SUPERFICIAL HEAD & NECK

(Neuro)cranium

• encloses brain

• skull cap = calvaria

• cranial base or floor = basicranium

Viscerocranium

• facial skeleton

  • lower part of orbit & down

Skull landmarks

• glabella

• nasion

• superciliary arch

• sutures

• occiput

• temporal fossa

• pterion

• temparomandibular joint (TMJ)

• zygomatic arch

• hard palate

Glabella

• space between eyes

• glabellar reflex

Nasion

suture between frontal & nasal bone

Superciliary arch

• brow

• more pronounced in males

Sutures

• coronal

• sagittal

• lambdoid

• squamous

Occiput

• back of head

• external occipital protuberance

Temporal fossa

includes temporalis M

Pterion

clinically important part of jaw where 4 bones meet (parietal, sphenoid, temporal, frontal)

• weak point of the skull

• underneath is middle meningeal A

Temparomandibular joint (TMJ)

mandible (jaw) articulates with braincase

Hard palate

palatine process (of maxilla) + palatine

Skull cavities

• cranial cavity

• orbit

• oral cavity

• nasal cavity

• paranasal sinuses: frontal, ethmoidal, maxillary, sphenoid

Cranial fossa

conform to the contours of the brain

• anterior cranial fossa

• middle cranial fossa

• posterior cranial fossa

Scalp

five layers of tissues compose the scalp

• Skin

• CT - dense

• Aponeurosis

• Loose CT

• Pericranium

Scalp proper

scalp layers 1-3

Epicranial aponeurosis

• = galea aponeurotica

• tendinous sheet covering calvaria

Pericranium

• dense CT

• forms external periosteum of calvaria

Superficial face muscles

• muscles of facial expression, sphincters/dilators of orifices

• mainly attached to skin of face

• supplied by facial N (CN VII)

• temporalis, occipital, masseter = not MM of facial expression

Superficial muscles of lateral neck

• platysma

• sternocleidomastoid

• trapezius

Platysma

tenses skin of neck

Sternocleidomastoid

divides neck into anterior & posterior triangles

• bilateral fxn: flexes neck

• unilateral fxn: lateral flexion, rotation of head to opposite side

Muscles of mastication

• masseter

• temporalis

• lateral/medial pterygoid

• innervation: mandibular N (trigeminal N)

Masseter

elevates/protracts mandible

Temporalis

elevates/retracts mandible

Lateral pterygoid

moves jaw side to side

Medial pterygoid

• moves jaw side to side

• protracts mandible

Superficial muscles of anterior neck

• suprahyoid group

• infrahyoid group

Suprahyoid M group

• everything above hyoid group

• elevates hyoid & larynx

• geniohyoid (XII)

• mylohoid (V)

• stylohyoid (VII)

• digastric anterior/posterior belly

• cranial nerves V, VII, XII

Infrahyoid M group

• everything below hyoid bone

• depresses hyoid & larnyx

• sternohyoid

• sternothyroid

• thyrohyoid (XII)

• ansa cervicalis & cranial nerve XII

Salivary glands

• parotid gland

• sublingual gland

• submandibular gland

Parotid gland

• largest salivary gland

• parotid duct

• cranial N IX (glossopharyngeal N)

Parotid duct

• pierces buccinator MM

• empties into upper oral cavity

Sublingual gland

• lies in floor of mouth between mandible & genioglossus M

• sublingual ducts

• cranial N VII (facial N)

Sublingual ducts

opens into floor of mouth

Submandibular gland

• lies inferior to body of mandible

• submandibular duct

• cranial N VII (facial N)

Submandibular duct

empties near lingual frenulum

Teeth

• 32

• tooth formula = (2,1,2,3/2,1,2,3 = incisor, canine, premolar, molar)

• deciduous: (milk teeth) premolars, incisors, canines

• permanents: molars

• cusps: slicing, grabbing, chewing