The energy loss (and deformation) seen with repeated load and unload cycles on the disc.
Deformation of the disc that occurs with a to sustained load.
A nerve trunk which supplies the muscles of any given joint also supplies the muscles that move the joint, and the skin distal to the insertions of the, muscles.
anterior horn of the cord is motor, posterior horn is sensory.
Activation of large diameter afferent nerves may inhibit smaller afferent pain fibers in the substantia gelatinosa on the dorsal horn of the cord.
When a painful stimulus is applied to a part of low sensibility in proximity with a part of much higher sensibility, the pain produced is felt in the area of higher sensibility rather than in the area to which the stimulus was applied.
The principle that maintains the laws of physics and chemistry cannot explain the nature of life.
Motor unit or functional spinal segment
A pair of adjacent vertebrae, connecting disc and ligamentous structures
Anterior motor unit
The portion of the motor unit that includes the PLL and the structures anterior to it (weight bearing)
Posterior motor unit
All the structures posterior to the PLL: posterior joints, articular capsule. Neural arches and the interconnecting ligaments.
An area of bone, fascia, and joints innervated by a single nerve root. (Sclerotogenous- referred pain originating from a sclerotome, e.g. facet syndrome or spondylolisthesis).
A group of muscles innervated by a single nerve root. (C7 myotome = wrist flexors, finger extensors, triceps)
An area of skin innervated by single nerve root.
Axoplasmic transport (AXT)
is important in nerve growth and maturation, sensory signaling and modulation of inflammation.
(FAXT) Fast transport of nutrients (for nerve growth and trophic) from cell body to axon and terminals (proximal to distal).
(SAXT) Slow or bulk. Transport from terminal to cell body. (distal to proximal) less common. Recycles NGF and neurotransmitters.
- T1-L2 (lateral horns)
- "fight or flight"
- short pre-ganglionic/ white rami
- long post-ganglionic/ gray rami
- sudomotor, pilomotor, responses
- CN 3,7,9,10, S2-4
- "rest and digest"
- long pre-ganglionic
- short post-ganglionic
Myelinated nerve fibers
- General (sensory and motor) A(alpha)
- Larger, faster
- Sensory Ia, Ib
Unmeylinated nerve fibers
- General (sensory and motor) C fiber
- Smaller, slower
- Sensory IV
Afferent/ Sensory neurons types
- Ia, Ib proprioception, kinesthsia (big/ fast)
- II proprioception, mechanoceptors
- III, IV mechanoceptors, hot, cold nociceptos (slow)
Golgi tendon organs
- Receptors located at the end of muscle that detect muscle tension. When stimulated inhibits muscle contraction.
- Golgi tendon organ=>Ib afferent=>inhibitory internucial=> inhibits (alpha) motor neuron => extrafusal fiber
- Intrafusal receptors that sensitive to length of intrafusal fibers.
- Annulo spiral/ flower spray endings=> Ia afferent=> distal horn=> (alpha) motor neuron=> extrafusal fiber
- Innervates muscle spindle, increasing Group Ia afferents. Affects background muscle tone.
- Annulo spiral/flower spray ending=> Ia afferent=> dorsal horn=> (gamma) motorneuron=> muscle spindle
Sensory receptors responsive to pain, hot and cold mechanoreceptors (C-fibers)
Receptors found in muscles, tendons, and joints that detect position and motion of the body.
A excitatory neurotransmitter involved with nociception (pain) and associated with mood disorders, anxiety, stress and fibromyalgia. (capsaicin relieves arthitic pain as it reduces the level of Substance P).
Increased afferent bombardment causing a decreased threshold for firing, with continued stimulation resulting in hyperactive responses.