Meninges (Quiz 4)

Question 1

________ is an essential interstitial nutrient source, but when surrounding the brain acts as a shock absorber and “floats” the brain in water and it will be cushioned

Answer 1

CSF

Question 2

The ____________ are 3 isolated layers that protect, cushion, provide a passageway for CSF, biochemically isolate neurons, keep sodium and potassium levels constant. The brain is mechanically suspended within the meninges

Answer 2

meninges

Question 3

The dense fibrous tissue of the cranial dura mater supports the brain and acts as the lining layer of the cranial bones. It is also called pachymeninx. The cranial dura is thick and includes an ______________ layer and an _______________ layer

Answer 3

internal meningeal (attached to the arachnoid mater), external endosteal

Question 4

The epidural space is between the dura mater and calvaria. Is the epidural space an actual space or potential space?

Answer 4

potential space

**following a trauma, blood may enter this “potential space” and accumulate forming an epidural hematoma (blood comes from ruptured meningeal a. or less commonly a torn dural venous sinuous)

Question 5

The cranial dura is continuous at the _________________ with the spinal dura mater

Answer 5

foramen magnum

Question 6

T/F: the subdural space in the cranial region is absent, but present in spinal region

Answer 6

true!

Question 7

The cranial subdural space is in the innermost dural layer, near the dura-arachnoid interface. Is the subdural space an actual or potential space?

Answer 7

potential space

Question 8

Is the subarachnoid space an actual space or potential space?

Answer 8

actual space, its filled with CSF and is usually enlarged in the cisterns

Question 9

Which meningeal layer is tightly attached to the brain?

Answer 9

pia mater

Question 10

There are locations where the inner dural layer separates from the external layer and projects into the cranial cavity. These extensions of dura reflect back on themselves to form double layer….

Answer 10

dural folds

Question 11

What are the 4 main dural folds?

test q

Answer 11

1) falx cerebri
2) tentorium cerebelli
3) falx cerebelli
4) diaphragma sellae

Question 12

Where is the falx cerebri found?

test q

Answer 12

between the cerebral hemispheres (within longitudinal fissure)

Question 13

Where is tentorium cerebelli found?

test q

Answer 13

over the cerebellum, between it and the cerebrum

Question 14

Where is falx cerebelli found?

test q

Answer 14

between the cerebellar hemispheres

Question 15

Where is diaphragma sellae found?

test q

Answer 15

-covers the pituitary gland
-allows infundibulum through

Question 16

There are no receptors for pain in the brain- at least no nociception is perceived. Neurosurgery can be performed without general anesthesia. The dura has sensory innervation from the ___________. Meningeal blood vessels are associated with these neurons. Headaches can be associated with dural sinus deformation/compression

Answer 16

trigeminal n.

Question 17

At the attached edges of dural folds the 2 cranial dura are separated to form venous channels called….

Answer 17

dural sinuses

Question 18

Where is the superior sagittal sinus found?

test q

Answer 18

attached at the edge of the falx cerebri

Question 19

Where are the L/R transverse sinuses found?

test q

Answer 19

along posterior line of attachment of the tentorium cerebelli

Question 20

Where is the straight sinus found?

test q

Answer 20

between cerebral falx and tentorium cerebelli

Question 21

All 4 of the dural sinuses meet in the _____________ of the sinuses near the internal occipital protuberance

Answer 21

confluence (swelling)

Question 22

Venous blood flows posteriorly in the superior sagittal and straight sinuses into the confluence, and from there through the transverse sinuses. Each transverse sinus continues, as the sigmoid sinus, which proceeds anteriorly and inferiorly through an S-shaped course and empties into the….

Answer 22

internal jugular v.

Question 23

Dural sinuses are roughly triangular in cross section and are lined with….

Answer 23

endothelium

Question 24

Sinuses are venous channels found between the endosteal and meningeal layers of _____ mater in the brain. They drain blood from the cortex, the meninges, and the scalp and deliver it to the internal jugular veins

Answer 24

dura

Question 25

The cranial arachnoid consists of an outer part which is several layers of cells that adheres to the inner cellular layer of the dura- the arachnoid barrier layer, and in inner part, the arachnoid trabeculae. The arachnoid is a thin, avascular membrane composed of a few layers of cells interspersed with bundles of ________

Answer 25

collagen

Question 26

Small strands of collagenous CT called _________________, covered with fibroblast like arachnoid cells, extend to the pia. This bridge across the subarachnoid space gives it a spider web like appearance

Answer 26

arachnoid trabeculae

Question 27

Arachnoid trabeculae help keep the brain suspended within the….

Answer 27

meninges

Question 28

In the meshes of the arachnoid trabeculae (subarachnoid space), CSF circulates. Although the arachnoid dips into the __________________, it does not dip into the individual sulci of hemispheres

Answer 28

longitudinal cerebral fissure

Question 29

Large subarachnoid regions contain a considerable volume of CSF, are called…..

Answer 29

subarachnoid cisterns

Question 30

What are the 4 main cisterns?

test q

Answer 30

1) cerebellomedullary cistern also known as cisterna magna
2) pontine cistern
3) interpeduncular cistern
4) superior cistern also known as quadrigeminal cistern

Question 31

Arachnoid trabeculae are particularly prominent in….

Answer 31

subarachnoid cisterns

Question 32

The CSF contained in the subarachnoid space is separated from venous blood. At many locations along dural sinuses, like along the superior sagittal sinus, small evaginations of the arachnoid, called ______________, herniate through the wall of the sinus. Here only a loose layer of arachnoid cells and a layer of endothelium between subarachnoid space and venous blood. Large clusters of arachnoid villi are called ______________ (lots of villi here)

Answer 32

arachnoid villi, arachnoid granulations

Question 33

Arachnoid villi are especially numerous in laterally directed dilations of the superior sagittal sinus, called….

Answer 33

venous lacunae or lateral lacunae

Question 34

Arachnoid villi are the major sites of reabsorption of _______ into the venous system. They work like one way valves (similar to lymphatic capillaries), allowing flow from the subarachnoid space into the venous blood but not in the reverse direction

Answer 34

CSF

Question 35

Pia mater is held in place by what glial cells?

Answer 35

astrocytes

Question 36

The cranial _____ mater is the thinnest and most delicate layer of the cranial meninges. It closely follows every convolution on the brain surface and enters every cerebral sulcus. This mater follows ALL of the contours of the brainstem and all of the folds of the cerebral and cerebellar cortices

Answer 36

pia

Question 37

The arachnoid and pia mater are continuous with each other, often regarded as 2 parts of a single layer, and so are sometimes referred to together as the…..

Answer 37

leptomeninges