190

Front 1

SPINAL DURA MATER

VS.

CRANIAL DURA MATER

Back 1

3. Epidural space

a. In contrast to spinal dura mater, cranial dura mater is not surrounded
by an epidural space; however, there is a potential epidural space
between the cranial dura mater and intracranial surface ofthe skull

Front 2

"POTENTIAL EPIDURAL SPACE"

Back 2

3. Epidural space

b Clinical note: the potential epidural space may become a real space
if, for example, there is a hemorrhage (epidural hematoma) between
the cranial dura mater and intracranial surface ofthe skull; tins may
result from rupture ofthe middle meningeal artery following a skull
fracture

Front 3

ARCHNOID

WHAT IS IT?

Back 3

B. Arachnoid

1 Translucent connective tissue membrane deep to the cranial dura mater
and separated from it by only a slitlike, potential subdural space

Front 4

ARCHNOID

FROM ITS DEEP SURFACE...

Back 4

B. Arachnoid

2 From its deep surface, thin, anastomosing connective tissue strands
extend through the cerebrospinal fluid within the sub.u-achnoid space
and merge with the pia mater covering the brain

Front 5

ARACHNOID

"ARACHNOID VILLI"

Back 5

B. Arachnoid

3 Arachnoid villi are tiny, fingerlike diverticula ofthe arachnoid that pro-
trude through the cranial dura mater into the superior sagittal sinus (or
its lateral lacunae); they are sites ofresorption of cerebrospinal fluid into
the venous system and, when they form aggregations called arachnoid
granulations, they may induce resorption of bone on the inner table ot
the skull, producing foveolae granulares

Front 6

PIA MATER

Back 6

C. Pia mater: microscopic connective tissue layer covering the surface of the
brain

Front 7

MIDDLE MENINGEAL ARTERY

-enter skull?
-courses? supplies?
-major function

-divides into? courses how?

Back 7

1. Middle meningeal artery
arises from the maxillary artery, enters the skull through foramen

b. Divides into an anterior and a posterior branch which course near
the pterion and toward the lambda, respectively

spmosum, and courses laterally within the groove for the middle
meningeal artery; although it lies within and supplies the cranial dura
mater, its major function is to supply the skull (tiny foramina can be
observed in the depth of its grooves)