SKULL SESSION bones rigidly connected by sutures to

SKULL SESSION- bones rigidly connected by sutures to protect brain; attach, move eyes I. CALVARIUM = SKULL CAP- Consists of bones linked by sutures FRONTAL (1)

BONES OF CALVARIUM PARIETAL (2) FRONTAL (1) SPHENOID (1) OCCIPITAL (1) TEMPORAL (2) NOSE

NOSE B. SUTURES 1. CORONAL SUTURE 2. SAGITTAL SUTURE 3. LAMBDOIDAL SUTURE C. LANDMARKS 1. BREGMA - MID POINT OF CORONAL SUTURE 2. LAMBDA - MID POINT OF LAMBDOIDAL SUTURE

D. FONTANELLES – MEMBRANES LINK BONES AT BIRTH 1. ANTERIOR FONTANELLE AT BREGMA - FONTANELLES PERMIT CRANIAL COMPRESSION AT BIRTH - CRANIAL GROWTH 2. POSTERIOR FONTANELLE - AT LAMBDA 3. LATERAL FONTANELLE AT PTERION

CORONAL SUTURE LANDMARKS 3. PTERION - JUNCTION OF TEMPORAL SPHENOID PARIETAL & FRONTAL BONES NOSE

INTRACRANIAL HEMATOMAS 1) EPIDURAL HEMATOMA – meningeal artery, rapid other: 2) SUBDURAL HEMATOMA – venous (bridging vein, sinus), slow 3) SUBARACHNOID HEMATOMA – cerebral artery (or vein) – aneurysm or tear, rapid if arterial

E. INTERNAL STRUCTURE OF CALVARIUM OUTER INNER MIDDLE 1. INNER & OUTER TABLES - HARD CORTICAL BONE MIDDLE LAYER - SOFT SPONGY BONE CALLED DIPLOE (DOUBLE IN GREEK)

2. DIPLOIC VEINS COURSE IN DIPLOE CONNECT BOTH TO CRANIAL CAVITY & SURFACE OF SKULL - CAN TRANSMIT INFECTION FROM SCALP TO BRAIN VIA EMISSARY VEINS

PARIETAL EMISSARY FORAMINA MASTOID EMISSARY FORAMINA

II. LANDMARKS AND BONES 1. FRONT OF SKULL FRONTAL BONE (1) NASAL BONES (2) ORBIT EYE SOCKET NASAL APERTURE ZYGOMATIC BONE (2)FORMS CHEEK MAXILLARY BONE (2)ALVEOLAR PROCESS FOR UPPER TEETH MANDIBLE(1)-ALVEOLAR PROCESS FOR LOWER TEETH

1. FRONT OF SKULL SUPRAORBITAL FORAMEN – IN MAXILLARY BONE ZYGOMATICO-FACIAL FORAMEN – IN ZYGOMATIC BONE INFRAORBITAL FORAMEN - IN MAXILLARY BONE MENTAL FORAMEN- IN MANDIBLE BELOW SECOND PREMOLAR TOOTH

2. LATERAL VIEW OF SKULL ZYGOMATIC ARCH- 1)ZYGOMATIC BONE 2)MAXILLARY BONE- ZYGOMATIC PROCESS 3)TEMPORAL BONE- ZYGOMATIC PROCESS TEMPORAL BONE - PARTS 1)MASTOID PROCESS - hard 2)SQUAMOUS PART- flat 3)TYMPANIC PART - ANT. TO EXTERNAL AUDITORY MEATUS 4)PETROUS PART – inside skull TEMPORO-MANDIBULAR JOINT- FROM RAMUS OF MANDIBLE

4. BASE OF SKULL - COMPLEX HARD PALATE OCCIPITAL CONDYLE FORAMEN MAGNUM C)HARD PALATEPALATINE BONES & PALATINE PROCESS OF MAXILLARY BONES B)OCCIPITAL BONE- HAS FORAMEN MAGNUM- SPINAL CORD; OCCIPITALCONDYLES- FOR C 1 -ATLAS

V. CRANIAL CAVITY- DIVIDED INTO DEPRESSIONS (FOSSAE) ANTERIOR CRANIAL FOSSA (ROOF OF NASAL CAVITY, ORBIT) MI DDLE CRANIAL FOSSA (ORBIT, NASAL CAVITY, FACE) POSTERIOR CRANIAL FOSSA (FACE, ORAL CAVITY, NECK)

ANTERIOR CRAN. FOSSA -FORMED: FRONTAL, ETHMOID, SPHENOID; CONTAINS: CNI (CRIBRIFORM PLATE), FRONTAL LOBES, OLFACTORY BULB MIDDLE CRAN. FOSSA -FORMED: SPHENOID, TEMPORAL, PARIETAL ; CONTAINS: CNII-VI -TEMPORAL LOBES -PITUITARY & BRAIN STEM POSTERIOR CRAN FOSSA FORMED: SPHENOID, TEMPORAL, OCCIPITAL, PARIETAL; CONTAINS - CNVII-XII CEREBELLUM, BRAINSTEM FORAMEN MAGNUM TRANSMITS SPINAL CORD, VERTEBRAL ARTERIES

SKULL SESSION 1: FORAMINA OF INTERIOR OF SKULL AND CRANIAL NERVES Basic facts: 1) Cranial nerves are numbered 1 -12 2) Learn foramina of interior of skull in anteriorposterior sequence; this reflects numbering of cranial nerves

ANTERIOR NOSE CRANIAL NERVES I II III, IV, V 1, VI V 2 V 3 Middle Meningeal A. VII, VIII IX, X, XI XII POSTERIOR

CRANIAL NERVES I. Olfactory II. Optic III. Oculomotor IV. Trochlear V. Trigeminal VI. Abducens VII. Facial VIII. Vestibulo‑cochlear IX. Glossopharyngeal X. Vagus XI. Accessory XII. Hypoglossal

CRISTA GALLI OF ETHMOID OLFACTORY FORAMEN – CN I OLFACTORY NERVE

OPTIC FORAMEN CN II OPTIC NERVE

SUPERIOR ORBITAL FISSURE – CN III, IV V 1, VI OPHTHALMIC VEINS

SELLA TURCICA CAVERNOUS SINUS

VENOUS SINUSES 7. Cavernous sinuses - in middle cranial fossa; on side of the body of the sphenoid bone; connected by Intercavernous sinus; receive blood from Sup. and Inf. Ophthalmic veins, Cerebral veins; drain to Sup. and Inf. Petrosal sinuses 8. Sup. and Inf. Petrosal sinuses - on petrous part of temporal bone Sup. drains to Transverse Inf. Drains to Internal Jugular

FORAMEN ROTUNDUM – CN V 2

FORAMEN OVALE – CN V 3 FORAMEN SPINOSUM

F. BLOOD SUPPLY TO CALVARIUM 1) OUTER SURFACE – ARTERIES TO SCALP 2) INNER SURFACE- MENINGEAL ARTERIES COURSE NEXT TO BONE; MISNAMED - SOUND LIKE SUPPLY MENINGES- MOST BLOOD TO BONES

OPENING OF CAROTID CANAL (FORAMEN LACERUM)

BASE OF CRANIUM FROM EXTERNAL SIDE HARD PALATE OCCIPITAL CONDYLE FORAMEN MAGNUM C)HARD PALATEPALATINE BONES & PALATINE PROCESS OF MAXILLARY BONES B)OCCIPITAL BONE- HAS FORAMEN MAGNUM- SPINAL CORD; OCCIPITALCONDYLES- FOR C 1 -ATLAS

MEDIAL AND LATERAL PTERYGOID PLATES EXTERNAL AUDITORY MEATUS

FORAMEN OVALE FORAMEN SPINOSUM

CAROTID CANAL – OPENS TO FORAMEN LACERUM INSIDE MIDDLE CRANIAL FOSSA

OPENING OF CAROTID CANAL (FORAMEN LACERUM)

INTERNAL CAROTID ARTERY: ENTERS SKULL PASSES THROUGH CAVERNOUS SINUS INTERNAL CAROTID ARTERY

VENOUS SINUSES 7. Cavernous sinuses - in middle cranial fossa; on side of the body of the sphenoid bone; connected by Intercavernous sinus; receive blood from Sup. and Inf. Ophthalmic veins, Cerebral veins; drain to Sup. and Inf. Petrosal sinuses 8. Sup. and Inf. Petrosal sinuses - on petrous part of temporal bone Sup. drains to Transverse Inf. Drains to Internal Jugular

DIAGRAM OF CAVERNOUS SINUS

SYMPATHETICS TO HEAD - First neuron Out T 1, T 2 Ascends Chain

SYMPATHETICS TO HEAD Second neuron In Superior Cervical Ganglia Joins Plexus on Internal and External Carotid Arteries 1) Unnamed branches 2) Few named branches Ex. Deep Petrosal N.

PLEXUS ON INT. CAROTID SUP. CERVICAL GANGLION SYMPATHETIC PLEXUS ON INTERNAL CAROTID ARTERY PATHWAY: - Preganglionic: OUT T 1, T 2 SYMPATHETIC CHAIN - Ascend Sympathetic Chain - synapse in Superior Cervical Ganglion OUT SPINAL CORD T 1, T 2 - Postganglionic: Distributed with Arteries Forms Plexus on Internal and External Carotid Arteries

CAVERNOUS SINUS SYNDROME CAUSES 1) an aneurysm of the internal carotid artery in the cavernous sinus, 2) infection or venous thrombus (blood clot) in cavernous sinus, or by 3) pituitary tumor encroaching into sinus. SPREAD OF INFECTION TO CAVERNOUS SINUS NERVES EFFECTED III, IV, V 1, V 2, and VI and Sympathetic fibers to orbit (travel on Internal Carotid)

CAVERNOUS SINUS SYNDROME SYMPTOMS 1) III - Ocular palsy (impaired eye movement) - Damage III - Dilated pupil (paralyze constrictor) - No pupillary light reflex (paralyze constrictor) - No accommodation (paralyze ciliary muscle) - Ptosis (drooping eyelid, paralyze levator palpebrae superioris) SPREAD OF INFECTION TO CAVERNOUS SINUS 2) V 1, V 2 Facial pain (pressure on nerves) 3) Sympathetics on Internal Carotid Ptosis (drooping eyelid) Miosis (constricted pupil)

INTERNAL AUDITORY MEATUS – VII, VIII

JUGULAR FORAMEN – CN IX, X, XI

HYPOGLOSSAL CANAL – CN XII FORAMEN MAGNUM

CRANIAL NERVES I. Olfactory II. Optic III. Oculomotor IV. Trochlear V. Trigeminal VI. Abducens VII. Facial VIII. Vestibulo‑cochlear IX. Glossopharyngeal X. Vagus XI. Accessory XII. Hypoglossal

OPTIC FORAMEN CN II OPTIC NERVE

FORAMINA OF ORBIT: OPTIC FORAMEN AND CANAL

SUPERIOR ORBITAL FISSURE – CN III, IV V 1, VI, OPHTHALMIC VEINS

SUPERIOR ORBITAL FISSURE INFERIOR ORBITAL FISSURE

2) SUPERIOR ORBITAL FISSURE BETWEEN GREATER AND LESSER WINGS OF SPHENOID, CONTAINS III, IV, V 1, VI, OPTHALMIC VEINS 1) OPTIC CANAL- IN BASE OF LESSER WING OF SPHENOID BONE, CONTAINS OPTIC NERVE & OPHTHALMIC ARTERY NOSE

INFERIOR ORBITAL FISSURE 1) INFERIOR ORBITAL FISSURE- SLIT BELOW SUP. ORBITAL FISSURE: BETWEEN SPHENOID & MAXILLARY - CONNECT PTERYGOPALATINE FOSSA AND INFRATEMPORAL FOSSA WITH ORBIT - CONTAINS INFRAORBITAL AND ZYGOMATIC N. , A. AND V. (V 2, MAXILLARY A. )

BONES OF ORBIT 3. MEDIAL WALL- INCLUDES MAXILLARY, LACRIMAL, ETHMOID, FRONTAL & SPHENOID (NASAL CAVITY IS MEDIAL TO MEDIAL WALL OF ORBIT) FRONTAL SPHENOID ETHMOID LACRIMAL MAXILLARY NOSE

ANTERIOR AND POSTERIOR ETHMOIDAL FORAMINA 2) ANT. & POST. ETHMOIDAL FORAMINA- BETWEEN ETHMOID & FRONTAL BONES CONNECT ORBIT & NASAL CAVITIES CONTAIN ANT & POST ETHMOIDAL N. , A. & V. (V 1 & OPHTHALIC A. )

NASOLACRIMAL DUCT OPENING OF 3) NASOLACRIMAL DUCT- IN MAXILLARY, LACRIMAL BONES & INF. NASAL CONCHA CONTAINS MEMBRANEOUS NASOLACRIMAL DUCT & TEARS NASOLACRIMAL DUCT

OTHER FORAMINA OF ORBIT- SERVES AS PASSAGEWAY FOR NERVES, VESSELS TO FACE, SCALP & NASAL CAVITY 1) SUPRAORBITAL NOTCH OR FORAMEN-IN FRONTAL BONE CONTAINS SUPRAORBITAL N. , A. and V. FROM V 1, OPTHALMIC A. and V. 2) INFRAORBITAL FORAMEN- IN MAXILLARY BONE CONTAINS INFRAORBITAL N. , A. and V. FROM V 2 & MAXILLARY