Scalp Flashcards
How many layers does the scalp have?
5
What do the fused first 3 layers make up?
Scalp proper
The dense CT of the scalp binds the _____ to the _____
- Skin
- Epicranial aponeurosis
What else is the epicranial aponeurosis called?
Aponeurotic layer
Which scalp layer do most of the blood and nerve supply to the scalp travel through?
2nd layer (dense CT layer)
The epicranial aponeurosis is a flat tendinous sheet connecting the bellies of which muscle?
Occipitofrontalis
Occipitofrontalis attachment points
- Superior nuchal line & EOP
- Supraorbital margins (no bony attachments
Which nerve is motor to the occipitofrontalis muscle?
Facial
Why do head wounds bleed so badly?
- Dense CT firmly ensheaths BVs (lacerated vessels can’t retract, thus stay open)
- Transverse wounds are also more serious (the cut severing the muscle/tendon would pull the bellies apart)
Layer of the scalp also known as a “dangerous zone”
Layer 4
What does the porous area of layer 4 of the scalp allow?
- Fluid buildup
- Infections to spread
What do veins in the layer 4 of the scalp allow for?
Communication with the cranial cavity
Where does bleeding in the subaponeurotic space spread?
- Laterally: Temporal line
- Anteriorly: Eyelid
What can bleeding in the subaponeurotic space cause?
Black eye
Nerves responsible for cutaneous innervation of the scalp
- CN V (all 3 branches)
- Cervical plexus C2-C3
Greater occipital nerve origin
Posterior ramus of C2
Third occipital nerve origin
Posterior ramus of C3
Greater auricular nerve origin
Anterior rami, cervical plexus of C2-C3
Lesser occipital nerve origin
Anterior rami, cervical plexus of C2-C3
Supra orbital nerve origin
Ophthalamic nerve (V1)
Supra trochlear nerve origin
Ophthalmic nerve (V1)
Zygomatico Temporal nerve origin
Maxillary nerve (V2)
Auriculotemporal nerve origin
Mandibular nerve (V3)
Nerve to the scalp of occipital region posterior to the vertex
Greater occipital
Nerve to the scalp of lower occipital regions
Third occipital
Nerve to the scalp under the inferior to the auricle
Greater auricular
Nerve to the scalp posterior to the auricle
Lesser occipital
Nerve to the anteriolateral forehead and scalp to the vertex
Supraorbital
Nerve to the medial forehead
Supratrochlear
Nerve to the hairless skin anterior to temporal fossa
Zygomaticotemporal
Nerve to anterior to the auricle and posterior 2/3s of temporal region
Auriculotemporal
Arterial supply of the scalp
- External carotid
- Internal carotid
Venous drainage of the scalp
External jugular
Veins passing through the skull
Emissary veins
What do emissary veins do?
Allow for alternative route for venous sinus
Occipital nerve blood supply
External carotid
Posterior auricular nerve blood supply
External carotid
Superficial temporal nerve blood supply
External carotid
Supraorbital nerve blood supply
Ophthalamic artery
Supratrochlear nerve blood supply
Ophthalamic artery
Scalp of occipital region posterior to the vertex blood supply
External carotid
Scalp of lower occipital regions blood supply
External carotid
Temple to the vertex blood supply
External carotid
Anteriolateral forehead and scalp to the vertex blood supply
Ophthalamic artery
Medial forehead blood supply
Ophthalamic artery
To where do most lymph nodes from the scalp drain?
Deep cervical lymph nodes
Cranial cavity contents
- Brain 🤨
- Meninges
- Dural venous sinuses
- Proximal portions of CNs
- BVs
Cranial fossa divisions
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
Shelf that lies above the orbits
Anterior cranial fossa
The anterior cranial fossa extends back to where?
Lesser wing of sphenoid bone
Middle cranial fossa anterior border
Anterior edge of greater wing of sphenoid
Middle cranial fossa posterior border
Superior ridge of petrous part of temporal bone
Posterior cranial fossa anterior border
Superior border of temporal bone
In the posterior cranial fossa, what does the dorsum sella separate?
Posterior cranial fossa from the hypophyseal fossa
Openings that communicate from the cranial cavity to another cavity
Foramina
