Nervous Tissue

Question 1

peripheral nerve

-where are its axons located?

Answer 1

axons with cell bodies that are located
-within dorsal root ganglia at each spinal nerve segment
axons of motor neuron cell bodies located within ventral horn of spinal cord

Question 2

sensory nerves

• other name
• function

Answer 2

afferent nerves

carry signals from receptors located throughout the body in the skin, muscles, connective tissue and visceral organs

Question 3

motor nerves

• other name
• function

Answer 3

efferent

innervate all muscle tissue, voluntary striated, cardiac striated, and smooth muscle

Question 4

each peripheral nerve we identify contains…

-called a…

Answer 4

contains both sensory and motor axons

called a mixed nerve

Question 5

where is the only place the sensory and motor axons of the peripheral nerves are separated?

Answer 5

central to (before) the formation of the spinal nerve
-the dorsal and ventral roots

Question 6

dorsal root
-contains
ventral root
-contains

Answer 6

dorsal: only sensory axons
ventral: only motor axons

Question 7

the formation of the spinal nerve occurs near or within which structure

Answer 7

intervertebral foramen

Question 8

distal to the formation of the spinal nerve, all identified nerve bundles are considered…

Answer 8

mixed nerves

Question 9

all peripheral nerves are encased in…

Answer 9

a series of CT coverings

Question 10

all nerve (CT) coverings consists of… (4)

Answer 10

mesoneurium
epineurium
perineurium
endoneurium

Question 11

each of these layers is made up of CT with… (2)

Answer 11

its own innervation (nervi nervosum)

its own vascular supply (vasa nervosum)

Question 12

mesoneurium

• alternate name
• function

Answer 12

name
-paraneurium (not to be confused with PERIneurium)
function
-covering of entire nerve that allows the nerve to move independently without being impinged or constricted by surrounding structures

Question 13

constriction of a nerve can result in…

Answer 13

irritation of the nerve

• causes it to fire abnormally
• OR
• restrict the axons from propogating their respective action potentials

Question 14

mesoneurium

-CT type

Answer 14

loose irregular CT

Question 15

epineurium

-encapsulates…

Answer 15

encapsulates entire nerve
more intimately attached to CT compartments of the nerve itself
can be seen encasing larger groups of axons called fascicles

Question 16

perineurium

-function

Answer 16

further subdivides nerve to smaller fascicles that begin to correspond closely to divisions heading toward specific muscles or dermatomes

Question 17

endoneurium

-most closely associated with…

Answer 17

individual axons

Question 18

functions of CT compartments of the axons of a peripheral nerve

Answer 18

allow for exchange of ions for actions potentials

allow for the exchange of nutrients and metabolites for the region of the nerve

Question 19

what aspects of the peripheral nerve give it the ability to “stretch” to accommodate movement around joints or areas of possible restriction

Answer 19

elastic property of the CT

slightly undulating arrangement of individual axons

Question 20

result of temporary compression of a peripheral nerve

-common names for this phemonemon

Answer 20

depletion of the vascular supply to the individual axons
-results in a loss of the ability to propagate action potentials
names
-foot or hand “falling asleep”

Question 21

result of prolonged compression of a peripheral nerve

Answer 21

longer lasting effect on the nerve similar to that of temporary compression

Question 22

what is the theory of adverse neural tension

Answer 22

includes the idea the the peripheral nervous system (PNS) is continuous with the central nervous system (CNS)
-with respect to both neural elements and CT elements

Question 23

meninges

-composition

Answer 23

CT

Question 24

outermost layer of the CNS

• name
• continuous with what part of the PNS?

Answer 24

dura mater

continuous within the intervertebral foramen with the epineurium

Question 25

perineurium

-continuous with what parts of CNS

Answer 25

continuous in part with dura mater

continuous in part with pia mater (innermost meningeal covering)

Question 26

endoneurium

-continuous with what part of the CNS

Answer 26

continuous with the pia mater

Question 27

implications of the theory of adverse neural tension

Answer 27

stresses put on peripheral nerves in terms of stretch necessarily are transmitted to the CNS covering (meninges)

Question 28

dura mater is connected with…

-what do these connections imply?

Answer 28

vertebrae
skull
implication
-movements of the spine may produce a stretch on the peripheral nervous system