Scalp, Cranial Cavity (Gross 2.1)

Front 1

What are the 5 layers of the scalp?

Back 1

Skin
CT (dense)
Aponeurosis
LCT
Pericranium

Front 2

What is in the CT (dense) layer?

Back 2

Blood vessels and nerves. CT around the vessels tends to hold cut vessels open, thus the scalp bleeds profusely when cut.

Front 3

What is in the Aponeurotic layer?

Back 3

Frontalis m., occipitalis m., and aponeurotic tendon between them

Front 4

What does the LCT layer do?

Back 4

facilitates movement between scalp proper (first three layers) and the skull.

Do to its loose consistency, infections tend to localize and spread in this layer.

Injuries can cause pooling of blood in this layer and it may spread forward deep to the skin of the eyelids, causing BLACK EYES.

Front 5

What is the pericranium?

Back 5

outer periosteum of the calvarium (skull)

Front 6

What is the sensory innervation of the scalp?

Back 6

Opthalamic div. of CN V- forehead and ant. scalp

Maxillary div. of CN V- ant. temple area

Mandibular div. of CN V- lat. temple area

Branches of cervical plexus- scalp post. and sup. to ear

Dorsal rami of C2/C3- post. scalp

Front 7

What are the blood vessels of the scalp?

Back 7

Opthalamic a.- Supratrochlear and Supraorbital aa.

Ext. Carotid- Occipital a. and Sup. temporal a.

(Veins similar to arteries)

Front 8

What is the lymph drainage?

Back 8

Cervical nodes (ultimately)

Front 9

What is the function of the skull

Back 9

House and protect the brain and special sense organs such as the ear and eye.

Serve as attachements for muscles involved in chewing and swallowing.

Front 10

What is the cranium?

Back 10

The skull EXCEPT the mandible

Consists of an upper calvarium and a lower facial skeleton

Front 11

What is the calvarium?

Back 11

Part of skull surrounding the cranial cavity

Front 12

What is the cranial cavity?

Back 12

Space within the calvarium.

Contains: brain, menenges, blood vessels, dural sinuses, parts of cranial nerves

Front 13

What is the pterion?

Back 13

Point in skull were frontal, parietal, greater wing of sphenoid, and temporal bones come together.

Deep to the pterion is the middle meningeal a. A fracture at the pterion may damage the artery, resulting in an EXTRADURAL HEMATOMA.

Front 14

What makes up the Ant. cranial fossa? What is located in it?

Back 14

Consists of: Frontal, ethmoid, and sphenoid bones

Contains: frontal lobe of brain

Front 15

Important features of Ant. cranial fossa?

Back 15

Frontal crest
Crista galli
Cribiform plate
Orbital portion of frontal bone
Lesser wings of sphenoid bone
Ant. clinoid processes
Optic canal

Front 16

What makes up the Middle cranial fossa? What is located in it?

Back 16

Consists of: sphenoid, temporal, and parietal bones

Contains: Temporal lobe of brain and cavernous sinus

Front 17

Important features of Middle cranial fossa?

Back 17

Body and greater wings of sphenoid, including stella turcica and its component parts

Ant. portion of peetrous temporal bone, including the TEGMEN TYMPANI

Various fissures, grooves, foramina, hiatuses

SOF
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
Opening of carotid canal
Groove for mid. meningeal a.
Groove and hiatus for Greater petrosal n.
Groove and hiatus for Lesser petrosal n.

Front 18

What makes up the Post. cranial fossa? What is located in it?

Back 18

Consists of: temporal and occipital, sphenoid (limited), parietal (limited)

Contains: parts of brain stem and cerebellum

Front 19

Important features of Post. cranial fossa?

Back 19

Clivus
Post. part of petrous temporal bone
Int. occipital protuberance
Foramen magnum
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Groove for Inf. petrosal sinus
Groove for transverse sinus
Groove for sigmoid sinus

Front 20

Dura mater

Back 20

2 layers: periosteal and meningeal

Where layers split, they form venous structures called dural sinuses.

Continuous with dura of spinal cord

Also forms DURAL PARTITIONS (separation of brain structures)

Front 21

Dural partitions

Back 21

Falx cerebri
Tentorium cerebelli
Falx cerebelli
Diaphragma sellae

Front 22

Falx cerebri

Back 22

Attaches to crista falli, frontal rest, and tentorium cerebelli

SEPARATES RIGHT AND LEFT CEREBRAL HEMISPHERES

Front 23

Tentorium cerebelli

Back 23

Attaches to occipital bone and petrous ridge of temporal hone.

Forms tentorial notch.

SEPARATES CEREBELLUM AND OCCIPITAL LOBES

Front 24

Falx cerebelli

Back 24

Attaches to tentorium and internal occipital crest

SEPARATES RIGHT AND LEFT CEREBELLAR HEMISPHERES

Front 25

Diaphragma sellae

Back 25

Covers hypophyseal fossa

Infundibulum of pituitary passes through a hole in it

Front 26

What is the dural blood supply?

Back 26

Middle meningeal a. from the maxillary a.

Enters skull through FORAMEN SPINOSUM and crosses the region of the pterion.

Front 27

What is the innervation of the dura mater?

Back 27

Branches of trigemnal n. (CN V) and upper cervical n.

Front 28

Arachnoid mater

Back 28

Thin layer, does not enter grooves of brain.

Arachnoid granulations which project into superior sagittal sinus

Front 29

Pia mater

Back 29

Right on surface of brain, enters all grooves and fissures of brain.

Front 30

Spaces

Back 30

Extradural: btwn skull and dura (potential space)

Subdural: btwn dura and arachnoid (potential space)

Subarachnoid: actual space btwn arachnoid and pia. FILLED WITH CSF.

Front 31

Dural partitions

Back 31

Falx cerebri
Tentorium cerebelli
Falx cerebelli
Diaphragma sellae

Front 32

Falx cerebri

Back 32

Attaches to crista falli, frontal rest, and tentorium cerebelli

SEPARATES RIGHT AND LEFT CEREBRAL HEMISPHERES

Front 33

Tentorium cerebelli

Back 33

Attaches to occipital bone and petrous ridge of temporal hone.

Forms tentorial notch.

SEPARATES CEREBELLUM AND OCCIPITAL LOBES

Front 34

Falx cerebelli

Back 34

Attaches to tentorium and internal occipital crest

SEPARATES RIGHT AND LEFT CEREBELLAR HEMISPHERES

Front 35

Diaphragma sellae

Back 35

Covers hypophyseal fossa

Infundibulum of pituitary passes through a hole in it

Front 36

What is the dural blood supply?

Back 36

Middle meningeal a. from the maxillary a.

Enters skull through FORAMEN SPINOSUM and crosses the region of the pterion.

Front 37

What is the innervation of the dura mater?

Back 37

Branches of trigemnal n. (CN V) and upper cervical n.

Front 38

Arachnoid mater

Back 38

Thin layer, does not enter grooves of brain.

Arachnoid granulations which project into superior sagittal sinus

Front 39

Pia mater

Back 39

Right on surface of brain, enters all grooves and fissures of brain.

Front 40

Spaces

Back 40

Extradural: btwn skull and dura (potential space)

Subdural: btwn dura and arachnoid (potential space)

Subarachnoid: actual space btwn arachnoid and pia. FILLED WITH CSF.

Front 41

Vertebral a.

Back 41

From subclavian a.

Passes through transverse foramen of C6-C2

Traverses post. arch of atlas

Enters Foramen magnum

Two vertebral aa. join to form BASILAR a.

supplies spinal cord and cerebellum

Front 42

Basilar a.

Back 42

supplies cerebellum and brain stem.

Gives off post. cerebral aa.

Front 43

Internal carotid

Back 43

Enters skull through carotid canal

crosses foramen lacerum

passes through cavernous sinus

occupies groove in sphenoid bone

Forms S shaped carotid siphon

BRANCHES: Opthalamic, Post. Communicating, Middle Cerebral and Ant. Cerebral aa.

Front 44

Cerebral arterial circle (of Willis)

Back 44

Encircles pituitary gland

CONSISTS:
Ant. + Post. Communicating
Ant. + Post. Cerebral
Internal Carotid

Front 45

Carotid Siphon

Back 45

Portion of int. carotid a from carotid canal UNTIL it divides into medial and ant. cerebral arteries

Site of stenosis and is a landmark on radiological images

Front 46

Cerebral, cerebellar, and brain stem veins

Back 46

Drain the brain and brain stem and empty into DURAL SINUSES

Front 47

Great cerebral vein (of Galen)

Back 47

Large vein which drains into the straight sinus

Front 48

Diploic v.

Back 48

drain the bone of the skyll and empty into the DURAL VENOUS SINUSES

Front 49

Emissary v.

Back 49

Connect areas outside the cranial cavity to the dural sinuses.

NO VALVES and thus infection can pass into the cranial cavity

Front 50

Dural sinuses

Back 50

Endothelial lined spaces btwn periosteal and meningeal layers of dura, basically functioning as a system of valveless veins

Blood from sinuses ends upin INTERNAL JUGULAR v.

Front 51

Sup. saggital sinus

Back 51

In sup. border of FALX CEREBRI

drains CEREBRAL, DIPLOIC, EMISSARY

Arachnoid granulations also drain CSF into it.

Drains into CONFLUENCE OF SINUSES

Front 52

Inf. saggital sinus

Back 52

Lower border of FALX CEREBRI

Few cerebral veins drain into it

Drains into STRAIGHT SINUS

Front 53

Straight sinus

Back 53

At junction of FALX CEREBRI and TENTORIUM CEREBELLI

Great Cerebral v (of Galen) and Inf. Saggital sinus drain into it

Drains into CONFLUENCE OF SINUSES

Front 54

Occipital Sinus

Back 54

In FALX CEREBELLI

Connects to vertebral venous plexus

Drains into CONFLUENCE OF SINUSES

Front 55

Confluence of Sinuses

Back 55

Space at INT. OCCIPITAL PROTUBERANCE

Sup. sagittal, straight and occipital sinuses drain INTO it.

Drains into RIGHT AND LEFT TRANSVERSE SINUSES

Front 56

Transverse sinuses

Back 56

Run along post. lat. attachements of TENTORIUM CEREBELLI

Recieve flood from Sup. Petrosal sinuses, cerebral, and cerebellar vv.

Blood from Sup. saggital goes RIGHT

Straight sinus goes LEFT

Drains into SIGMOID sinuses

Front 57

Sigmoid sinuses

Back 57

btwn transverse sinus and int. jugular v.

Drain transverse sinus and other vv.

Drains into INT. JUGULAR v. at jugular foramen

Front 58

Cavernous sinuses

Back 58

Lat. side of sphenoid body

Int. Carotid and cranial nn. pass through it

Drains cerebral v., opthalamic v., emissary v. and blood from SPHENOPERITAL plexus in the IT fossa

Infections can pass from outside cranial cavity to inside

Drain INTO SUP. + INF. PETROSAL SINUSES

Front 59

Intercavernous sinuses

Back 59

Connect right and left cavernous sinuses

Front 60

Sphenoparietal sinuses

Back 60

Along lesser wing of sphenoid bone

Drain DIPLOIC vv.

Front 61

Sup. Petrosal sinuses

Back 61

Along ridge of petrous bone

Drains Cavernous sinuses

Drain INTO TRANSVERSE SINUS

Front 62

Inf. Petrosal Sinuses

Back 62

Groove btwn petrous temporal bone and occipital bone

Drains cavernous sinuses and other vv.

Drain INTO INT. JUGULAR V

Front 63

Basilar Sinus

Back 63

Clivus of occipital bone

Connects inf. petrosal sinuses

Communicates w/ VERTEBRAL VENOUS PLEXUS

Front 64

Extradural hemmorrhage

Back 64

Btwn dura and skull

Tearing of middle meningeal a. due to head injury

Front 65

Subdural hemmorrhage

Back 65

Btwn dura and arachnoid

Torn cerebral vv where they enter SUP SAGITTAL SINUS

Occurs in very young and elderly or due to trauma

Front 66

Subarachnoid hemorrhage

Back 66

Btwn arachnoid and pia mater

Aneurysm of vessels of arterial circle