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RESPIRATORY
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Respiratory pathway
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Upper structures
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Nose and nasal passages
Paranasal sinuses
Larynx
Lower structures
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Trachea
Bronchi
Bronchioles
Lungs
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli.
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RESPIRATORY
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Nasal region
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Lumenal epithelium
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Nostrils:
stratified squamous epithelium:
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hair follicles extend into deeper parts
of mucosa and submucosa
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Rest of nasal region
pseudostratified ciliated columnar
epithelium;
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mucous glands and/or seromucous in
deeper parts of mucosa and
submucosa;
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epithelium is glandular, mucus;
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leucocytes, macrophages, etc.
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RESPIRATORY
Lamina propria: thin layer: cellular dense C.T.
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Muscularis mucosae: absent
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Submucosa: contains mucous and/or
seromucous glands:
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sometimes venous sinuses.
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Muscularis externa: absent
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except at junction with pharynx; skeletal
muscle tissue; swallowing.
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RESPIRATORY
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Larynx and other structures
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General features
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Larynx ; sound-production for vocalization;
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specialized upper part of trachea
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glottis; opening from pharynx into trachea;
Vibration of the vocal cords of the larynx
produces sound:
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in very vocal mammals the cords have a
much tougher epithelium
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stratified squamous epithelium.
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RESPIRATORY
Vocalization; voluntary control, larynx
muscularis ; several skeletal muscles
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Muscle vocalis;
located closest to the vocal cords ;
controls the pitch of the sound
produced.
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Wall of the larynx contains
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Cartilage hyaline:
Usually also have part of the epiglottis
in the section as well as the larynx
itself
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Composed of elastic cartilage.
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RESPIRATORY
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RESPIRATORY
Our slide set contains 3
slides of larynx:
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the frontal section
best illustrates the
structure of the larynx.
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RESPIRATORY
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Mucosa of larynx
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Upper larynx, above vocal cords:
with false vocal cords and
adjacent to epiglottis:
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stratified squamous or
pseudostratified epithelium;
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lamina propria unusually cellular
dense C.T.; no muscularis
mucosae
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Vocal cords:
epithelium stratified squamous
epithelium
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lamina propria as above;
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no muscularis mucosae;
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some loose C.T. in lamina propria.
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RESPIRATORY
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Lower larynx, below vocal cords:
pseudostratified ciliated columnar
epithelium
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tubular extensions through LP into
submucosa to seromucous glands:
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mixed laryngeal glands--mucus coating
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no muscularis mucosae
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RESPIRATORY
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RESPIRATORY
RESPIRATORY
Submucosa and muscularis of larynx
components intermingled to some extent
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dense CT (interwoven)
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some areas of loose C.T.
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contains mixed laryngeal glands in area below
vocal cords.
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RESPIRATORY
Two skeletal muscles visible in frontal
section of larynx
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vocal muscle, nearer to lumen in area of
vocal cords
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cross-section of sternohyoid muscle,
lateral to vocal muscle and separated
from it by thyroid cartilage
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origin is on sternum and insertion is on
hyoid bone, which is the skeletal base of
the tongue
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contraction moves entire tongue toward
back of mouth.
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RESPIRATORY
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Two laryngeal cartilages visible in frontal section
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Made of hyaline cartilage
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Thyroid cartilage
larger, more anterior and lying between
vocal and sternohyoid muscle
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Cricoid cartilage
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smaller, in lower part of larynx,
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closer to lumen,
not very different in size and shape from
the first tracheal cartilages lying
immediately below it.
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RESPIRATORY
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Tunica adventitia of larynx not distinct
composed of tissues peripheral to
the tracheal cartilages and muscles
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Lymphatic nodules may be present
submucosa and lamina propria in
upper part of larynx.
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RESPIRATORY
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Structures adjacent to upper larynx.
Epiglottis is between laryngeal and
pharyngeal
include:
stratified squamous lumenal
epithelium
seromucous glands (mixed
epiglottis glands) in submucosa
epiglottic elastic cartilage
dense-to-loose CT
pseudostratified ciliated columnar
epithelium
Hyoid bone is present
adjacent and lateral to the
sternohyoid muscle.
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RESPIRATORY
RESPIRATORY
May include a tonsil in the upper part of the
section
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tonsils; organs of the lymphoid system
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densely packed lymphatic nodules
adjacent to the lumenal stratified
squamous epithelium
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crypts of that epithelium extend partially
into the tonsil
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infiltrated by lymphocytes.
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RESPIRATORY
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Trachea
Tubular, extends from pharynx to point of
bifurcation of the two chief bronchi; carina
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larynx is specialized region of trachea.
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Anterior and parallel to the esophagus.
Wall of trachea contains skeletal structures
to prevent collapse of tube
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tracheal cartilages; incomplete rings (Cshaped); hyaline cartilage.
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gap is on the posterior side-- against the
esophagus
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RESPIRATORY
RESPIRATORY
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Mucosa of trachea
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Pseudostratified ciliated columnar
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Glandular; mucus.
Cilia beat upwards, to move
mucus to pharyngeal cavity,
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typically swallowed.
Tubular extensions through
lamina propria to seromucous
gland in submucosa.
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RESPIRATORY
RESPIRATORY
Lamina propria: thin; unusually
cellular dense C.T.
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No muscularis mucosae.
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Lumenal surface is smooth;
mucosa has no macroscopic or
microscopic folds, pits, or
projections.
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RESPIRATORY
RESPIRATORY
Submucosa of trachea and
muscularis of trachea
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Inner portion
mixed tracheal glands:
secrete mucus
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Tracheal cartilages (tracheal
rings): C-shaped
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hyaline cartilage.
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RESPIRATORY
RESPIRATORY
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Trachealis muscle:
smooth muscle tissue that spans the
gap of tracheal cartilage
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attaching to the cartilage
Trachealis muscle controls diameter
of trachea
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relaxes due to sympathetic
stimulation
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contracts due to
parasympathetic stimulation .
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Clumps of adipocytes or masses of
adipose tissue may also be present.
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RESPIRATORY
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Tunica adventitia of trachea
dense interwoven C.T. around
tracheal rings and trachealis muscle
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no definite, distinct outer boundary
sometimes clumps or masses of
adipocytes
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also present
veins, arteries, and nerves may be
present in section, in or adjacent
to this layer.
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RESPIRATORY
Chief bronchus (primary bronchus)
(singular: bronchus; plural: bronchi)
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At end of trachea, two chief
(primary) bronchi branch off, one to
each lung.
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Bifurcation point, aka carina
Each bronchus extends slightly into
the lung before branching
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secondary bronchi.
Histology of chief bronchus
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same as that of trachea.
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