(13) Superficial Face & Scalp

skull

28 bones of the head

paired bones of the skull

Parietals

Temporals

Lacrimals

Nasals

Inferior nasal conchae

Maxillae

Palatines

Zygomatics

Mallei

Incudes

Stapedes

unpaired bones of the skull

occipital, sphenoid, frontal, ethmoid, vomer, mandible

frontal bone

bone that forms the forehead. begins as 2 bones that fuse (not always completely) between 3 & 9 months.

metopic suture

the suture between the two ossification centers of the frontal bone. It usually disappears during development but is occasionally present in adults

parietal bone

bone between the frontal and occipital bones and forming the top and sides of the cranium

occipital bone

Bone forming the back and base of the skull.

temporal bone

Bone located at the sides and base of the skull.

sphenoid bone

bone that forms part of the base of the skull and parts of the floor and sides of the orbit

Zygomatic bone

the bone that forms the prominent part of the cheek and the outer side of the eye socket.

maxilla

bone that forms the upper jaw

mandible

bone that forms the lower jaw

nasal bone

bone that forms the bridge of the nose

lacrimal bone

bone making up part of the front inner walls of each eye socket

superior temporal line

the top of 2 faint lines along the lateral sides of the skull. upper attachment of fascia temporalis.

inferior temporal line

the bottom of 2 faint lines along the lateral sides of the skull. attachment of temporalis muscle

external occipital protuberance

Bump in the back of the head on the occipital bone. Attachment of nuchal & trapezius.

squamous part of temporal bone

disc-like part of temporal bone that makes up the lateral wall of the brain case

petrous part of temporal bone

Thick section of the temporal bone that covers inner ear structures.

mastoid process of temporal bone

projection of the temporal bone behind the ear

greater wing of sphenoid bone

part of sphenoid bone that forms a small area of lateral wall of brain case

pterion

Junction of frontal, parietal, sphenoid, and temporal bones. Weakest portion of brain case, and therefore the most likely area for fracture.

orbit

opening in the skull for the eyeball

piriform aperture

opening in the skull for the nasal canal

external auditory meatus

opening in the skull for the ear canal

foramen magnum

opening in the base of the skull in the occipital bone through which the spinal cord passes.

supraorbital foramen (if complete)/notch (if incomplete)

opening above each orbit allowing the passage of CN V1 and blood vessels

infraorbital foramen

opening under the orbit allowing the passage of CN V2 and blood vessels

mental foramen

Opening in the mandible allowing the passage of CN V3 and blood vessels.

palatine bone

bone that forms the posterior part of the hard palate

vomer

bone that forms the inferior portion of the nasal septum

syloid process

pole-like process extending downward from the temporal bone that serves as an attachment point for multiple muscles

occipital condyle

ridges on left and right of foramen magnum where the occipital bone articles with the atlas

foramen ovale

opening in the inferior medial sphenoid bone that allows the passage of CN V3

foramen spinosum

opening adjacent to the sphenoid spine

stylomastoid foramen

opening located on inferior skull, between the styloid process and mastoid process, that allows the passage of CN VII

jugular foramen

Opening medial to the styloid process through which the internal jugular vein passes

carotid canal

Opening medial to the styloid process through which the internal carotid artery passes into the cranial cavity

foramen lacerum

opening at junction of sphenoid, temporal, and occipital bones containing cartilage left over from ossification of skull base during development. Not a true opening in a living person.

Total Teeth in Adult

32 teeth. Each bilaterally symmetrical quadrant (left/right, upper/lower) has 2 incisors, 1 canine, 2 premolars, and 3 molars (although many people have their 3rd molars removed, in which case there are 28 teeth).

cranial nerves

12 pairs of nerves arising from the brain. Each is different, and may carry somatic motor, somatic sensory, visceral sensory, parasympathetics, and/or special sensory fibers.

*Sympathetic innervation does not originate within a CN but may "hitchhike"

blushing

sympathetic response unique to head and neck

Generalizations about cranial sympathetics

- Originate from T1 & T2 levels of spinal cord

- Sympathetics in head are postganglionic, with synapse occurring in cervical ganglia

- Postganglionic fibers are distributed along branches of internal and external carotid arteries, but may hitchhike on some cranial nerves

- Function to activate sweat secretion & dilate blood vessels (blushing)

superior cervical ganglion

C1-C4 levels. Highest ganglion in sympathetic chain.

middle cervical ganglion

C5-C6 levels

inferior cervical ganglion

C7-C8 levels

cranial nerves that carry preganlionic parasympathetics

1. Oculomotor Nerve (CNIII)

2. Facial Nerve (CN VII)

3. Glossopharyngeal Nerve (CN IX)

4. Vagus Nerve (CN X)

Preganglionic parasympathetics in the head synapse in

dissectible ganglia

*(Vagus is the exception)

Cranial parasympathetic ganglia

Ciliary Ganglion, Otic Ganglion, Pterygopalatine Ganglion, and Submandibular Ganglion. All are suspended by branches of the trigeminal nerve (CN V)

ciliary ganglion

one of the terminal ganglia of the parasympathetic system, located in the posterior orbit. Connected to ophthalmic nerve (V1), with preganglionics from CN III.

pterygopalatine ganglion

one of the terminal ganglia of the parasympathetic system, ending at the lacrimal and nasal glands. Connected to the maxillary nerve (V2), with preganglionics from CN VII.

otic ganglion

one of the terminal ganglia of the parasympathetic system, located in the parotid gland. connected to the mandibular nerve (V3), with preganglioncs from CN VII.

submandibular ganglion

one of the terminal ganglia of the parasympathetic system, located beneath the mandible. Connected to the mandibular nerve (V3), with preganglioncs from CN IX.

somatic sensation of the face

sensations of pain, temperature, touch, & pressure in the face and conjunctive.

Trigeminal Nerve (CN V)

provides somatic sensory innervation to the face & conjunctiva, and some somatic motor innervation. 3 divisions: Ophthalmic, Maxillary, Mandibular.

Ophthalmic Division of CN V (V1)

provides somatic sensation to the forehead, top of scalp, bridge & tip of nose, eye, & eyelid. branches into the supratrochlear nerve & supraorbital nerve.

Supratrochlear nerve

branch of the ophthalmic division of CN V that provides somatic sensation to the skin between the eyes and upper side of the nose. emerges above the trochlea.

Supraorbital nerve

branch of the ophthalmic division of CN V that provides somatic sensation to the forehead, scalp, eyebrow, and upper eyelid. Passes through the supraorbital foramen.

Maxillary Division of CN V (V2)

provides somatic sensation to the upper lip, nostril, lower eyelid, & a narrow strip up the side of the head. branches into the infraorbital nerve.

infraorbital nerve

branch of the maxillary division of CN V that provides somatic sensation to the skin of the lower eyelid, side of the nose, upper lip, and mouth. passes through the infraorbital foramen.

Mandibular Division of CN V (V3)

Provides somatic sensation to the Lower lip, chin, external ear, & side of face. Branches into the Long Buccal nerve, auriculotemporal nerve, and mental nerve.

long buccal nerve

branch of the maxillary division of CN V that provides somatic sensation to the cheek

Auriculotemporal nerve

branch of the mandibular division of CN V that provides somatic sensation to the side of the head

mental nerve

branch of the maxillary division of CN V that provides somatic sensation to the lower lip and chin

facial muscles insert on

skin/superficial fascia

occipitof

muscle of facial expression composed of frontalis and occipitalis

frontalis

facial muscle that raises eyebrows & wrinkles forehead. attaches to skin below eyebrows.

occipitalis

facial muscle that pulls scalp posteriorly. attaches to back of scalp

epicranial aponeurosis

Tendon that connects the occipitalis and frontalis muscles

corrugator supercilii

facial muscle that wrinkles skin between eyes

orbicularis oculi

facial muscle surrounding the eyes that has an orbital part and a palpebral part

orbital part of orbicularis oculi

facial muscle that closes eye forcefully. over skin of orbital margin.

palpebral part of orbicularis oculi

facial muscle that gently closes eyelids (such as in blinking). lies directly on eyelid.

orbicularis oris

facial muscle that closes and puckers lips. surrounds opening of mouth.

levator labii superioris

facial muscle that elevates upper lip. originates just below orbit & inserts on upper lip.

zygomaticus major

facial muscle that pulls corner of mouth posterosuperiorly (as in a smile). originates from zygomatic bone, inserts on corner of mouth. If bifid, 1 part inserts into side of cheek & creates a dimple.

Buccinator

Deepest facial muscle that keeps cheek taut & keeps food positioned during chewing. Embedded in inner cheek. Not associated with a facial expression. Attached to pterygomandibular raphe on 1 end and orbicularis oris on the other. Covered by a pad of buccal fat.

pterygomandibular raphe

Fold of tissue that extends from the junction of the hard and soft palates down to the mandible

depressor anguli oris

facial muscle that pulls corner of mouth inferiorly (as in a frown)

Platysma

broad sheet of muscle that tenses skin of the neck & pulls the lower part of the face downward. Covers most of anterior neck, from clavicle inferiorly to mandible superiorly.

wrinkles

lines on skin of face that occur with age due to facial muscle insertion on skin. Form perpendicular to muscle fiber direction.

Facial Nerve (VII)

conveys somatic motor innervation to all muscles of facial expression. exits skull through stylomastoid foramen. Branches: temporal, zygomatic, buccal, mandibular, cervical, posterior auricular.

temporal branch of facial nerve

superior most branch of facial nerve

zygomatic branch of facial nerve

branch of facial nerve that runs along upper cheek

buccal branch of facial nerve

branch of facial nerve that runs to the mouth

mandibular branch of facial nerve

branch of facial nerve that runs along the chin and lower lip

cervical branch of facial nerve

most inferior branch of facial nerve

posterior auricular branch of facial nerve

branch of facial nerve that runs posterior behind ear

parotid plexus

formed by the split of the temporal, zygomatic, buccal, mandibular, & cervical branches of the facial nerve. lies in parotid gland, although facial nerve does not innervate this.

Bell's Palsy

paralysis of the facial nerve, causing muscular weakness in one side of the face. eye will remain open, so people often have to wear an eyepatch.

botox works by

paralyzing branches of the facial nerve

parotid gland

salivary gland within the cheek just anterior to the ear that receives parasympathetic innervation via the Glossopharyngeal Nerve (CN IX)

parotid duct

Duct leading from the parotid gland over the masseter, through the buccinator & into the mouth, opening adjacent to the upper second molar

masseter

main muscle of chewing

parotid papilla

a flap of tissue on the mucosa opposite the maxillary second molar where the parotid gland drains

layers of the scalp

Skin, Connective Tissue (dense), Aponeurosis (galea aponeurotica), Loose connective Tissue, Pericranium (periosteum)

common carotid artery

Artery that supplies blood to the face, head, and neck. Branches into internal & external carotid.

internal carotid artery

branch of the common carotid that enters the skull, although 2 branches (supraorbital artery & supratrochlear artery) are superficial.

supraorbital artery

branch of the internal carotid that supplies blood to the upper eyelid and forehead

supratrochlear artery

branch of the internal carotid that supplies blood to the forehead region.