Image Based Question-66769

Nerve passing through canal/ fossa as shown in the Skull photograph (maked by a black arrow) is:

A. Glossopharyngeal Nerve.

B. Hypoglossal Nerve.

C. Cranial Part of Accessory Nerve.

D. Vagus Nerve.

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Correct Answer » B Explanation

Ans:B. Hypoglossal Nerve.

Canal marked in the image is Hypoglossal Canal.

STRUCTURES PASSING THROUGH VARIOUS FORAMINA

Foramen Ovale:

• Mnemonic: MALE

1. Mandibular Nerve (CN V3)
2. Accessory meningeal artery
3. Lesser petrosal nerve
4. Emissary vein (Cavernous sinus to pterygoid plexus)

• Occassionally anterior trunk of middle meningeal vein

Foramen Spinosum

• Mnemonic: MEN

1. Middle meningeal artery and vein (posterior trunk)
2. Emissary vein
3. Nervus spinosus (Meningeal branch of mandibular nerve)

Foramen Lacerum:

• Mnemonic: MEIG
• Structures passing whole length:

1. Meningeal branch of Ascending pharyngeal artery
2. Emissary vein

• Other structures partially traversing:

1. Internal carotid artery
2. Greater petrosal nerve

Carotid Canal:

• Internal carotid artery (ICA) with sympathetic plexus around it, and emissary vein

Foramen Rotundum:

• Maxillary nerve (CN V2)

Stylomastoid Foramen:

1. Facial nerve (CN VII)
2. Posterior Auricular artery (Stylomastoid branch)

Internal Auditory (Acoustic) Meatus:

1. Facial nerve (CN VII)
2. Vestibulo-cochlear nerve (CN VIII)
3. Nerves intermedius or pars intermedia of wrisberg
4. Labyrinthine vessels

Hypoglossal canal:

1. Hypoglossal nerve
2. Meningeal branch of Hypoglossal nerve
3. Meningeal branch of Ascending Pharyngeal artery
4. Emissary vein (Sigmoid sinus to internal jugular vein)

Jugular Foramen:

1. Anterior part: Inferior Petrosal Sinus

2. Middle part:

1. CN IX (Glossopharyngeal nerve)
2. CN X (Vagus nerve)
3. CN XI (Accesory nerve)
4. Meningeal branch of Ascending Pharyngeal Artery

3. Posterior part:

1. Internal Jugular vein (IJV) – Sigmoid sinus junction
2. Emissary vein (Sigmoid sinus to occipital vein)

c. Occipital artery

Mastoid canaliculus (entry) and Tympanomastoid fissure (exit):

• Auricular branch of vagus nerve (Arnold’s nerve or Alderman’s nerve)

Tympanic Canaliculus

• Tympanic branch of (CN IX) Glossopharyngeal nerve ( Jacobson’s nerve)

Incisive Foramen

1. Greater palatine vessels
2. Nasopalatine nerves

Greater Palatine Foramen:

• Mnemonic: GAP (Greater and Anterior Palatine Vessels)

1. Greater Palatine vessels
2. Anterior Palatine nerves

Lesser Palatine Foramen:

• Middle and Posterior Palatine nerve

Superior Orbital Fissure

• Divided into three parts by common tendinous ring of Zinn:-

Middle part (within the ring):

1. Occulomotor nerve (upper/lower division),
2. Nasociliary nerve
3. Abducent nerve

2. Lateral part (above the ring):

1. Trochlear nerve
2. Frontal nerve
3. Lacrimal nerve
4. Superior ophthalmic vein
5. Lacrimal artery (recurrent meningeal branch)
6. middle meningeal artery (orbital branch)
7. Ophthalmic artery ( Meningeal branch)

3. Medial part (below the ring):

1. Inferior ophthalmic vein
2. sympathetic nerves around ICA

Foramen magnum

• Mnemonic: MAVer
• Medulla oblongata
• Ascending parts of spinal accessory nerves
• Vertebral arteries