CHAPTER 24 Respiratory System
CHAPTER 24Respiratory System
RESPIRATION INCLUDES
� __________________
� Air moves in and out of lungs
� Continuous replacement of gases in alveoli (air sacs)
� __________________
� Gas exchange between blood and air at alveoli
2
� Gas exchange between blood and air at alveoli
� Transport of respiratory gases
� Between the lungs and the cells of the body
� Performed by the cardiovascular system
� __________________
� Gas exchange in capillaries between blood and tissue cells
Nasal cavity
Nasopharynx
Frontal sinus
Hyoid boneUPPER
RESPIRATORY
SYSTEM
LOWER
RESPIRATORY
SYSTEM
Nasal conchae
Nose
Larynx
Trachea
Bronchus
Sphenoidal sinus
Internal nares
FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM
Clavicle
Ribs
LEFT
LUNGRIGHT
LUNG
Bronchioles
Diaphragm
FUNCTIONS OF THE RESPIRATORY SYSTEM
1. Provides area for gas exchange between air and
blood
2. ____________________________________________
3. ____________________________________________
4. Produces sound involved in verbal 4. Produces sound involved in verbal
communication
5. Assists in regulation of blood volume, blood
pressure, and body fluid pH
RESPIRATORY EPITHELIUM
� ____________________________cells
� Except for the pharynx, smaller bronchi, and alveoli
� Function:
� ____________________________cells� ____________________________cells
� Found in the pharynx
� Function:
� _____________________________cells
� Found in the nasal cavity and lower respiratory tract
� Function:
Frontal sinusNasal conchae
Nasal vestibule
External nares
Nasal cavitySuperior
Middle
InferiorInternal nares
Entrance to auditory tube
Pharyngeal tonsil
Pharynx
Nasopharynx
Oropharynx
FIGURE 24.4A RESPIRATORY STRUCTURES IN THE HEAD AND NECK© 2015 Pearson
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A sagittal section of the head and neck
Epiglottis
Thyroid gland
Soft palate
Trachea
Thyroid cartilage
Laryngopharynx
Glottis
Vocal fold
a
Uvula
Vestibular fold
Inferior nasalconcha
Spinal cord Hyoid bone
Laryngopharynx
Tongue
Hard palate
Soft palate
Nasopharynx
Oropharynx
Epiglottis
Dens
of
axis
(C2)
C3
C4
C5
FIGURE 24.5 RESPIRATORY STRUCTURES IN THE HEAD AND NECK© 2015 Pearson Education, Inc.
Thyroid cartilage
Vestibular fold
Esophagus
Trachea
Tracheal cartilages
Pleural cavity
Vocal foldC6
C7
T1
T2
T3
RESPIRATORY SYSTEM: AIR FLOW
1. Air enters ____________________
2. Passes by the ______________________
3. Enters ___________________
4. Enters and flows in and around ______________
Air enters _____________________5. Air enters _____________________
6. Air enters nasopharynx area _____________
laryngopharynx
7. ___________
8. Bronchus
9. Bronchioles
NASAL CAVITY CONSISTS OF:
� Nasal bones
� Nasal septum
� Cartilage
� External nares
Alar Cartilage� Alar Cartilage
� Dorsum and apex of the nose
� Nasal conchae
Major alarcartilage
Apex
Dorsumof nose
Lateral nasalcartilage
Minor alar
FIGURE 24.3 RESPIRATORY STRUCTURES
IN THE HEAD AND NECK, © 2015 Pearson
Education, Inc.
Minor alarcartilage
Externalnares
LOWER RESPIRATORY SYSTEM: THE LARYNX
� Cylinder with cartilaginous walls stabilized by
ligaments and skeletal muscle
� Begins at level and vertebra C3 or C4 and ends
at C7.
� Unpaired Cartilage� Unpaired Cartilage
� Thyroid cartilage
� Cricoid cartilage
� Epiglottis
� Paired Cartilage
� Arytenoid cartilage
� Corniculate cartilage
� Cuneiform cartilage
Epiglottis
Lesser cornu
Hyoid bone
Thyrohyoid ligament(extrinsic)
LaryngealprominenceThyroid
cartilageLarynx
FIGURE 24.6A ANATOMY OF THE LARYNX© 2015 Pearson
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cartilage
Cricoid cartilage
Larynx
Cricothyroid ligament(intrinsic)
Cricotracheal ligament(extrinsic)
Trachea
Tracheal cartilages
Epiglottis
Thyroidcartilage
Vocalligament
Vestibularligament
Arytenoid cartilage
FIGURE 24.6B ANATOMY OF THE LARYNX© 2015 Pearson
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Cricoidcartilage
Arytenoid cartilage
Tracheal cartilages
FIGURE 24.7A THE VOCAL CORDS
Glottis (open)
Vocal fold
Vestibular fold
Corniculate cartilage
POSTERIOR
Cuneiform cartilage
Aryepiglotticfold
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Epiglottis
Root of tongue
ANTERIOR
Glottis in theopen position.
a
SOUND PRODUCTION
� Air passing through vocal cords
� Amplification of sound occurs in sinus cavities
� Production of definite sounds depends on movement
of the lips, tongue, and cheeks
Pitch depends on the diameter, length, and tension � Pitch depends on the diameter, length, and tension
in vocal cords
� Children have slender, short vocal folds = high-pitched
sound
� At puberty, vocal cords of males become thicker and
longer = deeper voice than females
Glottis (open)
Vocal fold
Vestibular fold
Corniculate cartilage
POSTERIOR
Cuneiform cartilage
Aryepiglottic
fold
Corniculate cartilage
Glottis (closed)
Vocal fold
FIGURE 24.7AB THE VOCAL CORDS© 2015 Pearson
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Epiglottis
Root of tongue Epiglottis
Vestibular fold
ANTERIOR
Glottis in theopen position.
Glottis in theclosed position.
a b
Hard palate
Soft palate
Bolus
Larynx
Tongue forcescompacted bolusinto oropharynx
Laryngeal movementfolds epiglottis;pharyngeal musclespush bolus intoesophagus
Soft palate
Tongue
Bolus
Epiglottis
Trachea
1
2
FIGURE 24.8 MOVEMENTS OF THE LARYNX DURING SWALLOWING
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Bolusesophagus
Epiglottis
Epiglottis
Bolus
Trachea
Bolus movesalong esophagus;larynx returnsto normal position
3
Tongue
Nasal cavity
Esophagus
Nasopharynx
Frontal sinus
Hyoid boneUPPER
RESPIRATORY
SYSTEM
LOWER
RESPIRATORY
SYSTEM
Nasal conchae
Nose
Larynx
Trachea
Bronchus
Sphenoidal sinus
Internal nares
FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM© 2015 Pearson
Education, Inc.
Clavicle
Ribs
LEFT
LUNGRIGHT
LUNG
Bronchioles
Diaphragm
TRACHEA
� Size: 11 cm by 2.5 cm diameter
� Bifurcates at the carina into right and left
bronchi at T5
� Contains 15-20 tracheal cartilages
� Each cartilage is a C-shaped ring� Each cartilage is a C-shaped ring
� Tracheal cartilages are connected by annular
ligaments
Trachealismuscle
Lumen of
Esophagus
FIGURE 24.9B ANATOMY OF THE TRACHEA
AND PRIMARY BRONCHI© 2015 Pearson
Education, Inc.
Respiratoryepithelium
Thyroidgland
Trachealcartilage
Lumen oftrachea
LM × 3The trachea
Larynx
FIGURE 24.9A ANATOMY OF THE TRACHEA AND PRIMARY BRONCHI© 2015 Pearson
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Primarybronchi
Lung tissue
RIGHT LUNG
Secondarybronchi
Root ofright lung
LEFT LUNG
Root ofleft lung
FIGURE 24.11
BRONCHI AND
BRONCHIOLES
Cartilage ring
Root of lung
Secondary (or inferior
lobar) bronchus
BRONCHIOLE
Primary bronchusLEFT LUNG
Tertiary (or
segmental)
bronchi
Secondary
(or superior
lobar)
bronchus
Cartilage plates
Visceral pleura
Respiratory
epithelium
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Smooth muscle
Lobule Respiratory
bronchioles
Terminal
bronchiole
Bronchioles
epithelium
Bronchopulmonarysegments ofsuperior lobe
Broncho-pulmonary
segments ofsuperior lobe
Broncho-
LEFTRIGHT
FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS© 2015 Pearson
Education, Inc.
Broncho-pulmonarysegments ofinferior lobe
Broncho-pulmonary
segments ofmiddle lobe
Broncho-pulmonary
segments ofinferior lobe
Gross anatomy of the lungs showingthe bronchial tree and its divisions.
a
PRIMARY BRONCHI
� Each primary bronchus enters lung at the point
of ________________
� The _______ is also the point of entrance and exit of
the pulmonary blood vessels
� The combination of the bronchus, artery, and � The combination of the bronchus, artery, and
vein is called the root
LUNGS AND PLEURA
Around each lung is a
flattened sac of serous
membrane called pleura
Parietal pleura – outer layer
Visceral pleura – directly on
lung
Pleural cavity – slit-like potential space filled with pleural fluid
� Lungs can slide but separation from pleura is resisted (like film between 2 plates of glass)
� Lungs cling to thoracic wall and are forced to expand and recoil as volume of thoracic cavity changes during breathing
lung
CXR(chest x-ray)
26
FIGURE 24.10A SUPERFICIAL ANATOMY OF
THE LUNGS
Trachea
Aortic arch
Superior lobe
Fibrous layer
of pericardium
Left lungRight lung
Superior vena cava
Superior lobe
Horizontal fissure
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of pericardium
Oblique fissure
Inferior lobe
Cut edge of
diaphragmLiver,
left lobeLiver,
right lobe
Middle lobe
Oblique fissure
Inferior lobe
Falciform ligament
Anterior view of the opened chestshowing the relative positions ofthe left and right lungs and heart
a
FIGURE 24.10B SUPERFICIAL ANATOMY OF
THE LUNGS
Diagrammatic views ofthe lateral surfaces ofthe isolated right andleft lungs
Apex
Horizontalfissure
Superiorlobe
Middle
Lateral Surfaces
Apex
Superior lobe
b
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Middlelobe
Inferiorlobe
Obliquefissure
Base
Inferiorlobe
Cardiacnotch
Obliquefissure
Base
RIGHT LUNG LEFT LUNG
FIGURE 24.10C SUPERFICIAL ANATOMY OF
THE LUNGS
Medial Surfaces
Diagrammatic views ofthe medial surfaces ofthe isolated right andleft lungs
Apex
Pulmonary arteries
Superior
lobe
Pulmonary
veins Pulmonary
veins
c
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Hilum
Inferior
lobe
Cardiac
impression
Horizontal
fissure
Oblique
fissure
RIGHT LUNG
Base
LEFT LUNG
veins
Oblique
fissure
STRUCTURE OF THE LUNGS
� The apex points superiorly and the base
inferiorly
� The _______ lung has ________ lobes
� Superior, middle, and inferior lobes
� Consists of a horizontal fissure and an oblique fissure� Consists of a horizontal fissure and an oblique fissure
� The ________ lung has ______ lobes
� Superior and inferior lobes
� Contains the oblique fissure
� Left lung has a cardiac notch
Apicoposterior
Anterior
Superior lingular
Inferior lingular
Bronchopulmonarysegments ofsuperior lobe
Anterior
Apical
Posterior
Anterior
Broncho-pulmonary
segments ofsuperior lobe
LateralBroncho-
LEFTRIGHT
FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS
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Inc.
Anteriorbasal
Lateralbasal
Medialbasal
Posteriorbasal
Superior
Broncho-pulmonarysegments ofinferior lobe
Lateral
MedialBroncho-
pulmonarysegments ofmiddle lobe
Anteriorbasal
Lateralbasal
Posteriorbasal
Medialbasal
Superior
Broncho-pulmonary
segments ofinferior lobe
Gross anatomy of the lungs showingthe bronchial tree and its divisions.
a
FIGURE 24.12B THE BRONCHIAL TREE AND
DIVISIONS OF THE LUNGS
Apical
Posterior
Anterior
Medial
Lateral
Superior
Bronchopulmonarysegments of
superior lobe
Bronchopulmonarysegments ofmiddle lobe
Apicoposterior
Anterior
Superior lingular
Inferior lingular
Bronchopulmonarysegments ofsuperior lobe
Superior
Medial basal
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Lateralbasal
Medialbasal
Bronchopulmonarysegments ofinferior lobe
Right lung, costal surface
Posteriorbasal
Anteriorbasal
Left lung, costal surface
Isolated left and right lungs have been colored to showthe distribution of the bronchopulmonary segments.
Posterior basal
Anterior basal
Lateral basal
Bronchopulmonarysegments ofinferior lobe
b
FIGURE 24.11
BRONCHI AND
BRONCHIOLES
Cartilage ring
Root of lung
Secondary (or inferior
lobar) bronchus
BRONCHIOLE
Primary bronchusLEFT LUNG
Tertiary (or
segmental)
bronchi
Secondary
(or superior
lobar)
bronchus
Cartilage plates
Visceral pleura
Respiratory
epithelium
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Smooth muscle
Lobule Respiratory
bronchioles
Terminal
bronchiole
Bronchioles
epithelium
Trachea
Tertiarybronchi
Smallerbronchi
Secondarybronchus
Leftprimary
bronchus
Visceralpleura
Branch ofpulmonaryartery
Bronchial artery (red),vein (blue), and
nerve (yellow)
Respiratorybronchiole
Elastic fibers
CapillarybedsBranch of
pulmonaryLymphaticvessel
Smooth musclearound terminalbronchiole
Arteriole
Terminalbronchiole
Bronchiole
Respiratoryepithelium
Bronchioles
FIGURE 24.13A BRONCHI AND BRONCHIOLES© 2015 Pearson
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Bronchopulmonarysegment
Alveoli in apulmonary
lobule
pulmonaryvein
Alveolar sac
Pleural cavity
Alveoli
vesselAlveolarduct
The structure of one portion of a single pulmonary lobule
Interlobularseptum
Visceral pleura
Parietal pleura
Bronchioles
Terminal bronchiole
Respiratory bronchiole
a
FIGURE 24.14A ALVEOLAR ORGANIZATION
Respiratory bronchiole
Smooth muscle
Alveolar duct
Alveolus
Elastic fibers
Smooth muscle
Capillaries
Basic structure of a lobule, cut to reveal thearrangement between the alveolar ducts and alveoli.A network of capillaries surrounds each alveolus.These capillaries are surrounded by elastic fibers.
Alveolarsac
a
FIGURE 24.14B ALVEOLAR ORGANIZATION
Alveolar
Alveoli
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Alveolar
sac
Alveolar
duct
SEM of lung tissue showing the appearanceand organization of the alveoli.
Lung tissue LM × 125
b
AVEOLAR DUCTS AND ALVEOLI
� Each lung has approx 150 million alveoli
� Network of capillaries surround each alveolus
� Capillaries drop off carbon dioxide and pick up
oxygen
� Elastic tissue surrounds each alveolus� Elastic tissue surrounds each alveolus
� Maintains the shape and position of each alveolus
during inhalation and exhalation
CELLS ASSOCIATED WITH ALVEOLI
� The cells associated with alveoli
�The lining consists of a single layer of
_______________
�These are called ___________________
________________are scattered among the �________________are scattered among the
type I pneumocytes
�_____________________secrete surfactant
�Surfactant prevents alveolar collapse
�_________________wander around
phagocytizing particulate matter
GAS EXCHANGE AT THE ALVEOLI
�Pulmonary arteries transport
carbon dioxide to the alveolar
capillaries
�Carbon dioxide leaves the capillaries Carbon dioxide leaves the capillaries
and enters the alveolar sacs
�Oxygen leaves the alveolar sacs and
enters the capillaries
�Oxygen enters the pulmonary veins
and returns to the heart to be pumped
to all parts of the body
FIGURE 24.14D
ALVEOLAR
ORGANIZATION
Red blood cell
Capillary lumen
EndotheliumNucleus of
endothelial cell
0.5 µm
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Alveolarepithelium
Fused basallaminae
Alveolar air space
The respiratory membrane.
Surfactant
d
THE PLEURAL CAVITIES AND PLEURAL
MEMBRANES
� The pleural cavity between the visceral and
parietal membranes consists of:
� Pleural fluid
� Reduces friction when the lungs move upon inhalation and
exhalation
� Pleurisy
� A condition in which the membranes produce too
much pleural fluid or the membranes adhere to the
thoracic wall thereby resulting in pain upon
inhalation and exhalation
FIGURE 24.15 ANATOMICAL RELATIONSHIPS
IN THE THORACIC CAVITY
Left lung,
superior lobe
Oblique fissure
Body of sternum
Pericardial
cavity
Right lung,
middle lobe
Right pleural
cavity
Rib
Visceral pleura
Ventricles
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Aorta Bronchi
Right lung,
inferior lobe
Atria
Posterior
mediastinum
Spinal cord
Left pleural cavity
Visceral pleura
Esophagus
Left lung,
inferior lobe
Parietal pleura
RESPIRATORY MUSCLES AND PULMONARY
VENTILATION
� Respiratory Muscles
� The muscles involved in pulmonary ventilation
(breathing) are:
� Diaphragm
� External intercostals
� Internal intercostals
RESPIRATORY MUSCLES AND PULMONARY
VENTILATION
� Diaphragm
� Contracts (lowers) to cause inhalation
� Relaxes (raises) to cause exhalation
� External intercostals
� Elevate the ribs to aid in inhalation� Elevate the ribs to aid in inhalation
� Internal intercostals
� Depress the ribs to aid in exhalation
Accessory
Respiratory Muscles
(Inhalation)
Scalene muscles
Pectoralis minor
muscle
Primary
Respiratory Muscles
(Inhalation)
Accessory
Respiratory Muscles
(Exhalation)
The Respiratory Muscles1
Sternocleidomastoid
muscleExternal intercostal
muscles
FIGURE 24.16 RESPIRATORY MUSCLES AND PULMONARY
VENTILATION (1 OF 4) © 2015 Pearson
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muscle
Internal intercostal
muscles
Primary
Respiratory Muscles
(Inhalation)
Rectus abdominis
Internal oblique muscle
(Exhalation)
Serratus anterior
muscle
Diaphragm
External oblique
muscle
Transversus thoracis
muscle
FIGURE 24.16RESPIRATORY MUSCLES
AND PULMONARY
VENTILATION (2 OF 4) Ribs andsternumelevate
The Mechanics of Breathing2
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Diaphragmcontracts
RESPIRATORY MUSCLES AND PULMONARY
VENTILATION
� Respiratory Movements
� Respiratory movements can be classified two ways:
eupnea or hyperpnea
� ________: quiet breathing
� May involve diaphragmatic (deep) breathing or costal
breathing (shallow breathing) or both
� During pregnancy, due to the uterus pushing upward on the
diaphragm , women typically use costal breathing
� ________________: forced breathing
� Generally requires the use of accessory breathing muscles
RESPIRATORY CHANGES AT BIRTH
� Prior to Birth
� Pulmonary arterial resistance is high
� Pulmonary vessels are collapsed
� Rib cage is compressed
� Lungs and passageways contain no air but do contain � Lungs and passageways contain no air but do contain
small amounts of fluid
� At Birth
� Air enters and forces the fluid out
� Closure of:
� Foramen ovale and ductus arteriosus
AGING AND THE RESPIRATORY SYSTEM
� The respiratory system becomes less efficient as
we age
� Noteworthy changes include:
� Elastic tissue begins to deteriorate
� Lungs cannot expand or constrict as much as they used to� Lungs cannot expand or constrict as much as they used to
� Movements of the ribs are restricted due to arthritis
� Some degree of emphysema, which hinders
breathing
� With age, roughly 1 square foot of respiratory
membrane is lost each year after age 30
� There are many diseases of the respiratory system, including asthma, cystic fibrosis, COPD (chronic obstructive pulmonary disease – with chronic bronchitis and/or emphysema) and epiglottitis
example:
normal emphysema
50
YOU MIGHT WANT TO THINK TWICE ABOUT
SMOKING….
51How does the histology of the respiratory track change when one smokes?