Nervous System

Question 1

Meningeal Layers

Answer 1

The epidural space, between the vertebrae and dura, is the location used for placing epidural anesthetic to block pain impulses entering the spinal core.

The subarachnoid space, between the pia and arachnoid, is used for placement of spinal anesthetic and is where CSF would be drawn for testing.

Question 2

Spinal and Cranial nerves

Answer 2

Question 3

Elongation of the spinal cord ___ while elongation of the spine ___.

Answer 3

Elongation of the spinal cord ceases in childhood while elongation of the spine continues into adolescence.

Question 4

Spinal cord segment

Answer 4

Region of the spinal cord contributing to one pair of spinal nevers.

Question 5

In most adults, the spinal cord ends at ___.

Answer 5

In most adults, the spinal cord ends at the L2 vertebral level.

This is taken advantage of for spinal puncture, which is always done inferior to the L2 vertebra. Instruments which are used for puncture are also designed to push away and thereby protect spinal nerves rather than puncturing them.

Question 6

Answer 6

C.

Question 7

Cranial Nerve nomenclature

Answer 7

Question 8

Spinal nerve nomenclature

Answer 8

Question 9

Spinal cord axial section

Answer 9

Here the “white matter” is shown in yellow.

Question 10

Spinal cord nuclei and ganglia

Answer 10

Question 11

Spinal roots and rami

Answer 11

Question 12

Dorsal Rami Distribution

Answer 12

Question 13

Dermatomes

Answer 13

Question 14

Ventral Rami Distribution in Thorax and Abdomen

Answer 14

Question 15

Ventral Rami Distribution Outside of Thorax and Abdomen

Answer 15

Question 16

Which category of nerves convey sensation from which dermatomes?

Answer 16

Cranial nerves convey sensation from the face and underlying structures

Ventral rami convey sensations from all dermatomes except the central back

Dorsal rami convey sensations from the dermatomes of the central back

Question 17

Answer 17

C.

Question 18

Answer 18

B.

Question 19

Spinal nerve types and organization

Answer 19

Question 20

Spinal nerve modality summary

Answer 20

Question 21

Cranial nerve modality summary

Answer 21

Note that there are no sympathetic visceral motor neurons.

Question 22

Spinal nerve fiber packaging

Answer 22

Question 23

Pathways and targets of somatic motor and visceral motor neurons

Answer 23

Question 24

Pathways and targets of somatic sensory and visceral sensory neurons

Answer 24

Question 25

No ____ fibers travel through the dorsal root.

Answer 25

No **motor** fibers travel through the dorsal root.

Question 26

Injury of a spinal nerve would cause. . .

Answer 26

Dorsal and ventral loss of somatic motor, somatic sensory, visceral motor, and visceral sensory activity to the associated dermatomes and underlying tissue. Remember, a **spinal nerve** is where dorsal and ventral roots meet and share fibers to supply dorsal and ventral rami.

Question 27

Root = \_\_\_\_ Ramus = \_\_\_\_ Spinal nerve = \_\_\_\_

Answer 27

Root = **sensory** Ramus = **motor** Spinal nerve = **both**

Question 28

Dorsal = \_\_\_\_\_ Ventral = \_\_\_\_\_

Answer 28

Dorsal = **posterior** Ventral = **anterior**

Question 29

Answer 29

B.

Question 30

Brudzinski’s Sign

Answer 30

her hips and knee flex forward when you attempt to flex her neck

Question 31

Kernig's tests

Answer 31

While a patients lies supine, you flex the hip to a right angle to the trunk with the ipsilateral knee flexed; the ipsilateral knee is then extended. The test is positive if the patient has severe neck/back pain and reflexively flexes upward

Question 32

Most common port of entry to meninges by bacteria

Answer 32

The nasal cavity

Question 33

Cauda equina

Answer 33

Nerves which descend past the end of the spinal cord at L2 which must be avoided when taking cerebrospinal fluid.

Question 34

Cerebrospinal fluid should be taken from adults from between. . .

Answer 34

L4 and L5

Question 35

At birth, the spinal cord ends between. . .

Answer 35

L1 and L3

Question 36

By adulthood, the spinal cord ends between. . .

Answer 36

L1 and L2

Question 38

How many cervical pairs and vertebrae are there?

Answer 38

8 cervical pairs, 7 cervical vertebrae. C1 nerves pass above the C1 vertebra, C8 nerves pass below the C7 vertebra.

Question 39

Nipple line

Answer 39

T4 dermatome

Question 40

Umbilicus line

Answer 40

T10 dermatome

Question 41

Anhydrosis

Answer 41

Lack of sweating

Question 42

Parasthesias

Answer 42

tingling sensation

Question 43

Herpes simplex hides in. . .

Answer 43

Dorsal root ganglia

Question 44

In a case of squashed nerve fibers. . .

Answer 44

Sensory nerves are affected before motor ones, so pain is an earlier finding than weakness. Also because each location only has one afferent nerve fiber, but multiple efferent nerve fibers.

Question 45

Afferent signals enter. . .

Answer 45

at multiple locations

Question 46

Efferent signals exit. . .

Answer 46

At one origin, but then branches