Skull basic structures. Neurocranium

Transcription

1 doc. MVDr. Květuše Lovásová, PhD. doc. MUDr. Adriana Boleková, PhD. MUDr. Stanislav Matéffy Skull basic structures Skull consists of two groups of bones: neurocranium (bones forming the brain box) splanchnocranium (bones forming the facial skeleton) Neurocranium Frontal bone Squamous part: external surface frontal tuber, glabella, superciliary arch, supraorbital margin, supraorbital notch (supraorbital foramen), frontal notch (frontal foramen), zygomatic process, temporal line Frontal sinus - septum of frontal sinuses internal surface groove for superior sagittal sinus, frontal crest, foramen cecum Orbital part (paired): Fossa for lacrimal gl. (lacrimal fossa), trochlear spine, trochlear fovea, ethmoidal notch, impressions of cerebral gyri (digitate impressions) Nasal part: nasal spine Anterior/posterior ethmoidal foramen (between orbital part of frontal bone and orbital plate of ethmoidal labyrinth of ethmoid) Ethmoidal bone (Ethmoid) Cribriform plate: crista galli - ala of crista galli (paired), cribriform foramina Perpendicular plate Ethmoidal labyrinth (paired): anterior/middle/posterior ethmoidal cells, ethmoidal bulla, orbital plate, supreme/superior nasal concha, middle nasal concha - uncinate process Sphenoidal bone (Sphenoid) Body of sphenoid:

2 sella turcica (Turkish saddle), hypophyseal fossa, dorsum sellae, posterior clinoid process, prechiasmatic sulcus, carotid sulcus, sphenoidal lingula, sphenoidal rostrum, sphenoidal crest, sphenoidal sinus - septum of sphenoidal sinuses, sphenoidal conchae/apertures Lesser wing (paired): jugum sphenoidale (sphenoidal yoke), anterior clinoid process, optic canal Superior orbital fissure Greater wing (paired): cerebral surface impressions of cerebral gyri (digitate impressions), cerebral yokes, foramen rotundum/ovale/spinosum temporal surface infratemporal crest infratemporal surface foramen ovale/spinosum, spine of sphenoid, sulcus of auditory tube orbital surface maxillary surface foramen rotundum Pterygoid process (paired): lateral plate pterygospinous process Pterygoid notch - pterygoid fossa, scaphoid fossa medial plate pterygoid hamulus pterygoid canal (Vidian) Foramen lacerum (after maceration of skull) Temporal bone (paired) Petrous part: apex of petrous part anterior surface trigeminal impression, groove for greater/lesser petrosal n., hiatus for greater/lesser petrosal n., arcuate eminence, tegmen tympani Superior border - groove for superior petrosal sinus posterior surface internal acoustic opening - internal acoustic meatus, subarcuate fossa, external opening of vestibular aquaeduct (vestibular canaliculus), posterior border - jugular notch, groove for inferior petrosal/sigmoid sinus, mastoid foramen Jugular foramen (partially bounded by jugular notch)

3 inferior surface musculotubal canal - septum of musculotubal canal canal for tensor tympani m., canal for auditory tube, carotid canal - caroticotympanic canaliculi, jugular fossa - mastoid canaliculus, external opening of cochlear canaliculus, petrosal fossula - tympanic canaliculus, styloid process, stylomastoid foramen, mastoid process, mastoid notch, occipital groove, mastoid foramen Tympanic part: external acoustic opening - external acoustic meatus, tympanic sulcus Tympanomastoid/tympanosquamous/petrotympanic/petrosquamous fissure Squamous part: zygomatic process, mandibular fossa - articular tubercle, groove for middle temporal a. Parietal bone (paired) frontal/occipital/sphenoid/mastoid angle external surface parietal tuber (parietal eminence), superior/inferior temporal line, parietal foramen internal surface groove for superior sagittal sinus, parietal foramen, groove for middle meningeal a. frontal/occipital/sagittal/squamous border Occipital bone Basilar part: pharyngeal tubercle, clivus, groove for inferior petrosal sinus Lateral part (paired): occipital condyle, hypoglossal canal, jugular tubercle, condylar fossa - condylar canal, jugular notch - intrajugular process, jugular process Jugular foramen (partially bounded by jugular notch) Squamous part: external surface external occipital protuberance, external occipital crest, supreme (highest)/superior/inferior nuchal line internal surface internal occipital protuberance, cruciform eminence, internal occipital crest, groove for superior sagittal sinus, groove for transverse/sigmoid sinus, cerebral/cerebellar fossa Foramen magnum

4 Calvaria (cranial vault) Frontal bone (partially), parietal bones, occipital bone (partially) Splanchnocranium Mandible Body of mandible: base of mandible: mental protuberance - mental tubercle, mental foramen, oblique line, mental spine, digastric fossa, sublingual/submandibular fossa, mylohyoid line alveolar part: alveolar arch, alveolar juga (alveolar yokes), dental alveoli - interradicular septa, interalveolar septa, Angle of mandible masseteric/pterygoid tuberosity Ramus of mandible (paired): coronoid process - temporal crest mandibular notch condylar process - head of mandible, neck of mandible - pterygoid fovea, mandibular foramen - mandibular canal, lingula of mandible, mylohyoid groove Maxilla (paired) Body of maxilla: orbital surface infraorbital groove, infraorbital canal, infraorbital margin anterior surface infraorbital foramen, canine fossa, anterior nasal spine, nasal notch infratemporal surface maxillary tuberosity - alveolar foramina and canals nasal surface lacrimal groove, conchal crest, lacrimal margin, greater palatine groove, maxillary hiatus maxillary sinus: zygomatic/frontal/ /palatine/alveolar recess Processes of maxilla: frontal process anterior lacrimal crest, lacrimal groove, ethmoidal crest alveolar process alveolar arch, juga alveolaria (alveolar yokes), dental alveoli - interradicular septa, interalveolar septa zygomatic process

5 palatine process incisive foramen - incisive canal, incisive suture, median palatine suture - palatine torus, transverse palatine suture, palatine grooves and spines, nasal crest Piriform aperture: bodies and frontal processes of maxillae and nasal bones Zygomatic bone (paired) orbital surface zygomaticoorbital foramen lateral surface zygomaticofacial foramen temporal surface zygomaticotemporal foramen temporal/frontal process Zygomatic arch: zygomatic process of temporal bone and temporal process of zygomatic bone Palatine bone (paired) Horizontal plate: nasal/palatine surface, nasal/palatine crest, posterior nasal spine Perpendicular plate: maxillary surface, nasal surface - conchal/ethmoidal crest, greater palatine groove, pyramidal process - lesser palatine foramina orbital process sphenopalatine notch - sphenopalatine foramen sphenoidal process Greater palatine foramen - greater palatine canal bounded by greater palatine groove of body of maxilla and perpendicular plate of palatine bone Inferior nasal concha (paired) Lacrimal bone (paired) posterior lacrimal crest, lacrimal groove, fossa for lacrimal sac Nasal bone (paired) Vomer Auditory ossicles: malleus (hammer), incus (anvil), stapes (stirrup) part of the middle ear (paired) Hyoid bone: body, greater/lesser horn in the anterior region of the neck Skull cavities On the internal cranial base: Anterior view of the skull: Lateral view of the skull: Anterior/Middle/Posterior cranial fossae Osseous (bony) nasal cavity, Orbit Temporal/Infratemporal/Pterygopalatine fossae

6 Cervical vertebrae (C1 C7) Cervical vertebrae C3 C6 Body: uncal process Arch: Lamina spinous process (bifurcated, C7 vertebra prominens) transverse process transverse foramen (for vertebral a. and v.), anterior tubercle (C6 carotid tubercle) and posterior tubercle, groove for spinal n. superior and inferior articular processes Pedicle superior and inferior vertebral notches (intervertebral foramen) Vertebral foramen triangular shaped Atlas (C1) Lateral mass (paired): superior articular surface joins by occipital condyle inferior articular surface joins by superior articular surface of C2 transverse process, transverse foramen Anterior arch: anterior tubercle, dental fovea joins by dens of axis Posterior arch: posterior tubercle, groove for vertebral a. Vertebral foramen Axis (C2) Body: dens of axis apex of dens, anterior and posterior articular surfaces Arch: Lamina spinous process transverse process anterior and posterior tubercles, transverse foramen, groove for spinal n. superior and inferior articular processes Pedicle superior and inferior vertebral notches (intervertebral foramen) Vertebral foramen Joints of head and neck Unmovable joints of skull Fibrous joints of skull (cranial syndesmoses): Cranial sutures coronal, sagittal, lambdoid, squamous sutures median and transverse palatine sutures

7 Fontanelles (fonticles) anterior, posterior, sphenoidal and mastoid fontanelles Gomphosis (dentoalveolar syndesmosis) Cartilaginous joints of skull (cranial synchondroses): Sphenooccipital synchondrosis disappears in the 18 th year of life Sphenopetrosal and petroocipital synchondroses (permanent) foramen lacerum (after maceration of skull) Osseous joints of skull (cranial synostoses): after ossification of sutures Movable joint of skull Synovial joint - temporomandibular joint Articular disc insertion of lateral pterygoid m. Direct ligaments lateral and medial ligg. Indirect ligaments stylomandibular lig. (angular tract - separates parotid and submandibular gll.) sphenomandibular lig. - protects maxillary a. pterygomandibular lig. (buccopharyngeal raphe) pterygospinous lig. Craniovertebral joints Atlantooccipital joints: anterior atlantooccipital membrane (from anterior longitudinal lig.) tectorial membrane (from posterior longitudinal lig.) posterior atlantoocipital membrane (from ligg. flava) Atlantoaxial joints: median atlantoaxial joint cruciform lig. of atlas, alar ligg., apical lig. of dens lateral atlantoaxial joints Muscles of head Mimetic mm. (muscles of facial expression) i.: facial n. Epicranius m.: complex of muscles attached to epicranial aponeurosis occipitofrontal m. frontal and occipital bellies temporoparietal m. Muscles of auricle: superior, anterior and posterior auricular mm.

8 Muscles of eye slit: orbicularis oculi m. orbital, palpebral and lacrimal parts depressor supercilii m. corrugator supercilii m. procerus m. Muscles of nose: nasalis m. transverse and alar parts depressor septi nasi m. Muscles of oral slit: orbicularis oris m. marginal and labial parts levator labii superioris m. levator labii superioris alaeque nasi m. zygomatic major and minor mm. levator anguli oris m. risorius m. depressor anguli oris m. depressor labii inferioris m. mentalis m. transversus menti m. buccinator m. the only deep muscle of head and the only mimetic muscle covered by fascia, is pierced by parotid duct Masticatory mm. (chewing mm.) innervated by branches of mandibular n. (V/3) masseter m. superficial and deep parts temporalis m. medial pterygoid m. superficial and deep parts lateral pterygoid m. superior and inferior heads (depressor of mandible) Muscles of neck Platysma m. (i.: cervical br. of facial n.) only mimetic m. of neck Sternocleidomastoid m. (i.: accessory n.) - sternal and clavicular parts, between their origins: minor supraclavicular fossa

9 Suprahyoid mm.: digastric m. anterior (i.: mylohyoid n.) and posterior (i: facial n.) bellies stylohyoid m. (i.: facial n.) mylohyoid m. mylohyoid raphe (i.: mylohyoid n.) geniohyoid m. = oral diapdragm (i: hypoglossal n.) Infrahyoid mm.: (i: cervical ansa) sternohyoid m. sternothyroid m. thyrohyoid m. omohyoid m. superior and inferior bellies Scalene mm: (i: anterior brr. of cervical spinal nn.) anterior, middle and posterior scalene mm. Scalene gap (fissure) between anterior and middle scalene mm. and 1st rib for subclavian a. and trunks of brachial plexus Prevertebral mm (deep cervical mm.): (i: anterior brr. of cervical spinal nn.) longus colli m. longus capitis m. rectus capitis anterior and lateral mm. Vessels of head and neck Common carotid a. in carotid sheath with internal jugular v. and vagus n. Right: starts from brachiocephalic trunk (shorter) Left: starts from aortic arch (longer) Carotid bifurcation (level of C3-4, carotid body chemoreceptor for O2 and CO2 External carotid a. Anterior branches: Superior thyroid a. runs medially below hyoid bone infrahyoid br. superior laryngeal a. - pierces thyrohyoid membrane with superior laryngeal n. sternocleidomastoid br. cricothyroid br. glandular brr. anterior and posterior

10 Lingual a. runs medially below hyoglossus m. suprahyoid br. anastomoses with infrahyoid br. of superior thyroid a. dorsal lingual brr. sublingual a. deep lingual a. Facial a. runs medially to stylohyoid m. and posterior belly of digastric m., pierces submandibular gl. and runs to face ventrally to insertion of masseter m. ascending palatine a. for palatine tonsil submental a. accompanies submental v. and mylohyoid n. glandular brr. for submandibular gl. inferior labial a. superior labial a. septal nasal br., lateral nasal a. angular a. anastomoses with dorsal nasal a. (from ophthalmic a.) Medial branch: Ascending pharyngeal a. posterior meningeal a. Posterior branches: Occipital a. runs in the occipital groove medially to mastoid notch Posterior auricular a. stylomastoid a. (into stylomastoid foramen) Terminal branches: Superficial temporal a. in front of auricle accompanied auriculotemporal n. and superficial temporal v. transverse facial a. runs below zygomatic arch zygomaticoorbital a. runs above zygomatic arch middle temporal a. frontal and parietal brr. for anastomosis with ophthalmic and occipital aa. Maxillary a. 3 parts: Mandibular part: between neck of mandible and sphenomandibular lig. inferior alveolar a. with inferior alveolar n. to mandibular canal mylohyoid br., dental and peridental brr., mental br. middle meningeal a. passes through foramen spinosum Pterygoid part: branches for muscles deep temporal aa., masseteric a., pterygoid brr., buccal a.

11 Pterygopalatine part: in pterygopalatine fossa superior posterior alveolar a. into maxillary tuberosity infraorbital a. superior anterior alveolar a. descending palatine a. sphenopalatine a. - nasopalatine a. pterygoid canal a. Internal carotid a. Carotid sinus mechanoreceptors for blood pressure Ophthalmic a. accompanies optic n. into optic canal central retinal a. lacrimal a. lateral palpebral aa. medial palpebral aa. anterior ethmoidal aa. (anterior meningeal a.) and posterior ethmoidal aa. supraorbital a. through supraorbital foramen/notch supratrochlear a. through frontal foramen/notch dorsal nasal a. Subclavian a. Right: from brachiocephalic trunk (shorter) Left: from aortic arch (longer) passes through scalene gap Intrascalenic part: Vertebral a. through transverse foramina C6 C1 Internal thoracic a. through superior thoracic aperture into thoracic cavity Thyrocervical trunk inferior thyroid a. ascending cervical a. with phrenic n. in front of anterior scalene m. suprascapular a. runs up to superior transverse scapular lig. Interscalenic part: Costocervical trunk in scalene gap deep cervical a. spinal brr. supreme intercostal a. for two first intercostal spaces Extrascalenic part: Transverse cervical a. pierces trunks of brachial plexus

12 Superficial veins: External jugular v. from occipital v. and posterior auricular v. receives: anterior jugular v., suprascapular v., transverse cervical v. Anterior jugular v. from submental vv. forms: jugular venous arch or v. mediana coli Deep veins: Internal jugular v. originates from sigmoid sinus, passes through jugular foramen, runs ventrolaterally to common carotid a. in carotid sheath accompanied vagus n. Receives veins from head and neck: retromandibular v. connection of superficial temporal v. and maxillary vv. superficial temporal v. frontal and parietal brr. maxillary vv. from pterygoid plexus facial v. runs straight at the face laterally to facial a. angular v. from supraorbital and supratrochlear vv. deep facial v. connection with pterygoid plexus superior and inferior labial vv. submental v. lingual v. deep lingual v. (for rapid absorption of medicaments) superior and middle thyroid vv. Subclavian v. passes in front of scalene fissure and opens in venous angle receives: external jugular v. Venous angle connection of internal jugular v. and subclavian v. behind sternoclavicular joint Right: receives right lymphatic duct Left: receives thoracic duct Vertebral v., inferior laryngeal v. and inferior thyroid v. open to brachiocephalic v. Lymphatic nodes of head: occipital lnn. mastoid (retroauricular) lnn. parotid lnn. facial (buccal) lnn. submental lnn.

13 submandibular lnn. main lymphatic nodes of head Superficial cervical lnn. anterior and lateral lnn. Deep cervical lnn. along internal jugular v.: jugulodigastric and juguloomohyoid lnn. retropharyngeal lnn. lingual lnn. along transverse cervical vessels: virchow's ln. along accessory n. by cranial, spinal and autonomic nerves Innervation of head and neck Cranial nerves: Olfactory n. (CN I) through cribriform plate of ethmoidal bone Optic n. (CN II) passes through optic canal accompanied ophthalmic a. Oculomotor n. (CN III) passes through superior orbital fissure (for rectus superior, inferior and medialis mm., inferior oblique m., levator palpebrae superioris m.) Trochlear n. (CN IV) passes through superior orbital fissure (for superior oblique m.) Trigeminal n. (CN V) trigeminal ggl. (semilunar ggl.) in trigeminal impression, sensory innervation of head and motor innervation for masticatory mm. Ophthalmic n. (CN V/1) passes through superior orbital fissure, sensory Lacrimal n. Frontal n. supraorbital n.: lateral br. (supraorbital foramen/notch) medial br. (frontal foramen/notch) supratrochlear n. Nasociliar n. anterior ethmoidal n.: medial, lateral, external nasal brr. posterior ethmoidal n. infratrochlear n. Maxillary n. (CN V/2) through foramen rotundum into pterygopalatine fossa, sensory Zygomatic n. zygomaticofacial br., zygomaticotemporal br. Infraorbital n. superior alveolar nn. superior dental plexus

14 pes anserinus minor: inferior palpebral brr. external and internal nasal brr. superior labial brr. Pterygopalatine nn. to pterygopalatine ggl. Mandibular n. (CN V/3) passes through foramen ovale into infratemporal fossa Motor branches: masseteric n., deep temporal, lateral and medial pterygoid nn. n. to tensor tympani, n. to tensor veli palatini Sensory branches: meningeal br. buccal n. auriculotemporal n. lingual n.: communicating br. to chorda tympani Mixed branch: inferior alveolar n. mandibular canal mylohyoid n. motor inferior dental plexus sensory mental n. sensory, through mental foramen Abducent n. (CN VI) passes through superior orbital fissure (for rectus lateralis m.) Facial n. (CN VII) enters internal acoustic pore, leaves stylomastoid foramen Intracranial branches: in petrosal part of temporal bone stapedius n. greater petrosal n. chorda tympani PS + taste fibres for anterior 2/3 of tongue Extracranial branches: posterior auricular n. digastric and stylohyoid brr. intraparotid plexus (pes anserinus major) for mimetic mm.: temporal brr. zygomatic brr. buccal brr. marginal mandibular br. cervical br. Vestibulocochlear n. (CN VIII) into internal acoustic porus, balance and hearing Glossopharyngeal n. (CN IX) through ventromedial part of jugular foramen tympanic n. lesser petrosal n. Jacobson's anastomosis (for parotid gl.)

15 carotid sinus n. from carotid body and sinus pharyngeal br. to pharyngeal plexus tonsillar brr. lingual brr. Vagus n. (CN X) through ventromedial part of jugular foramen, runs into carotid sheath between to common carotid a. and internal jugular v. meningeal br. auricular br. pharyngeal br. to pharyngeal plexus carotid body n. superior laryngeal n. internal br. sensory, pierces thyrohyoid membrane together with superior laryngeal vessels external br. motor (for cricothyroid m.) recurrent laryngeal n.: right loops around subclavian a. left loops around aortic arch superior and inferior cervical cardiac brr. Accessory n. (CN XI) spinal root: from spinal cord through foramen magnum to skull cranial root: from medulla oblongata both roots leave skull through ventromedial part of jugular foramen and split to: internal br. - joins vagus n. external br. - for trapezius and sternocleidomastoid mm. Hypoglossal n. (CN XII) through hypoglossal canal, for motor innervation of all muscles of tongue except of palatoglossus m. Spinal nerves: Cervical plexus anterior brr. of spinal nn. C1 C4 Motor nerves: cervical ansa innervates infrahyoid mm. superior (anterior) root: C1 runs together with hypoglossal n. inferior (posterior) root: C2 C3

16 phrenic n. runs in front of anterior scalene m., innervates diaphragm muscular brr. for deep cervical mm. Sensory nerves from punctum nervorum: transverse cervical n. connection with cervical br. of facial n. lesser occipital n. greater auricular n. accompanies external jugular v. supraclavicular nn. medial, intermediate and lateral nn. Brachial plexus anterior brr. of spinal nn. C5 Th1 Supraclavicular part Trunks: superior, middle, inferior through scalene fissure dorsal scapular n. suprascapular n. long thoracic n. subclavian n. Autonomic nerves: Sympathetic fibres run along vessels. Sympathetic ganglia of neck: superior cervical ggl. (C2 C3) middle cervical ggl. (C6) inferior cervical = cervicothoracic = stellate ggl. (C7) Parasympathetic fibres run inside of cranial nerves. Parasympathetic ganglia of head and neck: ciliary ggl. (CN III) - head pterygopalatine ggl. (CN VII) - head submandibular ggl. (CN VII) - neck otic ggl. (CN IX) - head