Endocrine System

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Endocrine Glands: harmone and their function

The endocrine system is made up of glands that produce and secrete HORMONES, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body’s Growth, Metabolism (the physical and chemical processes of the body), and sexual development and function. The hormones are released into the bloodstream and may affect one or several organs throughout the body.

Hormones are chemical messengers created by the body. They transfer information from one set of cells to another to coordinate the functions of different parts of the body.

The major glands of the endocrine system are the hypothalamus, pituitary, thyroid, parathyroids, adrenals, pineal body, and the reproductive organs (ovaries and testes). The pancreas is also a part of this system; it has a role in hormone production as well as in digestion.

The endocrine system is regulated by feedback in much the same way that a thermostat regulates the temperature in a room. For the hormones that are regulated by the pituitary gland, a signal is sent from the hypothalamus to the pituitary gland in the form of a “releasing hormone,” which stimulates the pituitary to secrete a “stimulating hormone” into the circulation. The stimulating hormone then signals the target gland to secrete its hormone. As the level of this hormone rises in the circulation, the hypothalamus and the pituitary gland shut down secretion of the releasing hormone and the stimulating hormone, which in turn slows the secretion by the target gland. This system results in stable blood concentrations of the hormones that are regulated by the pituitary gland.

Hypothalamus

The hypothalamus is located in the lower central part of the brain. This part of the brain is important in regulation of satiety, metabolism, and body temperature. In addition, it secretes hormones that stimulate or suppress the release of hormones in the pituitary gland. Many of these hormones are releasing hormones, which are secreted into an artery (the hypophyseal portal system) that carries them directly to the pituitary gland. In the pituitary gland, these releasing hormones signal secretion of stimulating hormones. The hypothalamus also secretes a hormone called somatostatin, which causes the pituitary gland to stop the release of growth hormone.

Pituitary Gland

The pituitary gland is located at the base of the brain beneath the hypothalamus and is no larger than a pea. It is often considered the most important part of the endocrine system because it produces hormones that control many functions of other endocrine glands. When the pituitary gland does not produce one or more of its hormones or not enough of them, it is called hypopituitarism.  The pituitary gland is divided into two parts: the anterior lobe and the posterior lobe. The anterior lobe produces the following hormones, which are regulated by the hypothalamus:

Growth hormone: Stimulates growth of bone and tissue (Growth hormone deficiency results in growth failure. Growth hormone deficiency in adults results in problems in maintaining proper amounts of body fat and muscle and bone mass. It is also involved in emotional well-being.)

Thyroid-stimulating hormone (TSH): Stimulates the thyroid gland to produce thyroid hormones (A lack of thyroid hormones either because of a defect in the pituitary or the thyroid itself is called hypothyroidism.)

Adrenocorticotropin hormone (ACTH): Stimulates the adrenal gland to produce several related steroid hormones

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): Hormones that control sexual function and production of the sex Steroids, estrogen and progesterone in females or testosterone in males.

Prolactin: Hormone that stimulates milk production in females.

The posterior lobe produces the following hormones, which are not regulated by the hypothalamus:

Antidiuretic hormone (vasopressin): Controls water loss by the kidneys

Oxytocin: Contracts the uterus during childbirth and stimulates milk production

The hormones secreted by the posterior pituitary are actually produced in the brain and carried to the pituitary gland through nerves. They are stored in the pituitary gland.

Thyroid Gland

The thyroid gland is located in the lower front part of the neck. It produces thyroid hormones that regulate the body’s metabolism. It also plays a role in bone growth and development of the brain and nervous system in children. The pituitary gland controls the release of thyroid hormones. Thyroid hormones also help maintain normal blood pressure, heart rate, digestion, muscle tone, and reproductive functions.

Parathyroid Glands

The parathyroid glands are two pairs of small glands embedded in the surface of the thyroid gland, one pair on each side. They release parathyroid hormone, which plays a role in regulating calcium levels in the blood and bone metabolism.

Adrenal Glands

The two adrenal glands are triangular-shaped glands located on top of each kidney. The adrenal glands are made up of two parts. The outer part is called the adrenal cortex, and the inner part is called the adrenal medulla. The outer part produces hormones called corticosteroids, which regulate the body’s metabolism, the balance of salt and water in the body, the immune system, and sexual function. The inner part, or adrenal medulla, produces hormones called catecholamines (for example, adrenaline). These hormones help the body cope with physical and emotional Stress by increasing the heart rate and blood pressure.,

The endocrine system is a collection of glands that produce hormones that regulate many important body functions, such as growth and development, metabolism, mood, sexual function, Reproduction, sleep, and stress response.

The endocrine system is made up of glands that produce hormones, which are chemical messengers that travel through the bloodstream to reach specific cells or organs. Hormones control a wide range of body functions, including growth and development, metabolism, mood, sexual function, reproduction, sleep, and stress response.

The endocrine system is regulated by the hypothalamus, which is a small region of the brain that controls many body functions. The hypothalamus releases hormones that stimulate or inhibit the release of hormones from other glands in the endocrine system.

The endocrine system is a complex and important system that plays a vital role in maintaining Health and well-being.

The following are the subtopics of the endocrine system:

  • Pituitary gland
  • Thyroid gland
  • Parathyroid glands
  • Adrenal glands
  • Pancreas
  • Gonads (testes and ovaries)
  • Pineal gland
  • Thymus gland
  • Hypothalamus

Pituitary gland

The pituitary gland is a small, pea-sized gland that is located at the base of the brain. It is often called the “master gland” because it produces hormones that control the function of other glands in the endocrine system.

The pituitary gland produces six major hormones:

  • Growth hormone (GH) stimulates growth and development.
  • Thyroid-stimulating hormone (TSH) stimulates the thyroid gland to produce thyroid hormones.
  • Adrenocorticotropic hormone (ACTH) stimulates the adrenal glands to produce cortisol.
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) stimulate the ovaries and testes to produce sex hormones.
  • Prolactin (PRL) stimulates milk production in Women.

Thyroid gland

The thyroid gland is a butterfly-shaped gland that is located in the neck. It produces thyroid hormones, which are essential for growth and development, metabolism, and mood.

Thyroid hormones are produced by two types of cells in the thyroid gland: follicular cells and C cells. Follicular cells produce thyroxine (T4) and triiodothyronine (T3), which are the main thyroid hormones. C cells produce calcitonin, which helps to regulate blood calcium levels.

Parathyroid glands

The parathyroid glands are four small glands that are located on the back of the thyroid gland. They produce parathyroid hormone (PTH), which helps to regulate blood calcium levels.

PTH increases the level of calcium in the blood by stimulating the bones to release calcium, by increasing the absorption of calcium from the intestines, and by decreasing the Excretion of calcium in the urine.

Adrenal glands

The adrenal glands are two small glands that are located on top of the kidneys. They produce a variety of hormones, including cortisol, aldosterone, and epinephrine.

Cortisol is a stress hormone that helps the body to respond to stress. Aldosterone helps to regulate blood pressure by controlling the reabsorption of sodium and water in the kidneys. Epinephrine, also known as adrenaline, is a hormone that helps the body to respond to emergencies.

Pancreas

The pancreas is a large gland that is located in the abdomen. It produces digestive ENZYMES and hormones, including insulin and glucagon.

Insulin helps the body to use glucose for energy. Glucagon helps the body to release glucose from the liver when blood sugar levels are low.

Gonads (testes and ovaries)

The gonads are the sex glands. In males, the gonads are the testes. In females, the gonads are the ovaries.

The testes produce testosterone, which is a hormone that helps to promote male sexual development and function. The ovaries produce estrogen and progesterone, which are hormones that help to promote female sexual development and function.

Pineal gland

The pineal gland is a small gland that is located in the brain. It produces melatonin, which is a hormone that helps to regulate sleep and wakefulness.

Thymus gland

The thymus gland is a small gland that is located in the chest. It produces T cells, which are white blood cells that help the body to fight infection.

Hypothalamus

The hypothalamus is a small region of the brain that controls many body functions, including temperature regulation, thirst, hunger, and sleep. It also plays a role in the endocrine system by regulating the release of hormones from the pituitary gland.

The endocrine system is a complex and important system that plays a vital role in maintaining health and well-being.

1. What is the nervous system?

The nervous system is the part of an animal’s body that coordinates the voluntary and involuntary actions of the animal and transmits signals between different parts of its body. In most types of animals it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor or efferent nerves, while those nerves that transmit information from the body to the CNS are called sensory or afferent. Spinal nerves serve both functions and are called mixed nerves. The PNS is divided into three separate subsystems, the somatic, autonomic, and enteric nervous systems. Somatic nerves mediate voluntary movement. The autonomic nervous system is further subdivided into the sympathetic and the parasympathetic nervous systems. The sympathetic system uses noradrenalin as its postganglionic neurotransmitter, and is activated to a large degree during the “fight-or-flight response”. The parasympathetic system uses acetylcholine as its postganglionic neurotransmitter, and is activated when organisms are in a relaxed state. The enteric nervous system functions to control the gastrointestinal system.

2. What is the endocrine system?

The endocrine system is a system of glands that produce hormones, which are chemical messengers that regulate the body. The endocrine system is made up of the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries, and testes. The hypothalamus is a small gland in the brain that controls the pituitary gland. The pituitary gland is a pea-sized gland at the base of the brain that produces hormones that control many other glands in the body. The thyroid gland is a butterfly-shaped gland in the neck that produces hormones that regulate metabolism. The parathyroid glands are four small glands in the neck that produce hormones that regulate calcium levels in the blood. The adrenal glands are two small glands on top of the kidneys that produce hormones that regulate the stress response. The pancreas is a gland behind the stomach that produces hormones that regulate blood sugar levels. The ovaries are two female reproductive organs that produce hormones that regulate the menstrual cycle and female sexual characteristics. The testes are two male reproductive organs that produce hormones that regulate sperm production and male sexual characteristics.

3. What is the difference between the nervous system and the endocrine system?

The nervous system and the endocrine system are two of the body’s major control systems. The nervous system uses electrical signals to control rapid, voluntary actions, while the endocrine system uses hormones to control slower, involuntary actions. The nervous system is made up of neurons, which are specialized cells that send and receive electrical signals. The endocrine system is made up of glands, which are organs that produce hormones. Hormones are chemical messengers that travel through the bloodstream to target cells throughout the body.

4. What are the functions of the nervous system?

The nervous system has many functions, including:

  • Controlling voluntary movement
  • Regulating involuntary actions, such as heart rate and breathing
  • Processing information from the senses
  • Controlling emotions
  • Thinking and memory

5. What are the functions of the endocrine system?

The endocrine system has many functions, including:

  • Regulating metabolism
  • Regulating growth and development
  • Regulating reproduction
  • Regulating the immune system
  • Maintaining homeostasis

6. What are some common disorders of the nervous system?

Some common disorders of the nervous system include:

  • Alzheimer’s disease
  • Parkinson’s disease
  • Multiple sclerosis
  • Epilepsy
  • Stroke
  • Head injury

7. What are some common disorders of the endocrine system?

Some common disorders of the endocrine system include:

  • Diabetes
  • Hypothyroidism
  • Hyperthyroidism
  • Cushing’s syndrome
  • Addison’s disease

  1. Which of the following is not a hormone?
    (a) Insulin
    (b) Epinephrine
    (c) Testosterone
    (d) Acetylcholine

  2. The endocrine system is responsible for:
    (a) Regulating metabolism
    (b) Controlling growth and development
    (c) Regulating reproduction
    (d) All of the above

  3. The pituitary gland is located in the:
    (a) Brain
    (b) Thyroid
    (c) Pancreas
    (d) Adrenal glands

  4. The thyroid gland produces the hormone:
    (a) Insulin
    (b) Epinephrine
    (c) Thyroxine
    (d) Testosterone

  5. The parathyroid glands produce the hormone:
    (a) Insulin
    (b) Epinephrine
    (c) Calcitonin
    (d) Testosterone

  6. The adrenal glands produce the hormones:
    (a) Epinephrine and norepinephrine
    (b) Aldosterone and cortisol
    (c) Both (a) and (b)
    (d) None of the above

  7. The pancreas produces the hormones:
    (a) Insulin and glucagon
    (b) Epinephrine and norepinephrine
    (c) Aldosterone and cortisol
    (d) None of the above

  8. The testes produce the hormone:
    (a) Testosterone
    (b) Estrogen
    (c) Progesterone
    (d) All of the above

  9. The ovaries produce the hormones:
    (a) Estrogen and progesterone
    (b) Testosterone
    (c) Aldosterone and cortisol
    (d) None of the above

  10. The pineal gland produces the hormone:
    (a) Melatonin
    (b) Epinephrine
    (c) Calcitonin
    (d) Testosterone

Answers:
1. (d)
2. (d)
3. (a)
4. (c)
5. (c)
6. (c)
7. (a)
8. (a)
9. (a)
10. (a)