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74 Cards in this Set
- Front
- Back
- 3rd side (hint)
What are the cervical and lumbar enlargements?
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cervical enlargement corresponds to the location where axons that supply the upper limbs enter and leave
lumbosacral enlargement is where axons supplying lower limbs enter and leave spinal cord |
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what is the conus medullaris?
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immediately inferior to lumbosacral enlargement
where nerves for lower limb exit |
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what is the cauda equina?
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the numerous roots of spinal nerves from lumbosacral enlargement and conus medullaris resemble a horse's tail
nerves from the lumbar, sacral and coccygeal |
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What are the anterior median fissure and posterior median sulcus?
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deep clefts partially separating the two halves of the cord.
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name the 3 columns of white matter
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ventral (anterior)
dorsal (posterior) lateral |
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what are the 3 columns of the gray matter?
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Anterior
Posterior Lateral |
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define tract.
Does it exist outside CNS |
pathway where individual axons ascend to the brain or descend from the brain.
No |
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What is a commisure?
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contain axons that cross from one side of the spinal cord to the other.
Central canal is in the center of the gray commisure |
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Describe rootlets and spinal nerves
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Spinal nerves arise from numerous rootlets along ventral and dorsal surfaces of the spinal cord. 6-8 rootlets combine to form both the ventral and dorsal roots.
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Where is the ganglion?
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Dorsal root
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What is the dorsal root ganglion?
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collections of cell bodies of the sensory neurons forming the dorsal roots of the spinal nerves
contains the nerve cell bodies of all the sensory neurons in that spinal nerve |
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What is a reflex arc?
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The simplest basic funtional unit of the nervous system because it is the basics:
receive a stimulus and produce a response |
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Name the meninges surrounding the spinal cord
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1. epidural space
2. dura mater 3. subdural space 4. arachnoid mater 5. subarachnoid space 6. pia mater |
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What is in the epidural space?
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spinal nerve roots, blood vessels areolar conn. tissue and fat
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What limits the lateral movement of the spinal cord?
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denticulate ligaments
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Where is the CSF in the spinal cord?
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subarachonoid space (btwn arachnoid mater and pia mater)
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What anchors the spinal cord to the coccyx and is continuous with pia mater?
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filum terminale
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Where is epidural anesthesia administered?
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epidural space (superficial to the meninges)
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Where does the spinal cord stop?
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2nd lumbar vertebra
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What cell bodies do the lateral horns of the gray mater in thoracic region correspond to?
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sympathetic motor neurons
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what is a funiculi?
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a white matter column
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What is a fasciculi?
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aka a tract
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Explain a reflex arc
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1. a stimulus is detected by a sensory receptor
2. A sensory neuron conducts action potentials through the spinal nerve and dorsal root to the spinal cord 3. in s.c. sensory neuron synapses with an interneuron 4. the interneuron synapses with a motere neuron 5. a motor neuron axon conducts action potentials through the ventral root and spinal nerve to an effector organ |
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Explain a stretch reflex
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1. muscle spindles detect stretch of the muscle
2. sensory neurons conduct action potentials to the spinal cord 3. Sensory neurons synapse directly with alpha motor neurons 4. Stimulation of alpha motor neurons results in action potentials being conducted to the muscle, causing it to contract and resist being strectched. This is how muscle tone is maintained |
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Golgi tendon organ
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prevents contracting muscles from applying excessive tension to tendons.
located within tendons near the tendon muscle junction |
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Describe the golgi tendon reflex
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1. golgi tendon organs detect tension applied to a tendonj
2. sensory neurons conduct action potentials to the spinal cord 3. Sensory neurons synapse with inhibitory interneurons that synapse with alpha motor neurons 4. Inhibition of the alpha motor neurons causes muscle relaxation, relieving the tension applied to the tendon. |
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Describe the withdrawl reflex
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1. Pain receptors detect a painful stimulus
2. Sensory neurons conduct action potentials to the spinal cord 3. Sensory neurons synapse with exitatory interneurons that synapse with alpha motor neurons 4. Excitation of the alpha motor neurons results in contration of the flexor muscles and withdrawal of the limb from the painful stimulus |
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Describe the withdrawl reflex with reciprocal innervation
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reinforces the efficiency.
1. during withdrawl reflex sensory neurons send action potentials from pain receptrs to the spinal cord 2. sensory neurons synapse with excitatory interneurons that are part of the withdrawal reflex 3. Collateral branches of the sensory neurons also synapse with inhibitory interneurons that are part of reciprocal innervation 4. The inhibitory interneurons synapse with alpha motor neurons supplying the extensor muscles, causing them to relax and not oppose the flexor muscles of the withdrawl reflex, which are contracting |
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What is gray matter?
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1. Neuronal cell bodies
2. Unmyelinated axons and dendrites of association and motor neurons 3. Neuroglia |
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What is white matter?
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consists of bundles of myelinated axons of sensory, association, and motor neurons called tracts
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What are the segments of the spinal cord?
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8 cervical
12 Thoracic 5 lumbar 5 saccral 1 coccygeal |
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Where does the central canal run and what does it communicate with in the brain?
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runs in middle of gray matter the length of the spinal cord
communicates with the 4th ventricle of the brain |
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Nuclei
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The gray matter on each side of the cord is subdivided into regions called horns.
Within the gray matter are clusters of neuronal cell bodies called nuclei (centers); each nucleus has a specific function |
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Dorsal horns
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sections of the spinal cord gray matter that project dorsally or posteriorly.
contain nuclei that receive SENSORY info from spinal nerves only. The axons entering the dorsal horns from the dorsal roots are the axons from the nueron cell bodies located in the dorsal root ganglion |
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Ventral horns
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project ventrally or anteriorly. contain nuclei composed of MOTOR neurons whose axons leave the spinal cord as ventral roots.
Somatic functions only |
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Lateral horns
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found between the dorsal and ventral horns and only in T1-L2 and S2-S4
contain nuclei of MOTOR neurons. The axons of thesee neurons exit via ventral roots AUTONOMIC motor functions only |
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What are essential characteristics of a reflex?
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Inborn
Unlearned Unconscious |
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What is a pathway?
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the route followed by a series of nerve impulses from their origin in one part of the body to their arrival elsewhere in the body
specific neuronal circuits and may include only a single synapse (monosynaptic) or more than one (polysynaptic) |
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Regardless of complexity, what must all reflex arcs include? (5)
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1. Receptor
2. Sensory neuron 3. Center of integration 4. Motor neuron 5. Effector |
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What is a receptor?
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distal end of a sensory neuron or an associated sensory structure that responds to a specific stimulus (change in the environment) by initiating a nerve impulse.
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What is a Sensory neuron?
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passes the nerve impulse generated by the receptor to the axon terminals located within the gray matter of the CNS. It's cell body is located in the dorsal root ganglion.
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What is the Center?
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region of CNS gray matter where the synapse (s) associated with reflex are located.
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What is a Motor neuron?
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Impulses triggered by the integrating center are carried by the motor neuron, whose cell body lies within the gray matter, to the part of the body that will respond.
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What is the Effector?
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muscle or gland stimulated by the motor neuron and which provides the response of the body to the change in the environment that stimulated the receptor in the first place!
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What is the endoneurium?
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Each individual nerve fiber, either sensory dendrite or motor axon, is surrounded by a connective tissue wrap called this.
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What is the perineurium?
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Groups of nerve fibers are arranged into fascicles (fasciculi) and each bundle is surrounded by another connective tissue wrap called this
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What is the epineurium?
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All fascicles of a spinal nerve are bound together by an outermost connective tissue called this.
This layer is a continuation of the dura mater. |
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What is a dermatome?
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skin, except over face and top of the head, is supplied by spinal nerves that carry somatic sensory nerve impulses to the s.c.
All spinal nerves except C1 serve a specific and constant segment of the skin. The area of skin that provides sensory input to the dorsal roots of one pair of spinal nerves or to one spinal cord segment is a dermatome. |
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Describe a Crossed Extensor reflex
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1. during withdrawal reflex, sensory neurons from pain receptors conduct action potentials to the spinal cord
2. Sensory neurons synapse with exitatory interneurons that are part of the withdrawal reflex. 3. the excitatory interneurons that are part of the withdrawal reflex stimulate alpha motor neurons that innervate flexor muscles, causing withdrawl of the limb 4. Collateral branches of the sensory neurons also synapse with exictatory interneurons that cross to the opposite side of the spinal cord as part of the crossed extensor reflex 5. Excitatory interneurons taht cross the pinal cor stimulate alpha motor neurons supplying extensor muscles in the opposite limb, causing them to contract and support body weight during the withdrawl reflex |
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What does the dorsal rami innervate?
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deep muscles of the dorsal trunk (movement of vertebral column)
connective tissue and skin of midline of back |
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What does the ventral rami innervate?
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intercostal nerves--intercostal muscles and skin of thorax
5 plexuses |
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What are the 5 plexuses of the ventral rami?
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cervical C1-C4
Brachial C5-T1 Lumbar plexus L1-L4 Sacral plexus L4-S4 Coccygeal plexus Co |
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What dermatomes do the cervical nerves cover?
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Head movement
Diaphragm movement Neck and shoulder movement Upper limb movement |
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What dermatomes do the thoracic nerves cover?
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Upper limb movement
Rib movement (breathing) Vertebral movement Postural back muscles |
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What dermatomes do the lumbar nerves cover?
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Hip movement
Lower limb movement |
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Discuss spinal cord injury
What are the 2 types of tissue damage? |
car accidents, gunshot wounds, falls
cervical or thoracolumbar junction usually concussion, contusion and laceration excessive flexion, extension, rotation, compression, bone or disk displacement 1. primary, mechanical damage 2. secondary, tissue damage (ischemia, edema, ion imbalances and excitotoxins (glutamate) |
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What are some important nerves from the cervical plexus?
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Hypoglossal
Accessory |
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What are some important nerves from the brachial plexus?
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Thoracodorsal
Subscapular Suprascpular Axillary Radial Musculocutaneous Medial and Lateral Pectoral Median Ulnar |
Sofferman likes to brach stones
This Super Sucks Ass Really Makes Me Mad Ugh |
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Where is brachial anesthesia administered?
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brachial plexus
between the neck and the shoulder posterior to clavicle |
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What are some nerves from the lumbar plexus?
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Femoral
Obturator Superior gluteal Inferior gluteal Sciatic |
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Pudendal Nerve Anesthesia
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site of anesthesia for episiotomy
OUCH. |
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What does the Co plexus innervate?
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motor innervation to the muscles of the pelvic floor and sensory cutaneous innervation to the skin over the coccyx.
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Anesthesia
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loss of sensation
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Hyperesthesia
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abnormal acuteness to sensation (especially pain, pressure or light)
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Paresthesia
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abnormal spontaneous sensation, such as tingling, prickling or burning
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Neuragia
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consists of spasms of throbbing or stabbing pain resulting from inflammation or damage along the pathway of a nerve
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Sciatica or Ischiadica
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neuralgia of sciatic nerve
pain down back of leg and thighj herniated lumbar disk usually causes it mechanical injuries or metabolic deficiencies can cause too |
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Neuritis
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inflammation of a nerve
mechanical injury or pressure viral or bactereial infection poisoning or vitamin deficiencies |
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Herpes
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virus reside in ganglia of sensory nerves
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varicella zoster virus
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chicken pox shingles
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poliomyelitis
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enterovirus
affects motor neurons in anterior horn of spinal cord paralysis and atrophy |
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Anesthetic leprosy
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bacterial infection of peripheral nerves
anesthesia, paralysis, ulceration and gangrene |
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Myotonic dystrophy
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autosomal dominant hereditary disease characterized by muscle weakness, dysfunction, and atrophy and by visual impairment as a result of nerve damage
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Myasthenia gravis
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reduction in number of functioning acetycholine receptors in postsynaptic terminals
fatigue and progressive muscular weakness |
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