Chapter 102: Trachea and Bronchi Flashcards
The trachea splits into principal bronchi (2) - then splits into…?
.. splits into lobar bronchi (one to each lung), segmental bronchi branch, subsegmental bronchi and bronchioles
How many tracheal rings do dogs have?
35 (can range up to 46)
At what point does the trachea have the thinnest cartilage and smallest CSA?
Thoracic inlet
What is the major blood supply to the trachea?
Segmental blood supply from cranial and caudal thyroid arteries
At the carina, blood supply shifts primarily to bronchoesophageal arteries
Name the venous and lymph drainage and innervation of the trachea?
Thyroid, internal jugular and bronchoesophageal veins
Lymph drainage - deep cervical, cranial mediastinal, medial retropharyngeal and tracheobronchial nodes
Right vagus and recurrent laryngeal nerve
What is a normal mucociliary flow rate in a dog?
10-15mm/min - speed and efficiency are hindered by increasing particle size and mucous viscosity
Left vagus results in only what % of contraction achieved by maximal stimulation of the right vagus nerve?
28.5%
What makes up the trachea?
- Hyaline cartilage rings
- Trachealis muscle
- Annular ligaments
How many cartilage rings are present in the right and left mainstem bronchi?
Left = 3
Right = 1
What are the three functions of the trachea?
Conduit for gases to and from the lungs
Warming and humidification to air
Mucociliary escalator
What is the maximum length of the incision for a transverse temporary tracheostomy?
What is the maximum recommended diameter of the tracheostomy tube?
Maximum incision 50% width of trachea
Maximum tube size 75% of tracheal diameter
What muscle needs to be separated on the approach to the cervical trachea?
Sternohyoideus
True or False: Tracheal size does not increase proportionally with the size of the dog?
True.
English bulldogs have smaller proportional to even other brachycephalics which are smaller than expected for body size.
What is the only way to diagnose bronchomalacia?
Tracheobronchoscopy
What are 3 methods for reducing tension at a tracheal anastomosis site?
Tension relieving sutures placed several rings proximal and distal
- Fixed ventroflexion of the neck
- Release of the annular ligament with preservation of the mucosa
How does age effect the strength of the trachea?
Juvenile trachea can only withstand 60% of the force of the adult trachea (higher water content with less collagen) so you can’t resect as much.
What breeds are predisposed to tracheal collapse?
What % may be affected by 6mo?
- Yorkies, min poodles, pomeranians, chihuahua, pug
- As many as 25%
What is the grading system for tracheal collapse?
- Grade I - 25% collapse (laxity of dorsal tracheal membrane)
- Grade II: 50% collapse
- Grade III - 75% collapse
- Grade IV - 100% collapse
Up to 50% of people who have ciliary dyskinesia also have situs inversus. The combination of situs, chronic rhinosinusitis, and bronchiectasis is called what?
Kartagener syndrome.
