Internal Structure Of Spinal Cord 1

Front 1

What are the laminae of the grey matter?

Back 1

1. Areas correspond to body parts/regions

Front 2

What are the nuclei of the posterior horn?

Back 2

1. Substantia gelatinosa

2. Nucleus prorpius

3. Clark's dorsal nucleus

Front 3

What are the conscious tracts?

Back 3

1. Gracile

2. Cuneate

3. Lateral spinothalamic

4. Ventral spinothalamic

Front 4

What is the function of the substantial gelatinosa?

Back 4

1. Pain and temperature

Front 5

Where do the efferent fibers of the substantial gelatinosa cross and ascend?

Back 5

1. Cross in white commissure

2. Ascend in lateral column of white matter

Front 6

What is the sensory function of the nucleus proprius?

Back 6

1. Light pressure

2. Crude touch

Front 7

How do the fibers of the nucleus proprius cross and ascend?

Back 7

1. Cross opposite side in white commissure

2. Ascend in anterior white matter

Front 8

What is the afferent function of Clark's dorsal nucleus?

Back 8

1. Proprioception via collaterals from poster column white matter

Front 9

How do the fibers of Clark's dorsal nucleus ascend?

Back 9

1. No crossing

2. Ascend on same side in posterior spinocerebellar tract

Front 10

What is the efferent function of the medial anterior group?

Back 10

1. Innervate axial trunk muscles

Front 11

What is the efferent function of the lateral group?

Back 11

1. Innervate muscles of upper and lower limbs

Front 12

What is the efferent function of the central group?

Back 12

1. Runs in phrenic nerve to diaphragm

2. Innervate trapezius and SCM

Front 13

What sensation is carried in the gracile tract?

Back 13

1. Proprioception and fine touch from lower 1/2 of body

Front 14

What is the origin of the gracile and cuneate tracts?

Back 14

1. Cells of dorsal root ganglion central process

Front 15

Where does the gracile tract terminate?

Back 15

1. Gracile nucleus in closed medulla

Front 16

What sensation does the cuneate tract carry?

Back 16

1. Proprioception and fine touch from upper 1/2 of body

Front 17

What is the termination of the cuneate tract?

Back 17

1. Cuneate nucleus in closed medulla

Front 18

What sensation does the lateral spinothalamic tract carry?

Back 18

1. Pain and temperature

2. From opposite 1/2 of body BELOW THE HEAD

Front 19

What is the origin of the lateral spinothalamic tract? Termination

Back 19

1. Origin: axons of SGR cross in front of central canal

2. Termination: posterolateral ventral nucleus of thalamus--- PLVN

Front 20

What sensation does the anterior spinothalamic tract carry?

Back 20

1. Crude touch and light pressure

2. Opposite side of body below the head

Front 21

What is the origin of the anterior spinothalamic tract? Termination?

Back 21

1. Origin: axons of nucleus proprius

2. Termination: PLVN of thalamus

Front 22

What tracts carry unconscious sensations?

Back 22

1. Dorsal spinocerebellar

2. Ventral spinocerebellar

3. Spinoolivary

4. Spinotectal

Front 23

Where must all conscious sensations reach in the brain?

Back 23

1. Sensory area in postcentral gyrus

Front 24

From where do sensory areas in the cerebral hemisphere receive sensation?

Back 24

1. Opposite half of body

Front 25

How are sensations transmitted from receptors to sensory areas?

Back 25

1. 3 neurons--- 1o, 2o, 3o

Front 26

What is the 1st order neuron in sensation transmission?

Back 26

1. Lies in dorsal root ganglion

2. Peripheral process--- receives sensation from receptors

3. Central--- transmits to 2nd order neuron

Front 27

What are the 2nd order neurons in sensory transmission?

Back 27

1. Spinal cord: pain, temperature and touch

2. Medulla: proprioception and fine touch

Front 28

What are the 3rd order neurons for all sensation?

Back 28

1. Lie in PLVNT of OPPOSITE side

2. Subsequently pass to post central gyrus

Front 29

What will a lesion in the dorsal column lead to?

Back 29

1. Loss of proprioception--- high stepping and unsteady gait

2. Occurs in tabes dorsalis

Front 30

What is syringomyelia?

Back 30

1. Over-enlargement in the central canal of the spinal cord

2. Due to fusion of the central canal with cysts in the grey matter

Front 31

What is hydromyelia?

Back 31

1. Overdistension of the central canal with ependymal cell

Front 32

What are the ssx of syringomyelia?

Back 32

1. Selective loss of pain and temperature sensation

2. "Dissociated sensory loss"--- light touch and proprioception sensation preserved

Front 33

What are the destinations in cortical pain processing?

Back 33

1. Somatosensory cortex-- conscious recognition

2. Cingulate gyrus (limbic)--- emotional

3. Insular cortex----autonomic (pain, sweating)

4. Reticular formation--- on/off switch

5. Intraluminar nuclei of thalamus

Front 34

What is the first order neuron in the trigeminal pathway?

Back 34

1. Trigeminal ganglion

Front 35

What is the second order neuron in the trigeminal pathway?

Back 35

1. Main sensory nucleus

2. Spinal nucleus

3. Trigeminal nucleus

Front 36

What is the third order neuron in the trigeminal pathway?

Back 36

1. Posteromedial ventral nucleus of thalamus (PMVNT)

Front 37

What is the function of the main sensory nucleus in the trigeminal pathway?

Back 37

1. Crude touch

Front 38

What is the function of the spinal nucleus in the trigeminal pathway?

Back 38

1. Pain and temperature

Front 39

What is the function of the mesencephalic nucleus of trigeminal in the trigeminal pathway?

Back 39

1. Proprioception and fine touch

Front 40

What is the first order neuron in the dorsal spinocerebellar tract?

Back 40

1. Dorsal root ganglion

Front 41

What is the second order neuron in the dorsal spinocerebellar tract?

Back 41

1. Clark's nucleus in posterior horn of grey matter

2. Axons ascend in the SAME side of spinal cord

3. Pass through inferior cerebellar peduncle to reach cerebellum of same side

Front 42

What is the function of the ventral/dorsal spinocerebellar tract?

Back 42

1. Control muscle tone

2. Coordination of movements an posture of individual muscles of trunk and lower limb on SAME SIDE

Front 43

What types of lesions lead to loss of sensation contralaterally?

Back 43

1. Damage to sensory area of cerebral cortex

2. Damage to 2nd order neuron

3. Damage to 3rd order neuron

Front 44

What type of lesion will lead to loss of sensation ipsilaterally?

Back 44

1. Damage to first order neuron