HEAD AND NECK DR. J.K. GERALD, (MD, MSc.)

HEAD AND NECK The Head The head is formed mainly by the skull with the brain and its covering meninges enclosed in the cranial cavity. The special senses, the eye and the ear, lie within the skull bones or in the cavities bounded by them.

INTRODUCTION TO SKULL Skull: skeleton of the head The skull is divided into two parts; -Cranium/brain box. -Facial skeleton. Several bones join together to form the “cranium”. -Vault - upper part of the cranium -base of the skull - the lowest part of the cranium The skull consists of overall 22 bones.

THE SKULL CONT…. CRANIUM Facial skeleton

THE SKULL CONT….. BONES OF THE CRANIUM Frontal bone: 1 FACIAL BONES: Frontal bone: 1 Parietal bones: 2 Occipital bone: 1 Temporal bones: 2 Sphenoid bone: 1 Ethmoid bone: 1 Zygomatic bones: 2 Maxillae: 2 Nasal bones: 2 Lacrimal bones: 2 Vomer: 1 Palatine bones: 2 Inferior conchae: 2 Mandible: 1

THE CRANIUM

FACIAL BONES

Occipital Bone Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2006. Human anatomy. 5th ed. Pearson Education.

Frontal Bone Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2008. Human anatomy. 6th ed. Pearson Education.

Temporal Bones Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2008. Human anatomy. 6th ed. Pearson Education.

Sphenoid Bone Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2008. Human anatomy. 6th ed. Pearson Education.

Ethmoid Bone Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2006. Human anatomy. 5th ed. Pearson Education.

Mandible Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2006. Human anatomy. 5th ed. Pearson Education.

Zygomatic Bone Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2006. Human anatomy. 5th ed. Pearson Education.

Maxilla Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2008. Human anatomy. 6th ed. Pearson Education.

Palatine Bones Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2008. Human anatomy. 6th ed. Pearson Education.

Vomer Martini, F. H., Timmons, M. J., Tallitsch, R. B. 2006. Human anatomy. 5th ed. Pearson Education.

Inferior Nasal Concha

Lacrimal and Nasal Bone

Hyoid Bone

THE BASE OF THE SKULL CONT… The interior of the base of the skull is divided into three cranial fossae I. Ant. Cranial Fossa – frontal lobes II. Middle Cranial Fossa – temporal lobes III. Post. Cranial Fossa – cerebellum, pons and medula oblongata. The anterior cranial fossa is separated from the middle cranial fossa by the lesser wing of the sphenoid The middle cranial fossa is separated from the posterior cranial fossa by the petrous part of the temporal bone.

OPENINGS STRUCTURES Mastoid foramen emissary v. branch of occipital a. Foramen magnum cruciate lig. tectorial membrane medulla oblongata ant. spinal a. post. spinal a. inf. venous plexus accessory n. Condylar canal emissary v. branch of occipital a Hypoglossal canal hypoglossal n. Stylomastoid foramen facial n. stylomastoid a. Jugular foramen inf. petrosal sinus 9th, 10th, 11th cranial n. sigmoid sinus Mastoid canaliculus auricular branch of vagus n. Tympanomastoid fissure Ext. acoustic meatus

Opening of chorda tympani n. Tympanic canaliculus tympanic branch of glossophryngeal n. Carotid canal int. carotid a. & its plexus of v. sympathetic n. Caroticotympanic canaliculi tympanic branch of int. carotid a. sympathetic n. Squamotympanic fissure Petrotympanic fissure Petrosquamous fissure Semi canal for auditory tube auditory tube Semi canal for tensor tympanic m. tensor tympanic m. Foramen lacerum

Foramen spinosum middle meningeal vessels meningeal branch of mandibular n. Foramen ovale mandibular n. accessory meningeal a Sphenovomerin canal Vomerovaginal canal Palatinovaginal canal phryngeal n. & vessels Pterygoid canal vidian n. Choanae Lesser palatine canal lesser palatine n. & vessels Greater palatine canal greater palatine n. & vessels Pterygomaxillary fissure maxillary n.

Inf. orbital fissure zygomatic n. Alveolar foramina post. & sup. alveolar n. Zygomaticotemporal foramen zygomaticotemporal n. & vessels Infraorbital foramen infraorbital n. & vessels Incisive canal nasopaltine n. Greater palatine a.

THE END

The face Facial vein communicates with the cranial venous sinuses. Thus infection from the face thus can reach the brain. The most dangerous area of the face is between the nasal opening and upper lip but the whole face is overall considered dangerous from the infection point of view.