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Introduction
1. Cardiopulmonary system
2. Pulmonary system
3. Neuromuscular system
3.1 Central nervous system
3.2 Anatomy and function of spinal cord
3.3 Peripheral nervous system
3.4 Differential diagnosis of central nervous system pathologies
3.5 Differential diagnosis of peripheral nervous system
3.6 Other neurological conditions
3.7 Interventions for neurological conditions
3.8 Vestibular system
4. Pediatrics
5. Musculoskeletal system
6. Other system
7. Non-systems
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3.2 Anatomy and function of spinal cord
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3. Neuromuscular system
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Anatomy and function of spinal cord

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Primary function of spinal cord

  • Acts a relay pathway between peripheral system and brain
    • Provides sensory information regarding the environment to the brain
    • Manages motor commands to the peripheral system in reaction to environment
    • Coordinates simple reflexes that do not have to go to brain such as withdrawal from pain, patellar reflex, etc

Anatomy of spinal cord

  • Cervical spine
    • Eight (8) nerves that provide innervation to neck and upper extremity
  • Thoracic spine
    • Twelve (12) nerves that provide innervation to upper chest, chest, abdomen, upper back
  • Lumbar spine
    • Five (5) nerves that provide innervation to legs and feet
  • Sacral spine
    • Five (5) nerves that provide innervation to sacrum and pelvis
  • Cocxygeal spine
    • One (1) nerve that provides innervation to the perineal area

Image #21

alt_text

https://upload.wikimedia.org/wikipedia/commons/7/72/Spinal_cord_details.jpg

Protective layers of spinal cord

  • Dura mater
    • Outermost protective layer
    • Space between dura and bony vertebral body referred to as epidural space which contains adipose tissue and blood vessels
  • Arachnoid
    • Middle layer with web-like appearance
    • Space between dura and arachnoid referred to as subarachnoid space and contains cerebrospinal fluid
  • Pia mater
    • innermost layer that is in direct contact with spinal cord

Image #22

alt_text

https://upload.wikimedia.org/wikipedia/commons/7/72/Spinal_cord_details.jpg

Definitions
Dorsal root
Sensory nerve that carries information from spinal cord to brain
Ventral root
Motor nerve that carries information from brain to spinal cord
Spinal nerve
Pathway for sensory and motor information to move between peripheral system and spinal cord
Denticulate ligament
Ligament that provides stabilization of the spinal cord
Posterior (dorsal) gray horn
Nerve fibers containing sensory information from the body
Lateral gray horn
Nerve fibers containing sympathetic nervous system information only found in thoracic, upper lumbar, and sacral regions of spinal cord
Anterior (ventral) gray horn
Nerve fibers containing motor neurons that control skeletal muscles
Posterior (dorsal) white column:
Nerve fibers containing sensory information from the body such as two point discrimination, fine touch, vibration, and proprioception
Lateral white column
Nerve fibers that contain sensory information such as pain, temperature, and crude touch
Anterior (ventral) white column
Nerve fibers containing sensory and motor nerve fibers that provide information to the contralateral brain
Sympathetic nervous system
Network of nerves that are enacted to aid in the response to physical activity, stress, or danger (fight or flight response)
Parasympathetic nervous system
Network of nerves that provide relaxation after the body has responded to stressful or dangerous situation (rest and digest response)

Image #23

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2019/07/1313_Spinal_Cord_Cross_Section-1339x1536.jpg

Spinal tracts

  • Ascending tracts
    • Carry sensory information such as touch, pain, and temperature from peripheral system to brain
    • Names of tracts/pathways:
      • Dorsal column-medial lemniscal: transmit light touch, deep pressure, two-point discrimination, and vibratory information to cerebrum via the thalamus- crosses in the medulla to the contralateral side
      • Anterior and lateral spinothalamic: transmit pain, crude touch, and temperature information to cerebrum via the thalamus- crosses in the medulla to the contralateral side
      • Spinocerebellar: transmit proprioceptive information to the cerebellar- does not cross; stays on same side

Image #24

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2019/07/1417_Ascending_Pathways_of_Spinal_Cord-1500x1536.jpg

  • Descending tracts
    • Carry motor information from brain to peripheral system to give voluntary commands of movement of axial and skeletal muscles
    • Names of tracts/pathway:
      • Anterior and lateral corticospinal: transmit commands to move axial and/or skeletal muscles

Image #24

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2021/02/1426_Corticospinal_Pathway-702x1536.jpg

Arterial circulation of spinal cord

  • Two (2) primary arteries of spinal cord
    • Anterior spinal artery
      • Supplies blood to the anterior two-thirds of the spinal cord with the exception of dorsal column
    • Posterior spinal artery
      • Provides blood supply to posterior spinal cord via two (2) branches that supply the dorsal sensory column, dorsal grey matter, and posterior columns

Primary function of spinal cord

  • Relay pathway between peripheral system and brain
  • Transmits sensory info to brain; manages motor commands to periphery
  • Coordinates simple reflexes (e.g., withdrawal, patellar reflex)

Anatomy of spinal cord

  • Cervical spine: 8 nerves, neck & upper extremity innervation
  • Thoracic spine: 12 nerves, upper chest, chest, abdomen, upper back
  • Lumbar spine: 5 nerves, legs & feet
  • Sacral spine: 5 nerves, sacrum & pelvis
  • Coccygeal spine: 1 nerve, perineal area

Protective layers of spinal cord

  • Dura mater: outer layer; epidural space with adipose & blood vessels
  • Arachnoid: middle, web-like; subarachnoid space with cerebrospinal fluid
  • Pia mater: innermost, direct contact with spinal cord

Key spinal cord structures and definitions

  • Dorsal root: sensory nerve, spinal cord to brain
  • Ventral root: motor nerve, brain to spinal cord
  • Spinal nerve: pathway for sensory & motor info between periphery and cord
  • Denticulate ligament: stabilizes spinal cord
  • Gray horns:
    • Posterior (dorsal): sensory info from body
    • Lateral: sympathetic nervous system (thoracic, upper lumbar, sacral only)
    • Anterior (ventral): motor neurons for skeletal muscles
  • White columns:
    • Posterior: sensory (touch, vibration, proprioception)
    • Lateral: sensory (pain, temperature, crude touch)
    • Anterior: sensory & motor fibers to contralateral brain
  • Sympathetic nervous system: fight or flight response
  • Parasympathetic nervous system: rest and digest response

Spinal tracts

  • Ascending tracts: sensory info to brain
    • Dorsal column-medial lemniscal: light touch, pressure, vibration, two-point discrimination (crosses in medulla)
    • Anterior/lateral spinothalamic: pain, crude touch, temperature (crosses in medulla)
    • Spinocerebellar: proprioception (does not cross)
  • Descending tracts: motor info from brain to periphery
    • Anterior/lateral corticospinal: voluntary movement of axial/skeletal muscles

Arterial circulation of spinal cord

  • Anterior spinal artery: supplies anterior 2/3 of spinal cord (except dorsal column)
  • Posterior spinal artery: supplies posterior cord, dorsal sensory column, dorsal grey matter, posterior columns
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Next  | 3.3 Peripheral nervous system
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Anatomy and function of spinal cord

Primary function of spinal cord

  • Acts a relay pathway between peripheral system and brain
    • Provides sensory information regarding the environment to the brain
    • Manages motor commands to the peripheral system in reaction to environment
    • Coordinates simple reflexes that do not have to go to brain such as withdrawal from pain, patellar reflex, etc

Anatomy of spinal cord

  • Cervical spine
    • Eight (8) nerves that provide innervation to neck and upper extremity
  • Thoracic spine
    • Twelve (12) nerves that provide innervation to upper chest, chest, abdomen, upper back
  • Lumbar spine
    • Five (5) nerves that provide innervation to legs and feet
  • Sacral spine
    • Five (5) nerves that provide innervation to sacrum and pelvis
  • Cocxygeal spine
    • One (1) nerve that provides innervation to the perineal area

Image #21

alt_text

https://upload.wikimedia.org/wikipedia/commons/7/72/Spinal_cord_details.jpg

Protective layers of spinal cord

  • Dura mater
    • Outermost protective layer
    • Space between dura and bony vertebral body referred to as epidural space which contains adipose tissue and blood vessels
  • Arachnoid
    • Middle layer with web-like appearance
    • Space between dura and arachnoid referred to as subarachnoid space and contains cerebrospinal fluid
  • Pia mater
    • innermost layer that is in direct contact with spinal cord

Image #22

alt_text

https://upload.wikimedia.org/wikipedia/commons/7/72/Spinal_cord_details.jpg

Definitions
Dorsal root
Sensory nerve that carries information from spinal cord to brain
Ventral root
Motor nerve that carries information from brain to spinal cord
Spinal nerve
Pathway for sensory and motor information to move between peripheral system and spinal cord
Denticulate ligament
Ligament that provides stabilization of the spinal cord
Posterior (dorsal) gray horn
Nerve fibers containing sensory information from the body
Lateral gray horn
Nerve fibers containing sympathetic nervous system information only found in thoracic, upper lumbar, and sacral regions of spinal cord
Anterior (ventral) gray horn
Nerve fibers containing motor neurons that control skeletal muscles
Posterior (dorsal) white column:
Nerve fibers containing sensory information from the body such as two point discrimination, fine touch, vibration, and proprioception
Lateral white column
Nerve fibers that contain sensory information such as pain, temperature, and crude touch
Anterior (ventral) white column
Nerve fibers containing sensory and motor nerve fibers that provide information to the contralateral brain
Sympathetic nervous system
Network of nerves that are enacted to aid in the response to physical activity, stress, or danger (fight or flight response)
Parasympathetic nervous system
Network of nerves that provide relaxation after the body has responded to stressful or dangerous situation (rest and digest response)

Image #23

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2019/07/1313_Spinal_Cord_Cross_Section-1339x1536.jpg

Spinal tracts

  • Ascending tracts
    • Carry sensory information such as touch, pain, and temperature from peripheral system to brain
    • Names of tracts/pathways:
      • Dorsal column-medial lemniscal: transmit light touch, deep pressure, two-point discrimination, and vibratory information to cerebrum via the thalamus- crosses in the medulla to the contralateral side
      • Anterior and lateral spinothalamic: transmit pain, crude touch, and temperature information to cerebrum via the thalamus- crosses in the medulla to the contralateral side
      • Spinocerebellar: transmit proprioceptive information to the cerebellar- does not cross; stays on same side

Image #24

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2019/07/1417_Ascending_Pathways_of_Spinal_Cord-1500x1536.jpg

  • Descending tracts
    • Carry motor information from brain to peripheral system to give voluntary commands of movement of axial and skeletal muscles
    • Names of tracts/pathway:
      • Anterior and lateral corticospinal: transmit commands to move axial and/or skeletal muscles

Image #24

alt_text

https://open.oregonstate.education/app/uploads/sites/157/2021/02/1426_Corticospinal_Pathway-702x1536.jpg

Arterial circulation of spinal cord

  • Two (2) primary arteries of spinal cord
    • Anterior spinal artery
      • Supplies blood to the anterior two-thirds of the spinal cord with the exception of dorsal column
    • Posterior spinal artery
      • Provides blood supply to posterior spinal cord via two (2) branches that supply the dorsal sensory column, dorsal grey matter, and posterior columns
Key points

Primary function of spinal cord

  • Relay pathway between peripheral system and brain
  • Transmits sensory info to brain; manages motor commands to periphery
  • Coordinates simple reflexes (e.g., withdrawal, patellar reflex)

Anatomy of spinal cord

  • Cervical spine: 8 nerves, neck & upper extremity innervation
  • Thoracic spine: 12 nerves, upper chest, chest, abdomen, upper back
  • Lumbar spine: 5 nerves, legs & feet
  • Sacral spine: 5 nerves, sacrum & pelvis
  • Coccygeal spine: 1 nerve, perineal area

Protective layers of spinal cord

  • Dura mater: outer layer; epidural space with adipose & blood vessels
  • Arachnoid: middle, web-like; subarachnoid space with cerebrospinal fluid
  • Pia mater: innermost, direct contact with spinal cord

Key spinal cord structures and definitions

  • Dorsal root: sensory nerve, spinal cord to brain
  • Ventral root: motor nerve, brain to spinal cord
  • Spinal nerve: pathway for sensory & motor info between periphery and cord
  • Denticulate ligament: stabilizes spinal cord
  • Gray horns:
    • Posterior (dorsal): sensory info from body
    • Lateral: sympathetic nervous system (thoracic, upper lumbar, sacral only)
    • Anterior (ventral): motor neurons for skeletal muscles
  • White columns:
    • Posterior: sensory (touch, vibration, proprioception)
    • Lateral: sensory (pain, temperature, crude touch)
    • Anterior: sensory & motor fibers to contralateral brain
  • Sympathetic nervous system: fight or flight response
  • Parasympathetic nervous system: rest and digest response

Spinal tracts

  • Ascending tracts: sensory info to brain
    • Dorsal column-medial lemniscal: light touch, pressure, vibration, two-point discrimination (crosses in medulla)
    • Anterior/lateral spinothalamic: pain, crude touch, temperature (crosses in medulla)
    • Spinocerebellar: proprioception (does not cross)
  • Descending tracts: motor info from brain to periphery
    • Anterior/lateral corticospinal: voluntary movement of axial/skeletal muscles

Arterial circulation of spinal cord

  • Anterior spinal artery: supplies anterior 2/3 of spinal cord (except dorsal column)
  • Posterior spinal artery: supplies posterior cord, dorsal sensory column, dorsal grey matter, posterior columns

More from Neuromuscular system

  • Central nervous system
  • Peripheral nervous system
  • Differential diagnosis of central nervous system pathologies
  • Differential diagnosis of peripheral nervous system
  • Other neurological conditions