Lecture Outline #14 PNS

Question 1

the neural tube

Answer 1

ectoderm folds inward to form a hollow tube. Anterior end swells - hollow brain. Posterior portion - spinal cord & central canal. Both are filled with csf

Question 2

cortex of spinal cord

Answer 2

white matter - myelinated axons

Question 3

medulla of spinal cord

Answer 3

grey matter - cell bodies (unmyelinated axons)

Question 4

central canal of spinal cord

Answer 4

filled w/ csf

Question 5

dura mater

Answer 5

thick, fibrous, outermost layer, endosteum for braincase

Question 6

epidural space

Answer 6

between bone & dura mater, target for epidural block

Question 7

subdural space

Answer 7

space between dura mater & arachnoid

Question 8

arachnoid

Answer 8

thin, intermediate layer, contains large BV’s which are supported by arachnoid trabeculae

Question 9

subarachnoid space

Answer 9

space between arachnoid & pia mater, contains denticulate ligaments, filled with csf, target for spinal tap

Question 10

pia mater

Answer 10

vascular, innermost layer, fused to spinal cord, BV’s form a network on surface of cord

Question 11

meningitis

Answer 11

inflammation of meninges (bacteria, virus, injury)

Question 12

conus medullaris

Answer 12

tapered termination of cord

Question 13

filum terminale

Answer 13

fiber extending from conus to coccyx, acts as a tether holding onto the spinal cord to no retraction

Question 14

posterior median sulcus

Answer 14

shallow longitudinal groove

Question 15

anterior median fissure

Answer 15

deep longitudinal groove

Question 16

cauda equina

Answer 16

roots & rootlets, extend off of conus medullaris

Question 17

dorsal root

Answer 17

contains sensory nerves, afferent information going to CNS, contains dorsal root ganglion.

Question 18

ventral root

Answer 18

contains motor neurons (somatic & autonomic), CNS to PNS)

Question 19

dorsal ramus

Answer 19

innervates skin/muscles of back, branches off of spinal nerve, sensory & motor information

Question 20

ventral ramus

Answer 20

innervates skin/muscles of thorax, abdomen, limbs, motor information going out

Question 21

rami communicantes

Answer 21

ANS, visceri, both sensory & motor information. takes a ride of ventral rami

Question 22

cord diameter variations

Answer 22

cervical & lumbar (accommodates a plexus) both have a lot of grey matter

Question 23

spinal nerve

Answer 23

where dorsal & ventral roots meet at intervertebral foramen

Question 24

cervical nerves

Answer 24

C1-C8, named for vertebra below

Question 25

thoracic, lumbar, sacral, coccygeal nerves

Answer 25

T1-T12, L1-L5, S1-S5, co1. named for vertebra above

Question 26

dermatomes

Answer 26

pieces/segments of innervated skin

Question 27

T4

Answer 27

nipples

Question 28

T10

Answer 28

umbilicus

Question 29

S2-S4 (pudendal)

Answer 29

genitalia

Question 30

referred pain

Answer 30

(internal) brain & spinal cord can't differentiate pains of organs & skin because it uses the same axons to perceive

Question 31

communication steps

Answer 31

rami communicantes, ventral rami, CNS to perceive

Question 32

cervical plexus

Answer 32

C1-C5, innervates neck muscles, levator scapulae, part of trapezius & SCM

Question 33

phrenic nerve

Answer 33

C3-C5 keeps the diaphragm alive (controls contractions)

Question 34

brachial plexus

Answer 34

C5-T1

Question 35

axillary nerve

Answer 35

C5-C6, actions of deltoid & teres minor

Question 36

radial nerve

Answer 36

C5-T1, extensors of arm, forearm, wrist, fingers, and brachioradialis

Question 37

median nerve

Answer 37

C5-T1, flexors of wrist & digits 1-3

Question 38

ulnar nerve

Answer 38

C8-T1, funny bone(posterior to medial epicondyle), flexor carpi ulnaris & flexors of digits 4-5

Question 39

musculotaneus nerve

Answer 39

C5-C7, flexors of the arm & forearm (brachialis & BB)

Question 40

erb's palsy

Answer 40

C4-C6, upper plexus injury

Question 41

klumpke's palsy

Answer 41

lower plexus injury

Question 42

lumbosacral plexus

Answer 42

T12-S4

Question 43

gluteal nerve

Answer 43

L4-S2, gluteals

Question 44

obturator nerve

Answer 44

L2-L4, adductors of thigh

Question 45

pudendal nerve

Answer 45

S2-S4, GI?UG sphincters, external genitalia & skin around anus

Question 46

femoral nerve

Answer 46

L2-L4, extensors of knee (anterior aspect)

Question 47

tibial nerve

Answer 47

semis, bf lh, flexors of ankle & toes

Question 48

fibular nerve common

Answer 48

thigh area, bf sh

Question 49

fibular nerve superficialis

Answer 49

fibularis muscles

Question 50

fibular nerve deep

Answer 50

dorsi-flexors of ankle/toes (tibialis anterior)

Question 51

the sciatic nerve

Answer 51

bundle of tibial & common fibular nerve

Question 52

reflexes

Answer 52

built in safety mechanism, innate: hardwired or acquired: trauma, experiences. Processing sites are the brain & spc, spc acts as a brain via interneurons, message is sent to brain. Motor - somatic or visceral. Contralateral movement - extensor & flexor flip which is contracting

Question 53

reflex arc steps

Answer 53

1. stimulus of the receptor (pain or stretch) 2. sensory neuron (dorsal root) sends info to CNS 3. Relays info (sensation relayed to brain & motor nerves) 4. Motor neuron (ventral root) is activated 5. Peripheral effectors respond (muscles & glands)

Question 54

cerebrovascular accident

Answer 54

stroke, blood flow to the brain is interrupted or damaged

Question 55

paralysis

Answer 55

loss of motor control

Question 56

paraplegia

Answer 56

paralysis of lower limbs, T6-L1

Question 57

hemiplegia (possible CVA)

Answer 57

paralysis of one side of body, right hemisphere will show on the left side, vica versa

Question 58

quadriplegia

Answer 58

paralysis of all 4 limbs, (C4 or C6)

Question 59

Death

Answer 59

break at C3 and above

Question 60

palsy

Answer 60

regional loss of sensory/motor function

Question 61

spina bifida & meningomyelocoele

Answer 61

malformation of spine & spc, lamina does not completely form spinal cord goes completely out to skin