Audrone R. Biknevicius, Ph.D.Audrone R. Biknevicius, Ph.D.Dept. Biomedical SciencesDept. Biomedical Sciences

Ohio University-Ohio University-College of Osteopathic MedicineCollege of Osteopathic Medicine

Intracranial ContentsIntracranial Contents

Periosteum

EndosteumOsteosacroma of femur in 10 yo malewww.mds.qmw.ac.uk/.../kb/pathology/ funmedpics/pathtes2.htm

Cancellous bone

Cortical bone

Cortical bone

Postcranial Skeleton

New England Journal of Medicinewww.boston.com/news/daily/ 02/carpenter.htm

What is the equivalent “interior” of the skull?

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outer lamina (table)

inner lamina (table)

diploe

Skull

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periosteum

periosteum

endosteum

General Connective

Tissue

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epicranium

endocranium

endosteum

CranialConnective

Tissue

Vertebral column Cranium

Firmly attached Pericraniumto vertebrae - firmly attached to outer

lamina

Endocranium - loosely attached to

inner lamina- continuous with

pericranium at sutures

Periosteum

Spinal Meninges

Pia materArachnoid mater

Dura mater

Brain

Spinalcord

Meninges

Cranial

Spinal

Cranial Meninges

Coronal section through superior sagittal sinus

Spinal meninges Cranial meningesDura* - single-layer - periosteal layer

(=endosteal layer)

- meningeal layer

Arachnoid - trabeculae - trabeculae

Pia - attached to spinal cord - attached to brain

- denticulate ligaments - filum terminale

Meninges

*Note: only dura is pain-sensitive; somatic sensory innervation primarily via trigeminal n.

Vertebral column SkullPeriosteum “Epidural space”Epidural space Dura-periosteal layerDura Dura-meningeal layer

Subdural spaceArachnoid Arachnoid

Subarachnoid spacePia PiaSpinal cord Brain

Superficial

Deep

Meningeal Spaces

Dural Folds

www.yoursurgery.com/ ProcedureDetails.cfm?BR=4&Proc=19

Dural Folds

Tentorium cerebelli

Falx cerebri

Tentorial incisure

Falx cerebri

Falx cerebelli

Tentorium cerebelli

Dural Folds

Falx cerebri

Tentorium cerebelli

Cerebralhemispheres

Cerebellum

Tentorial incisure

Coronal section

www.brain-tumour.net

Dural Venous Sinuses

Stern Essentials of Gross Anatomy

(meningeal layer)(periosteal layer)

Coronal section through falx cerebri & hypophyseal fossa

Dural Venous Sinsuses

Superior sagittal

sinus

Confluence of sinuses

Inferior sagittal

sinus

Straight sinus

Transverse sinus

Sigmoid sinus

Cavernous sinus

Superior & inferior petrosal sinus

Occipital sinus Internal jugular v.

(meningeal layer)

Stern Essentials of Gross Anatomy

Cavernous Sinus•Adjacent to sella turcica (sphenoid bone)

•Envelops: internal carotid a.; oculomotor, trochlear, ophthalmic & maxillary nn.

•Internal drainage: superior & inferior petrosal sinuses

•External drainage (connection with facial v.): pterygoid plexus & inferior ophthalmic v.

Cerebral Veins

Netter Atlas of Human Anatomy

Netter Atlas of Human Anatomy

Subdural (Dural Border) Hematoma

•Accumulation of venous blood between meningeal layer of dura & arachnoid

www.nlm.nih.gov

Commonly due to rupture of cerebral vein

Meningeal Arteries

Netter Atlas of Human Anatomy

anatome.ncl.ac.uk/tutorials/ skulleasy/text/page3.html

Pterion

Sutural intersection formed by:

1. Frontal 2. Parietal3. Squamous temporal4. Greater wing of

sphenoid

• Overlies anterior brs. of middle meningeal a.

Epidural (Extradural) Hematoma

•Accumulation of arterial blood between periosteal layer of dura & calvarium•Most commonly due to rupture of middle meningeal a.

dura

Ventricular System

Leonardo Da Vinci The Anatomy of Man

1489-1490

Cerebrospinal fluid (CSF):

•Clear, odorless fluid

•Resembles plasma butlow protein (<50mg/dL),low cell content (<5/mL)

Ventricles & Choroid Plexus

Netter Atlas of Human Anatomy

Intraventicular Flow of CSF:•Lateral ventricles

•Interventricular foramen(of Monro)

•Third ventricle

•Cerebral aqueduct(of Sylvius)

•Fourth ventricle

Total CSF volume in ventricles: ~25 ml

Netter Atlas of Human Anatomy

CSF exits ventricular system (4th ventricle) via:•Median aperature (foramen of Magendie)

•Lateral aperatures (foramina of Luschka)

Cisterna magna(cerebellomedullary cistern)

Pontine cistern

Total CSF volume in subarachnoid space:~100 ml

Netter Atlas of Human Anatomy

CSF resorption into venous system via arachnoid villi

www.vh.org/.../BrainAnatomy/ Ch2Text/Section02.html

middle meningeal a.

superior sagittal sinus

lacuna lateralis with arachnoid granulations

•Arachnoid granulations = macroscopic collections of arachnoid villi

Netter Atlas of Human Anatomy

NORMAL CONDITION•CSF production=resorption

•Normal CSF pressure (at lumbar cistern; recumbent patient)< 200 mmH2O -or-About 9 mmHg ((higher than normal venous pressure)

Non-Communicating Hydrocephalus

Aqueductal stenosis•CSF obstruction at cerebral aqueduct•Lateral and 3rd ventricles dilates

•Causes: congenital, neoplasm, inflammation, hemorrhage

Animated Ventricular Anatomy

www.csuchico.edu/~pmccaff/syllabi/ SPPA362/362unit11.htmlwww.thirdage.com/health/adam/ imagepage/18009.htm

Arterial supply to CNS

SKULL CHECKOUT - Today @ 5pm (G139)GROSS ANATOMY LAB - Monday afternoon•Slide overview first 10 minutes (begins @ 1:10 & 3:10)•Come prepared to dissect (dissecting tools, including new scalpel blades, & gloves)•No sandals or other open-toe shoes•Bring your skull to lab

Audrone R. Biknevicius, Ph.D.Audrone R. Biknevicius, Ph.D.Dept. Biomedical SciencesDept. Biomedical Sciences

Life Science Building 125 Life Science Building 125 Drop by or office hours by app’tDrop by or office hours by app’t

Vertebral ArterySpinal brs.: posterior & anterior spinal aa.Cranial brs.:

1) Posterior inferior cerebellar aa. 2) Basilar a.

Basilar ArteryCerebellar brs.:

1) Anterior inferior cerebellar a. 2) Superior cerebellar a.3) Labyrinthine a.

Cerebral brs.: Posterior cerebral a.

Internal Carotid Artery1) Ophthalmic a.2) Posterior communicating a.3) Middle cerebral a.4) Anterior cerebral a.

Cerebral Arterial Circle (of Willis)

Anterior Cerebral ArterySuperficial brs.: medial surface of cerebral

hemisphere (except occipital & inferior temporal lobes)

Deep brs.:1) Medial striate a. (recurrent artery of Heubner)

– head of caudate & parts of interior capsule & putamen

2) Other brs: anterior hypothalmus (preoptic and supraoptic regions)

*

Middle Cerebral ArterySuperficial brs.: lateral surface of cerebral

hemisphereDeep brs.:

1) Anterior chroidal a.: choroid plexus of lateral ventricle, globus pallidus, hippocampus, posterior limb of internal capsule

2) Other brs: putamen, caudate, most of anterior limb of internal capsule

*

Posterior Cerebral ArterySuperficial brs.: medial surface of occipital &

inferior temporal lobes

*

Posterior Cerebral ArteryDeep brs.:

1) Posterior choroidal a.: tectum, medial regions of thalamus, choroid plexus of third ventricle

2) Posterior medial group: pituitary, tuber cinereum, hypothalamus, mammillary bodies, anterior and medial parts of thalamus

3) Posterolateral group: lateral and medial genicular nuclei, caudal thalamus, pulvinar, lateral nuclear groups of thalamus