Synapses and the pupil reflex Quiz
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5 questions, one answer each
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1. Which ion entering the presynaptic knob causes vesicles to release acetylcholine?
- A. Sodium
- B. Potassium
- C. Calcium
- D. Chloride
2. Which products result from the hydrolysis of acetylcholine?
- A. Choline and ethanoate
- B. Glycerol and fatty acids
- C. Amino acids and ATP
- D. Glucose and phosphate
3. What happens to the iris muscles when a person moves from a bright room into a dim room?
- A. Circular muscles contract and radial muscles relax
- B. Both sets of muscle contract
- C. Both sets of muscle relax
- D. Radial muscles contract and circular muscles relax
4. Why can an impulse pass across a synapse in one direction only?
- A. Neurotransmitter is released only from the postsynaptic membrane
- B. Receptors are present only on the postsynaptic membrane
- C. Acetylcholinesterase is present only in the presynaptic knob
- D. Calcium ions leave the postsynaptic neurone
5. Several impulses from one presynaptic neurone arrive within a few milliseconds and trigger an action potential in the postsynaptic neurone. What is this called?
- A. Spatial summation
- B. Habituation
- C. Temporal summation
- D. Exocytosis