Download Respiratory System - eCurriculum

Respiratory System
Dr. Jack L. Haar
Functions of Respiratory System









Transport air to and from lungs
Maintains airway patency
Regulates air temperature
Humidifies air
Decreases air velocity
Cleanses air
Gaseous exchange
Olfaction
Phonation
MAJOR SUBDIVISIONS
– Extrapulmonary portion
– Intrapulmonary portion
Extrapulmonary portion
1. Nasal cavity
Nasal
2. Pharynx
Oral
Laryngeal
3. Larynx
4. Trachea
5. Primary bronchi
Extrapulmonary portion
1. Nasal cavity
Nasal
2. Pharynx
Oral
Laryngeal
3. Larynx
4. Trachea
5. Primary bronchi
MAJOR SUBDIVISIONS
– Extrapulmonary portion
– Intrapulmonary portion
Intrapulmonary portion
Secondary
bronchi
Larynx
Trachea
1. Secondary bronchi
2. Bronchioles (and
terminal bronchioles)
3. Respiratory bronchioles
4. Alveolar ducts
5. Alveoli
Intrapulmonary portion
1. Secondary bronchi
2. Bronchioles (and
terminal bronchioles)
3. Respiratory bronchioles
4. Alveolar ducts
5. Alveoli
Classification by function:
Conducting portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles (and
terminal bronchioles)
Classification by function:
Respiratory portion
1. Respiratory bronchioles
2. Alveolar ducts
3. Alveolar sacs
4. Alveoli
Terminal
bronchiole
RB
AS
RB
AD
Alveoli
Histology overview of respiratory
passageways


Mucosa: epithelium, lamina propria and muscularis mucosa
Epithelium: pseudostratified columnar epithelium with cilia and
goblet cells = Respiratory epithelium
Layers of “typical” conducting passageway

Lamina propria



Vascularized
Longitudial arranged
elastic fibers
Deepest layer



Elastic lamina OR
Muscularis mucosae OR
Neither
Submucosa – connective tissue layer; contains mixed (mucous and serous
secreting glands in larger passageways)
Bone or Cartilage – present to level of bronchioles where it drops out
Adventitia - connective tissue
TRANSITIONS
– Layers become thinner and
drop out
– Epithelium
- decreases in height
- goblet cells drop out
- cilia disappear
– Mixed glands drop out
– Cartilage drops out
Wall of alveolus where gas exchange occurs
Alveolus
(Inter)alveolar Septum
Simple squamous
epithelium
Connective tissue core
Reticular + elastic
fibers
and CT cells
Capillaries
Alveolus
Cap
Simple
squamous
epithelium
Variation on this layering theme
MAJOR SUBDIVISIONS
– Conducting portion
Conducts air from exterior to where
– Respiratory portion
gas can be exchanged,
i.e., alveoli
Extrapulmonary of Conducting Portion

Nasal cavities

Non-olfactory region
 Vestibules – transition
from skin
Non-olfactory
region

to respiratory epithelium
Nasal fossae




Respiratory epithelium,
Abundant blood vessels
Muscularis mucosae absent
Bones and cartilage for patiency
Nasal cavity
Non-olfactory region
Resp. epith.
Lam. propria
NO musc. muc.
Submucosa
(some cartilage)
Bone
Nasal cavity
Olfactory region
Olfactory region
U-shaped area in posterior, superior regions of nasal fossae
Superior concha
Non-olfactory
region
Olfactory
region
Nasal cavity
“Typical” nasal mucosa
Olfactory mucosa
Olfactory cells: bipolar neurons, single dendrite extends to surface
terminates in olfactory vesicle, non-motile cilia extend over surface
Supporting cells and basal cells as reserve
Olfactory
“Typical” nasal
mucosa
epithelium
Olfactory mucosa
Nasal cavity

Muscularis mucosae not present
Lamina propria blends with
submucosa

Bowmans glands flush odorants

Serous glands
of Bowman
“Typical” nasal mucosa
Olfactory mucosa

Pharynx
Nasal
 Oral
 Laryngeal

Extrapulmonary Components
of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles
Extrapulmonary-Conducting
Larynx
Larynx
Extrapulmonary-Conducting
1.
2.
3.
4.
5.
6.
7.
8.
Epiglottal cartilage
Thyroid cartilage
Cricoid cartilage
Tracheal cartilages
Vestibule
False vocal fold
Ventricle
True vocal fold with
vocal ligament
(dense reg elastic CT)
9. Vocalis muscle
1
5
6
7
2
8
9
3
3
4
2
Trachea
Extrapulmonary-Conducting
Larynx
MOST of mucosa is a
“typical” respiratory mucosa
with NO musc. mucosae.
EXCEPTIONS:
Stratified squamous moist
epithelium covering
epiglottis and true vocal fold
False
vocal
fold
VL
VM


Mixed glands in submucosa
Cartilage for patency



Thyroid and cricoid are hyaline
Epiglottis and smaller cartilages are elastic
Vocal apparatus



False vocal folds
Ventricle
True vocal folds


Vocal ligament - dense regular elastic CT
Vocalis muscle – skeletal muscle
Extrapulmonary
of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles
Trachea and Primary Bronchi are identical
Mucosa
Respiratory epithelium with prominent basement membrane
Longitudinal section
Esophagus
Trachea
LUMEN



Elastic lamina of longitudinally arranged elastic fibers
Mixed glands in submucosa
Cartilage rings for patency
Intrapulmonary Components
of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles
Secondary bronchus
B
2nd
Bronchus
Pulm
BV
Pulm
BV
Bronchiole
B
Surrounded by
ALVEOLI
2nd
Bronchus
Secondary bronchus
Surrounded by
ALVEOLI
Mucosa
Resp epithelium
Lamina propria
Musc. mucosae
Submucosa
Mixed glands
Cartilage plates
Adventitia
Cartilage
Intrapulmonary of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles

Walls of Bronchi and Bronchioles continue to decrease in size
Transition from secondary bronchus to bronchiole
Bronchus
Bronchiole
Bronchioles




No mixed glands
No cartilage
Epithelium: respiratory
in largest bronchioles
Epithelium: simple
columnar with cilia in
terminal bronchioles
Terminal bronchiole

Clara cells present among
simple columnar epithelial cells



Dome-shaped
Non-ciliated with granules
Secretions lower surface
tension
Clara cells

Lamina propria: longitudinally arranged elastic fibers


Muscularis mucosae: smooth muscle at greatest thickness
Submucosa: no glands, no cartilage, no bone
Elastic
fibers
Smooth
muscle
MAJOR SUBDIVISIONS
– Conducting portion
– Respiratory portion
Where gas exchange
actually occurs,
i.e., alveoli
Transitions
Bronchiole
to
Terminal
bronchiole
to
Respiratory
bronchiole
B
TB
RB
Transitions of bronchioles
Conducting
portion
Respiratory
portion

Respiratory bronchiole

Continues to decrease in diameter and thickness
Respiratory bronchiole




Simple cuboidal epithelium
Elastic fibers in lamina prop.
Muscularis mucosa of smooth muscle
Alveoli bulge off of wall
Alveolar duct


RB
Alveoli increase in number
Wall is reduced to rings
A
A
A
AD
Alveolar duct


Alveoli increase in number
Wall is reduced to rings
Alveolar sac


Multiple alveoli
No wall of cuboidal cells
Alveoli


Thin walled chambers, 200μm diameter, for gas exchange
Interalveolar septum separates alveoli
Interalveolar septum

CT core




Elastic/reticular fibers
Fibroblasts
Macrophages
Capillaries which form
80% of alveolar surface
Interalveolar septum

CT core




Elastic/reticular fibers
Fibroblasts
Macrophages
Capillaries which form
80% of alveolar surface
Epithelium lining alveoli

Pulmonary epithelial cells
(Small alveolar or type I)

Lines 95% of alveolar surface
Epithelium lining alveoli

Pulmonary epithelial cells
(Small alveolar or type I)

Lines 95% of alveolar surface
Epithelium lining alveoli

Septal cells (Great alveolar or
type II)

Regenerate type I and type II cells
Epithelium lining alveoli

Septal cells (Great alveolar
or type II)




Regenerate type I and type II
cells
Mitochondria, RER, Golgi
Vacuoles containing the
phospholipid surfactant
Surfactant lowers surface
tension of alveoli
Epithelium lining alveoli

Surfactant





Extracellular fluid layer lining
alveoli
Lowers surface tension,
preventing collapse of alveoli
during expiration
Covers underlying aqueous
hypophase
Appears during last weeks of
gestation
Respiratory distress syndrome
or hyaline membrane disease
may result
Macrophages


May be found in the CT core of interalveolar septum
Alveolar macrophages are in the alveolar space
Kohn’s pores



Opening in interalveolar septa
Equalize pressure between alveoli
Facilitate transfer of bacteria between alveoli
Air - blood barrier


Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina
Air - blood barrier


Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina
Air - blood barrier


Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina
Pleura




Mesothelium with C.T.
Visceral layer
Parietal layer
Function
 Lubrication
Pleura
Alveolus
Vascular supply to lungs

Blood to and from
alveoli

Pulmonary artery

Adjacent to
bronchial tree
Vascular supply to lungs

Blood to and from
alveoli

Pulmonary artery


Adjacent to bronchial
tree
Carries unoxygenated
blood
Vascular supply to lungs

Blood to and from alveoli
Capillary plexus in
interalveolar septa
Pulmonary veins


Travel away from
bronchial tree
Carry oxygenated blood
Nutrient vessels

Bronchial arteries


Vessels within wall of
bronchial tree
Supply nutrients to
passageways
themselves
Nutrient vessels

Bronchial arteries


Vessels within wall of
bronchial tree
Supply nutrients to
passageways themselves
Pathology
Effects of smoking
Running the numbers web site

http://www.portfolio.com/interactivefeatures/2007/12/running-the-numbers
Pathology
Nasal sinues
Emphysema
Asthma
Chronic bronchitis
Pneumonia
Functions of Respiratory System









Transport air to and from lungs
Maintains airway patency
Regulates air temperature
Humidifies air
Decreases air velocity
Cleanses air
Gaseous exchange
Olfaction
Phonation
TB or not TB?
That is the congestion.
Consumption be done about it?
Of cough, Of cough,
But it will take a lung, lung time!
-Walter Shakespear
http://www.path.uiowa.edu/virtualslidebox/
Table of Contents
Lung and respiratory tract
Lung (3 slides)
http://java.vcu.edu/som-histology/
Respiratory
Lung
Trachea I
Trachea II