Lecture 10: Small Animal thorax and Diaphragm Flashcards
The trachea is a tube that extends from the ___cartilage of the larynx to its ___in the thorax
Cricoid cartilage, biforcation
What is the tracheal carina
Structure that lies at the crest of the bifurcation where the trachea splits
How many C shaped hyaline cartilages line the trachea
35-40
What muscle lines the often part of the C-shaped hyaline tracheal cartilages
Trachealis muscle
Is the trachealis muscle dorsal or ventral
Dorsal
What structure unites the hyaline tracheal cartilage rings
Annular ligaments of the trachea
When does the bronchial tree begin
Bifurcation of the trachea
The right and left principal bronchi divide into __
Lobar bronchi
What structure is used to identify the lung lobes
Lobar bronchi
Lobar bronchi divide into
Segmental bronchi
Which lung/bronchus segment lacks hyaline cartilage
Bronchioles
Respiratory bronchioles give rise to ___. ___ and ___
Alveolar ducts, alveolar sacs and pulmonary alveoli
what is wrong
Tracheal collapse
What breeds commonly get tracheal collapse
Middle aged toy breeds, Yorkies and poms
What happens during tracheal collapse
C-shaped tracheal cartilage weakens and collapses progressively over time
What are the two types/regions of tracheal collapse
Intra or extra thoracic
What form of tracheal collapse is occurring when signs worsen during inspiration
Extrathoracic
What form of tracheal collapse is occurring when signs worse during expiration
Intrathoracic
What is grade I tracheal collapse
Tracheal membrane is slightly pendulous, cartilage maintains normal shape and lumen size is reduced by 25%
What is grade II tracheal collapse
Tracheal membrane is widened and pendulous, cartilage is partially flattened, and lumen size is reduced by 50%
Grade III tracheal collapse
Tracheal membrane almost in contact with the ventral trachea, cartilage is nearly flat and lumen size is reduced by 75%
Grade IV tracheal collapse
Tracheal membrane lying on dorsal cartilage, cartilage is flattened and may invert, and lumen is essentially closed
What grades is medical management reasonable for tracheal collapse
Grade I and II
What are some medical management options for grade I and II tracheal collapse
- Weight loss plan
- Harness instead of collars
- Avoid respiratory irritants
- Steroids, antiussives, bronchodilators, and sedatives