Motor End Plate: Structure, Function & Neurotransmission

Question 1

What is the width of a synapse

Answer 1

200A or 20nm wide

Question 2

What is formed between a skeletal muscle and the motor neurone that innervates it

Answer 2

Synapse

Question 3

What is the term given to the number of muscle fibres innervated by a single motor neurone

Answer 3

Motor unit

Question 4

What is the term given to the specialised portion of the sarcolemma of the muscle fibre innervated by a single motor nerve ending

Answer 4

Motor endplate

Question 5

The terminal ending fits into a depression of the muscle membrane which is thrown into folds called ______

Answer 5

Palisades

Question 6

What are the two components that make up the neurotransmitter Acetylcholine

Answer 6

Acetyl CoA, Choline

Question 7

What is the name of the enzyme that facilitates the genesis of ACh

Answer 7

Choline Acetyltransferase

Question 8

True or False, In the arrival of the nerve action potential, Ca 2+ voltage gated channels are opened in the terminal ending

Answer 8

True or False

Question 9

True or False, Cholinergic neurotransmission is Ca2+ independent

Answer 9

False, it is dependent

Question 10

What protein does Ca2+ ions bind to in the terminal endings

Answer 10

Calmodulin

Question 11

What neurotransmitter does Ca2+ ions bind to in the active zones, signalling its release

Answer 11

Synaptotagmin

Question 12

What is activated when Ca2+ binds to calmodulin

Answer 12

Ca2+-calmodulin kinase

Question 13

What does kinase phosphorylate in the nerve action potential causing synaptic vesicles to be loosened from their cyto-skeleton attachments

Answer 13

Synapsin 1

Question 14

What substance migrates and dock at the active zones

Answer 14

Synaptic vesicles

Question 15

What protein is involved in docking, binding & endocytosis of the synaptic vesicle

Answer 15

Synaptotagmin

Question 16

What is required for the fusion of synaptic vesicle to the Presynaptic membrane

Answer 16

SNARE proteins

Question 17

What SNARE protein is described as a v-snare, vesicular membrane protein

Answer 17

Synaptobrevin

Question 18

What snare proteins are described as a t-snare

Answer 18

Syntaxin, SNAP-25

Question 19

What snare protein contains two plasma membrane proteins

Answer 19

SNAP-25

Question 20

What Snare protein has small GTPase

Answer 20

Rab3

Question 21

What snare protein is inactivated by Tetanus toxin & amp; Botulinum toxins B, D, F, G

Answer 21

Synaptobrevin

Question 22

What SNARE protein is inactivated by Botulinum toxins C and A & amp; B, respectively

Answer 22

Syntaxin, SNAP-25

Question 23

What toxin causes Spastic paralysis by blocking presynaptic neurotransmitter release in CNS

Answer 23

Tetanus

Question 24

What toxin causes Flaccid paralysis by blocking ACh release at the n-m junction (Botox – achalasia, wrinkles)

Answer 24

Botulinum

Question 25

What snare protein regulates a multi protein complex

Answer 25

Rab3

Question 26

What snare protein may not be essential for docking or fusion

Answer 26

Rab3

Question 27

What snare protein maintains normal reserves of SVs for accelerated exocytosis during repetitive stimulation

Answer 27

Rab3

Question 28

What enzyme breaks down ACh into Choline and Acetate

Answer 28

acetylcholinesterase

Question 29

How many vesicles do each nerve action potential release

Answer 29

60 vesicles

Question 30

Approximately how many molecules of ACh does each synaptic vesicle contain

Answer 30

10,000

Question 31

What is summated to form the muscle action potential

Answer 31

EPPs

Question 32

True or False, Minute depolarizing spike potentials

Answer 32

True (Due to the spontaneous release of small quanta of ACh)

Question 33

True or False, an increase Ca 2+ ions at the end plate cause an increase in the size of the potential

Answer 33

True

Question 34

True or False, an increase Mg 2+ ions at the end plate cause an increase in the size of the potential

Answer 34

False, it is a decrease in Mg2+

Question 35

Minature Endplate Potential produce muscle action potentials

Answer 35

False, it doesn't

Question 36

In Ca 2+ removal, Ca 2+ is exchanged with which ion

Answer 36

Na 2+

Question 37

True or False. the removal of Ca 2+ is passive

Answer 37

False, it is active

Question 38

True or false, the use of buffers is used in Ca2+ removal

Answer 38

True

Question 39

What kind of disease id Myasthenia Gravis

Answer 39

Autoimmune Disease

Question 40

The antibodies in Myasthenia Gravis destroys what type of receptors on the skeletal muscles

Answer 40

Nicotinic Receptors

Question 41

What are the symptoms of Myasthenia Gravis

Answer 41

Weakness, Paralysis

Question 42

What syndrome resembles Myasthenia Gravis, and decreases ACh release

Answer 42

Lambert- Eaton Syndrome

Question 43

Antibodies in Lambert- Eaton Syndrome, work against which ion channel in the nerve endings at N-M junctions

Answer 43

Ca 2+