RESPIRATORY
SYSTEM
JOSEPHINE C. ABRAZALDO
Air enters the lungs rst passes by the roof of superior region of the
nasal cavity. Located in the roof of the nose is a highly specialized
epithelium , NO GOBLET CELLS OR MOTILE CILIA
detection and transmission of odors
3 cell types:
1. supportive
2.
basal
3. olfactory
fi
Olfactory cells end at the surface of the olfactory epithelium as small round
structures called OLFACTORY BULBS
olfactory : detect odorants
Supporting (sustentacular) barrier
against external env.
basal: sensory role
LARYNX
• Passage for air between
pharynx and trachea
• Organ of sound
production
• Acts as a valve that
closes during swallowing
to prevent food from
entering the lower
respiratory tract
• Wall contains skeletal
muscles and hyaline and
elastic cartilage (cricoid)
–complete circular ring &
thyroid (adam’s apple) &
ligaments
• Pseudostratified
columnar epith
diFiore`s Atlas of Histology
tracheal cartilage forms the incomplete cartilagenous ring
BRONCHIOLES
FXN: Conduct air; impt in
bronchoconstriction and bronchodilation
•
• Contain club (Clara) cells
or exocrine bronchiolar
cells - dome-shaped,
columnar, nonciliated cells
– secrete surfactant lipoproteins
and mucin in the fluid layer on
the epithelial surface
Alveoli: major sites of gas exchange
Alveolar cells : type I pneumocytes
cover 95% of the internal surface of
each alveolus, they are thin and
squamous ideal for gas exchange
Great alveolar cells : Type II
pneumocyte
Less prevalent, large, cuboidal
with apical microvilli
it decrease surface tension of
alveoli prevent alveoli from
collapsing
Alveolar macrophage: Dust cells
Alveolar wall
Mononuclear phagocytes, involve
in immunity. Collect inhaled
particles from the environment
and facilitate phagocytosis