Neuromuscular Flashcards Preview

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Flashcards in Neuromuscular Deck (23):
1

What pathway makes a muscle contract?

Motor neurone --> neuromuscular junctionv--> muscle

2

What innervates skeletal muscle fibres?

Motor neurons whose cell bodies arise in the ventral horn of the spinal cord

3

What are the synapses that are formed between motor neurons and muscles called?

Motor end plate

4

How many neurons does a muscle cell respond to?

Just 1

5

What occurs at the motor end plate?

Depolarisation

6

What is Lambert Eaton Myasthenic Syndrome?

Antibodies to presynaptic calcium channels leads to less vesicle release .
Strong assoc. with underlying small cell carcinoma

7

What is Botulism?

Clostridium botulinum
Cleave presynaptic proteins involved in vesicle formation and block vesicle docking with the presynaptic membrane. Rapid onset weakness without sensory loss.

8

What is Myasthenia Gravis?

Autoimmune
Antibodies to ACH receptors
Muscle weakness

9

What do 75% of patients with Myasthenia Gravis also have?

A thymus problem such as hyperplasia or thymoma

10

What is the treatment for Myasthenia Gravis?

Acetylcholinesterase inhibitor - Pyridostigmine
Thymectomy

11

What are treatments for acute Myasthenia Gravis?

Immunomodulating
Steroids / azathiprine
Plasma exchange or immunoglobulin in emergency

12

What surrounds skeletal muscle?

Thin layer of Endomysium

13

What are the fasicles encapsulated by?

Perimmysium

14

What helps form an individual muscle?

Large number of fascicles ensheathed in epimysium

15

Describe skeletal muscle?

Fibres are the stonest contractile unit
Long, cylindrical containing nucleii, mitochondria and sacromeres

16

Describe smooth muscle

Cells not striated
Single central nucleus
Gap junctions between cells
No sacromeres
More actin than myosin

17

How many muscle fibre types are there?

3

18

Describe muscle fibre type 1?

Slow oxidative, dense capillary network, myoglobin, resist fatigued

19

Describe type IIa muscle fibre?

Fast oxidative, aerobic metabolism

20

Describe type IIb muscle fibre?

Fast glycolytic, easily fatigued

21

What are fasciculations?

Visible, fast, fine spontaneous twitch
Occur when muscle becomes hyperexcitable
Issue with the MOTOR NEURON

22

What is Myotonia?

Failure of muscle to relax after use
Problem wit Chloride channel

23

What are symptoms/signs of muscle disease?

Myalgia
Muscle weakness
Wasting
Hyporeflexia