Question

Serotonin and melatonin is secreted by
A)Pancreas
B)Pineal body
C)Pituitary gland
D)Thymus

Answer 1

Hint:Chemical messengers which are secreted directly into the blood and help in regulating the functions of tissues and organs are known as hormones. Serotonin and melatonin are examples of hormones.

Complete answer:
Before finding the correct answer, let us know a little about glands. The organs which are responsible for secreting hormones are known as glands. There are two types of glands,
>Endocrine glands
>Exocrine glands

Option a: Pancreas secretes insulin and not serotonin and melatonin. Therefore, this is the incorrect option.
Option b: Pineal body secretes the hormone melatonin. Precursor of melatonin is serotonin, in the pineal gland serotonin is first methylated and then acetylated to produce melatonin.
Pineal gland also known as epiphysis is a small endocrine gland present in the brain. The various roles of >pineal gland have still not been understood completely. But some of its roles are,
>It regulates female reproduction and sexual maturation
>It controls the circadian rhythms
Option c: Pituitary glands secrete four types of hormones - ACTH, FSH (Follicle Stimulating Hormone), TSH (Thyroid Stimulating Hormone), and LH (Luteinizing Hormone). But it does not produce serotonin and melatonin. Therefore, this is the incorrect option.
Option d: Thymus secretes thymosin which is necessary for T Cell development and production. But it does not produce serotonin and melatonin. Therefore, this is the incorrect option.

Thus, the correct option is (b) Pineal body.

Note:Serotonin helps in stabilizing our mood and happiness. It also has a role in sleeping, digestion and eating. Melatonin helps in regulating physiological functions and circadian rhythms.