Respiratory System
CATS
• Respiratory system on cat:
– Diaphragm
– Visceral pleura
– Trachea
– Pharynx (Back of throat)
– Larynx
– Bronchus
Larynx (Esophagus behind)
Trachea
Lungs (visceral pleura is
shiny surface)
Diaphragm
Trachea
Primary Bronchi
Secondary
bronchi
MODELS
• Upper Respiratory model:
– External nares
– Nasopharynx
– Lingual frenulum (attachment under tongue)
– Oropharynx
– Uvula
– Palatine tonsil (part of the immune system)
– Laryngopharynx
– Thyroid gland
Nasopharynx
Uvula
Oropharynx
Laryngopharynx
• Trachea model:
– Trachealis muscle
– Arytenoid cartilage
– Cricoid cartilage
– Hyoid bone
– Thyroid cartilage
– Glottis (hole opening to the trachea)
– Epiglottis (“leaf-like” flap that covers glottis)
Hyoid bone
Epiglottis
Thyroid cartilage
Glottis
Arytenoid cartilage
Cricoid cartilage
Trachealis muscle
Thyroid gland
Hyoid bone
Epiglottis
Thyroid cartilage
Trachealis muscle
Thyroid gland
Cricoid cartilage
Hyoid bone
Epiglottis
Thyroid cartilage
Glottis
Vocal cord
Arytenoid cartilage
Cricoid cartilage
Larynx


The ability to vary the pitch of the voice
results from the tension in the vocal
cords.
The epiglottis is a leaf-shaped flap that
closes over the glottis during
swallowing to keep food from entering
the trachea.
Lung

The right lung is larger than the left
one.



More cigarette smoke gets in this side
Cancer is more common in the right lung
Most foreign substances in the air do
not reach the lungs because the ciliated
epithelium and mucus that line the
respiratory passages trap them and we
cough it up.
Thyroid cartilage
Cricoid cartilage
Thyroid gland
Trachea
Lung
Visceral pleura (shiny top layer)
Trachea
Primary Bronchi
Secondary Bronchi
Hilus (root)
SAC
Models
Hilus of lung
SAC Models
Trachea
Primary bronchus
Secondary bronchus
Tertiary bronchus
Bronchiole
Alveoli
Diaphragm

When the diaphragm contracts:



the thoracic cavity increases
the pressure inside the thoracic cavity
drops
The air flows into the lungs
SLIDE: LUNG
• Trachea
– Made of hyaline cartilage
– Lined with pseudostratified columnar epithelium
• Bronchi (larger, has cartilage)
• Bronchiole
• Alveolus (Functional unit of the lung)
Lung
Bronchi
Bronchiole
Alveoli
Lung
Lung
Alveoli
Bronchiole
Artery
Lung
Esophagus
Trachea