Neuroanatomy 2

Question 1

when does the spinal canal end?

Answer 1

L1-L2

Question 2

why do we take CSF from L4 level?

Answer 2

the spinal cord has ended so there is low risk of damaging it

Question 3

the region where the spinal cord terminates is called the …

Answer 3

conus medullaris

Question 4

what is the very end section of the spinal canal (NB not cord) called?

Answer 4

filum terminale

Question 5

what keeps the spinal cord in place in the spinal canal?

Answer 5

denticulate ligament (looks like teeth)

Question 6

the inner part of the spinal cord is made up of __ matter

Answer 6

grey

Question 7

the outer part of the spinal cord is made up of __ matter

Answer 7

white

Question 8

what is located in the centre of the spinal cord?

Answer 8

central canal

Question 9

when looking at a cross section of a spinal cord, how can you tell which side is posterior?

Answer 9

the part where the 2 horns of the grey matter meet the surface is posterior

Question 10

when discussing the spinal cord, anterior can also be called ___

Answer 10

ventral (think Av)

Question 11

which spinal segments contain a lateral horn and why?

Answer 11

T1-L2

contain the preganglionic sympathetic neurons (thoracolumbar)

Question 12

how many longitudinal arteries supply the spinal cord?

Answer 12

3 (1 anterior, 2 posterior)

Question 13

aside from the longitudinal arteries, which other arteries supply the spinal cord?

Answer 13

segmental and radicular arteries

Question 14

segmental arteries are derived from?

Answer 14

vertebral, intercostal and lumbar arteries

Question 15

where do radicular arteries exist?

Answer 15

around the dorsal and ventral roots (radicular means root)

Question 16

venous drainage of the spinal cord is similar to that of the arterial supply T or F

Answer 16

T

Question 17

what is the epidural space?

Answer 17

the space between the dura and the bone in the spinal cord (epidural is given here)

Question 18

where do sensory neurons go to?

Answer 18

the primary somatosensory cortex in the postcentral gyrus

Question 19

define ganglion

Answer 19

group of cell bodies located outwith the CNS

Question 20

where does the PNS begin?

Answer 20

spinal rootlets

Question 21

the anterior cerebral artery runs along the __ fissure

Answer 21

longitudinal

Question 22

why do some regions of the spinal cord have more grey matter than others?

Answer 22

more dermatomes to reach/longer route to travel eg for an arm will require more grey matter

Question 23

which pathway is in charge of sensation for fine touch and proprioception?

Answer 23

the dorsal column/medial lemniscus pathway

Question 24

what is a lemniscus?

Answer 24

band of white matter that travels up the spinal cord

Question 25

where do the fibres in the DCML pathway cross?

Answer 25

medulla oblongata

Question 26

sensory fibres from the LHS will be transmitted to the .... of the brain

Answer 26

RHS

Question 27

name the 2 synapse points in the DCML pathway

Answer 27

1. medulla | 2. thalamus

Question 28

where is the end point of the DCML pathway?

Answer 28

postcentral gyrus

Question 29

what does the spinothalamic tract control?

Answer 29

transmits sensory fibres for pain, temperature and deep pressure to the brain

Question 30

where do the spinothalamic tract fibres cross?

Answer 30

segmentally (switches sides) at the very start in the same area of the spinal cord as it originated

Question 31

what sensory pathway transmits pain fibres?

Answer 31

spinothalamic tract

Question 32

where do the fibres of the spinothalamic tract synapse?

Answer 32

thalamus

Question 33

where is the primary motor cortex located?

Answer 33

precentral gyrus

Question 34

main motor tract of the body

Answer 34

corticospinal tract

Question 35

where does the corticospinal tract start and end

Answer 35

precentral gyrus to spinal cord

Question 36

what does the corticospinal tract control?

Answer 36

fine, precise movement of distal limb muscles

Question 37

why is the corticospinal tract also called the pyramidal tract?

Answer 37

forms visible ridges that look like pyramids on the anterior surface of the medulla

Question 38

where does the corticospinal tract's fibres cross?

Answer 38

medulla around the foramen magnum

Question 39

all fibres of the CS tract cross at the medulla T or F

Answer 39

F, a few cross segmentally at a certain spinal level

Question 40

crossed fibres of the CS tract are referred to as...

Answer 40

lateral CST

Question 41

uncrossed fibres of the CS tract are referred to as...

Answer 41

ventral CST

Question 42

what would happen clinically if a CVA occurred in the CS tract?

Answer 42

patient would have spastic paralysis with hyperflexion of the upper limbs

Question 43

what does the tectospinal tract control?

Answer 43

``` MOTOR function (mainly visual and auditory) to cervical segments reflex function to head and neck ```

Question 44

where does the tectospinal cord start and end?

Answer 44

tectum (roof of midbrain) to spinal cord

Question 45

define the reticular formation

Answer 45

series of interconnected nuclei in the brainstem that carry out automatic functions in the body eg breathing

Question 46

what motor functions does the reticulospinal tract control?

Answer 46

voluntary movement eg walking

Question 47

fibres originating in the pons facilitate __ movements

Answer 47

extensor

Question 48

fibres originating in the medulla facilitate __ movements

Answer 48

flexor

Question 49

what tract is in charge of regaining your balance after a trip?

Answer 49

vestibulospinal tract

Question 50

main function of the vestibulospinal tract?

Answer 50

excitatory input to antigravity extensor muscles

Question 51

where does the vestibulospinal tract start and end?

Answer 51

vestibular nuclei of the pons and medulla to the spinal cord

Question 52

a lesion where would have a severe impact on the vestibulospinal tract?

Answer 52

midbrain

Question 53

if the vestibulospinal tract didnt work what would happen to muscle tone?

Answer 53

extensor muscle tone would overreact and the patient would become spastic

Question 54

a lesion in the corticospinal tract at RHS spinal cord level will cause loss of function in what side?

Answer 54

RHS as fibres have already crossed at the brain