Cranium, Scalp, Meninges & Brain

Question 1

The bony ___ provides rigid support for the brain

Answer 1

cranium

Question 2

Protective connective tissue membranes called ___ surround and partition portions of the brain

Answer 2

meninges

Question 3

_____ fluid acts as a cushioning fluid

Answer 3

cerbrospinal

Question 4

What is the purpose of the blood-brain barrier?

Answer 4

to prevent entry of harmful materials from the bloodstream

Question 5

What are the three dense regular CT layers that separate the soft tissue of the brain from the bones of the cranium referred to as?

Answer 5

cranial meninges

Question 6

What is the function of the cranial meninges?

Answer 6

enclose and protect blood vessels that supply the brain, contain and circulate CSF

Question 7

True or false?

Parts of the cranial meninges form some of the veins that drain blood from the brain

Answer 7

true

Question 8

Name the following meninge:

Tough membrane composed of two fibrous layers; strongest of the meninges

Answer 8

dura mater

Question 9

What are the two layers of the dura mater?

Answer 9

periosteal layer: superficial

meningeal layer: deep

Question 10

Name the following meninge:

lies immediately internal to the dura mater; partially composed of a delicate web of collagen and elastic fibers

Answer 10

Arachnoid

Question 11

Immediately deep to the arachnoid is the ___ space

Answer 11

subarachnoid

Question 12

Name the following cranial meninge:
innermost of the cranial meninges, thin layer of CT that tightly adheres to the brain and follows every contour of the brain surface

Answer 12

pia mater

Question 13

The meningeal layer of the dura mater extends as flat partitions deep into the cranial cavity at four locations called what?

Answer 13

cranial dural septa

Question 14

Name the 4 dura septa

Answer 14

falx cerebri; tentorium cerebelli; falx cerebelli; diaphragma selfae

Question 15

What sinuses are found in the dura septa?

Answer 15

superior and inferior sagittal sinuses, the straight sinus, the sigmoid sinus, and the transverse sinus

Question 16

Where does CSF circulate?

Answer 16

in the ventricles and subarachnoid space

Question 17

The CSF bathes the exposed surfaces of the ___ ___ ___ and completely surrounds it

Answer 17

central nervous system

Question 18

What 3 important functions does CSF perform?

Answer 18

buoyancy
protection
environmental stability

Question 19

What is CSF formed by?

Answer 19

choroid plexus in each ventricle

Question 20

What is CSF produced by?

Answer 20

secretion of fluid from the ependymal cells that originate from the blood plasma

Question 21

CSF is similar to blood plasma but has some differences in ion concentration. What are the differences?

Answer 21

contains more sodium, hydrogen, and calcium; contains less potassium

Question 22

Cavities or expansions within the brain that are derived from the lumen of the embryonic neural tube are called what?

Answer 22

brain ventricles

Question 23

Brain ventricles are continuous with one another as well as with the ___ __ of the spinal cord

Answer 23

central canal

Question 24

Four ventricles are located in the brain. Describe them.

Answer 24

two lateral ventricles are in the cerebrum; within the diencephalon is a smaller ventricle called the third ventricle; the fourth ventricle is located within the pons and cerebellum

Question 25

In regards to the two lateral ventricles in the cerebrum, they are separated by a thin medial partition called what?

Answer 25

septum pellucidum

Question 26

CSF flows from the third ventricle through the ___ ___ into the fourth ventricle

Answer 26

mesencephalic aquaduct

Question 27

As the CSF flows through the subarachnoid space, it removes waste products and provides ___ to support the brain

Answer 27

buoyancy

Question 28

What happens to excess CSF?

Answer 28

flows into the arachnoid villi, then drains into the dural venous sinuses

Question 29

True or false?

The greater pressure on the CSF in the subarachnoid space assures that CSF moves into venous sinuses

Answer 29

true

Question 30

This condition has been called “water on the brain” and is typically caused by an obstruction in CSF flow that restricts it reabsorption in the venous bloodstream

Answer 30

hydrocephalus

Question 31

How is hydrocephalus treated?

Answer 31

by inserting a ventriculoperitoneal shunt that drains to the abdominal cavity; or a ventriculostomy that creates a hole in the floor of the third ventricle that drains into the subarachnoid space

Question 32

This prevents exposure of neurons in the brain to drugs, waste products in the blood, and variations in levels of normal substances that could have adverse affect on brain function

Answer 32

blood-brain barrier

Question 33

What type of junctions in the blood-brain barrier prevent materials from diffusing across the capillary wall?

Answer 33

tight junctions

Question 34

____ act as “gatekeepers” that permit materials to pass to the neurons after leaving the capillaries

Answer 34

astrocytes

Question 35

The blood-brain barrier is reduced or missing in three distinct locations in the CNS, what are they?

Answer 35

choroid plexus; hypothalamus; pineal gland