Structure and Function of the Spinal Cord

Question 1

Anatomy of the spinal cord:

• Spinal cord extends from … to …
• Spinal cord narrows at … to form conus medullaris
• Terminal filum (pia extension) attaches to coccyx
• Space below … … vertebrae - lumbar cistern - will find cauda equina - dorsal and ventral roots of lumbar and sacral spinal nerves

Answer 1

• Spinal cord extends from atlas to L1
• Spinal cord narrows at L1 to form conus medullaris
• Terminal filum (pia extension) attaches to coccyx
• Space below first lumbar vertebrae - lumbar cistern - will find cauda equina - dorsal and ventral roots of lumbar and sacral spinal nerves

Question 2

Anatomy of the spinal cord:

• Spinal cord extends from atlas to L1
• Spinal cord narrows at L1 to form … …
• Terminal filum (pia extension) attaches to …
• Space below first lumbar vertebrae - lumbar cistern - will find … … - dorsal and ventral roots of lumbar and sacral spinal nerves

Answer 2

• Spinal cord extends from atlas to L1
• Spinal cord narrows at L1 to form conus medullaris
• Terminal filum (pia extension) attaches to coccyx
• Space below first lumbar vertebrae - lumbar cistern - will find cauda equina - dorsal and ventral roots of lumbar and sacral spinal nerves

Question 3

Anatomy of the spinal cord (2)

• Sits protected within … column (in … canal)
• Surrounded by the …

Answer 3

• Sits protected within vertebral column (in vertebral canal)
• Surrounded by the meninges

Question 4

Label the meninges

Answer 4

Question 5

Spinal cord is divided into four regions:

Answer 5

Question 6

Spinal cord - 4 regions:

Answer 6

Question 7

… enlargement - innervation to upper limb and … enlargement - innervation to lower limb

Answer 7

Cervical enlargement - innervation to upper limb and lumbosacral enlargement - innervation to lower limb

Question 8

Lumbar cistern contains what?

Answer 8

contains the cauda equina

Question 9

Spinal Nerves

• Spinal nerves connect the periphery to the spinal cord
• …. pairs, each formed by a dorsal root (… fibres) and ventral root (…. fibres)

Answer 9

• Spinal nerves connect the periphery to the spinal cord
• 31 pairs, each formed by a dorsal root (afferent fibres) and ventral root (efferent fibres)

Question 10

Spinal Nerves

• Spinal nerves connect the periphery to the spinal cord
• 31 pairs, each formed by a … root (afferent fibres) and … root (efferent fibres)

Answer 10

• Spinal nerves connect the periphery to the spinal cord
• 31 pairs, each formed by a dorsal root (afferent fibres) and ventral root (efferent fibres)

Question 11

Internal Anatomy (Spinal cord)

• Inner core, … matter
  
  • Neuronal cell bodies
  • H shaped
  • Ventral, lateral and dorsal horns(division of H shape)
• Outer, … matter
  
  • … axons
  • White columns/tracts/funiculi
• Note the expanded grey matter at levels that supply the limbs

Answer 11

• Inner core, grey matter
  
  • Neuronal cell bodies
  • H shaped
  • Ventral, lateral and dorsal horns(division of H shape)
• Outer, white matter
  
  • Myelinated axons
  • White columns/tracts/funiculi
• Note the expanded grey matter at levels that supply the limbs

Question 12

Internal Anatomy (Spinal cord)

• … core, grey matter
  
  • Neuronal cell bodies
  • … shaped
  • Ventral, lateral and dorsal horns (division of … shape)
• …, white matter
  
  • Myelinated …
  • White columns/tracts/funiculi
• Note the expanded grey matter at levels that supply the limbs

Answer 12

• Inner core, grey matter
  
  • Neuronal cell bodies
  • H shaped
  • Ventral, lateral and dorsal horns(division of H shape)
• Outer, white matter
  
  • Myelinated axons
  • White columns/tracts/funiculi
• Note the expanded grey matter at levels that supply the limbs

Question 13

Grey matter organisation

• … horn - neurons receiving sensory input
• … horn - preganglionic sympathetic neurons (autonomic)
• … horn - motor neurons

Answer 13

• Dorsal horn - neurons receiving sensory input
• Lateral horn - preganglionic sympathetic neurons (autonomic)
• Ventral horn - motor neurons

Question 14

Grey matter organisation

• Dorsal horn - neurons receiving … input
• Lateral horn - preganglionic … neurons (autonomic)
• Ventral horn - … neurons

Answer 14

• Dorsal horn - neurons receiving sensory input
• Lateral horn - preganglionic sympathetic neurons (autonomic)
• Ventral horn - motor neurons

Question 15

White matter organisation (1)

• Contains tracts
  
  • Long … tracts carry afferent (Sensory) impulses to centres within the brain
  • Long … tracts carry efferent (Motor) impulses from centres within brain
• Tracts to/from cerebral hemispheres - … (i.e. left cerebral hemisphere controls right side of body)

Answer 15

• Contains tracts
  
  • Long ascending tracts carry afferent (Sensory) impulses to centres within the brain
  • Long descending tracts carry efferent (Motor) impulses from centres within brain
• Tracts to/from cerebral hemispheres - crossed (i.e. left cerebral hemisphere controls right side of body)

Question 16

White matter organisation (1)

• Contains tracts
  
  • Long ascending tracts carry … (Sensory) impulses to centres within the brain
  • Long descending tracts carry … (Motor) impulses from centres within brain
• Tracts to/from … hemispheres - crossed (i.e. … cerebral hemisphere controls …. side of body)

Answer 16

• Contains tracts
  
  • Long ascending tracts carry afferent (Sensory) impulses to centres within the brain
  • Long descending tracts carry efferent (Motor) impulses from centres within brain
• Tracts to/from cerebral hemispheres - crossed (i.e. left cerebral hemisphere controls right side of body)

Question 17

White matter organisation (2)

• … column contains ascending tracts
• … column contains descending and ascending tracts
• … column contains mainly descending tracts

Answer 17

• Dorsal column contains ascending tracts
• Lateral column contains descending and ascending tracts
• Ventral column contains mainly descending tracts

Question 18

White matter organisation (2)

• Dorsal column contains … tracts
• Lateral column contains … and … tracts
• Ventral column contains mainly … tracts

Answer 18

• Dorsal column contains ascending tracts
• Lateral column contains descending and ascending tracts
• Ventral column contains mainly descending tracts

Question 19

Ascending (sensory) tracts

• Two types of sensory information carried in these tracts
• …
  
  • Information originating from inside the body (from muscles, joints, tendons)
• …
  
  • Information originating from outside the body (pain, temperature, touch)

Answer 19

• Two types of sensory information carried in these tracts
• Proprioceptive
  
  • Information originating from inside the body (from muscles, joints, tendons)
• Exteroceptive
  
  • Information originating from outside the body (pain, temperature, touch)

Question 20

Ascending (sensory) tracts

• Two types of sensory information carried in these tracts
• Proprioceptive
  
  • Information originating from … the body (from …, joints, …)
• Exteroceptive
  
  • Information originating from … the body (pain, …, …)

Answer 20

• Two types of sensory information carried in these tracts
• Proprioceptive
  
  • Information originating from inside the body (from muscles, joints, tendons)
• Exteroceptive
  
  • Information originating from outside the body (pain, temperature, touch)

Question 21

Ascending tracts - anatomy

• Often three neurons in circuit:
  
  • First order (primary sensory) neuron
    
    • Enters spinal cord via … root
  • Second order neuron
    
    • Ascends spinal cord or …
  • Third order neuron
    
    • Projects to the … …

Answer 21

• Often three neurons in circuit:
  
  • First order (primary sensory) neuron
    
    • Enters spinal cord via dorsal root
  • Second order neuron
    
    • Ascends spinal cord or brainstem
  • Third order neuron
    
    • Projects to the cerebral cortex

Question 22

Ascending tracts - anatomy

• Often three neurons in circuit:
  
  • … order (primary sensory) neuron
    
    • Enters spinal cord via … root
  • … order neuron
    
    • Ascends spinal cord or …
  • … order neuron
    
    • Projects to the … …

Answer 22

• Often three neurons in circuit:
  
  • First order (primary sensory) neuron
    
    • Enters spinal cord via dorsal root
  • Second order neuron
    
    • Ascends spinal cord or brainstem
  • Third order neuron
    
    • Projects to the cerebral cortex

Question 23

Dorsal column-medial lemniscus pathway

• … touch (from cutaneous mechanoreceptors)
• … (from muscle spindles, golgi tendon organs, joints)
• Provides brain with … information

Answer 23

• Fine touch (from cutaneous mechanoreceptors)
• Proprioception (from muscle spindles, golgi tendon organs, joints)
• Provides brain with positional information

Question 24

Dorsal column-medial lemniscus pathway

• Fine touch (from cutaneous …)
• Proprioception (from muscle …, … tendon organs, …)
• Provides brain with positional information

Answer 24

• Fine touch (from cutaneous mechanoreceptors)
• Proprioception (from muscle spindles, golgi tendon organs, joints)
• Provides brain with positional information

Question 25

What pathway provides brain with positional information?

Answer 25

Question 26

Dorsal column-medial lemniscus pathway - First order neurons

• Enter spinal cord and ascend dorsal column on same side within the:
  
  • Fasciculus … (medial)
  • Fasciculus … (lateral)
• Fibres ascend dorsal column uncrossed - … neurons in body
• First-order neurons synapse on second-order neurons in the …
• Axons are topographically organised
  
  • Fasciculus gracilis terminates in nucleus gracilis (gracile)
    
    • Information from … limb
  • Fasciculus cuneatus terminates in nucleus cuneatus (cuneate)
    
    • Information from … limb
• 2 bumps- gracile tubercle and cuneate tubercle

Answer 26

• Enter spinal cord and ascend dorsal column on same side within the:
  
  • Fasciculus gracilis (medial)
  • Fasciculus cuneatus (lateral)
• Fibres ascend dorsal column uncrossed - Longest neurons in body
• First-order neurons synapse on second-order neurons in the medulla
• Axons are topographically organised
  
  • Fasciculus gracilis terminates in nucleus gracilis (gracile)
    
    • Information from lower limb
  • Fasciculus cuneatus terminates in nucleus cuneatus (cuneate)
    
    • Information from upper limb
• 2 bumps- gracile tubercle and cuneate tubercle

Question 27

Dorsal column-medial lemniscus pathway - First order neurons

• Enter spinal cord and ascend dorsal column on same side within the:
  
  • Fasciculus gracilis (…)
  • Fasciculus cuneatus (…)
• Fibres ascend dorsal column … - Longest neurons in body
• First-order neurons synapse on second-order neurons in the medulla
• Axons are topographically organised
  
  • Fasciculus gracilis terminates in … … (gracile)
    
    • Information from lower limb
  • Fasciculus cuneatus terminates in … … (cuneate)
    
    • Information from upper limb
• 2 bumps- gracile … and cuneate …

Answer 27

• Enter spinal cord and ascend dorsal column on same side within the:
  
  • Fasciculus gracilis (medial)
  • Fasciculus cuneatus (lateral)
• Fibres ascend dorsal column uncrossed - Longest neurons in body
• First-order neurons synapse on second-order neurons in the medulla
• Axons are topographically organised
  
  • Fasciculus gracilis terminates in nucleus gracilis (gracile)
    
    • Information from lower limb
  • Fasciculus cuneatus terminates in nucleus cuneatus (cuneate)
    
    • Information from upper limb
• 2 bumps- gracile tubercle and cuneate tubercle

Question 28

Dorsal column-medial lemniscus pathway - Second-order neurons

• Cross in … and ascend to …
• Form medial … (ribbon-like)

Answer 28

• Cross in medulla and ascend to thalamus
• Form medial lemniscus (ribbon-like)

Question 29

Dorsal column-medial lemniscus pathway - Third-order neurons

• Project from thalamus to … cortex

Answer 29

• Project from thalamus to somatosensory cortex

Question 30

Dorsal column-medial lemniscus pathway - summary

Answer 30

Question 31

Damage to dorsal column

• Lesion on one side of spinal cord - E.g in multiple sclerosis
  
  • Loss of … discrimination + … on sameside
• Symptoms include sensory … - Loss of coordination and balance without visual cues (i.e. no positional information)
• Clinical test: … sign
  
  • Severe swaying on standing with eyes closed/feet together

Answer 31

• Lesion on one side of spinal cord - E.g in multiple sclerosis
  
  • Loss of tactile discrimination + proprioception on sameside
• Symptoms include sensory ataxia - Loss of coordination and balance without visual cues (i.e. no positional information)
• Clinical test: Romberg’s sign
  
  • Severe swaying on standing with eyes closed/feet together

Question 32

Damage to dorsal column

• Lesion on one side of spinal cord - E.g in multiple sclerosis
  
  • Loss of tactile discrimination + proprioception on … side
• Symptoms include sensory ataxia - Loss of … and … without visual cues (i.e. no positional information)
• Clinical test: Romberg’s sign
  
  • … swaying on … with eyes closed/feet together

Answer 32

• Lesion on one side of spinal cord - E.g in multiple sclerosis
  
  • Loss of tactile discrimination + proprioception on sameside
• Symptoms include sensory ataxia - Loss of coordination and balance without visual cues (i.e. no positional information)
• Clinical test: Romberg’s sign
  
  • Severe swaying on standing with eyes closed/feet together

Question 33

Spinothalamic tract

• … (From nociceptors)
• ..
• … touch

Answer 33

• Pain (From nociceptors)
• Temperature
• Crude touch

Question 34

Spinothalamic tract - First-order neurons

• Enter dorsal horn and form tract of …
  
  • Collateral branches given off at tip of dorsal horn
  • Run up or down 1-2 spinal segments
• Synapse in … … with second-order neurons

Answer 34

• Enter dorsal horn and form tract of Lissauer
• Collateral branches given off at tip of dorsal horn
• Run up or down 1-2 spinal segments
• Synapse in dorsal horn with second-order neurons

Question 35

Spinothalamic tract - First-order neurons

• Enter dorsal horn and form tract of Lissauer
  
  • … branches given off at … of dorsal horn
  • Run up or down 1-2 spinal segments
• … in dorsal horn with second-order neurons

Answer 35

• Enter dorsal horn and form tract of Lissauer
• Collateral branches given off at tip of dorsal horn
• Run up or down 1-2 spinal segments
• Synapse in dorsal horn with second-order neurons

Question 36

Spinothalamic tract - Second-order neurons

• Cross in dorsal horn at each level
• Ascend in … column to thalamus
  
  • Fibres from lower limb - … in tract
  • Fibres from upper limb - … in tract

Answer 36

• Cross in dorsal horn at each level
• Ascend in anterolateral column to thalamus
  
  • Fibres from lower limb - lateral in tract
  • Fibres from upper limb - medial in tract

Question 37

Spinothalamic tract - Second-order neurons

• Cross in dorsal horn at each level
• Ascend in anterolateral column to …
  
  • Fibres from … limb - lateral in tract
  • Fibres from … limb - medial in tract

Answer 37

• Cross in dorsal horn at each level
• Ascend in anterolateral column to thalamus
  
  • Fibres from lower limb - lateral in tract
  • Fibres from upper limb - medial in tract

Question 38

Spinothalamic tract - Third-order neurons

• Project from … to … cortex

Answer 38

• Project from thalamus to somatosensory cortex

Question 39

Spinothalamic tract summary

Answer 39

Question 40

Damage to anterolateral column

• Lesion on one side of spinal cord
  
  • Loss of pain, temperature and crude touch on … side
• … tract injury (E.g. cord … due to herniated disk)
  
  • Loss of lower limb pain first (Fibres sit ….)
• … tract injury (E.g. grey matter tumour)
  
  • Loss of upper limb pain first (fibres sit ….)

Answer 40

• Lesion on one side of spinal cord
  
  • Loss of pain, temperature and crude touch on opposite side
• Outer tract injury (E.g. cord compression due to herniated disk)
  
  • Loss of lower limb pain first (Fibres sit laterally)
• Inner tract injury (E.g. grey matter tumour)
  
  • Loss of upper limb pain first (fibres sit medially)

Question 41

Damage to anterolateral column

• Lesion on one side of spinal cord
  
  • Loss of …, … and … touch on opposite side
• Outer tract injury (E.g. cord compression due to … disk)
  
  • Loss of … limb pain first (Fibres sit laterally)
• Inner tract injury (E.g. grey matter …)
  
  • Loss of … limb pain first (fibres sit medially)

Answer 41

• Lesion on one side of spinal cord
  
  • Loss of pain, temperature and crude touch on opposite side
• Outer tract injury (E.g. cord compression due to herniated disk)
  
  • Loss of lower limb pain first (Fibres sit laterally)
• Inner tract injury (E.g. grey matter tumour)
  
  • Loss of upper limb pain first (fibres sit medially)

Question 42

Spinocerebellar tracts

• Unconscious muscle … (From muscle spindles, golgi tendon organs) - for smooth muscle …

Answer 42

• Unconscious muscle proprioception (From muscle spindles, golgi tendon organs) - for smooth muscle coordination

Question 43

Spinocerebellar tracts

• Only two neurons in pathway
• Comprises of 3 main tracts
  
  • E.g. … and … spinocerebellar tracts
    
    • Carries … information from trunk and lower limb
• Tracts terminate in the cerebellum on the same side (Left cerebellum controls left side of body)

Answer 43

• Only two neurons in pathway
• Comprises of 3 main tracts
  
  • E.g. anterior and posterior spinocerebellar tracts
    
    • Carries proprioceptive information from trunk and lower limb
• Tracts terminate in the cerebellum on the same side (Left cerebellum controls left side of body)

Question 44

Spinocerebellar tracts

• Only two neurons in pathway
• Comprises of 3 main tracts
  
  • E.g. anterior and posterior spinocerebellar tracts
    
    • Carries proprioceptive information from … and … limb
• Tracts terminate in the cerebellum on the … side (Left cerebellum controls … side of body)

Answer 44

• Only two neurons in pathway
• Comprises of 3 main tracts
  
  • E.g. anterior and posterior spinocerebellar tracts
    
    • Carries proprioceptive information from trunk and lower limb
• Tracts terminate in the cerebellum on the same side (Left cerebellum controls left side of body)

Question 45

Posterior Spinocerebellar tract

• First-order neurons
  
  • Synapse in … horn
• Second-order neurons
  
  • … in lateral column to cerebellum - Very … axons
• Lesion on one side of spinal cord
  
  • Uncoordinated lower limb muscular activity on … side
    
    • Although rarely damaged in isolation

Answer 45

• First-order neurons
  
  • Synapse in dorsal horn
• Second-order neurons
  
  • Ascend in lateral column to cerebellum - Very fast axons
• Lesion on one side of spinal cord
  
  • Uncoordinated lower limb muscular activity on same side
    
    • Although rarely damaged in isolation

Question 46

Posterior Spinocerebellar tract

• First-order neurons
  
  • Synapse in dorsal …
• Second-order neurons
  
  • … in lateral column to … - Very fast axons
• Lesion on one side of spinal cord
  
  • Uncoordinated … limb muscular activity on same side
    
    • Although … damaged in isolation

Answer 46

• First-order neurons
  
  • Synapse in dorsal horn
• Second-order neurons
  
  • Ascend in lateral column to cerebellum - Very fast axons
• Lesion on one side of spinal cord
  
  • Uncoordinated lower limb muscular activity on same side
    
    • Although rarely damaged in isolation

Question 47

Descending tracts

• Brain … … spinal cord
• Control of … activity
• Many descending tracts
• Grouped into pyramidal or extrapyramidal

Answer 47

• Brain down towards spinal cord
• Control of muscular activity
• Many descending tracts
• Grouped into pyramidal or extrapyramidal

Question 48

Descending tracts

• Brain down towards spinal cord
• Control of … activity
• Many descending tracts
• Grouped into … or …

Answer 48

• Brain down towards spinal cord
• Control of muscular activity
• Many descending tracts
• Grouped into pyramidal or extrapyramidal

Question 49

Corticospinal tract

• Great … motor pathway
• Pyramidal tract
• 2 neurons in circuit:
  
  • … motor (premotor) neurons
    
    • From cerebral cortex to ventral horn
  • … motor neurons
    
    • From ventral horn to skeletal muscle

Answer 49

• Great voluntary motor pathway
• Pyramidal tract
• 2 neurons in circuit:
  
  • Upper motor (premotor) neurons
    
    • From cerebral cortex to ventral horn
  • Lower motor neurons
    
    • From ventral horn to skeletal muscle

Question 50

Corticospinal tract

• Great voluntary motor pathway
• … tract
• 2 neurons in circuit:
  
  • Upper motor (premotor) neurons
    
    • From … cortex to … horn
  • Lower motor neurons
    
    • From … horn to skeletal muscle

Answer 50

• Great voluntary motor pathway
• Pyramidal tract
• 2 neurons in circuit:
  
  • Upper motor (premotor) neurons
    
    • From cerebral cortex to ventral horn
  • Lower motor neurons
    
    • From ventral horn to skeletal muscle

Question 51

Pyramidal tract

• Upper motor axons pass through the … of the …

Answer 51

• Upper motor axons pass through the pyramids of the medulla

Question 52

Pyramids of decussation

• Within the pyramids of the medulla, nerve fibres …
  
  • 80% cross midline - … corticospinal tract
  • 20% on same side - … corticospinal tract

Answer 52

• Within the pyramids of the medulla, nerve fibres decussate
  
  • 80% cross midline - lateral corticospinal tract
  • 20% on same side - anterior corticospinal tract

Question 53

Pyramids of decussation

• Within the pyramids of the …, nerve fibres decussate
  
  • …% cross midline - lateral corticospinal tract
  • …% on same side - anterior corticospinal tract

Answer 53

• Within the pyramids of the medulla, nerve fibres decussate
  
  • 80% cross midline - lateral corticospinal tract
  • 20% on same side - anterior corticospinal tract

Question 54

Lower motor neuron

• Excellent topographical organisation of lower motor neurons in ventral horn
  
  • Medial = t…
  • Anterolateral = … limb segments
  • Posterolateral = … limb segments

Answer 54

• Excellent topographical organisation of lower motor neurons in ventral horn
  
  • Medial = trunk
  • Anterolateral = proximal limb segments
  • Posterolateral = Distal limb segments

Question 55

Lower motor neuron

• Excellent topographical organisation of lower motor neurons in ventral horn
  
  • … = trunk
  • … = proximal limb segments
  • … = Distal limb segments

Answer 55

• Excellent topographical organisation of lower motor neurons in ventral horn
  
  • Medial = trunk
  • Anterolateral = proximal limb segments
  • Posterolateral = Distal limb segments

Question 56

Motor neuron disease

• Disruption of the corticospinal tract
• Upper motor neuron disease - Degeneration of upper motor neurons
  
  • Spastic … (… muscle tone)
  • … tendon reflexes
  • No significant muscle …
    
    • E.g. following a stroke
    • Stroke - … pyramids - symptoms opposite side, … pyramids = same side

Answer 56

• Disruption of the corticospinal tract
• Upper motor neuron disease - Degeneration of upper motor neurons
  
  • Spastic paralysis (increased muscle tone)
  • Overactive tendon reflexes
  • No significant muscle atrophy
    
    • E.g. following a stroke

Question 57

Motor neuron disease

• Disruption of the … tract
• Upper motor neuron disease - Degeneration of upper motor neurons
  
  • Spastic paralysis (increased muscle tone)
  • Overactive tendon reflexes
  • No significant muscle atrophy
    
    • E.g. following a …
    • Stroke - above pyramids - symptoms … side, below pyramids = … side

Answer 57

• Disruption of the corticospinal tract
• Upper motor neuron disease - Degeneration of upper motor neurons
  
  • Spastic paralysis (increased muscle tone)
  • Overactive tendon reflexes
  • No significant muscle atrophy
    
    • E.g. following a stroke
    • Stroke - above pyramids - symptoms opposite side, below pyramids = same side

Question 58

Lower motor neuron disease:

• Degeneration of lower motor neurons
  
  • Flaccid paralysis (… muscle tone)
  • … tendon reflexes
  • Muscle …
    
    • E.g. spinal muscular atrophy (A), Guillain-Barre syndrome (B)

Answer 58

• Degeneration of lower motor neurons
  
  • Flaccid paralysis (no muscle tone)
  • No tendon reflexes
  • Muscle atrophy
    
    • E.g. spinal muscular atrophy (A), Guillain-Barre syndrome (B)

Question 59

Lower motor neuron disease:

• … of lower motor neurons
  
  • Flaccid paralysis (no muscle tone)
  • No tendon reflexes
  • Muscle atrophy
    
    • E.g. spinal muscular … (A), …-… syndrome (B)

Answer 59

• Degeneration of lower motor neurons
  
  • Flaccid paralysis (no muscle tone)
  • No tendon reflexes
  • Muscle atrophy
    
    • E.g. spinal muscular atrophy (A), Guillain-Barre syndrome (B)

Question 60

Amyotrophic lateral sclerosis

• Selectively affects lower and upper motor neurons
  
  • Progressive muscle weakness and atrophy but mind intact
• Symptoms initially in limb or bulbar signs (speech and swallowing difficulties)
• … present when upper motor neurons affected
• … life span (about … years - due to … failure)
  
  • Affects ..-.. in 100,000

Answer 60

• Selectively affects lower and upper motor neurons
  
  • Progressive muscle weakness and atrophy but mind intact
• Symptoms initially in limb or bulbar signs (speech and swallowing difficulties)
• Spasticity present when upper motor neurons affected
• Short life span (about 5 years - due to respiratory failure)
  
  • Affects 4-5 in 100,000

Question 61

Amyotrophic lateral sclerosis

• Selectively affects lower and upper motor neurons
  
  • Progressive muscle … and … but mind …
• Symptoms initially in … or bulbar signs (… and … difficulties)
• Spasticity present when … motor neurons affected
• Short life span (about 5 years - due to respiratory failure)
  
  • Affects 4-5 in 100,000

Answer 61

• Selectively affects lower and upper motor neurons
  
  • Progressive muscle weakness and atrophy but mind intact
• Symptoms initially in limb or bulbar signs (speech and swallowing difficulties)
• Spasticity present when upper motor neurons affected
• Short life span (about 5 years - due to respiratory failure)
  
  • Affects 4-5 in 100,000

Question 62

Extrapyramidal tracts

• Do not pass through the pyramids
• Many extrapyramidal tracts:
  
  • Rubrospinal (From … nucleus (midbrain))
  • Reticulospinal (From … formation (pons))
  • Vestibulospinal (From … nuclei - medulla))
• Important for maintaining … and regulating … movements
• Lesions to extrapyramidal tracts cause movement disorders
  
  • e.g. dyskinesia (involuntary muscle movements), dystonia (involuntary muscle contractions)

Answer 62

• Do not pass through the pyramids
• Many extrapyramidal tracts:
  
  • Rubrospinal (From red nucleus (midbrain))
  • Reticulospinal (From reticular formation (pons))
  • Vestibulospinal (From vestibular nuclei - medulla))
• Important for maintaining posture and regulating involuntary movements
• Lesions to extrapyramidal tracts cause movement disorders
  
  • e.g. dyskinesia (involuntary muscle movements), dystonia (involuntary muscle contractions)

Question 63

Extrapyramidal tracts

• Do not pass through the …
• Many extrapyramidal tracts:
  
  • Rubrospinal (From red nucleus (…))
  • Reticulospinal (From reticular formation (…))
  • Vestibulospinal (From vestibular nuclei - …))
• Important for maintaining posture and regulating involuntary movements
• … to extrapyramidal tracts cause movement disorders
  
  • e.g. … (involuntary muscle movements), … (involuntary muscle contractions)

Answer 63

• Do not pass through the pyramids
• Many extrapyramidal tracts:
  
  • Rubrospinal (From red nucleus (midbrain))
  • Reticulospinal (From reticular formation (pons))
  • Vestibulospinal (From vestibular nuclei - medulla))
• Important for maintaining posture and regulating involuntary movements
• Lesions to extrapyramidal tracts cause movement disorders
  
  • e.g. dyskinesia (involuntary muscle movements), dystonia (involuntary muscle contractions)

Question 64

Summary of structure and function of the spinal cord

Answer 64