone.
Mucosa
Pseudostratified
epithelium
Lamina propria
Lumen
Fibromusculocartilaginous layer
Cartilage plate
Smooth muscle
Photomicrograph of a bronchus (35)
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Structures of the Respiratory Zone
• Consists of air-exchanging structures
• Respiratory bronchioles—branch from
terminal bronchioles
• Lead to alveolar ducts
• Lead to alveolar sacs
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Structures of the Respiratory Zone
Alveoli
Alveolar duct
Respiratory
bronchioles
Terminal
bronchiole
Alveolar duct
Alveolar
sac
(a)
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Figure 22.9a
Figure 22.9b Structures of the respiratory zone.
Respiratory
bronchiole
Alveolar
duct
Alveoli
Alveolar
sac
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Alveolar
pores
Structures of the Respiratory Zone
• Alveoli
• ~300 million alveoli account for tremendous
surface area of the lungs
• Structure of alveoli
• Type I cells—single layer of simple squamous
epithelial cells
• Surrounded by basal lamina
• Alveolar and capillary walls plus their basal
lamina form
• Respiratory membrane
© 2014 Pearson Education, Inc.
Anatomy of Alveoli and the Respiratory
Membrane
Terminal bronchiole
Respiratory bronchiole
Smooth
muscle
Elastic
fibers
Alveolus
Capillaries
(a) Diagrammatic view of capillary-alveoli relationships
© 2014 Pearson Education, Inc.
Figure 22.10a, b
Anatomy of Alveoli and the Respiratory
Membrane
Red blood
cell
Nucleus of type I
(squamous
epithelial) cell
Alveolar pores
Capillary
O2
Macrophage
Endothelial cell nucleus
Alveolus
Respiratory
membrane
Red blood cell
Type I cell
in capillary
of alveolar wall
Alveoli (gas-filled
Type II (surfactantair spaces)
secreting) cell
Capillary
CO2
Alveolus
Alveolar epithelium
Fused basement
membranes of the
alveolar epithelium
and the capillary
endothelium
Capillary endothelium
(c) Detailed anatomy of the respiratory membrane
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Figure 22.10c
Structures of the Respiratory Zone
• Structures of alveoli (continued)
• Type II cells—scattered among type I cells
• Are cuboidal epithelial cells
• Secrete surfactant
• Reduces surface tension within alveoli
• Alveolar macrophages
© 2014 Pearson Education, Inc.
Gross Anatomy of the Lungs
• Major landmarks of the lungs
• Apex, base, hilum, and root
• Left lung
• Superior and inferior lobes
• Fissure—oblique
• Right lung
• Superior, middle, and inferior lobes
• Fissures—oblique and horizontal
© 2014 Pearson Education, Inc.
Gross Anatomy of the Lungs
Anterior View of Thoracic Structures
Intercostal muscle
Rib
Parietal pleura
Pleural cavity
Visceral pleura
Lung
Pulmonary
artery
Trachea
Thymus
Apex of lung
Left
superior lobe
Oblique
fissure
Left inferior
lobe
Right superior lobe
Horizontal fissure
Right middle lobe
Oblique fissure
Right inferior lobe
Left
superior lobe
Left main
bronchus
Oblique
fissure
Pulmonary
vein
Impression
of heart
Oblique
fissure
Left inferior
lobe
Hilum
Heart
(in mediastinum)
Diaphragm
Cardiac notch
Base of lung
(a) Anterior view. The lungs flank mediastinal structures laterally.
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Apex of lung
Aortic
impression
Lobules
(b) Photograph of medial view of the left lung
Figure 22.11a, b
Intercostal muscle
Rib
Parietal pleura
Pleural cavity
Visceral pleura
Lung
Trachea
Thymus
Apex of lung
Right superior lobe
Horizontal fissure
Right middle lobe
Oblique fissure
Left
superior lobe
Oblique
fissure
Left inferior
lobe
Right inferior lobe
Heart
(in mediastinum)
Diaphragm
Cardiac notch
Base of lung
(a) Anterior view. The lungs flank mediastinal structures laterally.
© 2014 Pearson Education, Inc.
Figure 22.11a
Blood Supply and Innervation of the Lungs
• Pulmonary arteries
• Deliver oxygen-poor blood to the lungs
• Pulmonary veins
• Carry oxygenated blood to the heart
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Transverse Cut through the Superior Thorax
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
(d) Transverse section through the thorax, viewed from above. Lungs, pleural
membranes, and major organs in the mediastinum are shown.
© 2014 Pearson Education, Inc.
Figure 22.11d
The Pleurae
• A double-layered sac surrounding each lung
• Parietal pleura
• Visceral pleura
• Pleural cavity
• Space between the visceral and parietal pleurae
• Pleurae help divide the thoracic cavity
• Central mediastinum
• Two lateral pleural compartments
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Diagram of the Pleurae and Pleural Cavities
Intercostal muscle
Rib
Parietal pleura
Pleural cavity
Visceral pleura
Lung
Trachea
Thymus
Apex of lung
Right superior lobe
Horizontal fissure
Right middle lobe
Oblique fissure
Left
superior lobe
Oblique
fissure
Left inferior
lobe
Right inferior lobe
Heart
(in mediastinum)
Diaphragm
Cardiac notch
Base of lung
(a) Anterior view. The lungs flank mediastinal structures laterally.
© 2014 Pearson Education, Inc.
Figure 22.11a
The Mechanisms of Ventilation
• Two phases of pulmonary ventilation
• Inspiration—inhalation
• Expiration—exhalation
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Inspiration
• Volume of thoracic cavity increases
• Decreases internal gas pressure
• Action of the diaphragm
• Diaphragm flattens
• Action of intercostal muscles
• Contraction raises the ribs
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Expiration
• Quiet expiration—chiefly a passive process
• Inspiratory muscles relax
• Diaphragm moves superiorly
• Volume of thoracic cavity decreases
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Figure 22.14 Changes in thoracic volume and sequence of events during inspiration and expiration.
Sequence of events
Changes in anterior-posterior and
superior-inferior dimensions
Changes in lateral dimensions
(superior view)
1 Inspiratory muscles contract
(diaphragm descends; rib cage
rises).
Inspiration
2 Thoracic cavity and pleural
cavity increase in volume.
Ribs are
elevated and
sternum flares
as external
intercostals
contract.
3 Lungs are stretched; lung
volume increases.
External
intercostals
contract.
4 Air pressure in lungs
decreases.
5 Air (gases) flows into lungs.
Diaphragm moves
inferiorly during
contraction.
1 Inspiratory muscles relax
(diaphragm rises; rib cage
descends because of recoil of
costal cartilages).
Exspiration
2 Thoracic cavity and pleural
cavity decrease in volume.
Ribs and
sternum are
depressed as
external
intercostals
relax.
3 Elastic lungs recoil
passively; lung volume
decreases.
External
intercostals
relax.
4 Air pressure in lungs rises.
5 Air (gases) flows out of
lungs.
© 2014 Pearson Education, Inc.
Diaphragm
moves
superiorly
as it relaxes.