NORMAL ANATOMY OF THE LARYNX. 
veilhier.* The description given of it by 
Morgagni is, that it consists of a granular sub- 
stance of a livid whitish colour, from which 
under the pressure of the epiglottic or neigh- 
bouring muscles a fluid is poured out. Wris- 
_ bergt described it as a cartilage under the name 
of cuneiform. Cuvier and Wolff, as before 
stated, have confounded it with the cartilage of 
Santorini. Morgagni appears to have mistaken 
for glandular the yellow elastic tissue pene- 
trating its body. Lauth describes some mucous 
‘follicles about its base and internal surface, 
jut he opposes the views of Morgagni on the 
constitution of this body. This body is some- 
jmes absent in the human subject, but scarcely 
erin the quadrumana. Its structure is de- 
cidedly cartilaginous. 
The epiglottic gland. — Syn. glandula epi- 
ploitidis, Fab. Cass. Morg. The epiglottic 
_ gland is a name given to a mass of yellow 
‘ligamentous adipose and cellular substance, 
‘situated in the triangular space between 
e anterior surface of the epiglottis and the 
ngle of the thyroid cartilage; it is bounded 
nteriorly by the thyro-hyoid membrane, above 
by the thyro-epiglottic mucous membrane and 
ligament ; below, by the union of the epiglottis 
®, th the thyroid cartilage, and on each side by 
_ the mucous membrane passing from the thyroid 
tothe epiglottis. Berengarius speaks of it as a 
fleshy gland: Steno and many others as com- 
_ posed of granules, whose ducts perforate the 
 epiglottis and open on its posterior surface. 
_ Fabricius, Casserius, and Morgagni{ have de- 
scribed and figured these supposed granules 
_ and ducts. Bichat,§ Cloquet,|| Quain,{/ and 
* most modern anatomists adopt the same views. 
_ Morgagni, upon the same supposition as he 
4 had formed of the nature of the elastic tissue, 
_ considers the composition of the epiglottis to 
ij be chiefly glandular. Cloquet and Bichat 
_ admit the difficulty of detecting any follicular 
_ structure, nor could we discover any under the 
_ microscope ; and from what has been already 
_ stated on the structure of the epiglottis, we 
conclude, as of the arytenoid, that the structure 
_ which enjoys the name of epiglottic gland is 
not glandular. 
Mucous membrane.—The mucous membrane 
of the larynx is continuous with that which 
covers the mouth and pharynx. The posterior 
_ Surface of the larynx is bounded by the pharynx, 
and is lined by mucous membrane both on its 
De 
i 
* Traité d’Anat. 
+ Prime linex phys. anat. ade Haller, ed. Wris- 
berg. Gotting. 1780-8. p. 157. 
Morg. advers. anat. om. tab. ii. p. 48. 
§ ** Cet espace est occupé par un corps manifeste- 
_ ment celluleux, et graisseux, dans sa plus grande 
_ partie, mais qui est inferieurement recouvré de 
petits grains glanduleux, tantot agglommérés, tantot 
isolés, lesquels envoient sensiblement des prolonge- 
mens dans les trous dont est percée l’epiglotte : les 
en emens paroissent s’ouvrir sur sa surface 
aryngée, aux orifices qu’on y distingue. Quelque- 
fois les petits corps ylanduleux sont tellement 
Masqués par cette graisse jaunatre, qu’on ne peut 
les distinguer.” Traité d’Anat. descript. tom. ii. 
p- 385. 
Anat. descript. p. 245. 
Elem. of Anat. p, 858. 
111 
anterior and posterior surfaces. If the state- 
ment of Cruveilhier be correct, this singular 
duplication is not to be found elsewhere in the 
animal economy; afterwards it is reflected over 
the surface of the base of the tongue, and lines 
the interior surface of the epiglottis; in this 
space it forms three folds, called glosso-epiglottic, 
often described as the middle, and two lateral, 
which adhere closely to the surface of the epi- 
glottis. The mucous membrane being reflected 
over the free part of the epiglottis, to which it 
rather closely adheres, then lines its posterior 
surface and dips into the larynx. 
A duplication called the aryteno-epiglottic 
fold passes from each side of the lateral mar- 
gin of the epiglottis to the vertical apophysis of 
the arytenoid cartilage. This membrane is 
connected posteriorly with the mucous coat of 
the pharynx, anélines the posterior surface of 
the larynx; it is reflected over the arytenoid 
cartilages, and with the aryteno-epiglottic fold 
forms the posterior and lateral superior margin 
of the larynx ; covers the superior thyro-aryte- 
noid ligaments, penetrates to the bottom of the 
ventricles; from thence, after lining the inferior 
thyro-arytenoid ligaments, it passes through the 
chink of the glottis, covers the thyro and crico- 
arytenoideus lateralis muscles, and the internal 
surface of the cricoid cartilages, and becomes 
the investing membrane of the trachea. 
The laryngeal membrane is perforated by 
numerous mucous orifices of a peculiar pale 
rose-colour, and is remarkable for its great sen- 
sibility, more especially in the region above the 
rima glottidis. 
Lhe rima glottidis. Syn. cavum seu sinus la- 
ryngis The chink of the larynx is an aperture 
directed horizontally, connecting the supra and 
infra-laryngeal regions, and allowing the free 
transmission of air in respiration. It is bound- 
ed posteriorly by the arytenoid cartilages, ary- 
tenoid muscle and mucous membrane; laterally 
by the arytenoid cartilages and the thyro-aryte- 
noid ligaments, which, with the mucous mem- 
brane reflected over them, present nearly rect- 
angular-shaped valves, attached on three sides, 
leaving one, bounding the glottis, free; ante- 
riorly by the angle of the thyroid. Immedi- 
ately above it are the ventricles, one on each 
side. The intrinsic muscles of the larynx not 
only contribute to its functions in the produc- 
tion of voice, but determine its form. The form 
of the chink of the glottis is variable; in the 
state of repose, or that of ordinary respiration, 
it is triangular, the aperture dilating during 
inspiration and contracting during expiration. 
When the arytenoids are separated to the great- 
est extent by the crico-arytenoidei postici, it 
assumes a lozenge form ; if the posterior bases 
of the arytenoids are closed by the arytenoid 
muscles it becomes an ellipse; if the anterior 
apophyses of the arytenoids meet by the action 
of the crico-arytenoidei laterales, the chink may 
be divided into two parts. The length of the 
chink of the glottis is very variable, and bears a 
relation to that of the thyro-arytenoid ligaments ; 
like the latter, it increases with age in an arith- 
metical proportion until the period of puberty ; 
at that time its length in the male sex under- 
