_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)

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)

_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, ..., ...)

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)

Structure and Function of the Spinal Cord Flashcards by Chrissy Taaffe

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

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

How well did you know this?

Not at all

Perfectly

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

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

How well did you know this?

Not at all

Perfectly

Anatomy of the spinal cord (2)

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

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

How well did you know this?

Not at all

Perfectly

Label the meninges

How well did you know this?

Not at all

Perfectly

Spinal cord is divided into four regions:

How well did you know this?

Not at all

Perfectly

Spinal cord - 4 regions:

How well did you know this?

Not at all

Perfectly

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

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

How well did you know this?

Not at all

Perfectly

Lumbar cistern contains what?

contains the cauda equina

How well did you know this?

Not at all

Perfectly

Spinal Nerves

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

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

How well did you know this?

Not at all

Perfectly

Spinal Nerves

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

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

How well did you know this?

Not at all

Perfectly

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

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

How well did you know this?

Not at all

Perfectly

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

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

How well did you know this?

Not at all

Perfectly

Grey matter organisation

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

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

How well did you know this?

Not at all

Perfectly

Grey matter organisation

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

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

How well did you know this?

Not at all

Perfectly

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)

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)

How well did you know this?

Not at all

Perfectly

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)

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)

How well did you know this?

Not at all

Perfectly

White matter organisation (2)

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

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

How well did you know this?

Not at all

Perfectly

White matter organisation (2)

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

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

How well did you know this?

Not at all

Perfectly

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)

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)

How well did you know this?

Not at all

Perfectly

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, …, …)

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)

How well did you know this?

Not at all

Perfectly

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 … …

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

How well did you know this?

Not at all

Perfectly

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 … …

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

How well did you know this?

Not at all

Perfectly

Dorsal column-medial lemniscus pathway

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

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

How well did you know this?

Not at all

Perfectly

Dorsal column-medial lemniscus pathway

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

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

How well did you know this?

Not at all

Perfectly

What pathway provides brain with positional information?

_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

* 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

_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 ...

_Dorsal column-medial lemniscus pathway - Second-order neurons_ * Cross in ... and ascend to ... * Form medial ... (ribbon-like)

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

_Dorsal column-medial lemniscus pathway - Third-order neurons_ * Project from thalamus to ... cortex

* Project from thalamus to somatosensory cortex

_Dorsal column-medial lemniscus pathway - summary_

_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

* 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

_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

_Spinothalamic tract_ * ... (From nociceptors) * .. * ... touch

* Pain (From nociceptors) * Temperature * Crude touch

_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

* 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

_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

* 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

_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

* 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

_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

* 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

_Spinothalamic tract - Third-order neurons_ * Project from ... to ... cortex

* Project from thalamus to somatosensory cortex

_Spinothalamic tract summary_

_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 ....)

* 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)

_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)

_Spinocerebellar tracts_ * Unconscious muscle ... (From muscle spindles, golgi tendon organs) - for smooth muscle ...

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

_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)

* 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)

_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)

_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

* 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

_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

_Descending tracts_ * Brain ... ... spinal cord * Control of ... activity * Many descending tracts * Grouped into pyramidal or extrapyramidal

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

_Descending tracts_ * Brain down towards spinal cord * Control of ... activity * Many descending tracts * Grouped into ... or ...

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

_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

* 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

_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

_Pyramidal tract_ * Upper motor axons pass through the ... of the ...

* Upper motor axons pass through the **pyramids** of the **medulla**

_Pyramids of decussation_ * Within the pyramids of the medulla, nerve fibres ... * 80% cross midline - ... corticospinal tract * 20% on same side - ... corticospinal tract

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

_Pyramids of decussation_ * Within the pyramids of the ..., nerve fibres decussate * ...% cross midline - lateral corticospinal tract * ...% on same side - anterior corticospinal tract

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

_Lower motor neuron_ * Excellent topographical organisation of lower motor neurons in ventral horn * Medial = t... * Anterolateral = ... limb segments * Posterolateral = ... limb segments

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

_Lower motor neuron_ * Excellent topographical organisation of lower motor neurons in ventral horn * ... = trunk * ... = proximal limb segments * ... = Distal limb segments

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

_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

* 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

_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

_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)

* 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)

_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)

* 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)

_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

* 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

_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

_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)

* 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)

_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)

_Summary of structure and function of the spinal cord_