View of a Skull, 1489 by Leonardo Da Vinci. Kaan Yücel M.D., Ph.D Tuesday

Transcription

1 View of a Skull, 1489 by Leonardo Da Vinci Kaan Yücel M.D., Ph.D Tuesday

2 1.SKULL skeleton of the head cranium 22 bones excluding ossicles of the ear

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4 1.SKULL Mandible Lower jaw bone

5 Neurocranium 1.SKULL skeleton of the head Viscerocranium facial skeleton

6 22 bones in the cranium neurocranium Frontal bone- single Occipital bone- single Parietal bones- paired Temporal bones- paired Sphenoid bone- single Ethmoid bone- single

7 1 roof (calvaria) neurocranium 1 floor base (base of the skull) basicranium

8 CALVARIA TEMPORAL BONES PARIETAL BONES parts of the single frontal, sphenoid, & occipital bones CRANIAL BASE mainly parts of the Sphenoid bone Temporal bones Occipital bone

9 BONES OF THE NEUROCRANIUM

10 FRONTAL BONE OS FRONTALE

11 FRONTAL BONE 1. Squama vertical portion region of the forehead 2. Orbital portion frontal orbit/orbita frontalis horizontal portion formation of roofs of the orbital & nasal cavities Squama

12 ANTERIOR VIEW supra-orbital margin of the frontal bone angular boundary between squamous & orbital parts superciliary arches superior to supra-orbital margin & rim of the orbit prominence of these ridges greater in males glabella small depression between superciliary arches

13 ANTERIOR VIEW frontal eminences in some calvaria looks like a square

14 ANTERIOR VIEW Medially frontal bone projects inferiorly forms part of the medial rim of the orbit. Laterally zygomatic process of the frontal bone projects inferiorly forms upper lateral rim of the orbit. articulates with frontal process of the zygomatic bone.

15 ANTERIOR VIEW a persistent frontal suture or remnant of it In some adults Visible in the midline of the glabella Smooth, slightly depressed area between superciliary arches

16 INTERNAL VIEW Sagittal sulcus vertical upper part of the midline squama frontalis Frontal crest formed by the union of the edges of the sagittal sulcus median bony extension of the frontal bone Foramen cecum (blind the base of the frontal crest Nasal process downward projection of the nasal part of the frontal bone terminates as nasal spine

17 PARIETAL BONES OS PARIETALE Two parietal bones unite and form the sides & roof of the cranium. Each bone is irregularly quadrilateral in form.

18 PARIETAL BONES OS PARIETALE Parietal eminence (tuber parietale) an elevation near the centre of the convex and smooth external surface Superior and inferior temporal lines two curved lines crossing the middle of the bone in an arched direction

19 PARIETAL BONES OS PARIETALE Parietal foramen small, inconstant aperture posteriorly in the parietal bone near sagittal suture

20 TEMPORAL BONES OS TEMPORALE Situated at the sides and base of the skull. Contributes most of the lower portion of lateral wall of the cranium.

21 TEMPORAL BONES 3 parts 1. Squamous part 2. Tympanic part 3. Petromastoid part

22 Squamous part of the temporal bone large flat plate, forms the anterior & superior parts of the temporal bone contributes to lateral wall of the cranium articulates anteriorly with greater wing of the sphenoid bone superiorly with parietal bone

23 Squamous part of the temporal bone Zygomatic process anterior bony projection from the lower surface of the squamous part of the temporal bone Zygomatic arch zygomatic process of the temporal bone+temporal process of the zygomatic bone

24 Temporomandindibular joint mandibular fossa concave depression located squamous portion Head of the mandible enters here! articular tubercle downward projection of the anterior border of the mandibular fossa

25 Tympanic part of the temporal bone just below the origin of the zygomatic process External acoustic opening (pore) entrance to the external acoustic meatus (canal) leads to the tympanic membrane (eardrum).

26 Mastoid part of the temporal bone most posterior part of the temporal bone continuous with squamous part anteriorly articulates with parietal bone superiorly occipital bone posteriorly.

27 Mastoid part of the temporal bone mastoid process on the lateral aspect, cone-shaped projection from the inferior surface mastoid notch medial aspect of the mastoid process

28 Petrous part of the temporal bone lateral to the basilar part of the occipital bone between greater wing of the sphenoid anteriorly basilar part of the occipital bone posteriorly.

29 Petrous part of the temporal bone foramen lacerum apex of the petrous part forms one of the boundaries of this foramen. opening for the carotid canal large circular opening posterolateral to the foramen lacerum

30 Petrous part of the temporal bone Anterior surface 1. Arcuate eminence (Eminentia centre of the anterior surface. 2. Tegmen tympani tegmen (covering; covering, cover, protection) anterolateral to arcuate eminence,thin bony roof of the middle ear cavity.

31 Petrous part of the temporal bone Anterior surface 3. Groove for greater petrosal nerve (Sulcus nervi petrosi majoris) anterior to tegmen tympani. 4. Groove for lesser petrosal nerve (Sulcus nervi petrosi minoris) parallel and laterally to the groove for greater petrosal nerve.

32 Petrous part of the temporal bone Anterior surface 6. Trigeminal impression (Impressio trigeminalis) slight depression located medially marks the location of the sensory ganglion for the trigeminal nerve [V].

33 Petrous part of the temporal bone Anterior surface 6. Trigeminal impression (Impressio trigeminalis)

34 CAROTID CANAL 5. Carotid canal (Canalis caroticus) large circular opening posterolateral from the foramen lacerum along the petrous part of the temporal bone.

35 INTERNAL CAROTID ARTERY 1. Internal carotid artery 2. Vertebral artery 3. Cavernous sinus 4. Carotid canal 5. Anterior cerebral artery 6. Posterior cerebral artery

36 Petrous part of the temporal bone Jugular foramen large opening between the occipital bone & petrous vein draining the brain 3 of the 12 cranial nerves pass through here (CNs )

37 Styloid process needle-shaped bone marking projects from the lower border of the temporal bone. anteromedial to the mastoid process point of attachment for numerous muscles and ligaments stylomastoid foramen Transmits the nerve for the muscles of the face Posterior to the base of the styloid process Between styloid process & mastoid process CN VII FACIAL NERVE

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39 SPHENOIDAL BONE OS SPHENOIDALE at the base of the skull in front of the temporal bones 6 basilar part of occipital bone median portion body two great and two small wings extending outward from the sides of the body two pterygoid processes project from it below.

40 SPHENOIDAL BONE OS SPHENOıDALE sphenoidal crests formed by the sharp posterior borders of the lesser wings.

41 saddle-like bony formation on the upper surface of the body of the sphenoid Anterior & posterior clinoid processes

42 Clinoid means «bedpost» 4 processes (2 anterior 2 posterior) surround hypophysial fossa bed of the pituitary gland like the posts of a four-poster bed.

43 composed of three parts 1. tuberculum sellae (horn of saddle) 2. hypophysial fossa (pituitary fossa) 3. dorsum sellae (back of saddle)

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45 on each side of the body,4 foramina perforate the greater wings of the sphenoid Superior orbital fissure between the greater and the lesser wings Foramen rotundum posterior to medial end of the superior orbital fissure Foramen ovale posterolateral to the foramen rotundum Foramen spinosum posterolateral to the foramen ovale

46 Pterygoid processes lateral medial pterygoid plates Pterygoid fossa

47 Optical canal Chiasmatic sulcus

48 foramen magnum OCCIPITAL BONE OS OCCIPITALE at the back and lower part of the cranium cranial cavity communicates with the vertebral canal Major structures passing through spinal cord meninges & spinal cord vertebral arteries anterior & posterior spinal arteries spinal accessory nerve (CN XI)

49 4 parts of the occipital bone arranged around the foramen magnum Squama Basilar part Lateral (condylar) portions

50 external occipital protuberance external occipital crest descends from the protuberance toward the foramen magnum. superior nuchal line marks the superior limit of the neck. extends laterally from each side of the protuberance.

51 occipital condyles Two large lateral parts of the occipital bone Vertebral column-cranium articulation here

52 clivus (Lat., slope) shallow depression, incline behind the dorsum sellæ

53 cruciate eminence divides the interior surface into four fossae cerebral fossae cerebellar fossae internal occipital crest Lower divison of the cross! internal occipital protuberance Centre of the cross!

54 hypoglossal canal for the hypoglossal nerve (CN XII) superior to the anterolateral margin of the foramen magnum

55 superior nuchal line marks the superior limit of the neck. extends laterally from each side of the protuberance. inferior nuchal line less distinct.

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57 ETHMOID BONE Gk, ethmos, sieve sifter, eidos, form Light, spongy, & anterior part of the base of the cranium Between two orbits, at the roof of the nose Contributes to each of these cavities.

58 4 parts 1) A horizontal cribriform plate 2) Perpendicular plate 3) Two ethmoidal labyrinths Crista galli midline ridge Number 3

59 4 parts 1) A horizontal cribriform plate 2) Perpendicular plate 3) Two ethmoidal labyrinths

60 body and lesser wings of the sphenoid bone greater wings of the sphenoid Frontal bone E shallowest X squamous part of the temporal bone petrous part of the temporal bone X: dorsum sellae Occipital bone largest and deepest

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63 CORONAL SUTURE Frontal bones Parietal bones SUTURAE form of articulation margins of bones united by a thin layer of fibrous tissue SAGITTAL SUTURE Parietal bones LAMBDOID SUTURE Parietal bones Occipital bones

64 coronal & sagittal sutures intersect sagittal & lambdoidal sutures frontal, sphenoid, parietal & temporal bones

65 FONTANELLES parietal bones occipital bones anteriorly the junction of lambdoid & sagittal sutures Lambda 1 y old. Closed. halves of frontal bone anteriorly parietal bones the junction of sagittal, corona & frontal sutures Bregma 1.5 y old. Closed.

66 Sphenoidal & mastoid fontanelles fuse during infancy. less important clinically than midline fontanelles

67 Bone which bone Important structures passing through -particularly cranial nerves- A lesion here might result in Carotid canal Temporal Internal carotid artery and nerve plexus Problem in the anterior arterial supply of the brain; as a result; weakness (hemiplegia) and numbness in the face, and extremities on the opposite side of the body, difficulty in speech, visual loss, etc. Foramen magnum Occipital Continuation of brain and spinal cord; vertebral - arteries and nerve plexuses; roots of accessory nerve [XI]; meninges Foramen ovale Sphenoid Third branch of the CN V (Trigeminal nerve): Mandibular nerve [V3] Sensorial loss in the mandibular region of the face Foramen rotundum Sphenoid Second branch of the CN V (Trigeminal nerve): Maxillary nerve [V2] Sensorial loss in the maxillary region of the face Foramen spinosum Sphenoid - - Hypoglossal canal Occipital Hypoglossal nerve [XII] and vessels Loss of movement of the tongue. Internal acoustic meatus Temporal Facial nerve [VII]; vestibulocochlear nerve [VIII] Problems in hearing, balance, or movements of the facial (expression) muscles Jugular foramen Temporal Internal jugular vein; glossopharyngeal nerve - [IX]; vagus nerve [X]; accessory nerve [XI] Optic canal Sphenoid Optic nerve (II) Problems in vision. Stylomastoid foramen Temporal Facial nerve [VII] Loss of movement of the muscles of the Superior orbital fissure Sphenoid Oculomotor nerve (III) Trochlear nerve (IV) Branches of ophthalmic nerve (II) Abducens nerve (VI) face Problems in vision.