Select the correct options to fill up the blanks.
(i) With repeated use of drugs, the tolerance level of receptors present in our body _______.
(ii) Smoking increases ______ content and reduces the concentration of ___ in blood.
(iii) Cannabinoid receptors are present in the ______.
(iv) Morphine is a very effective ____ and ____.
(v) Opioids are extracted from the _____ of poppy plant, Papaver somniferum.