tympanic 
the tympanum, and connected with the malleus in a mam- 
mal or with the quadrate bone in a bird. It is very su- 
perficial in the human infant, where the tympanic bone is 
merely annular, and in those animals in which this bong 
is rudimentary or wanting ; but it is generally situated 
at the bottom of a deep tube. See cuts under tympanum 
and earl. Tympanic nerve, a branch of the glosso- 
pharyngeal, which enters the tympanum through a canal 
of the temporal bone to supply the mucous membrane 
of that cavity and of the Eustachian tube. Also called 
Jacobson's and Andersch's nerve. Tympanic notch. 
See notch. Tympanic pedicle, the suspensorium of 
the lower jaw in fishes. See epitympanic. Tympanic 
plate, the lamina of bone which forms the anterior wall 
of the tympanum and external auditory meatus, and the 
posterior part of the glenoid fossa. Tympanic plexus. 
See plexus. Tympanic resonance, tympanitic reso- 
nance (which see, under resonance). Tympanic ring, 
an annular tympanic bone or cartilage, to which the tym- 
panic membrane is attached. This bone of the ear may be 
a permanent complete ring, or may form an incomplete 
circle. In either case, it may characterize only the embryo 
or the infant, and grow into a tubular form, or may be in- 
flated as a tympanic bulla, sometimes of enormous dimen- 
sions. In man the ring is at first simply annular and 
incomplete, so that the ossicles of the tympanum are 
readily seen from the outside of the skull of the infant ; 
it acquires with age a tubular form, and becomes anky- 
losed with other elements of the temporal bone. 
II. n. 1. A bone of the ear of man and mam- 
mals, supporting the tympanic membrane, gen- 
erally annular or tubular, forming most of the 
meatus auditorius externus, or external audi- 
tory passage. Its outer extremity is known In human 
anatomy as the external auditory process; it is annular at 
birth, subsequently becoming elongated and cylindric. 
2. Below mammals, in animals in which the 
true tympanic is rudimentary or wanting, the 
quadrate or pedicellate bone, the representa- 
tive of the malleus ; the suspensorium of the 
lower jaw, or especially its uppermost piece, 
the hyomandibular or epitympanic : so called 
by some who suppose it to be the tympanic 
bone, from the fact that it in part supports 
the tympanic membrane. Sec quadrate, n., 
3 (a), hyomandibular, epitympanic, and other 
compounds of tympanic there cited. 3. In 
ornith., sometimes, the tympano-occipital, con- 
sidered as the true representative in birds of 
the tympanic of a mammal. 
tympanichord (tim'pa-ni-kord), n. [< NL. 
tympanum + Gr. o/x!?,'a string.] That branch 
of the facial nerve which traverses the tym- 
panum; the so-called chorda tympani. See 
chorda. Cones, 1887. 
tympanichordal (tim"pa-ni-k6r'dal), a. [< tym- 
panichord + -al.] Of or pertaining to the tym- 
panichord. Cows. 
tympaniform (tim'pa-ni-f6rm),a. [< NL. tym- 
panum + L. forma, form.] Resembling or hav- 
ing the form of a tympanum ; stretched like a 
drumhead: as, a tympaniform membrane. Hux- 
ley, Anat. Invert., p. 378. 
tyinpanisin (tim'pa-nizm),n. [< Gr. rv/nravov, 
a drum, + -ism.'] In pathol., distention by gas. 
tympanist (tim'pa-nist), . [< Gr. TVUTTOVOV, a 
drum, + -ist.] One who plays a tympan or 
drum. [Rare.] 
"Why is the Timpan called Tlmpan Naimh (or saint's 
Timpan), and yet no saint ever took a Timpan into his 
hands?" "I do not know," said the tiiupanvst. 
O'Curry, Anc. Irish, II. xxxi. 
Tympanistria (tim-pa-nis'tri-a), n. [NL. 
(Reichenbach, 1852), < Gr. Tv/mav'tarpia, fern, of 
rvfiiraviartic, a drummer, < rvnimvov, a drum : see 
tympanum.] 1. In ornith., a monotypic genus 
of South African doves. T. Weolor, the tambourine, 
Is credited with a peculiar resonance of voice or sort of 
6560 
2. In entom., a genus of hemipterous insects. 
Stal, 1861. 
tympanites (tim-pa-nl'tez), . [NL., < L. tym- 
l>ttnites, dropsy of the belly, < Gr. rvfiiravirtif, of 
or pertaining to a drum, < ri'inravov, a drum: 
see tympanum.'] Distention of the abdomen 
caused by the presence of air either in the in- 
testine or in the cavity of the peritoneum ; ab- 
dominal tympanism Uterine tympanites, tym- 
panism of the womb ; physometra. 
tympanitic (tim-pa-nit'ik), a. [< L. tympani- 
ticus, one who is afflicted with tympanites, < 
tympanites, tympanites: see tympanites.'] Per- 
taining to or of the nature of tympanites. 
Since then all he had eaten or drank or done had flown 
to his stomach, producing a tympanitic action in that or- 
gan. //. Kingsley, Eavenshoe, xii. 
Tympanitic dullness, the quality of a percussion-note 
in which the resonance is subnormal and in which the 
vesicular quality is absent. Tympanitic resonance. 
See resonance. 
tympanitis (tim-pa-m'tis), n. [NL., < tympa- 
n(um) + -itis. Cf. tympanites.] 1. Inflammation 
of the lining membrane of the tympanum, or 
middle ear. 2. Incorrectly, tympanites. 
tympanizet (tim'pa-niz), v. [< Gr. Tipn-av/ferti, 
beat the drum, < rvftmivov, a drum: see tympa- 
num.'] I. trans. To make into a drum. Oley, 
Life of G. Herbert (1671), M. 2. b. (Latham.) 
H. intrans. To act the part of a drummer. 
Coles. 
tympano, . See timpano. 
tympan o-Eusta chi an ( t im"pa-no-u-sta ' ki-an ) , 
a. Of or pertaining to the tympanum and the 
Eustachian tube. 
tympanohyal (tim^pa-no-hral), n. and a. [< 
tympan(um) + hy(oid)' + -al.] I. n. In zool. and 
anat., a small cartilage or bone of man and 
some other mammals, recognizably distinct at 
an early period, subsequently fused with its sur- 
roundings, constituting one of the elements of 
IP. 
tympanum 
II. n. A part of the skull of cetaceans, the 
so-called ear-bone of those animals, which con- 
sists of the periotic bones united with one an- 
other and with the tympanic, forming a single 
specially hard and durable bone readily de- 
tached from the rest of the skull. 
tympanosquamosal (tim"pa-n6-skwa-m6'sal), 
a. Common to the tympanic and the squamosal 
bone, as a suture or ankylosis: as, the Glaserian 
fissure of man is tympanosquamosal. 
tympanous(tim'pa-nus),a. [Formerly also iim- 
panous; ( tympan-y + -ous.] Swelled or puffed 
out; inflated; distended; figuratively, pompous. 
His proud tympatmis master, swell'd with state-wind. 
Middleton, Game at Chess, ii. 1. 
tympanum (tim'pa-uum), n.; pi. tympana 
(-nil), sometimes tympanums (-numz). [NL., 
< L. tympanum, < Gr. ri/nrajw, a drum, roller, 
area of a pediment, panel of a door: see tym- 
pan.] 1 . An ancient tambourine or hand-drum, 
either with a single head like the modern tam- 
bourine, or with both front and back covered 
(the back sometimes swelled out as in a ket- 
tledrum), and beaten either with the hand or 
with a stick. 2. In anat. and zool.: (a) The 
ear-drum considered as to its walls, its cavity, 
and its contents. In man and other mammals the 
tympanum is the middle ear, a hollow or recess in the 
Tambourine (Tympanistria bicolor). 
ventriloquial effect (whence the name). It is extensively 
whitish, with black-tipped wings and tail, and inhabits 
woodland. 
Visceral Arches of Chondrocranium of Human Fetus at third month, 
somewhat diagrammatic, enlarged. 
I, preoral (palatopterygoid) arch; z, first postoral (rnandibular) 
arch : 3, second postoral (nyoidean) arch : IP, internal pterygoid car- 
tilage ; EC, Eustachian cartilage ; AL, anterior ligament of malleus ; 
M, malleus: /, incus; //., long internal lateral ligament of lower 
jaw, connecting the malleus with the mandible (of which latter co is 
the coronoid process, cct the condyle, and the angle] ; bh, basi- 
hyal ; th, thyrohyal ; eh, ceratohyal ; SH, stylohyoid ligament, sus- 
pending the nyoid to SP, stylohyal, or so-called styloid process of the 
temporal bone, at the root of which, in line with the incus, is TH, the 
tympanohyal. (From the Proceedings of the Zoological Society of 
London, 1885, p. 572.) 
the compound temporal bone, and in man situ- 
ated at the root of the styloid process, in the 
course of the hyoidean arch. 
II. a. Specifying this cartilage or bone. 
tympanomalleal (tim"pa-n6-mare-al), a. Per- 
taining to the tympanic bone and the malleus : 
specifying a bone in the batrachian skull, later 
identified as the quadrate jugal. See cuts un- 
der Bana and temporomastoid. 
tympanomandibular (tim*pa-n6-man-dib'- 
u-lar), a. Of or pertaining to the tympanum, 
or tympanic bone, and the mandible, or lower 
jaw-bone, of some animals, as fishes: specify- 
ing one of the visceral arches of the head. See 
epitympanic, n., and tympanic, n., 2. 
tympano-occipital (tim"pa-no-ok-sip / i-tal), n. 
In ornith., a small bone, or slight ossification, 
in relation with the exoccipital bone and the 
outer ear of a bird, bounding the external ori- 
fice of the ear posteriorly, and considered to 
represent the true tympanic bone of a mam- 
mal. 
tympanoperiotic(tim // pa-n6-per-i-ot'ik), a. and 
n. I. a. Including or consisting of a tympanic 
bone united with the periotic bone proper: 
used especially with reference to the ear-bone 
of cetaceans. Huxley, Anat. Vert., p. 345. 
Mali 
MC 
Tympanum of Human Ear. The tympanic cavity, enlarged, is here 
viewed from the inside : the circular object is the tympanic membrane, 
or membrane of the ear-drum, upon which rests Mall, the malleus ; 
Inc, the incus; St, the stapes; ab, the horizontal axis alxjut which 
the malleus and incus turn slightly ; MC, cells in the mastoid part of 
the temporal. 
temporal bone, among several of the bones of which the 
temporal is composed, shut off from the meatus auditorius 
externus by the tympanic membrane, communicating 
with the back of the mouth by the Eustachian tube, in 
relation with the labyrinth, or inner ear, its inner wall 
forming part of the wall of the latter, and containing the 
chain of little bones called osaicula auditus, and usually 
the chorda tympani nerve. It is a part of the passage- 
way which in the early embryo is uninterrupted between 
the pharynx and the exterior, and in the adult is occluded 
only by the membrane of the tympanum. In the dry 
state of the parts, the bony walls of the human tympa- 
num present several openings : that leading outward 
through the external auditory meatus ; the orifice of the 
Eustachian tube; the openings of mastoid cells; the fe- 
nestra ovalis and fenestra rotunda, respectively the ter- 
minations of the scala vestibuli and scala tympani, com- 
municating with the vestibule and cochlea of the inner 
ear; the iter posterius, by which the chorda tympani 
nerve enters the tympanum from the aqueduct of Fallo- 
pius ; the iter anterius, by which the same nerve leaves 
the tympanum by the canal of Huguier ; the canal for 
the tensor tympani muscle; the Glaserian fissure, between 
the squamosal and the tympanic bones, for the laxator 
tympani muscle, tympanic artery, and slender process of 
the malleus, these last two openings being rifts between 
component bonea of the parts communicating, like the 
Eustachian tube, with parts outside the temporal bone ; 
and the minute orifice at the apex of the pyramid, for 
the passage of the stapedius muscle. In animals below 
mammals, as birds and reptiles, the tympanum contains 
the columella, when that bone exists, and is the cavity of 
the external ear when there is no external auditory mea- 
tus. Its membrane is often upon the surface of the head, 
and in some cases is a conspicuous structure of the ex- 
terior, as in a frog or toad. This is well shown in the 
cut under parotoid, where the circular formation just 
in front of the parotoid is the tympanum. See also cuts 
under earl and temporal, (b) The tympanic mem- 
brane; the ear-drum, in the restricted sense 
of that term : so used in physiology and aural 
surgery, and in common speech: as, a rup- 
ture of the tympanum. See tympanic mem- 
brane, under tympanic, (c) In ornith. : (1) The 
labyrinth at the bottom of the windpipe of 
sundry birds, as the mergansers and various 
sea-ducks: a, large irregular bony or gristly 
dilatation of the lower part of the trachea, 
often involving also more or less of the up- 
per ends of the bronchi. It is chiefly found, 
or most developed, in the male sex. (2) The 
naked inflatable air-sac on each side of the 
neck of certain birds, as grouse, especially 
the sage-grouse and prairie-hen, in which the 
ordinary cervical air-cells of birds are inor- 
dinately developed and susceptible of great 
distention. See cut under Cupidonia. (d) In 
rntiini., a tympanic membrane, stretched upon 
a chitinized ring, one surface being directed to 
the exterior, the other to the interior, in rela- 
tion with a trachea! vesicle and with nervous 
ganglia and nervous end-organs in the form of 
