Down regulation of a brain cells receptors occurs when a per

Down regulation of a brain cell\'s receptors occurs when a person uses drugs and: the cell divides and speeds up to release more neurotransmitters the cell retracts receptors sites to slow down message transmission because there are too many neurotransmitters the central nervous system slows down the central nervous system accelerates Cross-tolerance is defined as: when a person can no longer get high from a drug. When a person develops tolerance to other, similar drugs in the same category (e.g., two or more depressants such as heroin and morphine) when a person develops increased sensitivity to drugs in different categories (e.g., one depressant such as alcohol and one stimulant such as cocaine) when a person has both a physical and a psychological dependency Which of the following are signs of addiction? There is continued use despite experiencing physical or psychological problems and consequences. The substance is used two or more times per week. A behavioral addiction is engaged in three or more times per week. Use of the substance or engaging in the behavior results in the desired effects. Dendritic \"spines\" (\"memory bumps\") grow in the synapse when the nerve is stimulated by sensory input. true false Of all the stimulants, the strongest physical and mental dependency develops from nicotine in tobacco. true false Which of the following statements most accurately represents the use of plant-based psychoactive substances? Plant-based psychoactive drugs are uncommon today and rarely used. Today marijuana is the only plant-based psychoactive substance that is still used. All plants that psychoactive substances are illegal today.

Solution

18. option B. the cell retracts the receptors when too many neurotransmitters are present as a feedback mechanism.

19.Option B. when a person develops a tolerance to other drug while using a similar kind of drug.

20. option A. when the use of ny substance is continued without considering the consecuences.

21. True. A sensory input is required to grow the memory bumps in the synapse

22. true

23. Option B could be correct .(options are not correct because there are many substances which are legally used as a phytoactive substances)