Tobacco inhalation causes

Haemoglobin is having maximum affinity with

Write a note on a chemical which interacts with the cannabinoid receptors present in the brain?

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The outline structure of a drug is given below.

$(a)$ Which group of drugs does this represent ?

$(b)$ What are the modes of consumption of these drugs ?

$(c)$ Name the organ of the body which is affected by consumption of these drugs.