Nervous coordination and muscles

Question 1

Explain why there is a delay between the change in potential of the presynaptic and postsynaptic membrane (2)

Answer 1

Due to the time it takes for the neurotransmitter to diffuse
Across the synaptic cleft

Question 2

Outline what causes the thick and thin myofilaments to slide past each other when the myofibril contracts (3)

Answer 2

Myosin head (thick filament) binds to actin molecules in thin filaments
Myosin head bends, pulling thin filaments along thick filaments
Myosin head detaches then reattaches further along thin filament

Question 3

How can damage to the myelin sheath of neurones cause muscular paralysis? (3)

Answer 3

Leads to saltatory conduction
Slows the nerve impulse
Reaching the neuromuscular junction