Download Lungs - Dr. Par Mohammadian

PowerPoint® Lecture Slides
prepared by
Barbara Heard,
Atlantic Cape Community
College
CHAPTER
22
The Respiratory
System: Modified
by Dr. Par
Mohammadian
© 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
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
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
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-conduits to gas
exchange sites
– Includes all other respiratory structures;
cleanses, warms, humidifies air
• Diaphragm and other respiratory muscles
promote ventilation
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
Figure 22.2a The external nose.
Epicranius,
frontal belly
• The Nose - Two regions:
external nose &
Root and
bridge of nose
nasal cavity
Dorsum nasi
Ala of nose
Apex of nose
• External nose-root, bridge,
dorsum nasi, and apex
– Philtrum-shallow vertical
groove inferior to apex
Naris (nostril)
Surface anatomy
– Nostrils (nares)-bounded
laterally by alae
Figure 22.2b The external nose.
Frontal 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
Nasal bone
The Nose
• Nasal cavity: Divided by midline nasal septum
– Posterior nasal apertures (choanae=funnels)
open into nasopharynx
– Roof of the nose: ethmoid & sphenoid bones
– Floor: hard (bone) & soft palates (muscle)
– Nasal conchae: Increase mucosal area; Enhance
air turbulence)
Vibrissae (hairs) filter coarse particles from inspired air
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
Figure 22.3b The upper respiratory tract.
Cribriform plate
of ethmoid bone
Sphenoid sinus
Posterior nasal
aperture
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic tube
Uvula
Frontal sinus
Nasal cavity
Nasal conchae
(superior, middle
and inferior)
Nasal meatuses
(superior, middle,
and inferior- grooves)
Nasal vestibule
Nostril
Hard palate
Soft palate
Tongue
Lingual tonsil
Hyoid bone
Functions of the Nasal Mucosa and
Conchae
• During inhalation, conchae and nasal
mucosa
– Filter, heat, and moisten air
• During exhalation these structures
– Reclaim heat and moisture
Pharynx (throat)
•
Muscular tube from base of skull to C6
– Connects nasal cavity and mouth to larynx and esophagus
– Composed of skeletal muscle
•
Three regions:
Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Passageway for food and air
Regions of the pharynx
Figure 22.3b The upper respiratory tract.
Pharyngeal tonsil (adenoids) on
posterior wall (traps & destrys
pathogens)
Pharyngotympanic (auditory) tubes
drain and equalize pressure in
middle ear
Uvula: prevents food from entering
the nose
Nasopharynx
Pharyngeal tonsil
Opening of
pharyngotympanic tube
Uvula
Oropharynx
Palatine tonsil
Isthmus of the
fauces
Tongue
Lingual tonsil
Hyoid bone
Laryngopharynx
Extends to larynx, where
continuous with esophagus
Esophagus
Larynx
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Trachea
Thyroid gland
Illustration
Isthmus of fauces-opening to oral
cavity
Palatine tonsils-in lateral walls of
fauces
Lingual tonsil-on posterior
surface of tongue
When eating and giggling,
food comes out of our nose!
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
Esophagus
Larynx
Epiglottis
Vestibular fold
Thyroid cartilage
Vocal fold
Cricoid cartilage
Trachea
Thyroid gland
Figure 22.4a The larynx.
Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
In men larger: due to testosterone)
Cricothyroid ligament
Cricoid cartilage
Cricotracheal ligament
All hyaline cartilage
except epiglottis
Anterior superficial view
Tracheal cartilages
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.
Larynx (voice box)
•
Vocal ligaments-deep to laryngeal mucosa
– Form core of vocal folds (true vocal cords)
• Glottis-opening between vocal folds
• Folds vibrate to produce sound as air rushes up from lungs
•
Vestibular folds (false vocal cords)
– Superior to vocal folds
– No part in sound production
– Help to close glottis during swallowing
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
Vocal folds in open position; open glottis
Trachea
• Windpipe–from larynx into mediastinum
• Wall composed of three layers
– Mucosa-ciliated pseudostratified epithelium
with goblet cells
– Submucosa-connective tissue with
seromucous glands
– Adventitia-outermost layer made of
connective tissue; encases C-shaped rings of
hyaline cartilage
Trachea
• Trachealis
– Connects posterior
parts of cartilage rings
– Contracts during
coughing to expel
mucus
• Carina
– Spar of cartilage on
last, expanded
tracheal cartilage
– Point where trachea
branches into two
main bronchi
Carina of
trachea
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
Bronchi and Subdivisions
• Air passages undergo 23 orders of
branching  bronchial (respiratory) tree
• From tips of bronchial tree  conducting
zone structures  respiratory zone
structures
© 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
• 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
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
Inferior lobe
of left lung
Left side longer; right wider traps a foreign object that has entered the passageway
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
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
Alveoli
Alveolar duct
Respiratory bronchioles
Terminal
bronchiole
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-µm-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
Figure 22.9a Alveoli and the respiratory membrane.
Terminal bronchiole
Respiratory bronchiole
Smooth
muscle
Scanning electron
micrograph of
pulmonary
capillary
casts (70x)
Elastic
fibers
Alveolus
Capillaries
Diagrammatic view of capillary-alveoli relationships
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
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
• Root-site of vascular and bronchial attachment
to mediastinum
• Costal surface-anterior, lateral, and posterior
surfaces
• Composed primarily of alveoli
• Balance–stroma-elastic connective tissue 
elasticity
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 to accommodate the
heart
– Separated into superior and inferior lobes by
oblique fissure
Lungs
• Right lung
– Superior, middle, inferior lobes separated by
oblique and horizontal fissures
• Bronchopulmonary segments (10 right
lung, 8–10 left lung) separated by connective
tissue septa
– If diseased can be individually removed
• Lobules-smallest subdivisions visible to
naked eye; served by bronchioles and their
branches
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.
Figure 22.10b Anatomical relationships of organs in the thoracic cavity.
Apex of lung
Pulmonary
artery
Left
superior lobe
Left main
bronchus
Oblique
fissure
Pulmonary
vein
Left inferior
lobe
Cardiac
impression
Hilum of lung
Oblique
fissure
Aortic
impression
Lobules
Photograph of medial view of the
left lung.
Figure 22.11 A cast of the bronchial tree (segments).
Right lung
Right
superior
lobe (3
segments)
Left lung
Left superior
lobe
(4 segments)
Right
middle
lobe (2
segments)
Right
inferior lobe
(5 segments)
Left inferior
lobe
(5 segments)
Pleurae
Thin, double-layered serosa:
Parietal pleura
– Covers the thoracic wall and superior face of the
diaphragm
– Continues around heart and between lungs
Visceral pleura
– Covers the external lung surface
– Divides the thoracic cavity into three chambers
• The central mediastinum
• Two lateral compartments, each containing a lung