Intracranial Contents Intracranial Contents Audrone R. Biknevicius, Ph.D. Dept. Biomedical Sciences Ohio University- College of Osteopathic Medicine

Postcranial Skeleton Periosteum Cortical bone Cancellous bone Periosteum Cortical bone Cancellous bone Cortical bone Osteosacroma of femur in 10 yo male www.mds.qmw.ac.uk/.../kb/pathology/ funmedpics/pathtes2.htm Endosteum

www.boston.com/news/daily/ 02/carpenter.htm What is the equivalent “interior” of the skull? New England Journal of Medicine www.boston.com/news/daily/ 02/carpenter.htm

Skull xx xx xx xx xx xx xx xx x x x x x outer lamina (table) diploe Skull xx xx xx xx outer lamina (table) xx xx xx xx diploe x x x x inner lamina (table) x

General Connective Tissue General Connective Tissue xx xx xx xx periosteum xx xx xx xx endosteum x x x x periosteum x

Cranial Connective Tissue Cranial Connective Tissue xx xx xx xx epicranium xx xx xx xx endosteum x x x x endocranium x

Periosteum Vertebral column Cranium Firmly attached Pericranium Periosteum Vertebral column Cranium Firmly attached Pericranium to vertebrae - firmly attached to outer lamina Endocranium - loosely attached to inner - continuous with pericranium at sutures

Spinal Meninges Pia mater Arachnoid mater Dura mater

Meninges Cranial Brain Spinal cord Spinal

Cranial Meninges Coronal section through superior sagittal sinus

Meninges Spinal meninges Cranial meninges Meninges Spinal meninges Cranial meninges Dura* - single-layer - periosteal layer (=endosteal layer) - meningeal layer Arachnoid - trabeculae - trabeculae Pia - attached to spinal cord - attached to brain - denticulate ligaments - filum terminale *Note: only dura is pain-sensitive; somatic sensory innervation primarily via trigeminal n.

Meningeal Spaces Superficial Vertebral column Skull Meningeal Spaces Superficial Vertebral column Skull Periosteum “Epidural space” Epidural space Dura-periosteal layer Dura Dura-meningeal layer Subdural space Arachnoid Arachnoid Subarachnoid space Pia Pia Spinal cord Brain Deep

Dural Folds

Dural Folds Tentorial incisure Falx cerebri Tentorium cerebelli Falx cerebri Tentorial incisure Tentorium cerebelli www.yoursurgery.com/ ProcedureDetails.cfm?BR=4&Proc=19

Dural Folds Falx cerebri Tentorium cerebelli Falx cerebelli

Falx cerebri Tentorium cerebelli Tentorial incisure Falx cerebri Cerebral hemispheres Tentorium cerebelli Tentorial incisure Cerebellum Coronal section www.brain-tumour.net

Dural Venous Sinuses

(periosteal layer) (meningeal layer) (periosteal layer) (meningeal layer) Coronal section through falx cerebri & hypophyseal fossa Stern Essentials of Gross Anatomy

Dural Venous Sinsuses Superior sagittal sinus Inferior sagittal sinus Superior sagittal sinus Inferior sagittal sinus Cavernous sinus Superior & inferior petrosal sinus Straight sinus Sigmoid sinus Confluence of sinuses Occipital sinus Transverse sinus Internal jugular v.

Cavernous Sinus Adjacent to sella turcica (sphenoid bone) 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. (meningeal layer) Stern Essentials of Gross Anatomy

Netter Atlas of Human Anatomy Cerebral Veins Netter Atlas of Human Anatomy

Netter Atlas of Human Anatomy Subdural (Dural Border) Hematoma Netter Atlas of Human Anatomy Commonly due to rupture of cerebral vein Accumulation of venous blood between meningeal layer of dura & arachnoid www.nlm.nih.gov

Netter Atlas of Human Anatomy Meningeal Arteries Netter Atlas of Human Anatomy

Pterion Sutural intersection formed by: Frontal Parietal Sutural intersection formed by: Frontal Parietal Squamous temporal Greater wing of sphenoid Overlies anterior brs. of middle meningeal a. anatome.ncl.ac.uk/tutorials/ skulleasy/text/page3.html

Epidural (Extradural) Hematoma dura Accumulation of arterial blood between periosteal layer of dura & calvarium Most commonly due to rupture of middle meningeal a.

Leonardo Da Vinci The Anatomy of Man 1489-1490 Ventricular System Cerebrospinal fluid (CSF): Clear, odorless fluid Resembles plasma but low protein (<50mg/dL), low cell content (<5/mL) Leonardo Da Vinci The Anatomy of Man

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

(cerebellomedullary cistern) 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 CSF resorption into venous system via arachnoid villi Netter Atlas of Human Anatomy

superior sagittal sinus superior sagittal sinus lacuna lateralis with arachnoid granulations middle meningeal a. www.vh.org/.../BrainAnatomy/ Ch2Text/Section02.html 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 Causes: congenital, neoplasm, inflammation, hemorrhage Aqueductal stenosis CSF obstruction at cerebral aqueduct Lateral and 3rd ventricles dilates

Animated Ventricular Anatomy Animated Ventricular Anatomy

Arterial supply to CNS www.csuchico.edu/~pmccaff/syllabi/ SPPA362/362unit11.html www.thirdage.com/health/adam/ imagepage/18009.htm

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. Dept. Biomedical Sciences Audrone R. Biknevicius, Ph.D. Dept. Biomedical Sciences Life Science Building 125 Drop by or office hours by app’t

Vertebral Artery Spinal brs.: posterior & anterior spinal aa. Vertebral Artery Spinal brs.: posterior & anterior spinal aa. Cranial brs.: Posterior inferior cerebellar aa. Basilar a.

Basilar Artery Cerebellar brs.: 1) Anterior inferior cerebellar a. Basilar Artery Cerebellar brs.: 1) Anterior inferior cerebellar a. 2) Superior cerebellar a. 3) Labyrinthine a. Cerebral brs.: Posterior cerebral a.

Internal Carotid Artery Internal Carotid Artery Ophthalmic a. Posterior communicating a. Middle cerebral a. Anterior cerebral a.

Cerebral Arterial Circle (of Willis)

Anterior Cerebral Artery * Anterior Cerebral Artery Superficial brs.: medial surface of cerebral hemisphere (except occipital & inferior temporal lobes) Deep brs.: Medial striate a. (recurrent artery of Heubner) – head of caudate & parts of interior capsule & putamen Other brs: anterior hypothalmus (preoptic and supraoptic regions)

Middle Cerebral Artery * Middle Cerebral Artery Superficial brs.: lateral surface of cerebral hemisphere Deep brs.: Anterior chroidal a.: choroid plexus of lateral ventricle, globus pallidus, hippocampus, posterior limb of internal capsule Other brs: putamen, caudate, most of anterior limb of internal capsule

Posterior Cerebral Artery * Posterior Cerebral Artery Superficial brs.: medial surface of occipital & inferior temporal lobes

Posterior Cerebral Artery Posterior Cerebral Artery Deep brs.: Posterior choroidal a.: tectum, medial regions of thalamus, choroid plexus of third ventricle Posterior medial group: pituitary, tuber cinereum, hypothalamus, mammillary bodies, anterior and medial parts of thalamus Posterolateral group: lateral and medial genicular nuclei, caudal thalamus, pulvinar, lateral nuclear groups of thalamus