Growth regulators in plants are usually hormones -substances synthesized in one part of the plant and translocated to another part where they exert their effect. They are frequently called growth hormones. A plant growth hormone may be defined as any organic chemical which controls either by stimulation, inhibition or alternation , the growth, development and differentiation of the plant. The five main group of naturally occurring growth regulators are the auxins, gibberelins, Cytokinins , ethylene and abscidic acid . Each of these chemically different types of growth hormones has characteristic influence on the growth and differentiation of plant cells. The influence of growth hormones extends to all phases of germination,dormancy , flowering, senescence and growth movements.
TYPES OF HORMONES:-
There are many types of hormones that play different roles in the human body. Hormones are chemical messengers that are produced by various glands and organs in the body and are released into the bloodstream to regulate different physiological processes.
★Here are some common types of hormones
These are the most common type of hormones and include insulin, growth hormone, and oxytocin. Peptide hormones are made up of short chains of amino acids and are produced in glands such as the pancreas and pituitary gland.
These hormones are derived from cholesterol and include hormones such as testosterone, estrogen, and progesterone. Steroid hormones are produced by glands such as the gonads (testes and ovaries) and the adrenal glands.
★Amino acid-derived hormones★
These hormones are derived from amino acids and include hormones such as adrenaline, noradrenaline, and thyroid hormones. Amino acid-derived hormones are produced by glands such as the adrenal glands and the thyroid gland.
These hormones are derived from lipids (fats) and include hormones such as prostaglandins and leukotrienes. Lipid-derived hormones are produced by various cells throughout the body and play a role in inflammation, immune response, and other processes.
These are chemicals that transmit signals in the nervous system and can also act as hormones. Examples of neurotransmitters that can also function as hormones include dopamine, serotonin, and norepinephrine.
These hormones are made up of longer chains of amino acids and include hormones such as insulin, growth hormone, and luteinizing hormone (LH). Peptide/protein hormones are produced by glands such as the pancreas, pituitary gland, and hypothalamus.
These hormones act locally and do not circulate in the bloodstream. Examples of local hormones include prostaglandins, which are involved in inflammation and pain response.
These are just some examples of the different types of hormones found in the human body. Hormones play a critical role in regulating various physiological processes, including growth and development, metabolism, immune function, reproductive function, and stress response, among others
IMPORTANCE OF HORMONES:-
Hormones play a crucial role in regulating various physiological and behavioral processes in the human body. They are chemical messengers produced by glands in the endocrine system and released into the bloodstream, where they travel to target cells or organs to exert their effects.
★Here are some key reasons why hormones are important:
★Regulation of body functions★
Hormones help regulate a wide range of body functions, including metabolism, growth and development, immune response, digestion, stress response, sexual development and reproduction, sleep-wake cycles, mood, and many others. They act as signaling molecules that communicate instructions to cells and organs, helping to maintain overall physiological balance and homeostasis.
★Growth and development★
Hormones are critical for growth and development during childhood and adolescence. For example, growth hormone released by the pituitary gland stimulates bone and muscle growth, while thyroid hormones regulate metabolism and brain development. During puberty, sex hormones like estrogen and testosterone drive sexual development and secondary sexual characteristics.
Hormones play a fundamental role in the reproductive system. In females, hormones like estrogen and progesterone regulate the menstrual cycle, ovulation, and pregnancy. In males, testosterone is responsible for sperm production and sexual function. Hormones also influence fertility, libido, and other aspects of sexual health.
★Response to stress★
Hormones are involved in the body’s response to stress, both acute and chronic. For example, the adrenal glands release cortisol in response to stress, which helps the body cope with stressful situations by increasing blood sugar levels, suppressing inflammation, and regulating immune response. Chronic stress can disrupt hormonal balance and have detrimental effects on health.
★Mood and emotions★
Hormones play a role in regulating mood and emotions. Serotonin, dopamine, and norepinephrine are examples of hormones that are involved in regulating mood, motivation, and emotional well-being. Imbalances in these hormones have been associated with mood disorders such as depression and anxiety
★Metabolism and energy balance★
Hormones are involved in regulating metabolism and energy balance. Thyroid hormones, for example, regulate metabolism and energy production in cells, while insulin regulates glucose metabolism and plays a role in diabetes. Leptin, a hormone produced by fat cells, regulates appetite and body weight.
★Maintenance of bone health★
Hormones such as estrogen, testosterone, and parathyroid hormone are critical for maintaining bone health. They regulate bone formation and resorption, and imbalances in these hormones can lead to conditions such as osteoporosis.
Hormones are involved in growth and development, reproduction, stress response, mood and emotions, metabolism, and many other essential functions in the body.
ROLE OF HORMONE:-
Hormones play a crucial role in many processes throughout the body. They are chemical messengers that are produced by glands in the endocrine system, and they help regulate a variety of bodily functions, including growth and development, metabolism, reproduction, mood, and stress response.
★Some examples of hormones and their functions include:
(1) INSULIN:- regulates blood sugar levels and helps cells absorb glucose for energy.
(2) TESTOSTERONE AND ESTROGEN:- play a key role in sexual development and reproductive function.
(3) THYROID HORMONE:- regulate metabolism and energy levels.
(4) CORTISOL:-regulates the body’s response to stress.
(5) GROWTH HORMONE:- promotes growth and development in children and adolescents.
(6) MELATONIN:-regulates sleep patterns.
(7) ADRENALINE:-triggers the body’s fight-or-flight response to danger.
(8) OXYTOCIN:-plays a role in social bonding and reproductive function.
Hormones are chemical messengers that regulate a wide range of physiological processes in the body. They are produced by various glands, including the pituitary gland, thyroid gland, adrenal gland, pancreas, ovaries, and testes.
Hormones play a crucial role in maintaining homeostasis in the body, which is the stable internal environment required for optimal functioning. They regulate processes such as growth and development, metabolism, reproductive functions, stress response, and immune function.
For example, insulin, a hormone produced by the pancreas, regulates glucose metabolism and helps to maintain stable blood sugar levels. Thyroid hormones, produced by the thyroid gland, regulate metabolism and energy expenditure. Adrenaline and cortisol, produced by the adrenal glands, are involved in the body’s stress response. Estrogen and testosterone, produced by the ovaries and testes respectively, regulate reproductive functions and secondary sex characteristics.