Scalp And Cranial Cavity Flashcards
What are the borders of the scalp?
Superior nuchal line of occipital bone and the superior orbital margins if the frontal bone, laterally it extends to the zygomatic arch.
What are the borders of the face?
Is the anterior aspect of the head, from the chin to the forehead, and from ear to ear.
What tissue makes up the scalp and what does each layer house / do?
S C A L P
Skin - outermost layer
Connective tissue (dense) - subcutaneous layer rich in neuromuscular structure
Aponeurotic layer (epicranial aponeurosis) - suturing required here to close gaping wounds
Loose connective tissue - separates first 3 layers with the underling pericranium and Calvaria
Pericranium - external periosteal layer
What structures are contained within the skin layer of the scalp?
Where thickest?
Hair follicles, sweat and sebaceous glands.
It is thickest over the occipital bone
What structures are contained within the dense connective tissue layer of the scalp?
Subcutaneous layer, richly vascularised and with cuntaneous nerves.
What structures are contained within the aperoneurotic layer of the scalp?
Tendon and muscle of the occipitofrontalis
Layer prevents superficial wounds from gaping open. When this is compromised, then sutures are required.
What structures are contained within the loose connective tissue layer of the scalp?
Explain the spaces and the issues caused in this layer
Loose packing material (areolar tissue)
- allows free movement of outer layers over the underlying calvaria
Contains spaces susceptible to distortion with fluid or infection spread
- infection can spread to eyelid or the nose because the frontal belly of occipitofrontalis muscle inserts into skin and tissue not bone
- infection doesn’t spread below zygomatic arch or posteriorly down to the neck due to attachments at superior nuchal line and zygomatic arch
What structures are contained within the pericranium layer of the scalp?
External periosteum of the skull
Periosteum = dense vascular tissue surrounding bone surface other than at joints
What nerve innervates the pink area of the head?
CN V - trigeminal nerve
CNV1 - ophthalmic branch
CNV2 - maxillary branch
CNV2 - mandibular branch
What branches does the ophthalmic nerve (CNV1) give rise to?
Supraorbital
Supratrochlear
Infratrochlear
External nasal
Lacrimal
What branches does the maxillary nerve (CNV2) give rise to?
Zygomaticotemporal
Zygomaticofacial
Infra-orbital
What branches does the mandibular nerve (CNV3) give rise to?
Auriculotemporal
Buccal
Mental
What nerves innervate the green area of the head?
Cervical nerves C2, C3 and C4 - greater occipital nerve and the third occipital nerve
What nerves innervate the yellow area of the head?
Cervical plexus, C3 and C2 with the great auricular nerve
What arteries and their sub divisions supply which areas of the scalp?
Internal carotid artery (supraorbital, supratrochlear) - anterior scalp
External carotid artery (superficial temporal, posterior auricular, occipital) - lateral and posterior scalp
What veins and their sub divisions drain the face and scalp?
Same names as arteries however occipital vein drains to internal vein not external
Internal jugular vein (occipital vein, supratrochlear, supraorbital)
External jugular vein (posterior auricular vein, superficial temporal vein)
What lymphatics drain the scalp?
Posteriorly = mastoid and occipital nodes drain to deep cervical nodes
Anteriorly = pre-auricular and parotid nodes
What are the cranial fossa?
Anterior cranial fossa, middle cranial fossa and posterior cranial fossa
Where are the buttresses on the skull
Frontonasal butress - from area between maxillary canines to the central frontal bone
Zygomatic arch lateral orbital margin butress - molars to lateral frontal and temporal bone
Occipital buttress - transmit forces lateral to foramen magnum down the spinal column
