Term
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Definition
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Term
Alpha Motor Neuron F(x), Location of Cell Bodies, Altername name |
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Definition
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Innervates extrafusal muscles fibers, causes contraction Cell bodies are found in ventral horn of the spinal cord For Cranial Nerve innervated muscles (eyes for example) cell bodies are found in th brainstem Also may be called LOWER MOTOR NEURONS/LMN
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Term
Upper Motor Neurons (UMN) Location, F(x) |
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Definition
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Cell Bodies are located in the Cerebral Cortex & Brainstem Modulate LMNs by either synapsing directly with them or more commonly with interneurons UMNs tracts have an inhibitory influece on many reflexes
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Term
Nerve Fiber Types (Descending Size Order) |
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Definition
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Aalpha: proprioceptors of skeletal muscle, highly myelinated ABeta: Mechanoreceptors of skin, myelinated Adelta: Pain, temp, lightly myelinated - responsible for sharp or immediate pain C: Temp,pain, itch, unmyelinated - responsible for dull throbbing pain felt later Agamma: innervate proprioreceptors (muscle spindles), causes contraction of intrafusal muscle fibers B: Apparently none of our business
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Term
Deep Tendon/Stretch Reflex Two nerve types involved with the intrafusal fibers |
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Definition
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Stretching sensed by muscle spindle/intrafusal fibers Muscle spindle afferent innervation done by Type 1a sensory fibers that work when muscle is stretched - send signal to counteract, contract the muscle Gamma Motor Neurons: cause contraction of muscle spindle fibers so that the Type 1a fibers can work even if your muscle is contracted. Essentially, contracted muscle would cause loose intrafusal fibers and would then not be able to stimulate Type 1a nerves in intrafusal fibers, gamma motor neurons keep the area tight (like a tiger) so that the Type 1a sensory neurons are fully functional throughout the whole range of muscular contraction
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Term
Golgi Tendon Organ Location, F(x) & Innervation Type |
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Definition
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Located in tendons (fuckin duh) Senses changes in muscle tension, can act to protect muscle from developing too much tension Type 1B innervation, considered proprioceptive
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Term
| "Who is your Daddy and what does he do?" |
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Definition
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Arnold in Kindergarten Cop
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Term
| Upper Motor Neuron Lesions |
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Definition
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Hyper reflexia, Increased tone, Spasticity Clasp knife reflex Inverse Myotactic Reflex: relaxes muscles (allows it to be moved by outside force) in response to too much force Babinski Reflex: light rub heel to lateral metarpal pad (how alluring), toes & foot should ventriflex, if damaged an adult (like a normal baby) will either not flex does at all or dorsiflex the foot. - This is a signal of UMN lesion.
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Term
Lesions to Spinal Cord or Brainstem LMN Lesions (damage to ventral horn, alpha Motor Neurons [aMN)]) |
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Definition
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Hyporeflexia Muscle Wasting Fasiculations (muscle ticks) In severe cases enogh to see flaccid paralysis - decreased reflexes to the point of NO voluntary movement
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Term
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Definition
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Only a sensory component Example: Burning skin Other chemicals are released: histamine, Substance P
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Term
1.Drugs Effecting ACh release at the neuromuscular junction 2. Drugs effecting receptors
3. Ach-esterase inhibitors |
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Definition
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1. Botulinum toxin: makes old ladies hotter 2. d-tubocurarine: muscle relaxant 3. physostigmine & organophosphates: probably not good recreational drugs
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Term
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Definition
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Disease of the neuromuscular junction autoimmune disease, antibodies are formed against ACh receptors Presentation: ptosis (dropping eyelids), Dysanthia (slurred speech), cranial nerve muscles are weakened and fatigued, this gets worse with use and as the day goes on Cure: AChase inhibitors relieve symptoms to overcome effect of too little receptors
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Term
| Lambert-Eaton myasthenic syndrome |
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Definition
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NM junction autoimmune disease, antibodies fromed against presynaptic voltage gated Ca2+ channels at the NMJ. Presentation: muscle weakness preferentially affecting limbs, however muscle contraction gets better with use Presentation is similiar to but ultimately different than Myasthenia gravis
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