NMJ

Question 1

The resting membrane potential in a neurone is maintained predominantly

Answer 1

Leak of potassium ions out of the cell

Question 2

What is Ach broken down into

Answer 2

Acetate and choline

Question 3

What moves calcium back into the sarcoplasmic retinaculum

Answer 3

SERCA pumps

Question 4

3 types of fibres

Answer 4

Slow oxidative - fatigue resistant 
fast oxidative (type A ii) 
fast glycolytic fibres ( type B)

Question 5

what is Myasthenia gravis

Answer 5

an autoimmune disease that destroy the nAchR

Question 6

Clinical signs of myasthenia gravis

does it get better as the day goes on ?

Answer 6

Ptosis, , Gower sign(struggle getting up) , diplopia(double vision) , slurred speech and facial paralysis

normal gets better as day goes on too

Question 7

Treatment for Myasthenia Gravis

Answer 7

Pyridogostigmine - this inhibits AchE so there is enough Ach to bind to remaining receptors

Question 8

What are the problems with Organophosphate poisoning - farmer

Answer 8

Inhibits AchE

Question 9

Signs and symptoms of organophosphate poisoning

Answer 9

Increase saliva and tear production. Miosis, sweating, tremors and confusion and vomit

Question 10

Treatment of OP poisoning

Answer 10

Atropine - blocks and bind to receptors so less Ach can bind

Question 11

Function of Botulinum toxin

Answer 11

inhibits Ach to be released from the synaptic cleft

Question 12

Signs and symptoms of botulinum toxin

Answer 12

Muscle paralysis, respiratory and heart failure , Dysphagia

medical uses for migraines

Question 13

What do depolarising neuromuscular blockers do ?

Answer 13

Ach receptor agonists so bind to Each receptors and generate AP so prolonged and cannot depolarise

Question 14

What do non-depolarising neuromuscular blockers do?

how is it treated

Answer 14

competitive antagonists so don’t let ion channels open so Ach cannot bind

treated via inhibition of AchE

Question 15

What is a motor unit?

Answer 15

Group of muscle fibres and a single motor neurone that supplies it

Question 16

What is the Epimysium?

and where does it come from

Answer 16

Outer layer of connective tissue that surrounds the muscle. Comes from the tendon.

Question 17

What is the Function of the Epimysium? -2

Answer 17

it allows the muscle to contract more powerfully whilst still maintaining structural integrity.
It separates muscles from other tissues allowing them to act independently.

Question 18

What are fascicles?

Answer 18

They are made up of bundles of muscle fibres(cells) - next subdivision within the muscle

Question 19

What is the connective tissue layer around the Fascicles?

And what is its function?

Answer 19

Perimysium surrounds muscle fibres

plays role in transmitting lateral contractile movements.

Question 20

What is the connective tissue around each muscle fibre? and its function( what does it contain)

Answer 20

Endomysium - this contains all the capillaries and nerves

Question 21

By what process do myoblasts differentiate into Muscle fibres

Answer 21

Myogenesis

Question 22

What are myofibrils?(actin and myosin)

Answer 22

These are fibrous proteins that make of muscle cells and they are made of thick and thin filaments

Question 23

Triad system to T tubules consist of

Answer 23

Two terminal cisternae ( release CA2+ ) and central T tubule

Question 24

When the wave of depolarisation travels along the sarcolemma what type of calcium channels are opened?

Answer 24

Voltage gated L type channels or DHPR for drugs

Question 25

The voltage gated CA channel opens which open what kind of ligand gated calcium channel.

Answer 25

RYR

Question 26

What type of troponin protein does calcium bind to?

Answer 26

Troponin C

Question 27

How is calcium returned to the terminal cisternae?

Answer 27

SERCA pumps using energy from ATP

Question 28

How does the depolarisation of a cardiomyocyte differ than that of a normal skeletal muscle cell?

Answer 28

Darker part of the cell are the intercalated discs
T tubule and terminal cisternae of sarcoplasmic reticulum is shorter and forms a diad.
T tubule found at level of 2 discs compared to skeletal being at A-I junction

Question 29

Types of Leavers acronym

Answer 29

123 FLE

Question 30

The arrangement of muscle fibres in fascicles contribute to the muscle force and speed. How does the length and quantity differ?

Answer 30

Longer and more parallel fibre arrangement = more muscle shortening ( less powerful as less fibres) e.g. sartorial
Greater number of muscle fibres = greater power e.g. rectus femoris

Question 31

Agonist

Answer 31

Prime mover , major force to complete movement

Question 32

Antagonist

Answer 32

produce opposing force

aids in controlling motion

Question 33

Synergistic muscle actions

Answer 33

these types of muscles contract to
prevent unwanted movements
or aid the acton of the agonist

Question 34

Duchenne muscular dystrophy is what and due to what protein degenerated

what clinical sign is normally present

Answer 34

Muscle degeneration and weakness due to protein dystrophin that normally keeps muscle cells intact.

X linked inherited degenerative disease - Gowers sign

Question 35

what is Lambert eaton myasthenic syndrome

Answer 35

rare that affects the signals sent from the nerves to the muscles - muscles are unable to tighten - lung cancer
autoimmune
constiatipation, swallowing , dizziness and dry mouth and erectile dysfunction