Sensory system, spinal cord and brainstem L6

Question 1

How long is the spinal cord

Answer 1

42-45

Question 2

What percentage of vertebral column is the spinal cord

Answer 2

upper 2/3

Question 3

Where does the spinal cord extend from

Answer 3

foramen magnum–> L1/L2

Question 4

Enlargements of the spinal cord=

Answer 4

cervical and lumbosacral

Question 5

A spinal segment=

Answer 5

1 spinal nerve coming out

Question 6

Order of the spinal cord and number of nerves

Answer 6

Cervical 8
Thoracic 12
Lumbar 5
Sacral 5
coccyx 1

Question 7

Ventral root=

Answer 7

purely motor (efferent)

Question 8

Dorsal root=

Answer 8

Purely sensory (afferent)

Question 9

Spinal nerve=

Answer 9

dorsal + ventral roots

Question 10

Where does the spinal nerve lie

Answer 10

intervertebral foramen

Question 11

Everything from the spinal cord distal is___

Answer 11

mixed

Question 12

Reason the spinal cord doesn’t extend all the way through the vertebral column

Answer 12

Developmental–> in utero

Question 13

At what stage of pregnancy does the the vertebral column grow longer than the cord

Answer 13

past three months

Question 14

What is the tapering down of the spinal cord called

Answer 14

conus medullaris

Question 15

Where is the conus medullaris found

Answer 15

L1/L2 (lower in child)

Question 16

What is the cauda equina

Answer 16

a bunch of roots sitting in the subarachnoid space

Question 17

What does the cauda equina NOT contain

Answer 17

spinal nerves

Question 18

What is the filum terminal

Answer 18

continuation of the pia matter that continues down to the bottom end of the subarachnoid space, containing the cauda equina

Question 19

What is the lumbar cistern

Answer 19

cerebrospinal fluid creating an anatomical lake without much neuro tissue

Question 20

What does the lumbar cistern contain

Answer 20

Filum terminal

nerve roots of the cauda equina

Question 21

Where to take lumbar tabs from

Answer 21

L3/L4 or L4/L5

Question 22

What happens to the amount of white matter as you travel down the spinal cord

Answer 22

decreases

Question 23

What is a commissure

Answer 23

an axon that crosses one side of the CNS to the other

Question 24

Deccussation=

Answer 24

crossing over the midline

Question 25

Ipsilateral=

Answer 25

on the same same

Question 26

Contralateral=

Answer 26

on the opposite side

Question 27

3 neurons of ascending pathways

Answer 27

First order second order third order

Question 28

First order neurons=

Answer 28

stimuli from external receptors --> cell bodies in dorsal roots

Question 29

Second order neurons=

Answer 29

spinal cord & brainstem tracts | Decussate (cross midline)

Question 30

Third order neurons=

Answer 30

thalamus via internal capsule

Question 31

Which tracts are conscious perception;

Answer 31

dorsal columns | spinothalamic

Question 32

what tratcs are unconscious perception;

Answer 32

spinocerebellar * spinotectal spinoreticular Spino-olivary

Question 33

Dorsal columns enter

Answer 33

via dorsal roots

Question 34

dorsal columns ascend

Answer 34

ipsilateral

Question 35

Dorsal columns synapse at the brain stem with

Answer 35

gracile and cuneate nuclei in medulla oblangata

Question 36

Fibres that run to the gracile nuclei form the_____

Answer 36

fasciculus gracilis (medial)

Question 37

Which area of the body does the fasciculus gracilis fibres represent

Answer 37

lower 1/2 (most medial fibres)

Question 38

Fibres that run to the cuneate nuclei form the ______

Answer 38

Fasciculus cuneatus (lateral)

Question 39

Fasciculus cuneatus fibres represent what area of the body

Answer 39

upper 1/2 of the body (lateral fibres)

Question 40

Dorsal root second order neurons start in the;

Answer 40

Nucleus (cuneate or gracile),

Question 41

Dorsal root second order decussate in____

Answer 41

The brain stem

Question 42

What tract do the dorsal root second order neurons form after the brain stem

Answer 42

medial lemniscus

Question 43

Where does the medial lemniscus tract run to

Answer 43

the contralateral thalamus

Question 44

Where do the third order neurons of the DCML run

Answer 44

from the contralateral thalamus to the corresponding part of the cerebral cortex

Question 45

DCML=

Answer 45

Dorsal column medial lemniscus

Question 46

What does the DCML sense

Answer 46

``` dicrimminative aspects of tactile and proprioceptive sensation; fine touch pressure vibration conscious proprioception ```

Question 47

spinothalamic tract first order neurons; (2 part story)

Answer 47

come into the spinal cord and synapse with the dorsolateral fasciculus, then rises up one or 2 segments ipsilaterally

Question 48

spinothalamic tract second order;

Answer 48

decussate straight away and ascend contralaterally (anterior to the ventral horn)

Question 49

What does the spinothalamic tract form in the brainstem

Answer 49

a spinal lemiscus (which stays on the same side)

Question 50

What does the anterior spinothalamic tract sense

Answer 50

crude touch

Question 51

What does the lateral spinothalamic tract sense

Answer 51

pain and temperature

Question 52

Spinocerebellar=

Answer 52

unconcious proprioception

Question 53

What does the dorsal spinocerebellar tract sense from

Answer 53

muscle spindles, golgi tendon organs, touch & pressure receptors

Question 54

The dorsal spinocerebellar tract enters at ?

Answer 54

T1-T2

Question 55

where do the 2nd order tracts in the dorsal spinocerebellar tract start and raise

Answer 55

nucleus dorsalis and raise ipsilaterally to the cerebellum (not thalamus)

Question 56

What is the ventral spinocerebellar tract used to sense

Answer 56

movement control

Question 57

Difference of the ventral and dorsal spinocerebellar tracts

Answer 57

the ventral decussates --> contralateral ascent