Hormones are chemical substances that are secreted from endocrine glands or endocrine systems.

The hormone acts as a regulatory substance delivered in a life form and transported in tissue liquids like blood or sap that stimulate specific cells or tissues right into it.

Role of Hormones in Initiating Reproductive Function

Hormones regulate the onset of puberty and the maturation of reproductive organs.

• The testes release the male hormone or testosterone at the onset of puberty. This causes secondary changes in boys
• With the onset of puberty in girls, ovaries produce female hormones or oestrogen that fosters the breasts. Milk secreting glands or mammary glands are present inside the breasts
• Progesterone aids in the regulation of your menstrual cycle. However, its primary function is to prepare your uterus for pregnancy. Each month, after you ovulate, progesterone helps thicken the uterine lining in preparation for a fertilised egg. If no fertilised egg is present, progesterone levels fall and menstruation begins

The pituitary gland or master gland controls the secretion and production of another hormone known as oxytocin secreted from an endocrine gland.

Reproductive Phase of Life in Humans

A person can reproduce when their testes and ovaries begin to produce gametes. Gametes remain mature and productive longer in males as compared to females.

• The reproductive phase starts at 10-12 years of age and lasts approximately 45 to 50 years in females
• With puberty’s onset, the ova get mature. One ovum matures and one of the ovaries releases it in about 28 to 30 days
• At this time, the uterus wall thickens for receiving the egg. If it gets fertilised, then this results in pregnancy
• If fertilisation does not occur, then the thick lining of the uterus and its blood vessels are shed off, which causes bleeding in women and is referred to as menstruation
• Menstruation occurs in a month with a gap of 28 to 30 days
• Menarche is the first menstrual flow that begins at puberty
• The menstrual cycle stops at 45 to 50 years of age. Menopause is the end of menstruation

Hormones in Humans

• The endocrine gland or Pituitary gland is present at the base of the brain. Testes and ovaries on stimulation secrete respective hormones. Other endocrine glands in the body include the thyroid gland, pancreas gland, and adrenals gland

• Diabetes is caused by a lack of insulin and glucagon hormone, which is produced by the pancreas
• The secretion of adrenaline hormones maintains blood salt balance. The adrenal gland produces adrenaline, which aids the body in adjusting to a stressful situation such as anger
• Sweat, oil, and salivary glands all secrete their contents via ducts. Because hormones are released directly into the bloodstream, they are referred to as ductless glands or endocrine glands
• The thyroid, also known as the thyroid gland, is a type of endocrine gland found in vertebrates. It is found in the human neck and is made up of two connected lobes. The thyroid isthmus is a thin band of tissue that connects the lower two-thirds of the lobes. The thyroid gland is located just below the Adam’s apple in the front of the neck

Hormones’ Role in Completing the Life Cycles of Insects and Frogs

Insects and Frogs undergo various changes to become adult moths. Metamorphosis refers to the physiological transition from larva to adult. Insect hormones control metamorphosis in insects.

• Thyroxine produces thyroid hormone that controls metamorphosis in a frog. Thyroxine is produced in the presence of iodine in water

Conclusion

Hormones are chemical substances that are secreted from endocrine glands or endocrine systems. Hormones are responsible for controlling various body actions; they also control the onset of puberty and maturity of the reproductive parts. The testes release the male hormone or testosterone at the onset of puberty. This causes secondary changes in boys. And the ovaries produce the female hormone or oestrogen in girls. The reproductive phase starts at 10-12 years of age and lasts approximately 45 to 50 years in females.  Menstruation occurs in a month with a gap of 28 to 30 days. Menarche is the first menstrual flow that begins at puberty, and Menopause represents the end of menstruation in life. The thyroid gland produces the thyroxine hormone. The pancreatic gland produces insulin hormone. Secretion of the adrenal gland’s hormones maintains the salt balance in the blood. Adrenaline is produced by the adrenal gland that helps the body adjust to a stressful situation like anger. Glands such as sweat, oil, and salivary glands release their secretions through ducts. Hormones are directly released into the bloodstream, and so they are called ductless glands or endocrine glands.