Visual Apparatus and Orbit: Layers of the Orbit 141

Middle layer of the left orbit (superior aspect). The roof

of the orbit and the superior extra-ocular muscles have

been removed.

Deeper layer of the left orbit (superior aspect). The optic nerve has

now been removed.

28 Ophthalmic artery

29 Superior ophthalmic vein

30 Nasociliary nerve

31 Levator palpebrae superioris muscle

(reflected)

32 Superior rectus muscle (reflected)

33 Lateral branch of supra-orbital nerve

34 Lacrimal nerve and artery

35 Lateral rectus muscle

36 Meningolacrimal artery (anastomosing

with middle meningeal artery)

37 Trochlea

38 Medial branch of supra-orbital nerve

39 Medial rectus muscle

40 Anterior ethmoidal artery and nerve

41 Long ciliary nerve

42 Superior oblique muscle and trochlear

nerve

43 Common tendinous ring

44 Olfactory tract

45 Basilar artery and pons

46 Optic nerve (external sheath of optic

nerve, divided)

47 Ciliary ganglion

48 Ophthalmic nerve (divided, reflected)

49 Inferior branch of oculomotor nerve

and inferior rectus muscle

50 Superior branch of oculomotor nerve

51 Internal carotid artery

142

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Visual Apparatus and Orbit: Lacrimal Apparatus and Lids

Lacrimal apparatus of the left eye.

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Lacrimal apparatus of the

left eye (schematic drawing).

Red = Palpebral portion of the

orbicularis oculi muscle.

Lids and lacrimal apparatus of the left eye. Parts of the

eyelids have been removed to reveal the underlying eyeball.

The maxillary sinus has been opened.

1 Orbicularis oculi muscle

2 Superior lacrimal canaliculus

3 Lacrimal sac

4 Inferior lacrimal canaliculus

5 Nasolacrimal duct

6 Inferior nasal concha

7 Upper eyelid

8 Eyeball

9 Lateral palpebral ligament

10 Infra-orbital artery and nerve

11 Maxillary sinus

12 Lacrimal gland

13 Medial palpebral ligament

14 Aponeurosis of levator palpebrae superioris muscle

15 Palpebral portion of the orbicularis oculi muscle

16 Infra-orbital foramen

17 Palpebral conjunctiva of lower lid

Position of Oral and Nasal Cavities 143

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During evolution, the oral and nasal

cavities of the human head were situated

upon each other, so the human face

developed in the frontal plane. The nasal

cavities are separated by the nasal

septum. They contain three conchae,

where openings to the ethmoidal and

maxillary sinus are located. Posteriorly

the two nasal cavities open into the

nasopharynx through the choanae.

The oral cavity is separated from the

nasal cavity by the palate. When the mouth

is closed, the oral cavity is fully occupied

by the tongue, which is characterized

by its high mobility, necessary for the

development of speech and song. Specific

lymphatic organs (tonsils) are located at

the entrance of the nasopharynx in both

the nasal and oval cavities to protect the

digestive tract from infection. The

respiratory and digestory tracts cross

each other within the nasopharynx, the

most important requirement for the

development of speech.

1 Hypophysis within hypophysial fossa

2 Frontal sinus

3 Middle nasal concha

4 Inferior nasal concha

5 Hard palate

6 Soft palate

7 Pharynx with auditory tube

8 Tongue

9 Pharynx with palatine tonsil

10 Mandible

11 Larynx

Median sagittal section through the head. The palate separates nasal and oral

cavities. The base of the skull forms an angle of about 150° at the sella turcica

(dotted line).

2.4 Oral and Nasal Cavities

Median sagittal section through the head (schematic drawing).

The tongue has been disposed to show the connection of the oral

cavity with the pharynx and the position of the palatine tonsil.

144 Nasal Cavity: Paranasal Sinuses

1 Sphenoidal sinus

2 Superior meatus

3 Middle meatus

4 Tubal elevation

5 Pharyngeal tonsil

6 Pharyngeal orifice of

auditory tube

7 Salpingopharyngeal fold

8 Pharyngeal recess

9 Soft palate

10 Uvula

11 Frontal sinus

12 Spheno-ethmoidal recess

13 Superior nasal concha

14 Middle nasal concha

15 Inferior nasal concha

16 Vestibule

17 Inferior meatus

18 Hard palate

19 Grooves for the middle

meningeal artery and

parietal bone (yellow)

20 Maxillary hiatus

21 Perpendicular process of

palatine bone

22 Openings of ethmoidal air

cells

23 Opening of frontal sinus

24 Medial pterygoid plate (red)

25 Horizontal plate of palatine

process

26 Ethmoidal air cells

27 Maxillary sinus

28 Nasal septum

29 Pterygoid hamulus

30 Nasal bone (white)

31 Frontal process of maxilla

(violet)

32 Palatine process of maxilla

(violet)

33 Nasal atrium

Lateral wall of the nasal cavity. Septum removed.

Bones of left nasal cavity (medial aspect). Schematic diagram showing the position of

paranasal sinuses. Openings indicated by arrows.

Nasal Cavity: Paranasal Sinuses 145

Median section through the head with nasal and oral cavities. The middle and inferior nasal conchae have been partly removed to

show the openings of paranasal sinuses.

Lateral wall of nasal cavity. Openings indicated by red arrows

(schematic drawing).

1 Great cerebral vein (Galen’s vein)

2 Tectum of midbrain

3 Straight sinus

4 Sphenoidal sinus

5 Cerebellum

6 Pharyngeal tonsil

7 Cerebellomedullary cistern

8 Median atlanto-axial joint

9 Spinal cord

10 Oral part of pharynx

11 Falx cerebri

12 Corpus callosum and anterior cerebral

artery

13 Frontal sinus

14 Optic chiasm and pituitary gland

15 Superior nasal concha and ethmoidal

bulla

16 Semilunar hiatus

17 Accessory openings to maxillary sinus

and cut edge of middle nasal concha

18 Vestibule

19 Opening of nasolacrimal duct

20 Inferior nasal concha (cut)

21 Opening of auditory tube

22 Incisive canal

23 Levator veli palatini muscle

24 Salpingopharyngeal fold

25 Lingual nerve and submandibular

ganglion

26 Submandibular duct

27 Nasofrontal duct

28 Nasolacrimal duct

29 Spheno-ethmoidal recess

(of Rosenmüller)

30 Salpingopalatine fold

146 Nasal Cavity: Nerves and Arteries

Nerves of the lateral wall of nasal cavity. Sagittal section through the head.

Mucous membranes partly removed, pterygoid canal opened.

1 Facial nerve

2 Internal carotid artery and

internal carotid plexus

3 Superior cervical ganglion

4 Vagus nerve

5 Sympathetic trunk

6 Optic nerve and ophthalmic

artery

7 Oculomotor nerve

8 Internal carotid artery and

cavernous sinus

9 Sphenoidal sinus

10 Nerve of the pterygoid canal

11 Pterygopalatine ganglion

12 Descending palatine artery

13 Lateral inferior posterior

nasal branches and lateral

posterior nasal and septal

arteries

14 Greater palatine nerves and

artery

15 Lesser palatine nerves and

arteries

16 Branches of ascending

pharyngeal artery

17 Lingual artery

18 Epiglottis

19 Anterior ethmoidal artery

20 Olfactory bulb

21 Olfactory tract

22 Nasopalatine nerve

23 Choanae

24 Frontal sinus

25 Crista galli

26 Anterior ethmoidal artery

and nerve, and nasal branch

of anterior ethmoidal artery

27 Nasal septum

28 Septal artery

29 Crest of nasal septum

30 Hard palate

31 Tentorium cerebelli

32 Trochlear nerve

33 Trigeminal nerve with

motor root

34 Internal carotid plexus

35 Lingual nerve with chorda

tympani

36 Medial pterygoid muscle and

medial pterygoid plate

37 Inferior alveolar nerve

38 Sympathetic trunk

39 Oculomotor nerve

40 Palatine nerves

41 Tongue

42 Trigeminal ganglion

43 Trigeminal nerve (n. V)

44 Facial nerve (n. VII)

45 Geniculate ganglion

46 Stylomastoid foramen

47 Medial pterygoid muscle

Nasal septum. Dissection of nerves and vessels.

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