Spinal Cord, Brain and Meninges

Question 1

Where is the epidural space?

Answer 1

deep to vertebral canal but SF to dura mater

Question 2

Where do you insert needle for epidural block?

Answer 2

into epidural space at the sacral hiatus (caudal epidural) or lumbar region (lumbar epidural)

will affect dorsal and ventral roots in these regions

Question 3

Describe dura mater, where does it end?

Answer 3

tough, SF connective tissue layer

forms dural sac around spinal cord and terminates at S2 vertebral level

Question 4

Describe arachnoid mater, where is it located?

Answer 4

more delicate connective tissue, located deep to dura mater

Question 5

Where is the subarachnoid space? What does it contain?

Answer 5

located deep to arachnoid mater and SF to pia mater

contains CSF- functions to protect CNS

Question 6

What is the lumbar cistern?

Answer 6

enlarged subarachnoid space in the lower lumbar region of the vertebral column, ends at S2 vertebral level

Question 7

Describe pia mater, where is it located?

Answer 7

thin connective tissue layer closely adhered to spinal cord and brain

located deep to subarachnoid space

Question 8

What are denticulate ligaments? Function?

Answer 8

lateral extensions of the pia mater which pass though the arachnoid mater and attach on the internal surface of dura mater

anchor spinal cord

Question 9

What are the spinal cord enlargements? Where are they located?

Answer 9

cervical- C4-T1 (ventral rami give rise to brachial plexus)

lumbosacral-L1-S3 (ventral rami give rise to lumbosacral

Question 10

What is the conus medullaris? Where does it end?

Answer 10

made up of spinal cord segments

usually ends around L1-L2 in adults, can end around L3 in children

Question 11

Where would you perform a lumbar puncture? What can you use as a landmark?

Answer 11

L3-L4 or L4-L5 to avoid conus medullaris

iliac crests- L4

Question 12

What is the cauda equina? Where is it located?

Answer 12

made up of elongated lumbosacral (& coccygeal) dorsal and ventral roots

located within the lumbar cistern of the subarachnoid space

Question 13

Where do you inject anesthetic for subarachnoid block?

Answer 13

into lumbar cistern, affects dorsal and ventral roots of cauda equina

Question 14

What is the filum terminale? Function?

Answer 14

consists of pia mater, remnants of caudal spinal cord and takes on layers of arachnoid mater and dura mater

extends from conus medullaris to anchor spinal cord

Question 15

Where are ventral and dorsal roots located?

Answer 15

within the vertebral canal

Question 16

Where are dorsal root ganglia located?

Answer 16

in intervertebral foramina

Question 17

Where are ventral and dorsal rami located?

Answer 17

outside vertebral column

Question 18

The skull is made up of…

Answer 18

neurocranium (cranial vault)

viscerocranium (facial skeleton)

Question 19

Function of neurocranium? Two made parts?

Answer 19

protect brain and associated structures

calvaria (roof)

basicranium (floor)

Question 20

Where is the sagittal suture located? coronal? lambdoid?

Answer 20

btwn 2 parietal bones

btwn frontal & parietal

btwn occipital, temporal and parietal bones

Question 21

Func. of fontanelles?

Answer 21

provide flexibility and allow for growth of brain

Question 22

Where is the pterion region?

Answer 22

junction of frontal, parietal, sphenoid and temporal bones

very thin bone at this location

Question 23

What can be damaged with fracture at pterion?

Answer 23

anterior branch of middle meningeal a. (primary blood supply to dura), causing an epidural hematoma which can be fatal if not treated

Question 24

How does cranial dura mater differ from spinal dura mater?

Answer 24

cranial dura mater is composed of two layers

• external periosteal layer
• internal periosteal layer

Question 25

What supplies blood to the dura mater?

Answer 25

middle meningeal a.

Question 26

What innervates the cranial dura mater?

Answer 26

Trigeminal (CN V) and vagus (CN X) root of HA and migraine pain

Question 27

Why is the dura-arachnoid junction clinically relevant?

Answer 27

space may develop here due to trauma (rupture of cerebral vein), forming a subdural hematoma

Question 28

What are arachnoid granulations?

Answer 28

extensions of the cranial arachnoid mater which allows CSF to drain into the venous system

Question 29

What forms dural reflexions?

Answer 29

2 fused layers of meningeal dura, dive btwn parts of the brain

Question 30

Name the 4 dural reflexions

Answer 30

falx cerebri, tentorium cerebelli, falx cerebeli, diaphragm sellae

Question 31

Where is the falx cerebri located?

Answer 31

btwn cerebral hemispheres in sagittal plane

Question 32

where is the tentorium cerebelli located?

Answer 32

btwn the occipital lobes of the cerebrum and the cerebellum in the transverse plane

Question 33

Where is the falx cerebelli located?

Answer 33

btwn cerebral hemispheres in sagital plane

Question 34

Where is the diaphragm sellae located?

Answer 34

attached to clinoid processes forms roof over pituitary gland but allows passage of infundibulum and veins

Question 35

Where are the dural venous sinuses located? Where do they receive/drain blood to?

Answer 35

btwn periosteal and meningeal layers of dura receive blood from brain drain into internal jugular vv.

Question 36

Where is the superior sagittal sinus located? inferior sagittal sinus?

Answer 36

within the superior border of falx cerebri within inferior border of falx cerebri

Question 37

What forms the straight sinus? located?

Answer 37

union of great cerebral vein and inferior sagittal sinus junction of falx cerebri and tentorium cerebelli

Question 38

What forms the confluence of sinuses?

Answer 38

union of superior sagittal straight and occipital sinuses

Question 39

Where are the transverse sinuses located? Continue to form...

Answer 39

within posterior border of tentorium cerebelli sigmoid sinuses once they exit tentorium cerebelli

Question 40

What sinuses form deep grooves in the occipital and temporal bones?

Answer 40

sigmoid sinuses

Question 41

What are the cavernous sinuses? What do they drain into?

Answer 41

venous plexuses located on either side of the hypophysial fossa superior petrosal sinus, inferior petrosal sinus, pterygoid plexuses

Question 42

What is located within the cavernous sinus?

Answer 42

internal carotid a. abducent nerve (CN VI)

Question 43

What nerves are located within the lateral walls of the cavernous sinus?

Answer 43

oculomotor (CN (III) trochlear (CN IV) ophthalmic (CN V1) maxillary (CN V2)

Question 44

What is cavernous sinus syndrome? cause?

Answer 44

damage of the structures passing though the cavernous sinus causes by tumors, arterial rupture of infx

Question 45

What separates the cerebral hemispheres?

Answer 45

longitudinal fissure and falx cerebri

Question 46

gyri aka...

Answer 46

folds

Question 47

sulci aka...

Answer 47

grooves

Question 48

What does the brainstem consist of?

Answer 48

midbrain, pons, medulla oblongata gives rise to most of the cranial nerves

Question 49

What supplies blood to the posterior brain? How do these arteries reach the cranium?

Answer 49

Vertebral arteries: basilar a > posterior cerebral aa > posterior communicating aa. travel superiorly within the transverse foramina of C6-C1, enter cranium via foramen magnum

Question 50

What supplies blood to the anterior brain? how do they enter the skull?

Answer 50

internal carotid aa. enter skull via carotid canal and runs superior to foramen lacerum

Question 51

What are the branches of the internal carotid a.?

Answer 51

anterior cerebral a. ophthalmic a. middle cerebral

Question 52

What is the cerebral arterial circle (circle of willis)? What is it made up of?

Answer 52

anastomoses of anterior and posterior circulation of brain internal carotid, anterior cerebral, anterior communicating, posterior communicating, posterior cerebral some ppt don't have a complete circle