fall lecture 18

Question 1

what is a spinal cord

Answer 1

• information highway between brain and body
• tissue the size of an index finger

Question 2

what do spinal nerve pairs do

Answer 2

• receives sensory information and sends motor signals to effector

Question 3

function of spinal cord

Answer 3

• conduction
• locomotion
• reflexes

Question 4

conduction

Answer 4

• bundles of fibers passing info up and down spinal cords
• (electrical signals)

Question 5

locomotion

Answer 5

• repetitive, coordinated actions of several muscle groups
• delivers impulses
• locomotion could be lost due to spinal cord injury (paralysis)

Question 6

reflexes

Answer 6

• tests pathways
• involuntary, stereotyped responses to stimuli
• if you wack someones knee and it doesn’t move spinal cord could be damaged

Question 7

where do pairs of spinal nerves arise from

Answer 7

• cervical, thoracic, lumbar and sacral

Question 8

cauda equina

Answer 8

• nerve roots resemble horse tail
• branch out by buttcrack

Question 9

what do meninges do

Answer 9

• cover brain and spinal cord

Question 10

what are the 3 meninges

Answer 10

• dura mater
• arachnoid mater
• Pia mater
  (in order from superficial to deep)

Question 11

Dura mater

Answer 11

• ” tough mother “
• tough collagenous membrane surrounded by epidural space field with fat and blood vessels

Question 12

Epidural

Answer 12

• do not block pain, reduces pain
• go outside of dura
• when placing an epidural, you wait for a loss of resistance when reaching dura fat

Question 13

spina bifida

Answer 13

• failure of vertebral arch to close and cover spinal cord
• dura forms outside of body
• caused by deficiency of folic acid (vitamin B)

Question 14

Arachnoid mater

Answer 14

• filled with cerebrospinal fluid
• has white “webs”
• creates subarachnoid space

Question 15

Pia mater

Answer 15

• delicate membrane adherent to spinal cord
• thin, clear, tight wrapping

Question 16

Grey mater

Answer 16

• any part of a neuron that doesn’t have myelin
• ex. dendrites, cell body, parts of knob
• shaped like a butterfly

Question 17

White mater

Answer 17

• myelinated axons; tracts
• take info up very quickly

Question 18

ascending

Answer 18

• toward brain

Question 19

desending

Answer 19

• away from brain

Question 20

decussation

Answer 20

• everything on left body is interpreted by right brain and vice versa
• stimulus and end result in the brain are on opposite sides of body
• when fibers cross sides
  most nerve pathways undergo this

Question 21

contralateral

Answer 21

• organ of stimulus and place of interpretation in brain are on opposite sides

Question 22

ipsilateral

Answer 22

• no decussation / no crossing over

Question 23

spinal tracts

Answer 23

• can be ascending
• can be descending

Question 24

most pathways

Answer 24

• take 3 neurons / synapses to reach destination (usually the cortex; outer region of brain)

Question 25

Decussation happens

Answer 25

• in 2nd order neuron in medulla

Question 26

Ascending pathway

Answer 26

• Spinothalamic pathway

Question 27

spinothalamic pathway

Answer 27

• pain, pressure, tickle, ect..
• decussation of 2nd order neuron

Question 28

descending tracts

Answer 28

• tectospinal tract
• reticulospinal tract
• vestibulospinal tract

Question 29

tectospinal tract

Answer 29

• reflex to sights and sounds behind us

Question 30

reticulospinal tract

Answer 30

• controls limb movements to maintain posture and balance
• weather or not were falling over
• activity in response to inner ear signals
• balence and spinning

Question 31

vestibulospinal tract

Answer 31

• activity in response to inner ear signals
• balence and spinning

Question 32

diseases effecting the ventral root/ motor response

Answer 32

• poliomyelitis
• Amyotropich lateral sclerosis

Question 33

poliomyelitis

Answer 33

• caused by poliovirus (spread by fecally contaminated water)
• scar left by vaccine
• destroys ventral roots
• “people have very skinny limbs with this virus

Question 34

Amyotrophic lateral sclerosis

Answer 34

• ALS
• death typically within 3 years
• motor neurons are attacked leading to 100% paralysis
• Steve Gleason and Ice bucket challenge

Question 35

ramus

Answer 35

• branch off of spinal nerves

Question 36

plexus

Answer 36

• collection of nerves
• when a ramus reacts with several branches

Question 37

what could could lead to loss of breath

Answer 37

• a disruption in the nerve signals of the plexus

Question 38

shingles

Answer 38

• attacks only 1 nerve pathway
• getting a virus (ex. flu or covid) could cause your body to forget how to fight off chicken pox and you could get shingles
• can have lingering effects and cause patients to go crazy due to pain

Question 39

dermatome

Answer 39

• overlapping of spinal nerve regions
• ex. when having tooth surgery, they ask when your tongue goes numb

Question 40

grade 3 reflex

Answer 40

• when you see spread of the reflex to adjacent muscle groups ex. when you see reflex on opposite side

Question 41

grade 2 reflex

Answer 41

• normal

Question 42

grade 1 reflex

Answer 42

• reduced compared to normal reflex

Question 43

grade 0 reflex

Answer 43

• no reflex at all

Question 44

clonus

Answer 44

• grade 4 reflex
• an abnormal reflex response that involves involuntary and rhythmic muscle contractions