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Textbook
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 Compare and contrast central nervous systems pathologies part 1
3.5 Compare and contrast central nervous systems pathologies part 2
3.6 Peripheral nervous system conditions
3.7 Other neurological conditions
3.8 Interventions for neurological conditions
3.9 Vestibular system
4. Pediatrics
5. Musculoskeletal system
6. Other system
7. Non systems
Wrapping up
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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 the spinal cord

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

Anatomy of the spinal cord

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

Protective layers of the 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 a web-like appearance
    • Space between arachnoid and Pia referred to as subarachnoid space and contains cerebrospinal fluid
  • Pia mater
    • Innermost layer that is in direct contact with the spinal cord
Spinal cord anatomy
Spinal cord anatomy
Definitions
Dorsal root
Sensory nerve that carries information from the spinal cord to the brain
Ventral root
Motor nerve that carries information from the brain to the spinal cord
Spinal nerve
Pathway for sensory and motor information to move between the peripheral system and the 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 are only found in the thoracic, upper lumbar, and sacral regions of the 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
The sympathetic nervous system is a division of the autonomic nervous system responsible for preparing the body to respond to physical activity, psychological stress, or perceived danger. It initiates the “fight-or-flight” response by increasing heart rate, blood pressure, and respiratory rate to enhance oxygen delivery to working muscles and vital organs. The SNS also dilates the pupils and bronchioles, redirects blood flow away from nonessential processes such as digestion, and stimulates the release of glucose and fatty acids for immediate energy use. These coordinated physiological changes allow the body to react quickly and effectively to demands that require heightened alertness, strength, or endurance.
Parasympathetic nervous system
The parasympathetic nervous system is a division of the autonomic nervous system that promotes recovery, conservation of energy, and maintenance of homeostasis following periods of stress or exertion. Often referred to as the “rest-and-digest” system, it works by decreasing heart rate and blood pressure, constricting the pupils and bronchioles, and stimulating gastrointestinal activity, nutrient absorption, and waste elimination.
Cross section of spinal column
Cross section of spinal column

Spinal tracts

  • Ascending tracts
Pathways of spinal cord
Pathways of spinal cord

  • Carry sensory information such as touch, pain, and temperature from the peripheral system to the brain

    • Dorsal column-medial lemniscal: transmits light touch, deep pressure, two-point discrimination, and vibratory information to the 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 cerebellum- does not cross; stays on the same side

  • Descending tracts

    • Carry motor information from the brain to the peripheral system to give voluntary commands of movement of axial and skeletal muscles

    • Anterior and lateral corticospinal: transmit commands to move axial and/or skeletal muscles

    • Anterior corticospinal: motor system that descends uncrossed in the front of the spinal cord, controlling trunk/axial muscles for posture,

    • Lateral corticospinal: Motor system where fibers cross over (decussate) in the lower medulla, forming the lateral tract, which then controls the opposite (contralateral) side of the body controlling the movements of the extremities, particularly fine coordinated movements.

Arterial circulation of the spinal cord

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

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