IB Unit 4: Muscle contraction & movement

Which structure of the motor unit is labelled X in the diagram above?

• Axon

• Cell body

• Dendrite

• Motor end plate

What is the muscle contraction where length of the muscle remains the same?

• Isotonic concentric

• Isotonic eccentric

• Isometric

• Isokinetic

What is the structure labelled X in the diagram above?

• Muscle

• Axon

• Dendrite

• Cell body

Which muscle contraction occurs when the muscle lengthens under tension?

• Isokinetic

• Isometric

• Eccentric

• Concentric

Which type of contraction occurs in the rectus femoris while performing a squat (moving from position A to B)?

• Isometric

• Isotonic eccentric

• Isotonic concentric

• Isokinetic eccentric

What is the sequence of a motor unit signal travelling from the brain to the muscle?

• Synapse, axon, cell body, dendrite, motor end plate

• Synapse, dendrite, cell body, axon, motor end plate

• Motor end plate, dendrite, cell body, axon, synapse

• Synapse, dendrite, axon, cell body, motor end plate

What describes the role of acetylcholine in skeletal muscle contraction?

• To open an axon’s synaptic vesicle

• To close an axon’s synaptic vesicle

• To open a motor-end plate channel

• To block a motor-end plate channel

Which is the correct sequence of neural impulse transmission to the muscle?

• cell body → dendrite → axon → motor end plate

• motor end plate → dendrite → axon → cell body

• dendrite → axon → cell body → motor end plate

• dendrite → cell body → axon → motor end plate

What is the structure labelled X in the motor unit above?

• Axon

• Synapse

• Muscle

• Motor end plate

Which part of the motor neuron is nearest to the muscle fibre it stimulates?

• Axon

• Dendrite

• Motor unit

• Motor end plate