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