Thickest layer of the scalp

Contains the hair follicles

Heavily vascularized

Arteries, veins, and nerves of the scalp are located here

Emissary veins connect this layer to the dural venous sinuses, providing channels for infections to spread

Head wounds that pierce the skin and connective tissue layers bleed profusely

Continuous with superficial fascia of the posterior part of the neck

Also called galea aponeurotica

Continuous with the occipitofrontalis m.—anteriorly with the frontalis, posteriorly with the occipitalis

Blends laterally with the temporal fascia

Its surgical manipulation is important in cosmetic surgery

Head wounds that pierce the skin, connective tissue, and aponeurosis layers bleed and gape open from the pull of the 2 bellies of the occipitofrontalis

Skin, connective tissue, and aponeurosis layers are adherent and often called “scalp proper”

Thin and mobile

Helps form a subaponeurotic layer that extends from the eyebrows to the superior nuchal line and external occipital protuberance

Allows substances such as bacteria and blood to pass freely

Separates with scalp avulsion

Exits the orbit at the medial angle accompanied by the supratrochlear n.

Ascends to the scalp at the frontal notch

Anastomoses with the contralateral supraorbital and supratrochlear aa.

Branches from the ophthalmic a. as the artery passes the optic n.

Passes medially to the levator palpebrae superioris and superior rectus mm. to join the supraorbital n.

Passes through the supraorbital foramen (notch) and ascends superiorly along the scalp

Anastomoses with the supratrochlear and superficial temporal aa.

Begins posterior to the neck of the mandible and travels superiorly (terminal branch of the external carotid a.)

Joined by the auriculotemporal n.

Anastomoses with a majority of other branches supplying the scalp

Arises within the parotid gland

Passes superiorly between the mastoid process and the external fibrocartilage of the outer ear

Anastomoses with the superficial temporal and occipital aa.

Branches along the inferior margin of the posterior belly of the digastric and stylohyoid mm.

Hypoglossal n. wraps around it from the posterior part of the vessel, traveling anteriorly

Passes posteriorly along the mastoid process, making a groove on the bone

Pierces the fascia that connects the attachment of the trapezius with the sternocleidomastoid m.

Ascends in the connective tissue layer of the scalp, dividing into many branches

The terminal part is accompanied by the greater occipital n.

Anastomoses with the posterior auricular and superficial temporal aa.

Begins on the forehead, where it communicates with the superficial temporal v.

Passes inferiorly along the forehead parallel with the vein of the opposite side

At the medial angle of the orbit, it joins the supraorbital and the angular v.

Begins on the forehead, where it communicates with the superficial temporal v.

Passes inferiorly superficial to the frontalis m. and joins the supratrochlear v. at the medial angle of the orbit and the angular v.

Descends posteriorly to the zygomatic root of the temporal bone alongside the auriculotemporal n. to enter the substance of the parotid gland

Unites with the maxillary v. to form the retromandibular v.

Begins on the side of the scalp, posterior to the auricle

Passes inferiorly and joins the posterior division of the retromandibular v. to form the external jugular v.

Begins on the posterior portion of the scalp at the vertex

Passes from superficial to deep through the attachment of the sternocleidomastoid m. to the skull

Has a mastoid emissary v. that connects it to the transverse sinus

The vein’s termination is variable, but it usually passes inferiorly to join the internal jugular v.

The frontal nerve passes anteriorly in the orbit after branching from the ophthalmic division of the trigeminal

The frontal nerve divides into supratrochlear and supraorbital nerves

The supratrochlear continues to pass anteriorly toward the trochlea once the supratrochlear a. joins it within the orbit

In the trochlear region, it exits the orbit at the frontal notch

Ascends along the scalp, at first deep to the musculature in the region, before piercing them to reach the cutaneous innervation along the scalp

1 of the 2 terminal branches of the frontal n. in the orbit

Passes between the levator palpebrae superioris m. and periosteum of the orbit

Continues anteriorly to the supraorbital foramen (notch)

At the level of the supraorbital margin, it sends nerve supply to the frontal sinus, skin, and conjunctiva of the upper eyelid

Continues to ascend superiorly along the scalp

Divides into medial and lateral branches, which travel up to the vertex of the scalp

Arises from the zygomatic n. in the pterygopalatine fossa, and passes through the inferior orbital fissure to enter the lateral wall of the orbit and branches into the zygomaticotemporal and zygomaticofacial branches

Passes on the lateral wall of the orbit in a groove in the zygomatic bone, then through a foramen in the zygomatic bone to enter the temporal fossa region

Within the temporal fossa, it passes superiorly between the bone and the temporalis m. to pierce the temporal fascia superior to the zygomatic arch

Passes along the skin of the side of the scalp

Normally arises as 2 roots, between which the middle meningeal a. passes

Runs posteriorly just inferior to the lateral pterygoid and continues to the medial aspect of the neck of the mandible

As it passes posteriorly to the mandible, it provides sensory innervation to the temporomandibular joint

Turns superiorly with the superficial temporal vessels between the auricle and the condyle of the mandible deep to the parotid gland

On exiting the parotid gland, ascends over the zygomatic arch and divides into branches along the scalp

Wraps around and travels superiorly along the posterior border of the sternocleidomastoid

At the skull, it passes through the investing layer of deep cervical fascia and continues superiorly posterior to the auricle to supply the skin in the area

Bone— anterior midline of the maxilla and mandible

Muscular— angle of the mouth where fibers blend with levator anguli oris, depressor anguli oris, zygomaticus major, and risorius mm.

Closes lips

Protrusion of lips

Pursing of lips

Sphincter of the mouth

Muscle fibers encircle the mouth

Angle of the mouth

Some fibers blend and provide origin for the orbicularis oris m.

Elevates the angle of the mouth (e.g., in smiling)

Makes nasolabial furrow more pronounced

Dimples typically are caused by deformities in this muscle (e.g., muscle is bifid)

Also called the “laughing muscle” owing to its action

Lateral upper lip

Some fibers blend and provide origin for the orbicularis oris m.

Alar cartilage of the nose

Lateral upper lip (blending with orbicularis oris and levator labii superioris mm.)

Elevates the upper lip

Dilates the nostril

Lower lip

Fibers blend and provide origin for the orbicularis oris m.

Elevates lower lip

Protrudes lower lip (e.g., when drinking)

Pterygomandibular raphe

Alveolar margins of the maxilla and mandible

Some fibers blend and provide origin for the orbicularis oris

Some fibers blend into the upper and lower lips

Aids in mastication, keeping the bolus between cheek and teeth

Helps forcibly expel air

Helps create a sucking action