Head & Neck

·         The lateral pterygoid muscles, acting bilaterally, protract the jaw and, acting unilaterally, rotate the jaw during chewing. Because the fibers of the superior head of the lateral pterygoid muscle insert onto the anterior aspect of the articular disk of the temporomandibular joint as well as onto the head of the mandible, spasm of this muscle, such as in a yawn, can result in dislocation of the mandible by pulling the disk anterior to the articular tubercle. Reduction is accomplished by pushing the mandible downward and back, so that the head of the mandible reenters the mandibular fossa.

·         Structures passing between skull and superior constrictor muscle ( LEAP is on Top)

1. Levator Palati.

2. Eustachian tube

3. Ascending Palatine Artery (Branch of Facial Artery)

4. Ascending Pharyngeal Artery (br. of ECA)

5. Tensor Palati.

Structures passing between Superior and Middle Pharyngeal Constrictors (SG)

1. Stylopharyngeus

2. Glossopharyngeal Nerve.

Structures Passing between Middle and inferior constrictors (SIL)

1. Superior thyroid artery

2. Internal Laryngeal nerve

3. Laryngeal Artery and Vein.

Structures passing below Inferior Constrictor Muscle (RI)

1. Recurrent Laryngeal Nerve.

2. Inferior Thyroid artery.

·         ICA:

1. Cervical Part                                  :  No branches of ICA in the neck.

2. Petrous part          (PC)                       :  1. Carotico-tympanic artery.

                                                                2. Pterygoid Artery.

3. Cavernous Part        (MISC)             :  1. Cavernous branches

                                                                2. Superior Hypophyseal artery

                                                                3. Inferior Hypophyseal Artery

                                                                4. Meningeal artery.

4. Cerebral Part  (OMAPA)                               :  1. Ophthalmic artery

                                                                2. ACA - ANterior Cerebral Artery.

                                                                3. MCA- Middle Cerebral artery.

                                                                4. Posterior Communicating artery.

                                                                5. Anterior Choroidal Artery

·         Nerve supply of the Tongue

Motor supply :

All the intrinsic muscles, except the palatoglossus are supplied by the hypoglossal nerve. the palatoglossus is supplied by the cranial part of accessory nerve through the pharyngeal plexus .

Sensory supply :

Anterior 2/3rd of the tongue - lingual nerve is the nerve of general sensation and the chordatympani is the nerve of taste for the anterior two-thirds of the tongue .

Posterior 2/3rd of tongue - the glossopharyngeal nerve is the nerve for both general sensation and taste sensation for the posterior 1/3rd of the tongue .

The posterior most part of the tongue is supplied by the vagus nerve through the internal laryngeal branch .

·         You may be able to reduce blood flow to Kiesselbach’s area by holding both sides of the upper lip and also pressing on the incisive foramen. Kiesselbach’s area on the nasal septum is just superior and posterior to the external nasal aperture. Many nosebleeds occur in this area since it is exposed to most of the incoming air.

·         Skull foramen and structures passing through them

1- HYPOGLOSSAL CANAL - hypoglossal nerve

2- INTERNAL CAROTID ARTERY - passes thru both carotid canal and foramen lacerum

3- GREATER PALATINE FORAMEN - anterior palatine nerve

4- LESSER PALATINE FORAMEN - posterior palatine nerve

5- NASOPALATINE NERVE - incisive foramen

6- SUPRA ORBITAL FORAMEN OR NOTCH - supraorbital nerve

7- SUPRA ORBITAL FISSURE - inferior opthalmic vein

8- INFRA ORBITAL FORAMEN - infra orbital nerve

9- ZYGOMATIC NERVE - infra orbital fissure

10- ZYGOMATICO FACIAL FORAMEN - zygomatico facial branch of the sixth nerve

11- OPTIC CANAL - central retinal vein

12 - FORAMEN ROTUNDUM - maxillary division of the trigeminal nerve

13- FORAMEN OVALE - Mandibular nerve, Accessory meningeal artery, Lesser petrosal nerve and missary veins (mnemonic : MALE).

14- FORAMEN SPINOSUM - middle meningeal artery

15- JUGULAR FORAMEN - 9 , 10 , 11 th cranial nerves

16- MASTOID FORAMEN - meningeal branch of occipital artery

17- TYMPANO MASTOID FISSURE - auricular branch of vagus ( vidian r alderman n )

18- FACIAL NERVE - stylomastoid foramen

19- CHORDA TYMPANI NERVE - petro tympanic fissure.

·         Lymphatic drainage of tongue :

1. Tip Of Tongue ------> Submental

2. Ant 2/3rd Lateral Border -----> Ipsilateral Submandibular

3. Ant 2/3rd Centrally -------> Submandibular Nodes On Both Sides

4. Post 1/3rd -------> Upper Deep Cervical Lymph Nodes

5. Final Node To Be Involved -------> Jugulo Omohyoid ------> Deep Cervical

·         Sub Mandibular Gland

Sup. Salivatory Nucleus → Sensory Part of VII N →  Facial Nerve à Chorda Tympani →  Lingual Nà

Sub Mandibular Ganglion →  Gland

·         Parotid Gland

Inferior Salivatory Nucleus → Glossopharyngeal Nerve →  Jacobson’s Nerve →  Tympanic Plexus →  Lesser Superficial Petrosal Nerve →  Ottic Ganglion →  Auriculotemporal Nerve à Parotid Gland

·         Lacrimal Gland

Lacrimatory Nucleus à Sensory Part of Facial N à Facial Nerve à Geniculate Ganglion à Greater Supf. Petrosal Nerve à Joins with deep petrosal Nerve from sympathetic Plexus to form Nerve of Pterygoid Canal/Vidian Nerve à Pterygopalatine Ganglion à Maxillary Nerve à Zygomatico temp oral Nerve à Lacrimal Nerve à LacrimalGland

·         The ciliary ganglion receives preganglionic parasympathetic nerves from the Edinger-Westphal nucleus (cranial nerve III) that synapse in the ciliary ganglion. Those collections of postganglionic parasympathetic nerve cell bodies innervate the sphincter pupillae muscles, which constrict the pupil, closing it during bright-light conditions. The geniculate ganglion houses the pseudounipolar cell bodies that receive taste information from the presulcal (anterior 2/3) of the tongue. The otic ganglia is a parasympathetic ganglia that contains postganglionic parasympathetic nerves to stimulate the parotid salivary gland (preganglionic fibers from cranial nerve IX). The pterygopalatine (sphenopalatine) ganglion contains postganglionic parasympathetic nerves to stimulate the lacrimal gland and glands of the nose and paranasal sinuses (preganglionic parasympathetic fibers from cranial nerve VII). The semilunar (trigeminal) ganglion contains pseudounipolar cell bodies that receive pain, touch and temperature information from the face via the trigeminal nerve. The submandibular ganglion contains postganglionic parasympathetic nerves to stimulate the submandibular and sublingual salivary glands (preganglionic parasympathetic fibers from cranial nerve VII).

·          

 ·         When the parasympathetic fibers to the eyeball are stimulated, the pupil constricts and the ciliary muscle contracts, resulting in a thicker lens and enhanced vision for near objects (accommodation). Dilation of the pupil, contraction of capillaries in the iris, and enhanced ability to see distant objects (flattening of the lens) result from stimulation of sympathetic nerves.

·         The tensor tympani is innervated by the trigeminal nerve, and the stapedius is innervated by the facial nerve.

·         The lingual nerve is joined by the chorda tympani in the infratemporal fossa. Therefore, the lingual nerve contains general somatic afferent (GSA) fibers whose cell bodies are located in the trigeminal ganglion and special somatic afferent (SSA) or taste fibers that have cell bodies located in the geniculate ganglion. In addition, the lingual nerve carries parasympathetic preganglionic general visceral efferent (GVE) fibers that originated from the chorda tympani; the cell bodies are located in the superior salivatory nucleus in the pons. The chorda tympani and lingual nerves contain no fibers from the otic, submandibular, pterygopalatine, or dorsal root ganglia.

·         The nerve of the pterygoid canal (vidian nerve) contains taste (special visceral afferent [SVA]) fibers from the palate, general visceral afferent (GVA) fibers, postganglionic sympathetic fibers, and preganglionic parasympathetic fibers.

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