Though some disagreement exists regarding the exact boundary between the upper and lower respiratory tracts, URTIs occur in the respiratory tract above the lungs including throat (pharyngitis), nasopharynx (nasopharyngitis), sinus (sinusitis), larynx (laryngitis), epiglottis (epiglottitis) or trachea (
trachealis).
Miller reported that the
trachealis muscle consists of transverse bands that unite with the cornua of C-shaped tracheal cartilage rings (8).
An extrinsic compression of the mid-trachea and
trachealis muscle from posterior was seen with 90% lumen compression but without direct invasion of the trachea (Figure 1).
White, "Mechanisms of smoothmuscle contraction elicited by cationic proteins in guinea pig
trachealis," American Journal of Physiology--Lung Cellular and Molecular Physiology, vol.
N: nonciliated cell, M: hypertrophy of mucosal smooth muscle, I: inflammatory cell, G: hyperplasia of submucosal mucous gland, L: tracheal lumen, B: blood vessels, T:
trachealis muscle, E: epithelium, and P: polycaprolactone (PCL) bellows-type scaffold.
The trachea in caprines is a 'U' shaped cartilaginous and membranous tube that extend caudally from larynx, at level of 2nd cervical vertebra to 3rd thoracic vertebra (Nzalak et al., 2013), The trachea consists of 48-60 cartilages, to the insides of which
trachealis muscle is attached (Konig and Liebich, 2007).
Electromechanical coupling in canine
trachealis muscle: acetylcholine contractions.
Unlike mammals, the avian trachea is composed of closely spaced, complete tracheal rings with no musculus
trachealis. (6) The typical avian trachea is 2.7 times longer and 1.3 times wider than that of a comparative mammal.
Photomicrograph of the trachea of red fox: Cartilartilagines tracheales (ct), musculus
trachealis (m), Lamina propria (p), epithelium (e), perichondrium (pc), adventitia (ad), goblet cells (G), blood vessel (v), tall columnar cells (T), basal cells (B), cilia (C), neuroendocrine cells (N).
The posterior tracheal wall lacks cartilaginous support, which is provided only by the thin band of the
trachealis muscle.
Hank's solution was used for washing the
trachealis tissue and cells.
The components of the tracheal tube included structures like cartilaginous rings (cartilagines tracheales), the tracheal annular ligaments (ligamenta anularia tracheae) (which connect the cartilage rings), the muscular layer or
trachealis muscles (musculus
trachealis), and the mucous membrane.
