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Flashcards in Skull Overview And Meninges Deck (51)
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1
Q

Cranium components

A

Neurocranium and viscerocranium

2
Q

Neurocranium

A

. Cranial vault
. Bony case surrounding brain and its meninges
. Calvarium: sup. Braincase (skull cap, membranous neurocranium)
. Basicranium: cranial base, cartilaginous neurocranium, chondrocranium (floor of braincase)

3
Q

Viscerocranium

A

. Facial skeleton surrounds the openings of oral cavity, nasal cavity, and much of the orbits
.forms primarily in pharyngeal arches from neural crest cells
.

4
Q

Bones in neurocranium

A
. 2 parietal 
. 2 temporal 
. Frontal 
. Sphenoid 
. Ethmoid
. Occipital
5
Q

Viscerocranium

A
. 2 maxillae
. Zygomatics 
. 2 each palatines, lacrimals, nasals 
. 2 inf. Nasal conchae
. Vomer
. Mandible
6
Q

Structure of cranial bones

A

. Bones of skull have inner and outer plates of compact bone
. Spongy bone (diploe) lies btw 2 plates of compact bone that contains marrow
. Compact bone provides strength
. Spongy bone make skull lighter

7
Q

Cranial sutures

A

. Fibrous joint
. Margins of articulating bones interlock along wavy line
. Fuse by adulthood

8
Q

Fontanelles

A

. Fibrous joints
. Wide area of fibrous tissue located btw bones in fetal and newborn skulls
.bones grow toward one another and they close by 18 months old

9
Q

Synchondroses

A

. Articulating bones united by hyaline or fibrous cartilage
. Limited movements are permitted
. Form btw bones that have cartilaginous origin

10
Q

Synovial joints of cranium

A

. Articular surfaces covered w/ articular hyaline cartilage
. Bone surfaces separated from one another by joint cavity
. Temporomandibular joint: modified hinge joint w/ movement in 2 planes
. Joints btw auditory ossicles

11
Q

Cranial cavities

A
. Neurocranium 
. Nasal 
. Oral 
. Orbital 
. Middle ear (tympanic)
12
Q

Paranasal sinuses

A
. Bony-air filled spaces lined w/ mucous membranes 
. Secretions drain into nasal cavity 
. Frontal
. Maxillary
. Ethmoid air cells 
. Sphenoid
13
Q

Frontal bone

A

. Supraorbital foramen transmits supraorbital n. (CN V1) a., and v.
. Orbital plate
. Metopic suture
. Temporal lines continue onto parietal bones, attachment of temporal fascia and temporalis m.

14
Q

Parietal bones characteristics

A

. Sup. Sagittal sinus groove
. Depression for arachnoid granulation located w/in sup. Sagittal sinus groove
. Middle meningeal grooves

15
Q

Maxillae characteristics

A

. Alveolar process
. Infraorbital groove, infraorbital canal, and infraorbital foramen transmit the infraorbital n. (CV V2), a., and v.
. Palatine process

16
Q

Hard palate

A

. Separates oral and nasal cavities
. Forms roof of the oral cavity and floor of nasal cavity
. Formed by palatine processes of maxillae and horizontal plates of palatine bones
. Includes greater and lesser palatine foramina

17
Q

Zygomatic bone

A

. Orbital process
. Malar surface
. Temporal surface
. Temporal process articulates w/ zygomatic process of temporal bone to form zygomatic arch

18
Q

Orbital cavities

A

. Paired orbital cavities house orbits

. Formed by frontal, greater/lesser wings, orbital plate of ethmoid, maxillae, zygomatic, lacrimal, and palatine

19
Q

Superior orbital fissure

A

. Connects cranial and orbital cavities
. Transmits oculomotor n. (CN III), trochlear n. (CN IV), abducens n. (CNVI), branches of ophthalmic n. (CN V1) and sup. Ophthalmic v.

20
Q

Inferior orbital fissure

A

. Connects orbital cavity w/ pterygopalatine fossa, infratemporal and temporal regions
. Transmits maxillary n., infraorbital vessels, branches from pterygopalatine ganglion

21
Q

Optic foramen

A

. Connects orbital and cranial cavities

. Transmits optic n. (CN II) and ophthalmic a.

22
Q

Opening of nasolacrimal duct

A

. Connects orbital cavity and the nasal cavity

. Transmits nasolacrimal duct

23
Q

Piriform (nasal) aperture

A

. External opening into nasal cavities
. Aperture formed by nasal bones and maxillae
. Bony and caritlaginous nasal septum divides nasal cavity into R and L sides
. Nasal conchae: visible as curved bony plates on lat. walls of nasal cavity, covered in nasal mucosa

24
Q

Mandible characteristics

A

. Ramos, body, and angle of mandible
. Alveolar process
. Mental protuberance
. Head (condyle) of mandible: forms part of temporomandibular joint (TMJ)
. Mandibular foramen: transmits inf. Alveolar n. (CN V3), a., and v.
. Mental foramen: transmits mental n. (CN V3), a., and v.

25
Q

Temporal bone characteristic

A

Squamous portion
. Petrous portion
. Tympanic portion
. Zygomatic process
. Mastoid and styloid processes: attachment sites for muscles and ligaments
. External auditory meatus: a bony canal from the outer ear to the tympanic membrane
. Articular eminence
. Mandibular (glenoid) fossa; forms part of TMJ
. Carotid canals: Passage of the internal carotid arteries into the head

26
Q

Occipital bone characteristics

A
Superior nuchal line
. External occipital protuberance
. Spheno-occipital synchondrosis
. Foramen magnum
. Occipital condyle: Convex, joint surfaces for articulation with the C1 vertebra
. Hypoglossal canals (transmit CN XII)
. Jugular foramina: Passage of the internal jugular veins and some cranial nerves out 
of the head
27
Q

Sphenoid bone characteristics

A

. Greater wings form parts of the orbit, basicranium, and sides of the skull
. Lesser wings form parts of the orbit and basicranium
. Optic canal
. Body of
. Med. and lat. pterygoid plates: Paired inf. projections that serve as muscle attachment sites
. Foramen ovale (transmits CN V3)
. Foramen spinosum
. Sphenoid sinus
. Sella turcica
. Hypophyseal fossa holds the pituitary gland
. Dorsum sellae

28
Q

Ethmoid bone characteristics

A
. Cribriform plate with foramina
. Crista galli
. Ethmoid air cells
. Orbital plates of
. Perpendicular plate of
. Middle nasal concha
29
Q

Anterior cranial fossa (ACF)

A

. Supports frontal lobes of brain and forms roof of the orbits
. Composed of the orbital plates of the frontal bone, the lesser wings of the sphenoid, and the cribiform plate

30
Q

Middle cranial fossa (MCF)

A

. Supports temporal lobes of the brain
. Midline part: sella turcica that includes hypophyseal fossa which houses pituitary gland
. Composed of greater wings and body of sphenoid, squamous and petrous portions of temporal bones, and parietal bones

31
Q

Posterior cranial fossa (PCF)

A

. Supports cerebellum, pons, and medulla oblongata of the brain
. Composed of petrous portions of the temporal bones, dorsum sellae of the sphenoid, and basal portion of the occipital bone
. Sloping surface of sphenoid and occipital bone leading to foramen magnum (Clivus)
. Contains internal acoustic meats, jugular foramen, and foramen magnum

32
Q

pia mater

A

. Innermost layer directly adhered to surface of brain

33
Q

Arachnoid mater

A

. Transparent membrane separated from pia mater by subarachnoid space
. Subarachnoid space contains CSF
. Arachnoid trabeculae: thin strands of arachnoid mater that attach to the pia mater
. Arachnoid granulations: tuft-like projections of arachnoid mater that protrude through inner layer of dura and drain CSF into dural venous system

34
Q

Dura mater

A

. Outermost, fibrous layer
. Inner meningeal layer and outer endosteal layer that adheres to inner surface of the skull and forms internal layer of periosteum
. Sensory innervation via trigeminal n., vagus n., and upper cervical spinal nn.
. Blood supply: L/R middle meningeal aa. Arising in the infratemporal fossae and enter the skull through foramina spinosum

35
Q

Dural folds

A

. Inner layer of dura projects into neurocranium cavity forming 4 folds that help support and separate parts of brain

36
Q

Falx cerebri

A

. Sickle-shaped vertical partition that separates cerebral hemispheres in the midline
. Attaches to crista galli ant. And the internal occipital protuberance post.
. Inf. Margin is unattached except post. Where it attaches to tentorium cerebelli

37
Q

Tentorium cerebelli

A

. Wide arched fold that lies in horizontal plane and separates the occipital lobes in the middle cranial fossa from the cerebellum in post. Cranial fossa
. Attaches anterolat. To sphenoid bone, post. To occipital bone along groove for transverse sinuses and in midline to falx cerebri
. Anteromedial. Concave border is unattached, opening btw free edges of tentorium cerebelli is tentorial notch

38
Q

Falx cerebelli

A

. Vertical projection that lies in post. Cranial fossa and separates cerebellar hemispheres
. Attaches to internal occipital protuberance and foramen magnum

39
Q

Diaphragma sellae

A

. Circular horizontal fold located over hypophyseal fossa in the sella turcica
. Central aperture for the stalk of pituitary gland

40
Q

Dural venous sinuses

A

. Endothelium-lined spaces btw layers of cranial dura mater
. Lie btw inner and outer dural layers or btw folded inner layers of dura
. Function as veins enclosed w/in dura
. Carry venous blood from brain and meninges as well as CSF drained from arachnoid granulations
. All dural venous sinuses ultimately drain their contents into internal jugular v. At the jugular foramen

41
Q

Superior sagittal sinus

A

. Lies in midline
. Superior edge of the falx cerebri
. Courses ost. To internal occipital protuberance and then bends to the right to form the right transverse sinus

42
Q

Inferior sagittal sinus

A

. Lies in midline
. Inf. Free margin of falx cerebri
. Courses post. To the junction of the falx cerebri and tentorium cerebelli and drains into straight sinus

43
Q

Straight sinus

A

. Occupies area where tentorium cerebelli and falx cerebri meet
. Courses post. To the internal occipital protuberance where it bends left to form left transverse sinus

44
Q

Paired transverse sinuses

A

. Begin as continuations of the straight and sup. Sagittal sinuses
. Course along post. Attachment of the tentorium cerebelli
. As they leave plane of tentorium cerebelli lat. they curve inf. Along the occipital bone as sigmoid sinuses

45
Q

Paired sigmoid sinuses

A

. Course inferomedially in the post. Cranial fossa to jugular foramina where they form the start of the internal jugular vv.

46
Q

Confluence of sinuses

A

. Dilation near internal occipital protuberance that represents junction of the straight, sup. Sagittal, occipital, and transverse sinuses

47
Q

Paired cavernous sinuses

A

. Lie on either side of the sphenoid body in the middle cranial fossa btw inner and outer layers of dura
. CN III, IV, V1, and V2 course w/in lat. wall of cavernous sinus
. Internal carotid a. And CN VI course w/in the sinus itself
. Sinus receives drainage from various sources including ophthalmic vv.

48
Q

. Epidural hematoma

A

. Lie btw skull and outer layer of dura
. Due to tear in middle meningeal a. Resulting in a slow, localized accumulation of blood that may compress the brain and require aspiration or craniotomy to remove the hematoma

49
Q

Sub dural hematoma

A

. Located in subdural space (potential space)

50
Q

Subdural hematoma

A

. In subdural space, a potential space btw inner layer of dura and arachnoid mater

51
Q

Subarachnoid hemorrhages

A

. Bleed into subarachnoid space

. Common following cerebrovascular accident (stroke)