6 - Scalp, Meninges, Dural Sinus & Cranial Cavity

Front 1

name (and describe) the five layers of the SCALP

Back 1

Skin
Connective Tissue- thick, dense layer w/ bv's and cut. nn's
Aponeurosis- epicranial aponeurosis, connects bellies of the occipitofrontalis m.
Loose Connective Tissue- allows free mvmt of scalp proper (first 3 layers)
Pericranium- thin ct called periosteum, closely attatched to the calvaria (skull bone)

Front 2

name the 4 cutaneous nn that come off of CN V in front of the ear

Back 2

V1 branch= supraorbital (lateral) & supratrochlear nn. (medial)
V2 branch= Zygomaticotemporal n.
V3 branch= Auriculotemporal n.

Front 3

name the 1 cutaneous n that innervates the area immedeiately inferior to the ear

Back 3

great auricular n. (C2, C3)

Front 4

name the 2 cutaneous nerves that innervate the area behind the ear

Back 4

greater occipital n. (dorsal ramus of C2)
lesser occipital n. (ventral ramus of C2)

Front 5

name the two arteries that supply the anterior scalp.

what is their origin?

Back 5

supraorbital a. and supratrochlear a.

<-- ophthalmic a. <-- internal carotid a. <-- common carotid a.

Front 6

name the 3 arteries that supply the posterior scalp

what is their origin?

Back 6

Occipital a.
Posterior auricular a.
Superficial temporal a.

branches of the external carotid a.

Front 7

___________ veins from the scalp can penetrate the skull and drain into the dural venous sinuses

Back 7

emissary

note: these have NO valves; therefore, can change directions --> infection

Front 8

CC: Scalp infections

which layer is the danger area of the scalp? why?

Back 8

danger area: layer 4: loose connective tissue; b/c pus and blood can spread into this layer --> infection. the infection can be spread into the intracranial cavity through the emissary vv's

Front 9

CC: Scalp lacerations

most common head injury requiring surgical care;

why does profuse bleeding occur?

Back 9

there are abundant anastomoses that occur here

Front 10

what does spinal nerve C1 give sensory innervation to?

Back 10

NOTHING!!!

C1 is strictly motor... therefore there is no dermatome!

Front 11

name the 3 meningeal layers and their 3 associated spaces between the skull and the brain

Back 11

skull
epidural space -1
dura mater -1
subdural space -2
arachnoid mater -2
subarachnoid space -3
pia mater -3
brain

Front 12

which space contains the CSF

Back 12

subarachnoid

Front 13

what creates the granular foveola in the calvaria?

what is their significance?

Back 13

the diverticulum (arachnoid granulations)

they return CSF to venous drainage

Front 14

what are the 2 layers of the dura mater?

how do they contribute to sinus formation?

which one continues and dura mater in the spinal cord?

Back 14

1) periosteal (endosteal) layer- lines internal surface of the calvaria
2) meningeal layer- up against the arachnoid (with subdural space btw);

the 2 layers separate to form dural sinuses and the meningeal layer with line septum btw brain compartments

the meningeal layer will continue as the dura mater of the spinal cord

Front 15

what major artery causes a depression in the calvaria of the skull?

what is its origin?

Back 15

middle meningeal a. (through foramen spinosum)

<-- maxillary a <--external carotid a.

Front 16

where is the pia mater?

vascular or avascular?

Back 16

the pia mater is closely adhered to the brain

it's HIGHLY VASCULARIZED via a network of fine blood vessels

Front 17

CC: Epidural (extradural) hematomas

-where is blood trapped?
-caused by?
-history?

Back 17

-blood is trapped between dura and inner calvaria;
-caused by tearing of ARTERIAL vessles (esp. middle meningeal a.)
-typical hist: loss of consciousness --> improvement (lucid interval) --> then rapid deterioration

Front 18

CC: subdural hematoma

-where is blood trapped?
-caused by?

Back 18

-blood is trapped btw dura and arachnoid in subdural space
-generally caused by tearing of venous structures

-more diffuse than epidural hematoma

Front 19

CC: subarachnoid hemorrhage

-where is blood trapped?
-caused by?
-history?

Back 19

-blood is flowing through the grooves of the brain
-caused by the rupture of intracranial vessels
-history= worst headache of my life, stiff neck, loss of consciousness

Front 20

what a. provides major arterial supply to the dura mater?

Back 20

middle meningeal a.

Front 21

name the 4 dural septa/meningeal compartments (from the meningeal (not periosteal) layer of dural mater)

Back 21

1) Falx cerebri- separates cerebral hemispheres
2) Falx cerebelli- separates cerebellar hemispheres
3) Tantorium cerebelli- separates 2 cerebral hemispheres from 2 cerebellar hemispheres
4) Sellar diaphragm- roof of hyposeal (pituitary) fossa

Front 22

name the 11 dural sinus and explain how they are connected

Back 22

1) superior sagittal sinus, 2) inferior sagittal sinus, 3) transverse sinuses, 4) superior pertrosal sinuses, 5) cavernous sinuses, 6) anterior intercavernous sinus, 7) posterior intercavernous sinus, 8) straight sinus, 9) sigmoidal sinus 10) inferior petrosal sinus, 11) occipital sinus

Front 23

what 5 nn's, 1 artery, and plexus are contained within the cavernous sinus?

Back 23

CN's: III, IV, V1, V2, and VI
a: internal carotid a.
plexus: sympathetic plexus

Front 24

what bone is the sella turcica located on?

Back 24

the sphenoid bone

Front 25

what does the superior petrosal sinus connect?

Back 25

the posterio-superior portion of the cavernous sinus to the transverse sinus

Front 26

what does the inferior petrosal sinus connect?

Back 26

the posterio-inferior portion of the cavernous sinus to the internal jugular v.

Front 27

CC: Cavernous sinus thrombosis

Back 27

a clot in the cavernous sinus can compress structures contained in th sinus (CN III, IV, VI, V1, & V2 & the internal carotid a); petuitary tumors can invade the cavernous sinus; due to the presence of nn in the sinus, the tumor is usually unresectable

Front 28

What is the "danger area" of the face?

Back 28

the connection btw the facial vv and cavernous sinus, due to the superior and inferior ophthalmis vv, provide a route for the intracranial spread on infections

Front 29

what are the 2 terminal branches that come off the internal carotid a to make up the anterior system of the arterial brain supply?

Back 29

the anterior and middle cerebral aa

Front 30

for the posterior system of the arterial brain supply, there are a pair of arteries, the ______A____ aa. that come together with the PICA's (___B___) to form the ____C____a. Three other aa's join this artery before it joins the Circle of Willis, what are they?

Back 30

A- vertebral aa.
B- Posterior inferior cerebellar aa.
C- Basillar a.

1) Anterior inferior cerebellar aa.
2) Superior cellebellar aa.
3) Posterior cerebral aa.

Front 31

T/F the olfactory bulb is CN 1

Back 31

FALSE!!
**remember the hairbrush analogy**

CN I actually consists of the rootlets that enter into the cribiform plate of ethmoid bone

Front 32

which CN comes from the dorsal (vs ventral) aspect

Back 32

CN IV

Front 33

Name and describe the communicating arteries in the Circle of Willis

Back 33

1) Anterior Communicating a. (only 1)
runs between 2 anterior cerebral aa.
2) Posterior Communicating aa. (2)
run between internal carotid a. and the posterior inferior cerebral a.

Front 34

trace blood flow around the Circle of Willis from posterior aspect to anterior

Back 34

vertebral aa + posterior inferior cerebellar aa. (PICA) --> basilar a. + anterior inferior cerebellar aa. (AICA), superior cerebellar aa., posterior cerebral aa. --> posterior communicating aa. --> internal caroitid aa. + middle cerebral aa. --> anterior cerebral aa. --> anterior communicating a.

Front 35

what are the origins of the PICA and AICA aa?

Back 35

Posterior inferior cerebellar aa: come from vertebral aa.

Anterior inferior cerebellar aa.: come from basilar a.