Practical anatomy

Front matter

! UNITED STATES OF AMERICA.*

PRACTICAL ANATOMY.

A NEW ARRANGEMENT

Preface

THE AMERICAN EDITOR.

The Editor of the following pages, believing that a dissector suited to the wants of the American Student should be much more condensed than those in general use, has made the following arrangement of the London Dissector. In its preparation the arrangement has been entirely altered, and the nomenclature in many cases changed. The Ligamentous system : illustrations and numerous other additions in various parts of the work have been made; everything considered unnecessary erased ; and the whole presented as near as possible in topographical order. The minute anatomy of parts, and the smaller ramifications of the nervous and vascular systems have been omitted, belonging as they do more properly to systematic treatises on Special Anatomy.

The work has been prepared with an eye single to the faithful economy of the Student's time.

D. HAYES AGJSTEW.

August, 1856.

cm)

PREFACE

TO THE

SECOND EDITION

BY THE AMERICAN EDITOR.

The first edition of this book on Practical Anatomy having been exhausted, and the favorable manner in which it has been received, have induced the preparation of a second edition.

The same care in this as in the former one has been observed, to compress the matter into as small a compass as would consist with perspicuity.

D. HAYES AGNEW,

1611 Chestnut Street.

Chapter I. General Observations In Reference To Dissecting

The student about commencing the duties of the dissecting room, should be supplied with a good apron to protect his clothes from being soiled and a dissecting case of good quality. The knife should be held like a pen, and moved by the fingers and thumb, not by the wrist and elbow, and sometimes, as I have seen, by the shoulder. The student should practice its use also with the left hand; such an education will be of great advantage, especially in surgical operations. In the dissection of a part, it is a good rule not to turn off more of the skin than is necessary for the exposure of the part, and always to replace it again during the interval of dissection. Generally I think it better to turn off the structures in the order of superposition ; as the skin, superficial fascia, deep fascia, etc. In dissecting a muscle the parts should be made tense, which is done by blocks properly placed under the subject. The cellular membrane which immediately invests the muscle, must be kept extended by the hand or forceps, -and the edge of the knife carried steadily in the direction of its fibres. This rule admits of no exceptions, and should never be lost sight of by the student.

There are many operations which may be done on the subject without injuring the parts for dissection; such as the ligation of arteries; passage of instruments

2 (9)

through the nasal fossae and their introduction into the ^Eustachian tube; introduction of catheter, both in the male and female, etc.; and these should be practiced with care. The grand object of the student in the examination of the human body, should be not only to recognize its constituents, but above all the relation which they sustain to each other; this is the only knowledge worth obtaining, and the want of it accounts for the blunders, confusion, and ignorance which are so frequently seen in the profession. Another point of much importance is order and cleanliness. Hence all drippings from the subject should be wiped up with the sponge, and no scraps allowed to accumulate about the table. Much apprehension is sometimes expressed by students about poisoned wounds. It is well if there be any abrasions of the skin to cover it with collodion before engaging in dissecting ; but since the introduction of the chloride of zinc as an antiseptic all danger from this source is removed. Where an accidental cut is inflicted, the part should be washed, and well drawn by the mouth. The common practice of cauterizing with the nitras argenti, I think is in many cases positively injurious, unless well drawn first.

Chapter II. Dissection Of The Head

Of the External Parts of the Head.

The integuments of the head are thick, and covered with hair ; under the cutis there is a cellular substance, which is much condensed, and closely connected with the epicranium, or expanded tendon of the occipito-frontalis. This connection renders the dissection of that muscle difficult.

EXTERNAL PARTS OF THE HEAD. 11

An incision should be made from the root of the nose over the median line of the head, terminating behind at the occipital protuberance; a second from the commencement of the first, over the eyebrows to the external angular process of the frontal bone; a third from the occipital protuberance to the mastoid process of the temporal bone ; by dissecting very carefully the flap outward, the entire muscle and intervening tendon or aponeurosis will be exposed.

The Occipito-frontalis is the only muscle which properly belongs to the hairy scalp ; it is a single broad digastric muscle.

Arising, on each side of the head, fleshy and tendinous, from the transverse ridge of the occipital bone, as far forward as the mastoid process ; it forms a broad, thin tendon, which covers the whole upper part of the cranium.

Inserted, fleshy, on each side, into the orbicularis palpebrarum, skin of the eyebrows, and the internal angular process of the os frontis and os nasi. The last insertion answers to the Pyramidalis Nasi of some books.

Situation. The tendon adheres firmly by cellular membrane to the skin, but very loosely to the pericranium or periosteum of the cranium, by a loose cellular layer, which might be called the subaponeurotic fascia. At its insertion it intermixes with the muscles of the upper part of the face.

Use. To pull the skin of the head backward, raise the eyebrows, and corrugate the skin of the forehead.

Bloodvessels seen in the dissection of the scalp are the Frontal, emerging from the internal angle of the orbit and passing up the middle of the head. Supra-orbital out of the Supra-orbital foramen; both branches of the Ophthalmic. On the side of the head the Temporal, from the external carotid, behind the Posterior Occipital, and Posterior Auricular from the external carotid. All anastomose in the scalp.

The Supra-orbital Nerves coming out of the supra-orbital foramen. The Frontal Nerve, a branch of the ophthalmic, which last is the first branch of the fifth pair; on the side, branches of the Portio Dura and Inferior Maxillary Nerves ; and behind, the Occipitalis Minor and Major — the former from the superficial plexus of the neck, and the latter the main stalk of the second cervical spinal nerve.

The muscles of the ear are of three classes.

1. The common muscles move the external ear; they are not always so distinct as to admit of a clear demonstration.

(1) Attollens Aurem — Arises from the tendon of the occipito-frontalis, and from the aponeurosis of the temporal muscle.

Inserted into the upper part of the root of the cartilage of the ear, opposite to the antihelix. Use. To draw the ear upward.

(2) Anterior Auris — Arises, thin and membranous, from the posterior part of the zygomatic process of the temporal bone.

Inserted into a small eminence on the back of the helix, opposite to the concha.

Use. To draw the eminence a little forward and upward.

(3) The Retrahentes Auris — Arise, by two or three distinct slips, from the external and posterior part of the mastoid process, immediately above the insertion of the sterno-cleido mastoideus.

Inserted into that back part of the ear which is opposite to the septum, dividing the scapha and concha.

Use. To draw the ear back and stretch the concha.

Before describing the proper muscles of the ear, notice the following. The part usually called ear is for the most part cartilaginous; appended to it below is a pendulous portion, the Lobus, composed of granulated fat and dense cellular membrane ; with the exception of this, all above is the Pinna. The deep cavity in the middle is the Concha. Dividing the upper part of the concha into two unequal fossae is a ridge which runs along the circumference of the pinna and ends in the lobus; this is the Helix — within it another, the Antihelix. On the anterior part of the concha is a projec-

EXTERNAL PARTS OP THE HEAD. 13

tion, the Tragus, and opposite another, the Antitragus. Under the rim of the helix is the Fossa Innominata, and in the bifurcation of the helix is the Scapha. The external Auditory Meatus is about one inch in depth, its direction moderately forward and inward; under the skin which lines the meatus are the Ceruminous Glands.

2. The proper muscles of the ear must be here described; but the student must not expect to meet with them distinctly marked in every subject: in general, they are very confused and indistinct.

(1) Helicis Major — Arises from the upper and acute part of the helix, anteriorly.

Inserted into its cartilage, a little above the tragus. Use. To depress the part from which it arises.

(2) Helicis Minor — Arises from the inferior and anterior part of the helix.

Inserted into the crus of the helix, near the fissure on the cartilage opposite to the concha. Use. To contract the fissure.

(3) Tragicus — Arises from the middle and outer part of the concha, at the root of the tragus, along which it runs.

Inserted into the point of the tragus.

Use. To pull the point of the tragus a little forward.

(4) Antitragicus — Arises from the internal part of the cartilage that supports the antitragus ; and, running upward, is

Inserted into the tip of the antitragus as far as the inferior part of the antihelix.

Use. To turn the tip of the antitragus a little outward, and depress the extremity of the antihelix toward it.

(5) Transversus Auris — Arises from the prominent part of the concha on the dorsum of the ear.

Inserted opposite to the outer side of the antihelix. Use. It draws the parts to which it is connected toward each other, and stretches the scapha and concha.

Chapter III. Dissection Of The Face

Of the Muscles.

To expose these muscles an incision should be carried from the root of the nose to its tip, around the margin of the nostril to the centre of the upper lip, down to its margin, around its border to an opposite point on the lower lip, and then to the symphysis of the chin. From the termination of the last a second may be carried along the base of the jaw to the mastoid process of the temporal bone. Reflect the integuments outward.

Under the integuments of the face, there is always a considerable quantity of adipose membrane; many of the muscles are very slender, and lying imbedded in this fat, require careful dissection. The whole side of the face is also supplied with numerous ramifications of the facial nerve, or portio dura of the seventh pair. These nervous twigs are generally removed with the integuments. If it is desired to save them, the skin only should be removed first.

Twelve pairs of muscles, and one single muscle, are described in this dissection.

1. The Orbicularis Palpebrarum — Arises from the internal angular process of the frontal bone, and from a tendon at the inner angle of the eye, by a number of fleshy fibres which pass round the orbit, covering first the superior and then the inferior eyelid, and also the bony edges of the orbit.

Inserted, by a short round tendon, the Tendo Oculi, into the nasal process of the superior maxillary bone. The above tendon lies across the lachrymal sac.

Situation. This muscle is intermixed, at its upper part, with the occipito-frontalis.

Use. To shut the eye, by bringing down the upper lid, and pulling up the lower; the fibres contracting toward the inner angle, as to a fixed point, compress the eyeball and lachrymal gland, and convey the tears toward the puncta lachrymalia.

The ciliaris is only a part of the muscle covering the cartilages of the eyelids, which are called the Cilia or Tarsi; Maxillo- palpebral.

2. The Corrugator Supercilii — Arises, fleshy, from the internal angular process of the os frontis ; it runs outward and a little upward, to be

Inserted into the inferior fleshy part of the occipito-frontalis muscle, extending outward as far as the middle of the superciliary ridge.

Situation. This muscle is concealed by the occipito-frontalis. It lies close to the upper and inner part of the orbicularis palpebrarum, with which it is connected.

Use. To smooth the skin of the forehead, by pulling it down after the action of the occipito-frontalis. When it acts more forcibly, it pulls down the eyebrow and skin of the forehead, and produces vertical wrinkles.

3. The Compressor Naris — Arises, narrow, from the outer part of the ala nasi, and neighboring part of the os maxillare superius. From this origin a number of thin separate fibres run up obliquely along the cartilage of the nose toward the dorsum nasi, where the muscle joins its fellow, and is

Inserted, slightly, into the lower part of the os nasi and nasal process of the superior maxillary bone.

Situation. It is superficial; its origin is connected with the levator labii superioris absque nasi.

Use. To compress the ala toward the septum nasi; but, if the fibres of the occipito-frontalis, which adhere to it, act, the upper part of this muscle assists in pulling the ala outward. It also corrugates the skin of the nose.

4. Levator Labii Superioris Al^ique Nasi — Arises by two distinct origins : the first from the nasal process of the superior maxillary bone, where it joins the os frontis at the inner canthus of the eye; it descends along the nasal process, and is inserted into the outer part of the ala nasi, and into the upper lip. The second arises, broad and fleshy, from the margin of the orbit ar process of the superior maxillary bone, immediately above the foramen infra-orbitarium ; it runs down, becoming narrower, and is inserted into the upper lip and orbicularis oris.

Situation. The first portion is sometimes called Levator Labii Superioris Alseque Nasi, and the second Levator Labii Superioris Proprius. Their origins are partly covered by the orbicularis palpebrarum. They descend more outwardly than the ala nasi.

Use. To raise the upper lip toward the orbit, and a little outward; the first portion will also draw the ala nasi upward and outward.

Bloodvessels and Nerves. — Below the orbital origin of this muscle will be seen the Infra-orbital Bloodvessels and Nerves coming out of the infra-orbital foramen. The artery is from the internal maxillary, the nerve from the superior maxillary branch of the fifth pair; a nerve of common sensation.

5. Zygomaticus Minor — Arises from the upper prominent part of the os malse, and, descending obliquely downward and forward, is

Inserted into the upper lip near the corner of the mouth.

Situation. Its origin is covered by the orbicularis palpebrarum.

Use. To draw the corner of the mouth and upper lip obliquely upward and outward.

6. Zygomaticus Major — Arises, fleshy, from the os mate, near the zygomatic suture.

Inserted into the angle of the mouth, appearing to be lost in the depressor anguli oris, and orbicularis oris.

Situation. Its origin is partially covered by the orbicularis palpebrarum; it lies more outwardly than the zygomaticus minor.

Use. To draw the corner of the mouth and under lip upward and outward.

7. The Levator Anguli Oris — Arises, thin and fleshy, from a depression of the superior maxillary bone betwixt the root of the socket of the first dens molaris, and the foramen infra-orbitarium.

Inserted, narrow, into the angle of the mouth.

Situation. It lies more outwardly than the levator labii superioris alaeque nasi ; it is in part concealed by that muscle, by the zygomaticus minor, and part of the zygomaticus major. At its insertion it is connected with the depressor anguli oris.

Use. To draw the corner of the mouth upward.

8. The Depressor Anguli Oris — Arises, broad and fleshy, from the lower edge of the inferior maxillary bone, at the side of the chin, and gradually becoming narrower, is

Inserted into the angle of the mouth.

Situation. This muscle is firmly connected with the platysma myoides; at its insertion it is blended with the zygomaticus major and levator anguli oris.

Use. To pull down the corner of the mouth.

9. The Depressor Labii Inferioris — Arises, fleshy and broad, from the side of the lower jaw, a little above its lower edge; it runs obliquely upward and inward, and is

Inserted into the edge of the under lip.

Situation. This muscle, at its insertion, decussates with its fellow. It is in part covered by the depressor anguli oris. It forms the thick part of the chin, and has its fibres interwoven with fat.

Use. To pull the under lip downward.

10. The Buccinator — Arises, tendinous and fleshy, from the lower jaw as far back as the root of the coronoid process ; from the upper jaw, as far back as the pterygoid process of the sphenoid bone; it then continues to arise from the alveolar processes of both jaws, as far forward as the dentes cuspidati. The fibres run forward, and are

Inserted into the angle of the mouth.

Situation. This muscle lies deep, adheres to the membrane that lines the mouth; and a quantity of fat is always found between its fibres and the other muscles

2*

9. 10. 11. 12. 13. 14.

PRACTICAL ANATOMY.

Fig. 1.

Muscles of the Face.

Frontal portion of the Occipito-Frontalis.

Its Posterior or Occipital portion.

Its Aponeurosis.

Orbicularis Palpebrae, which conceals the Corrugator Supercilli, and Tensor Tarsi of Horner.

Pyramidalis Nasi.

Compressor Naris.

Orbicularis Oris.

Levator Labii Superioris Alaeque Nasi.

Levator Labii Superioris.

Zygomaticus Minor.

Zygomaticus Major.

Depressor Labii Inferioris.

Depressor Anguli Oris.

Levator Labii Inferioris.

15. Superficial Portion of the

Masseter.

16. Its Deep Portion.

17. Attrahens.

18. Buccinator.

19. Attollens Auriculae Muscle.

20. Temporal Aponeurosis which

conceals the Temporal Muscle.

21. Retrahens Auriculae Muscle.

22. Anterior Belly of the Digas-

tric — the Tendon is seen passing through the Loop formed by the Cervical Fascia.

23. Stylo-hyoid Muscle.

24. Mylo-hyoid Muscle.

25. Sterno-mastoid Muscle.

26. Upper part of the Trapezius

— the Muscle between 25 and 26 is the Splenius.

and integuments. It is partly concealed by the masseter, and by the muscles which pass to the angle of the mouth, as the levator and depressor anguli oris, and zygomaticus major. It is inserted behind these muscles. In the cheek it is connected with the platysma myoides.

Use. To draw the angle of the mouth backward and outward, and to contract its cavity, by pressing the cheek inward.

The single muscle is the

Orbicularis Oris. — It consists of two planes of semicircular fibres, which decussate at the angles of the mouth. These fibres are formed chiefly by the muscles which are inserted into the lips; they surround the mouth. The superior portion runs along the upper lip, the inferior portion along the under lip.

Situation. It is connected and intermixed with the insertions of all the preceding muscles of the face. Some of the fibres are connected to the septum nasi, and are by Albinus termed Nasalis Labii Superioris.

Use. To shut the mouth by contracting and drawing both lips together.

At this stage of the examination the Facial Artery will be brought into view, a branch of the external carotid mounting over the lower jaw in front of the masseter muscle, passing under the depressor anguli oris and ascending as high as the angle of the eye, where it is called Angular Artery. Its branches, enumerated from below upward, are as follows: Masseter branches to the masseter and buccinator muscles. Inferior Labial to muscles of the lower lip. Inferior Coronary to edge of lower lip. Superior Coronary along the edge of the upper lip. Lateralis Nasi to the ala and septum of the nose. Nerves. — Anterior Dental, some distance back from the symphysis of the lower jaw, comes out of the anterior dental foramen, and is the termination of the inferior maxillary or 3d branch of the 5th pair. Any filaments coming forward from the outer portion of the face are from the portio dura of the 7th pair.

11. Depressor Labii Superioris Al^eque Nasi — Arises, thin and fleshy, from the os maxillare superius, where it forms the alveoli of the dentes incisiva and dens caninus; thence it runs up under part of the levator labii superioris ateque nasi.

Inserted into the upper lip and root of the ala nasi.

Situation. It is concealed by the orbicularis oris and levator labii superioris alaeque nasi. It may be discovered by inverting the upper lip, and dissecting on the side of the frsenum, which connects the lip to the gums.

Use. To draw the upper lip and ala nasi downward and backward.

12. The Levator Labii Inferioris — Arises from the lower jaw at the root of the alveolus of the lateral incisor.

Inserted into the under lip and the skin of the chin.

Situation. Those two small muscles are found by the side of the frsenum of the lower lip. They lie under the depressor labii inferioris.

On the side of the face we observe two strong muscles, and two other muscles are concealed by the angle of the inferior maxilla.

Behind the masseter and overlaying a portion of it is the Parotid Gland (a salivary gland). It is wedged in between the angle and ramus of the jaw and the cartilage of the ear, extending up as high as the zygoma, and down into the neck. Its deep surface rests upon the styloid process of the temporal bone and is insinuated into all the irregularities about this point: its color is pinkish, and consists of lobules held together by cellular tissue. It has no proper capsule, but is covered by the extension of the fascia of the neck. The external carotid artery runs through its substance, giving it many branches, called Parotidean. The Portio Dura, or facial nerve, after it escapes from the stylo-mastoid foramen, passes through it also on its way to the face, and its several branches form a looped connection over the masseter called the Pes Anserinus. From the anterior and upper part, a white canal (sometimes two for a little way) passes forward over the masseter muscle to its anterior edge, beneath which it dips, and, perforating the buccinator, empties into the mouth opposite the 2d molar of the upper jaw. This is the Parotid Duct (duct of Steno). It is accompanied by branches of the portio dura nerve, and the Transverse Facial Artery from the external carotid.

1. The Masseter is divided into two portions, "which decussate one another.

The Anterior Portion arises, tendinous and fleshy, from the superior maxillary bone, where it joins the os malse; from the lower edge of the os malge, and from its zygomatic process. The strong fibres run obliquely downward and backward, and are inserted into the outer surface of the side of the lower jaw, extending as far back as its angle.

The Posterior Portion arises, principally fleshy, from the inferior surface of the os malae, and of the whole of the zygomatic process, as far back as the tubercle before the socket for the condyle of the lower jaw. The fibres slant forward, and are inserted, tendinous, into the outer surface of the coronoid process of the lower jaw.

Situation. The anterior portion conceals almost the whole of the posterior portion. The greater part of this muscle is superficial. Below it is covered by the platysma myoides ; and above, a small portion of it is concealed by the origin of the zygomaticus major.

Use. To pull the lower to the upper jaw, and to move it forward and backward.

2. Temporalis — Arises, fleshy, from a semicircular ridge in the lower and lateral part of the parietal bone, from all the squamous portion of the temporal bone, from the external angular process of the os frontis, from the temporal process of the sphenoid bone, and from an aponeurosis which covers the muscle. From these different origins the fibres converge, descend under the bony jugum formed by the zygomatic processes of the temporal and cheek bones.

Inserted, by a strong tendon, into the upper part of the coronoid process of the lower jaw, to which it adheres on every side, but more particularly its forepart, where the insertion is continued down to near the last dens molaris. If the zygoma is removed, a better view will be had.

Situation. This muscle is of a semicircular shape. It is covered by a fascia or aponeurosis. This fascia adheres to the bones which give origin to the upper part

PRACTICAL ANATOMY.

of the muscle, and descending over it, is inserted into the jugum and adjoining part of the os malse and os frontis. This insertion is by two leaves, leaving a space between containing some fat. The temporalis, at its origin, lies under the expanded tendon of the occipito-frontalis, and under the small tendons which move the external ear. Its insertion is concealed by the jugum and by the masseter; so that, to expose it, the masseter must be cut away.

Use. To pull the lower jaw upward and press it

against the upper.

Fig. 2.

The two Pterygoid Muscles. The Zygomatic Arch and the greater part of the ramus of the lower jaw have been removed, in order to bring these muscles into view.

1. The Sphenoid Origin of the

External Pterygoid Muscle.

2. Its Pterygoid Origin.

3. The Internal Pterygoid Mus-

cle.

In order to expose the following muscles, we must remove the muscles of the cheek and jaw, the masseter and insertion of the temporalis must be taken away, and the coronoid process of the inferior maxilla removed by a saw.

3. The Pterygoideus Externus — Arises from the outer side of the external plate of the pterygoid process of the sphenoid bone, from part of the tuberosity of the os maxillare adjoining to it, and from the root of the temporal process of the sphenoid bone. It passes backward and outward, to be

Inserted into a depression in the neck of the condyloid process of the lower jaw, and into the anterior and inner part of the ligament of the articulation of that bone.

ARTERIES OF THE FACE. 23

Situation. This muscle passes almost transversely from the skull to its insertion. It is concealed by the muscles of the face and neck, and by the ascending processes of the lower jaw.

Use. When this pair of muscles act together, they bring the jaw horizontally forward. When they act singly, the jaw is moved forward, and to the opposite side.

4. The Pterygoideus Internus — Arises, tendinous and fleshy, from the inner and upper part of the internal plate of the pterygoid process of the sphenoid bone, rilling all the space between the two plates ; and from the pterygoid process of the os palati between these plates.

Inserted, by tendinous and fleshy fibres, into the inside of the angle of the lower jaw.

Situation. To expose this muscle, the jaw must be removed from its articulating cavity, and then pulled forward, and toward the opposite side; or it may be sawn across at its symphysis, and the other half removed. It is larger than the pterygoideus externus; and between thetwo muscles there is a considerable quantity of cellular membrane, and the trunk of the Inferior Maxillary and Gustatory Nerves. Like that muscle, it is concealed by the lower jaw and facial muscles. Along its posterior edge, we observe the Ligamentum Laterale Maxillae Inferioris, a ligamentous band, which extends from the back part of the styloid process to the angle of the lower jaw.

Use. To draw the jaw upward, and obliquely toward the opposite side.

Arteries.

The External Carotid is found ascending behind the parotid gland. It perforates the gland at its upper part, ascends over the zygomatic process immediately before the ear, and divides into the anterior, middle, and posterior temporal arteries, which ramify over the side of the head, giving also branches to the forehead and occiput.

PRACTICAL ANATOMY.

The Internal Maxillary passes behind the condyloid process of the lower jaw; it directs its course toward the bottom of the orbit of the eye ; and it is at this point that it sends off its numerous branches. (1) Arteria Media Durje Matris passes through the spinal hole of the sphenoid bone into the cranium, and is distributed to the dura mater. (2) A. Maxillaris Inferior, or Inferior Dental, runs downward, enters the foramen at the root of the ascending processes of the lower jaw, then passes through the canal of the lower jaw; supplying the teeth and sockets, and emerges by the foramen mentale, to be distributed to the chin. It is accompanied by a nerve and one or two veins. (3) A. Pterygoide^e and A. Temporales Profunda are small branches of the internal maxillary which pass to the pterygoid muscles, and to the inner part of the temporal muscle. (4) A. Pharynge^:, branches to the pharynx, palate, and base of the skull. (5) A. Alveolaris, which gives branches to the teeth of the upper jaw, and to the jaw bone itself. (6) A Branch (spheno-palatine) through the foramen spheno-palatinum to the nose; and (7) An Artery through the palato-maxillary canal to the palate.

Fig. 3.

The Internal Maxillary Artery and its Branches.

A. External Carotid Artery.

a. Internal Maxillary Artery.

b. Arteria Tympanica.

c. Arteria Pterygoidea.

Dentalis Inferior.

Arteria Meningea Parva.

Arteria Buccalis.

Arteria Alveolaris, or Maxillaris Superior.

Arteria Meningea Magna.

Infra-Orbitalis.

Anterior Mental Artery.

The continued trunk of the internal maxillary enters the orbit by the spheno-maxillary slit. It sends off a