The Endocrine System
The endocrine system is the body's slow chemical communication system. The endocrine system is the collection of glands, each secreting different types of hormones that regulate growth, metabolism, development, tissue function, sexual functions, reproduction, sleep, mood, and many other things. This system is made up of major glands which secrete hormones into the bloodstream and affect other tissues, including the brain. When these hormones act on our brains, they have an influence on our interest in food, sex, and aggression. The endocrine system is very similar to the nervous system, in that they both produce molecules that act on receptors elsewhere. However, these two system also are different. While the nervous systems signals travel rather fast, the endocrine messages take longer to travel from the gland to the tissue.
Functions of the endocrine system
The endocrine system is responsible for many things such as:
1. Growth
2. Reproduction
3. Metabolism
4.Stress responses
5.Calcium and hormone levels
6.Water balance
1. Growth
2. Reproduction
3. Metabolism
4.Stress responses
5.Calcium and hormone levels
6.Water balance
Major glands in the endocrine system
1. Hypothalamus- The hypothalamus is located in the lower central area of the brain and helps the rest of the endocrine system remain in contact with the nervous system by producing chemicals that will activate or suppress the actions of the pituitary gland. This allows the hypothalamus to translate messages from the nervous system and inform the body that it needs to perform a certain action.
2. Pituitary Gland- The pituitary gland is located just beneath the hypothalamus, and is often considered the most valuable part of the endocrine system. It controls many of the other glands in the endocrine system with the hormones it secretes. Emotions, changes of the season and many other signals can affect the amount of hormones the pituitary gland produces. As light patterns, feelings and others are sensed by the brain, the hypothalamus sends a signal to the pituitary gland which consists of the anterior lobe and the posterior lobe. The anterior lobe manages the action of adrenals, thyroid and the reproductive glands. It produces endorphins, growth hormones, thyrotopin, prolactin or corticotropin. Endorphins reduce the feeling of pain, control the menstrual cycle and signal the use of the reproductive organs. Growth hormones determine how nutrients taken into the body will be used and stimulate bone growth. Thyrotropin stimulates the thyroid gland. Prolactin activates milk production in women's breasts. Corticotropin stimulates the adrenal glands.The posterior lobe secretes antidiuretic hormone and oxytocin. The antidiuretic hormone controls the water level in the human body. The oxytocin helps to contract the uterus of a woman when having a baby.
3. Adrenal Glands- The adrenal glands are located at the tops of the kidneys. These contain two parts, the adrenal cortex and adrenal medulla. The adrenal cortex produces corticosteroids which help to balance the levels of water and salt in the body. These can be altered based on sexual development, the function of the metabolism or signals from the immune system. The adrenal medulla produces catecholamines which are used to regulate the heart rate and blood pressure as a reaction to stress in the environment.
4.Thyroid Gland- The thyroid is located in the front of the lower neck. This gland produces hormones that stimulate the metabolism, which controls how fast the body breaks down food and used this fuel to create energy. The more of this chemical is in the bloodstream, the faster your metabolism will function. If the thyroid becomes sluggish it can lead to weight gain and digestive disorders. The thyroid also controls brain and nervous system development in children.
5. Parathyroids- There are four parathyroids which are clustered together near the thyroid. These create the parathyroid hormone which works with calcitonin to control the level of calcium within the bones and in the blood.
6. Pineal Gland- The pineal gland is located in the middle of the brain. It creates the hormones called melatonin that are used to make you fall asleep at night and wake up in the morning based on the light levels the body perceives.
7. Reproductive Glands- In women, the reproductive glands consist of the ovaries, which are located in the pelvis. These are used to produce estrogen and progesterone which controls breast growth, the regulation of the menstrual cycle and to monitor pregnancy. The ovaries also contain the eggs used in reproduction.
In men, the reproductive organs are the testes which are located in the scrotum. These secrete androgens such as testosterone that will help signal puberty, body and penis growth, deepening voice and the creation and maintenance of facial hair.
Men and women each have levels of estrogen and testosterone that must be maintained for healthy development.
8. Pancreas- The pancreas is an organ in the upper abdomen and is about 6 inches long located behind the stomach. The pancreas has two main functions. One is that it makes enzymes, which helps the body digest proteins, fats, and carbohydrates before they can be absorbed in the intestine. Another one of its functions is that it makes hormones, the most important hormone that it makes is insulin, which control how the body uses and stores sugar (glucose), which is its main source of energy.
2. Pituitary Gland- The pituitary gland is located just beneath the hypothalamus, and is often considered the most valuable part of the endocrine system. It controls many of the other glands in the endocrine system with the hormones it secretes. Emotions, changes of the season and many other signals can affect the amount of hormones the pituitary gland produces. As light patterns, feelings and others are sensed by the brain, the hypothalamus sends a signal to the pituitary gland which consists of the anterior lobe and the posterior lobe. The anterior lobe manages the action of adrenals, thyroid and the reproductive glands. It produces endorphins, growth hormones, thyrotopin, prolactin or corticotropin. Endorphins reduce the feeling of pain, control the menstrual cycle and signal the use of the reproductive organs. Growth hormones determine how nutrients taken into the body will be used and stimulate bone growth. Thyrotropin stimulates the thyroid gland. Prolactin activates milk production in women's breasts. Corticotropin stimulates the adrenal glands.The posterior lobe secretes antidiuretic hormone and oxytocin. The antidiuretic hormone controls the water level in the human body. The oxytocin helps to contract the uterus of a woman when having a baby.
3. Adrenal Glands- The adrenal glands are located at the tops of the kidneys. These contain two parts, the adrenal cortex and adrenal medulla. The adrenal cortex produces corticosteroids which help to balance the levels of water and salt in the body. These can be altered based on sexual development, the function of the metabolism or signals from the immune system. The adrenal medulla produces catecholamines which are used to regulate the heart rate and blood pressure as a reaction to stress in the environment.
4.Thyroid Gland- The thyroid is located in the front of the lower neck. This gland produces hormones that stimulate the metabolism, which controls how fast the body breaks down food and used this fuel to create energy. The more of this chemical is in the bloodstream, the faster your metabolism will function. If the thyroid becomes sluggish it can lead to weight gain and digestive disorders. The thyroid also controls brain and nervous system development in children.
5. Parathyroids- There are four parathyroids which are clustered together near the thyroid. These create the parathyroid hormone which works with calcitonin to control the level of calcium within the bones and in the blood.
6. Pineal Gland- The pineal gland is located in the middle of the brain. It creates the hormones called melatonin that are used to make you fall asleep at night and wake up in the morning based on the light levels the body perceives.
7. Reproductive Glands- In women, the reproductive glands consist of the ovaries, which are located in the pelvis. These are used to produce estrogen and progesterone which controls breast growth, the regulation of the menstrual cycle and to monitor pregnancy. The ovaries also contain the eggs used in reproduction.
In men, the reproductive organs are the testes which are located in the scrotum. These secrete androgens such as testosterone that will help signal puberty, body and penis growth, deepening voice and the creation and maintenance of facial hair.
Men and women each have levels of estrogen and testosterone that must be maintained for healthy development.
8. Pancreas- The pancreas is an organ in the upper abdomen and is about 6 inches long located behind the stomach. The pancreas has two main functions. One is that it makes enzymes, which helps the body digest proteins, fats, and carbohydrates before they can be absorbed in the intestine. Another one of its functions is that it makes hormones, the most important hormone that it makes is insulin, which control how the body uses and stores sugar (glucose), which is its main source of energy.
ENDOcrine glands vs. Exocrine glands
Endocrine Glands
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Exocrine glands
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