Freiburger historische Bestände - digital

53

Appendix.

Facial muscles of Camel. Elk.

54

3. M. maxillo-labialis.

PI. 11, fig. 4.

Of the m. maxillo-labialis only the portio inferior is developed.
This arises tendinously from the maxillary bone, ventrad and partially
laterad of the foramen infraorbitale. The muscular body
is flat, radiating like a fan forwards and upwards; the posterior
rather short fascicles run upwards, inserting themselves into a
thin aponeurosis, which inside the m. nasolabialis spreads out
upon the nasal surface. The next fascicles radiate towards the
nostril, inserting themselves along the posterior and lateral circumference
, the inferior ones running into the upper lip. The
muscle is covered by the m. nasolabialis, but a little behind the
nostril the latter is pierced by a portion of maxillo-labialis-fascicles
which proceed along the mediad margin of the nostril.

4. Buccinator-group.

PI. 5, 6; PI. 11, fig. 4; PI. 16, fig. 1 and 2.

The m. buccinatorius consists of two layers. The superficial
layer (PI. 5; PI. 16, fig. 1), which is rather powerful, especially
anteriorly, extends posteriorly to the m. masseter; and consists
of arched, transverse fascicles that stretch from the upper to the
lower jaw, turning round the angle where the cheek and the gingiva
meet. Posteriorly, in the region in front of the m. masseter,
the gl. buccales inf. form a large, extended, continuous glandular
mass, mostly covered by the transverse bundles of the buccinator.
In front, towards the angle of the mouth, the layer becomes
more powerful and passes direct into the pars rimana. In the
upper lip the latter forms a rather narrow muscular brim along
the margin of the lip, whereas, in the under lip, it is considerably
higher, the bundles being disposed here in the following
way: Along the margin of the lip a considerable number of
bundles proceed parallel thereto; the inferior bundles, however,
go obliquely forwards and downwards, passing in an arc inside
the gingiva, inserting themselves into the lower jaw somewhat
below the alveolar margin (PI. 16, fig. 1.) A rather considerable
layer of the gl. labiales inf. is covered by the superficial layer of
the buccinator (PI. 6). The following yet remain to be described:
Closely behind the angle of the mouth, in the region between the
bundles, that turn forwards to form the pars rimana, and the entrance
of the pars zygomatica, there are a number of the most
superficial bundles which behave in a peculiar manner; these
bundles proceed straight upwards, partly spreading somewhat
fan-wise and inserting themselves rather high upon the maxillary
bone, almost up to the nasal bone (v. PI. 5, where these bundles
are distinctly seen thrusting up under the m. nasolabialis; comp.
PI. 16, fig. 1).

Covered by the superficial transverse layer there is a deep
longitudinal layer (PI. 6; PI. 16, fig. 2). This layer stretches along
the whole row of teeth so that the posterior part thereof has its
place within the m. masseter. It arises from the posterior part
of the maxillary bone (tuber maxillse), from the mucous membrane
, and from the anterior margin of the ramus ascendens
mandibular, at first forming a thick continuous layer, the bundles
of which stretch longitudinally forwards. On their way several
of these bundles insert themselves into the mucous membrane,
partly thrusting between the pretty numerous but rather small
gl. buccales, which are spread over most of the mucous membrane
(v. PI. 6; numerous pits are seen on the outside of the
mucous membrane, in which these glands have had their place).
At first the bundles pass longitudinally, straight on, but as they
approach the angle of the mouth, they turn obliquely upwards in
the direction of the angle of the mouth and the upper lip, so that
none of the bundles of this layer reach into the under lip (PI. 16,
fig. 2). The lower bundles insert themselves into the mucous
membrane just behind the angle of the mouth, whereas the others
take the following course: The upper bundles (a, PI. 6; comp. PI.
16, fig. 2) run upwards in a body, and insert themselves into the
maxillary and the intermaxillary bones, mostly covered by the
bundles of the superficial layer mentioned above. The other

bundles (ft, PI. 6) however, proceed obliquely into the upper lip?
turn round the angle where the upper lip and the gingiva meet,
and are inserted into the intermaxillary bone just above the alveolar
margin. As a direct continuation of these bundles there is
in the rest of the upper lip (the anterior portion of the lip) a continuous
layer of bundles going from the margin of the upper lip
in an arc round the angle where the mucous membrane of the
upper lip and the gingiva unite, and inserting, farther on, into
the intermaxillary bone (PI. 16, fig. 2). Here we have the pars
supralabialis m. buccinatorii.

In the upper lip there are numerous small gl. labiales sup.
placed between the fascicles.

The Tiz. nasalis (PI. 6) arises from the intermaxillary bone
in the space from the median line unto near the canine, close
above the insertion of the portio supralabialis m. buccinatorii.
The bundles radiate from here upwards, the mediad ones turning
in a bow up to the portion below the nostril where they insert
themselves; the lateral ones spreading up to the lateral and posterior
circumference of the nostril. On PI. 6 these bundles are
seen stepping out above the portio supralabialis.

The 777. mentalis forms a thin muscular brim which arises from
the anterior part of the lower jaw just below the insertion of
the m. buccinatorius and radiates with its bundles downwards
to the skin of the under lip. On Plate 5 and 6 these bundles
are seen stepping out below the pars rimana.

5. M. rectus nasi and m. rectus labii.

In the »soft nasal tube« there are fascicles which extend from
the skin of the exterior face of the nasal tube to the skin of the
interior face of the nasal tube; and in the lips there are bundles
going from the skin to the mucous membrane. We have limited
ourselves to a microscopical statement of the presence of these
bundles, but can say nothing further of their number and other facts.

2. ELK.

fcf junior — Q. senior J

1. Platysma-sphincter-group.

The sphincter superficialis is wanting, at all events on the head.

The platysma forms a continuous, flat, narrow, but rather
powerful muscular body, coming from the neck and the occiput
and running almost straight forwards. The bundles are longitudinal
, almost parallel to the longitudinal axis of the head and
only bend slightly upwards in the anterior part. The muscle
goes across the angle of the mandible, covering the lower part of the
masseter and the buccinator, and making for the angle of the
mouth and the under lip. 4—5 cm behind the angle of the
mouth it meets with the pars zygomatica, which with its lower
bundles also makes for the angle of the mouth, and in a space
of about a couple of cm behind the latter the two muscles unite
so closely that a limit between them cannot be shown. The
platysma bundles end partly at the angle of the mouth partly
in the under lip, where they thrust between the bundles of
the pars rimana m. buccinatorii.

Dorsad the muscular body of the platysma passes into a
thin aponeurosis that covers the other muscles of the face. In
this aponeurosis there are posteriorly imbedded some scattered
muscular fascicles, radiating forwards and upwards, especially in
the part covering the parotis and the masseter.

The pars zygomatica arises independently from the zygoma
with a thin but rather broad aponeurosis, outside the masseter.
About the anterior margin of this muscle it passes into a narrow
but rather powerful muscular body that goes a little obliquely
forwards, and downwards, towards the upper lip and the angle
of the mouth. As already mentioned, it joins the platysma a
little behind the latter. The upper bundles proceed into the
upper lip where they mingle with the bundles of the pars rimana.

The sphincter profundus consists of two portions quite sepa-

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