[=Notice= in examination: 1. _Contents_—mucus; lymph; pus or blood;
amount; foreign bodies; false membranes, etc. 2. _Larynx_—condition of
epiglottis; œdema, ulcers, sloughs, polypi; same of superior opening
to cavity. _Ventricles_—condition of mucous membranes, etc. _Vocal
Cords_—thickness, color, œdema, ulcers, etc. _Cartilages_—condition
of; ossification; caries, etc. 3. _Trachea_—contents; mucous membrane;
cartilaginous rings; ossification of; caries; denuded of mucous
membrane, etc.]
_Inflammation_, _ulceration_, _œdema_, _necrosis of the cartilages_,
_tumors_ and _false membranes_ are the more usual pathological
conditions of these parts that may claim the attention in a post-mortem
examination.
=Inflammation= of the mucous membrane of the larynx (laryngitis) and
trachea, will appear as a diffused redness, with some thickening of the
membrane, and within which may be traced many _small, congested
blood-vessels_. It may be important to distinguish the redness of
inflammation, from that attending the early stage of decomposition,
which, it is an interesting fact to know, first appears in these parts.
Immediately after death, the mucous membrane is _pale_, except in death
from suffocation or laryngitis. In a day or two it becomes of a dusky
red, which is distinguished from that of inflammation by _the absence of
congested vessels_; the redness of decomposition, also, having a
superficial filmy appearance, as if washed with dirty wine.
=Ulceration= of the larynx commences in the mucous membrane, but may
extend to the deeper parts. The more usual location is upon the
epiglottis, or on the margin of the glottis and vocal cords. Impairment
of the voice to a greater or less degree, will have attended either
inflammation or ulceration of the vocal cords. It is to be borne in
mind, however, that aphonia may arise from some impairment of the nerves
of the larynx, in which case, a post-mortem examination will fail to
reveal any morbid condition of the mucous membrane or vocal cords.
Pulmonary consumption we sometimes find accompanied with the presence of
ulcers upon the posterior walls of the larynx, with evidence of
inflammation in the surrounding parts. Whether these arise from
tubercles in the mucous membrane, or ulceration of the mucous follicles,
is uncertain.
=Œdema= of the larynx, is attended with great swelling of the mucous
membrane, from serous effusion into the submucous tissues, and
frequently attends chronic inflammation of the parts, with ulceration.
It may, however, be of an erysipelatous character, occurring as the
result of exposure to infection. The surface appears red, pulpy and
swollen, from infiltration of the submucous tissue. Œdema of the larynx,
is confined to the parts around the epiglottis, and margins of the
glottis, never descending below the true vocal cords, owing to the close
adhesion of the mucous membrane to the fibrous structure of the cord,
without any intervening areolar tissue.
=Necrosis of the Cartilages= of the larynx, may occur in the advanced
stage of laryngitis with ulceration. In this manner the epiglottis, with
the arytenoid, the cricoid, and even thyroid cartilages may, to a
greater or less extent, be destroyed.
=Abscesses= may also form, where the cartilages are so much involved,
these in some cases breaking upon the outside, and establishing
fistulous communications through which air may escape during
respiration.
=Tumors= of the larynx, may be found _first_, outside of the cavity,
imbedded in some portion of its tissues; and may include encysted, fatty
or fibrous tumors; or, _second_, they may be found in the interior,
springing from the mucous membrane, and resembling polypi in their form
and structure. They are sometimes granular or cauliflower-like in
appearance, and vary in size from a pea to a hazel-nut.
=False Membranes= may be found in the larynx and trachea in fatal cases
of croup or diphtheria. In croup, the membrane adheres but slightly to
the mucous structure beneath, which will be found red and congested, but
may form a complete tubular lining to both larynx and trachea, extending
also into the bronchial tubes.[7] It is usually tougher in the larynx
and upper portion of the trachea, becoming softer and more gelatinous in
the lower portion of the trachea and bronchial tubes. Much difference of
opinion has been entertained as to the nature of this substance. It may,
however, be considered as a morbid secretion from the inflamed mucous
surfaces, in a semi-fluid form, which, in consequence of the presence of
albuminous matter, coagulates upon exposure to air.
The false membrane of croup may generally be distinguished from that of
diphtheria by the fact, _First_, That the latter is usually confined to
the fauces, sometimes extending to the larynx, rarely to the trachea.
_Second_, That diphtheritic membrane occurs more in patches, is tougher,
is more directly incorporated with the mucous surface beneath, and is
removed with more difficulty. _Third_, A microscopic examination shows
the membrane to be composed mainly of fibrine in a fibrillated
condition, with granular corpuscles and pus cells.