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Flashcards in Skull Deck (62):
1

Layers of Scalp (superficial-deep)

Skin
Connective tissue - dense
Aponeurosis - galea aponeurotica
Loose connective tissue
Pericranium - periosteum

2

Galea Aponeurotica

Aponeurosis connecting frontalis and occiptalis muscle

3

Pericranium

Connective tissue structure sitting right outside skull

4

2 Clinical Considerations of Scap

Dense connective tissue layer - lots of blood vessels and can't fall back self, so head wounds are gaping holes with lots of blood
Loose connective tissue layer - "danger area of scalp," can spread infections across entire scalp area and occasionally into brain

5

5 Arteries to Scalp (+ source/path)

Occipital - ext. carotid, back of skull
Posterior auricular - ext. carotid, behind ear
Superficial temporal - ext. carotid, in front of ear
Supraorbital - int. carotid, side of nose/eye socket
Supratrochlear - int. carotid, just medial to supraorbital a.

6

Anastomosis b/w External and Internal Carotid A.s

Supraorbital + supratrochlear (internal carotid) and superficial temporal (ext. carotid)

7

6 Innervators of Scalp (and source/roots) (post-ant)

Greater occipital n. - cervical n., C2/3
Lesser occipital n. - cervical n., C2/3
Auriculotemporal n. - trigeminal n., V
Zygomaticotemporal n. - trigeminal n., V
Supraorbital n. - trigeminal, V
Supratrochlear n., - trigeminal, V

8

Fontanels

Soft spots in newborns to allow cranial growth

9

Flat Bone Structure (3)

Outer table, diploe marrow space, inner table

10

Skull Bone Structure

22 bones make up skull
Flat bone
Formed by mesenchymal, NOT endochondral bone growth

11

Foramina

Allow passage of nerves/vessels in and out of skull

12

3 Depressions in Base of Skull

Anterior, middle, and posterior fossa

13

Crista galli

Ridge along midline of anterior fossa where dura mater attaches

14

Cribiform plate of ethmoid bones

Holey region around crista galli in anterior fossa where CN I sends its nerve fibers through

15

Sella turcica

"Saddle" structure in medial part of middle fossa where pituitary gland sits

16

Superior orbital fissure

Just anterior/lateral to sella turica, carries nerves and vessels into/out of orbit

17

Orbital Canal

Space b/w sella turcica and superior orbital fissure that carries optic n. (II) in/out of orbit

18

3 Foramen of Middle Fossa (anteromedial-posterolateral)

Foramen rotundum, ovale, and spinosum

19

Carotid canal

Posteromedial to 3 foramen of middle fossa, where internal carotid a. runs

20

Trigeminal Impression

On lateral wall of sella turcica in middle fossa, site of trigeminal ganglion

21

Trigeminal Ganglion (3)

Dorsal root ganglion, pseudounipolar sensory cell bodies

22

Tegmen Tympani

At border of middle/posterior fossa, Sits on top of petros ridge to form roof of tympanic cavity

23

Foramen magnum

Huge foramen in posterior fossa where spinal cord/vertebral a.s run through

24

Internal acoustic meatus

Space where CN 7 and 8 run through, kind of on posterior fossa side of tegmen tympani

25

Jugular foramen

Where internal jugular v. begins and CN IX,X, XI run through, large foramen just lateral to foramen magnum

26

Hypoglossal foramen

Small foramen on lateral border of foramen magnum, carries hypoglossal n. (XII) through it

27

Grooves for Dural Venous Sinuses

Grooves running around edge of posterior foramen, venous drainage sites for brain

28

Dural Venous Sinuses

Blood drainage but not true veins, more a tent of dura mater with just endothelial lining

29

Dura mater

Tough outside layer of meninges that tightly adheres to skull

30

4 Layers of Cranial Meninges (superficial - deep)

Dura mater
Arachnoid - subarachnoid space
Pia mater

31

Formation of Dural Venous Sinus

Dura mater splits and half goes down and fuses together while half just runs straight across, forming a triangular space blood can travel in

32

Arachnoid granulations

Tufts of arachnoid projecting into dura mater/dural venous sinus and drains cerebrospinal flood into dural venous sinus as well

33

Falx cerebri

Midline invagination of dura mater, attaches on crista galli

34

Tentorium cerebelli

Posterior invaginations of dura matera separating cerebellum and cerebrum

35

Diaphragma sella

Connection of dura mater running around pituitary gland and holding it in place

36

Lateral lacunae

lateral projections of dural sinus triangle

37

Superior sagital sinus

Superior middle DVS, runs at falx cerebri split

38

Inferior sagital sinus (2)

DVS that runs at inner, free edge of falx cerebri and joins Great Cerebral v. to form straight sinus

39

Great Cerebral v. (of Galen)

Runs kind of in middle of brain (around pineal gland) and meets inferior sagital sinus to form straight sinus

40

Straight sinus

DVS that runs from inferior sagital sinus-greater cerebral v. junction and runs along where falx cerebri and tentatorium cerebelli meet

41

Confluence of sinuses (4)

Where straight, superior sagital, transverse, and small occiptal sinuses all meet on posterior skull

42

Transverse sinuses

Run along tentatorium cerebelli from confluence of the sinuses to drain into sigmoid sinus

43

Sigmoid sinus

S-shaped sinus on base of skull that drains into internal jugular v. at jugular foramen

44

Opthalmic veins

Drain from anterior orbit and form cavernous sinuses

45

Cavernous sinuses

Big sinuses on either side of pituitary and terminate into superior and inferior petrosal sinus

46

Intercavernous (circular) sinus

Runs around pituitary and acts as conduit b/w cavernous sinuses

47

Inferior Petrosal Sinus

Goes from cavernous sinus straight to jugular foramen

48

Superior Petrosal Sinus

Comes off cavernous sinus and goes over to juncture of transverse and sigmoid sinuses

49

Cavernous Sinus Thrombosis

Clot in cavernous sinus, can damage structures running through there

50

"Danger Area" of Face

Triangle at front of face that zit infections can spread to cause cavernous sinus thrombosis

51

2 Blood Supply Systems to Brain

Vertebral system - vertebral a.s
Carotid system - internal carotid a.

52

Basilar Artery

Fusion of vertebral a.s after they bend medially through foramen magnum

53

Internal carotid a.

Travels through carotid canal and cavernous sinus and supplies brain

54

Cerebral Arterial Circle (of Willis)

Circular arterial loop connecting vertebral and carotid systems of brain (interal carotid a.s and basilar a.)

55

6 Components of Cerebral Arterial Circle

Anterior communicating a.
Anterior cerebral arteries
Internal carotid arteries
Posterior communicating a.s
Posterial cerebral a.s
Basilar a.

56

Anterior communicating a.

Connects anterior cerebral a.s

57

Anterior cerebral a.s

Anterior branches of internal carotid a.s to form cerebral arterial circle

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Posterior communicating a.s

Come off each interal carotid a.s and run posteriorly to join posterior cerebral a.s

59

Posterior cerebral a.s

Terminating branches of basilar a.s, flare out laterally

60

2 Structures in Middle of Cerebral Arterial Circle

Pituitary gland flanked by each optic nerve

61

6 Structures running through Cavernous Sinus

Oculomotor N. (III)
Trochlear n. (IV)
Internal carotid a.
Abducens n. (VI)
Ophthalmic branch of trigeminal n. (V1)
Maxillary branch of trigeminal n. (V2)

62

2 Structures Running through Foramen Spinosum

Middle meningeal a./v.