Diseases Of Nmj And Motor Unit

Front 1

Name 2 diseases that affect the soma of the muscle unit.

Back 1

Polio and ALS (Lou Gehrig's Disease)

Front 2

Name 4 types of things that affect the axon of the muscle unit

Back 2

Toxins, Drugs, Neuropathy, Axotomy (axon snipped)

Front 3

Name 2 diseases that affect the Schwann cells

Back 3

Guillain-Barre and diphtheria

Front 4

Name 1 disease and 1 toxin that affect the nerve ending of a motor unit

Back 4

Botulinism, Lambert-Eaton disease

Front 5

Name an issue that can affect the synaptic cleft.

Back 5

Absence of acetylcholinesterase

Front 6

Name 2 diseases that can affect the end plate.

Back 6

Myasthenia Gravis, nACh-release defects

Front 7

Name 2 types of defects that can affect the muscle fibers themselves.

Back 7

Myotonias and muscular dystrophies.

Front 8

Name 3 symptoms of lesions of the nerve soma/axon

Back 8

Muscle atrophy/weakness, fibrillations, and loss of muscle fibers

Front 9

Where does polio usually strike in the body? How does transmission occur?

Back 9

Hits the motor neurons of the ventral horn...transmission is person-to-person and can be oral/mucosal/fecal

Front 10

Is polio UMN or LMN?

Back 10

LMN

Front 11

How do Schwann cell lesions affect conduction?

Back 11

Conduction is either slowed or blocked altogether.

Front 12

What is botulin toxin? How does it cause paralysis?

Back 12

Product of anaerobic bacteria that reduces ACh release by acting on presynaptic proteins affecting EXOCYTOSIS.

Front 13

What is alpha-latrotoxin? How does it work? What are the symptoms?

Back 13

Black widow spider venom; works by making you dump all your ACh at once. This causes tetany, which eventually gives way to flaccid paralysis.

Front 14

What is beta-bungarotoxin? How does it work?

Back 14

Toxin in snake venom, reduces ACh release by acting on proteins that cause exocytosis.

Front 15

How does curare work?

Back 15

non-depolarizing blockade of ACh receptors on the post-synaptic membrane of the NMJ.

Front 16

Lambert Eaton Disease: Causes, Pathophysiology, Symptoms, Comorbidities, Treatment

Back 16

Causes: autoimmune--antibodies against voltage-gated Ca2+ channels in motor neuron terminals leading to insufficient ACh release. Symptoms: muscle weakness--repeated attempts must be made to build ACh up to acceptable amounts....reduced EPP amplitude, but miniEPP is unchanged. ...EMG shows crescendo.Comorbidity: Oat-Cell Carcinoma of the Lung.Treatment: Immunosuppressive drugs...calcium gluconate...4-aminopyridine to prolong presynaptic AP...chemo for the cancer

Front 17

Lambert-Eaton is often associated with what other illness

Back 17

Small-cell (Oat Cell) carcinoma of the lung

Front 18

What is Slow Channel Syndrome?

Back 18

Inherited form of myasthenia causing muscle weakness, rapid fatigue, progressive atrophy. It's caused by ACh binding to AChR's and causing PROLONGED opening of channels, leading to a DEPOLARIZATION BLOCK.

Front 19

What are the symptoms of ACh-esterase deficiency at the end plate? (ie, how does the muscle respond to high and low frequency stimulation?) Describe the EPP amplitude. What type of disease is this?

Back 19

-EPP amplitude is prolonged and larger than normal
-If you stimulate a single motor nerve and low frequency, you get a single muscle twitch
-High frequency motor nerve stimulation=temporal EPP summation and a DEPOLARIZATION BLOCK
Considered a form of congenital myasthenia

Front 20

Myasthenia gravis is caused by what? How do you treat it? Are there any other diseases associated with it?

Back 20

Autoimmune response to nAChR's. ACh is unable to reach the cross-linked receptors undergoing resorption.
-Tx with steroid (for autoimmunity) and either neostigmine or pyridostigmine.
-Sometimes associated with thyroid cancer

Front 21

Symptoms of myasthenia gravis

Back 21

-Weakness of limbs, cranial nerve muscles
-Ptosis
-Diplopia
-Exhaustion that recoups after rest
-Difficult swallowing and frequent choking
-weakness/paralysis occurs later in the day
-tensilon test positive

Front 22

How does the EMG of a myasthenia gravis patient look?

Back 22

EMG shows a "waning pattern" after repeated stimulation http://o.quizlet.com/i/XElFDMvXK-MV5rfeWDktmg.jpg

Front 23

Define and list the symptoms of Myotonia congenita, aka "Chloride Channel Syndrome".

Back 23

Genetic disease in which fewer chloride channels are expressed and inserted into the cell membrane. Your muscles don't relax as quickly (no Cl- to offset K+ influx during recovery), so you end up with stiffness and hypertropy. There's also a prolonged relaxation phase.

Front 24

What's the difference between fasciculation and fibrillation?

Back 24

A fasciculation is the irregular, spontaneous twitching of fibers composing motor units & are linked to firing of sick alpha-motor neurons. They are VISIBLE through the skin. Also, fasciculation does not necessarily denote pathology, as does fibrillation. They are NOT associated with diseases occurring at the NMJ or the muscle itself. Only the motor neuron.

A fibrillation occurs when muscle fibers lose contact with their innervating axon producing a spontaneous action potential, "fibrillation potential" that results in the muscle fiber's contraction. These contractions are not visible under the skin and are detectable through needle electromyography (EMG) and ultrasound.[2] Fibrillations do not occur in healthy individuals.