dorsal column medial leminiscal pathway

Question 1

what is this pathway important for

Answer 1

discriminative touch

Question 2

what is included in discriminative touch

Answer 2

• fine, two point touch
• pressure and stretch of the skin
• vibrations
• proprioreception

Question 3

what is proprioception

Answer 3

knowing ones position of joints and muscles in space
cerebellum and CNS needs to be aware of this

Question 4

what is a tract

Answer 4

a bundle of axons in the central nervous system

Question 5

is the dorsal column medial leminiscal pathway acscending or descending

Answer 5

ascending

Question 6

what are meissners corpuscles

Answer 6

found in dermal papillae
pick up fine touch

Question 7

what are merkels discs

Answer 7

found in stratum basal of the epidermis
specific receptors pick up superficial pressure and very fine touch

Question 8

what do pacinian corpuscles detect

Answer 8

pressure and vibration
found in dermis and hypodermis

Question 9

what are the peritrichial nerve endings

Answer 9

nerve fibres wrapped around hair follicles that detect the movement of the hairs

Question 10

what do ruffini corpuscles detect

Answer 10

stretch of the skin and vibrations

Question 11

what are the two fibres important for proprioception

Answer 11

extrafusasl and intrafusal

Question 12

wha are extrafusal fibres

Answer 12

these are the contracting fibres of the skeletal muscle, they are chain fibres and react to the onset of stretch

Question 13

what are intrafusal fibres

Answer 13

these detect stretch and will respond to the progression of stretch

Question 14

what are the proprioceptive fibres of the body

Answer 14

extrafusal and intrafusal fibres of skeletal muscle

Question 15

what are muscle spindles

Answer 15

type 1a fibres, proprioceptive

Question 16

describe golgi tendon organs

Answer 16

receptors that pick up tendon stretching like when muscles are contracting
if the tendon is pulled on too much, there is a protective response because of these receptors
carried on 1b fibres

Question 17

what pain comes from a delta fibres

Answer 17

fast pain and crude touch

Question 18

what do a alpha fibres get stimulation from

Answer 18

muscle spindles and golgi tendon organs

Question 19

what do a beta fibres take stimulation from

Answer 19

receptors in the skin

Question 20

how fast is a alpha axons

Answer 20

120 metres a second

Question 21

how fast are a delta fibres

Answer 21

30 metres a second

Question 22

what type of stimulation is a beta

Answer 22

pressure touch and vibration

Question 23

how do fibres enter the spinal cord

Answer 23

they come in through the first order neuron located in the dorsal root ganglion
they funnel in

Question 24

information for the lower half of the body enters the spinal cord at which vertebral level

Answer 24

T6 or below

Question 25

what is a ganglion

Answer 25

a group of cell bodies in the peripheral nervous system

Question 26

describe somatotopic arrangement of the spinal cord

Answer 26

the medial region has the fibres from the lowest region, and as you move out more laterally the fibres go from sacral to lumbar to thoracic, and then certical is on the very outer portion

Question 27

where are second order neurons found

Answer 27

brainstem, at the medulla

Question 28

what are the fibres called when the second order neurons cross over in the brainstem

Answer 28

the internal arcuate fibres