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The SCALP&
Cranial Meninges
done by : C.W.T
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SCALP
The skin & subcutaneous tissue that covers the cranial vault
Extent:
sup. Nuchal lines (post.)
Supraorbital margins (ant.)
Zygomatic arches (lat.)
5 layer:indicated by its letters
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S: Skinthin except?? Occipital part many hair follicles & ? sabaeceous glands rich in bld. Supply
C: Connective tissuethick, dens C.T. septa& fat lobules
rich in bld. Supply
* Bld. Vessels of scalp are running within this layer
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A: Aponeurosis (flat tendon)Epicranial aponeurosisGalea Aponeurotica
strong tendinous sheet
provides attachment for:occipitofrontalis m.& ?? Laterally
To the temporal fascia
*1st 3 layers move together asone unit & called:
Scalp proper
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L: Loose C.T.has many potential spaces
sponge like layer
* allows free movement ofscalp proper over bone.
P: Periosteumouter C.T. layer that surroundsthe bones of calvaria
firmly attached to the bone
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Innervations to The ScalpAnt.:
Supratrochlear & Supraorbital n.(from ?? ) ophthalmic n. (v1)
Lat.:
Zygomaticotemporal n. ( from? ) maxillary n. (v2) Auriculotemporal n. ( from? )
maxillary n. (v2) Post.:
lesser occipital n.(C2, ant. ramus )Greater occipital n.(C2, post. ramus )
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Arteries of The ScalpIn Which Layer?
Ant.:Supratrochlear &Supraorbital a. ( ICA)
Lat.:Superficial temporal a.(ECA )
Post.:Post. Auricular a.
Occipital a.(ECA )
* Scalp is an area of anastomosis between branches of ICA & ECA
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Clinical: Injuries to The Scalp
* The scalp is one of the richest areas of bld. Supply in the body.2 Sources: ECA & ICA
Small inj. to the scalp can result in sever prolonged bleedingDue to:
1. rich blood supply
2. separation of vessel endsby C.T. Septa & the aponeurosis
Rx.: suturing the injury
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Scalp Infections
- Pus or blood spreads easily in The loose connective tissue layerof SCALP (Danger area of scalp)
- Infection or fluid in this layer (pus or bld.) cannot pass posteriorlyor laterally, WHY??
Post.: nuchal lines Lat.: temporal lines
- instead , Infection or fluid in this layer (pus or bld.) can spreadeither:
anteriorly eyelids & root of nose black eye or Ecchymosis
into the cranial cavity through emissary veins meninges
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Dura Mater
most external partdouble layered membrane
2 layers:ext. periosteal layer(periosteum of calvarian bones)
Int. meningeal layer- tough, thick fibrous membrane
continues at F. magnum to SC
* Brain Venous Sinuses are located between periosteal &
meningeal layers of dura
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Dural ReflectionsFoldings of internal meningeal layer between brain compartments
(septa ) to restrict the rotatory displacement of the brain ( fxn. )
4 main reflections:falx cerebri
falx cerebelli
tentorium cerebelli
sellar diaphragm
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Arachnoid Mater
Thin, intermediate layer that attaches to pia mater throughweb-like arachnoid trabeculaeAvascular layer
Held against dura by pressure of CSF
Subarachnoid space:between arachnoid & pia
contains: arachnoid trabeculae & Cerebrospinal fluid ( CSF )
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Pia Mater
Very thin & delicate membrane that is highlyvascularized
Adheres to brain surface & follows its contours
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Meningeal Spaces
Epidural Space:between dura & bonenot present normallyhappens pathologically(as hemorrhage )
Subdural Space:between ? arachnoidmater and dura mater
not present normally
Subarachnoid Space:a real spacecontains CSF
http://en.wikipedia.org/wiki/Arachnoid_materhttp://en.wikipedia.org/wiki/Arachnoid_materhttp://en.wikipedia.org/wiki/Arachnoid_materhttp://en.wikipedia.org/wiki/Dura_materhttp://en.wikipedia.org/wiki/Dura_materhttp://en.wikipedia.org/wiki/Arachnoid_materhttp://en.wikipedia.org/wiki/Arachnoid_materhttp://en.wikipedia.org/wiki/Arachnoid_mater8/2/2019 The SCALP Meninges E-learning
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Arterial Supply to Meninges(Dura & Calvaria)
Middle Meningeal a. & Accessory Meningeal a.:
Main meningeal artery
From?? it is the third branch of the first part (retromandibularpart) of the maxillary artery , the largest branche and one of the twoterminal branches of the external carotid artery
Pass through?? foramen spinosum
2 Anterior meningeal a.:
From ethmoidal a. from ?? from the ethmoidal arterywhich is also come from the theobthalamic a. which is branch of ICC
http://en.wikipedia.org/wiki/Maxillary_arteryhttp://en.wikipedia.org/wiki/External_carotid_arteryhttp://en.wikipedia.org/wiki/Foramen_spinosumhttp://en.wikipedia.org/wiki/Foramen_spinosumhttp://en.wikipedia.org/wiki/External_carotid_arteryhttp://en.wikipedia.org/wiki/Maxillary_artery8/2/2019 The SCALP Meninges E-learning
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4 Post. Meningeal a.:
2 from ascending pharyngeal a.
Pass through ?? one pass through 1.hypoglossal canal and the other from the 2.ugular(at the lower part of petrous part of temporal bone).
& 2 smaller branches from??one from the vertebral a. pass through 3.foramen magnum and thefourth post meningeal a. from the occipital a. which pass through the4.mastoid foramen.
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