functions of the endocrine system

A hormone is an organ that secretes chemical substances into the bloodstream.

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Both the nervous and endocrine systems send electrical and chemical signals for internal communication.

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Research indicates that as levels of happiness increase, cortisol levels appear to increase as well.

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The adrenal glands control internal sleep and waking cycles.

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The nervous system communicates internally by releasing hormones through the bloodstream.

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lecture

Section 1 00:00:01 PROFESSOR: There are many ways our body sends messages in order to help regulate bodily function, like mood, body heat, and so forth. One way our body communicates is through the endocrine system. This sends chemical messengers in the form of molecules like the ones in the picture through our bloodstream to perform specific functions. 00:00:19 So in this section, we're going to answer the question, how do our bodies communicate through the bloodstream? This is section one of Functions of the Endocrine System. Our objectives are to describe the structure and function of the endocrine system, to compare and contrast the communication processes of the nervous and endocrine systems, and to describe how hormones influence internal and 00:00:40 external behavior. In this section, we'll be describing the structure and function of the endocrine system. The endocrine system works within the nervous system to coordinate and regulate the body. It releases chemicals into the bloodstream to help control physiological functioning. So the endocrine system controls things like our mood, 00:00:58 metabolism, development, and reproduction. The hypothalamus controls the endocrine system. It regulates various physiological and emotional reactions. The hypothalamus also regulates our internal environment in response to the external world, and sends alerts from the brain to the pituitary gland to secrete hormones to other glands regulating emotional and other 00:01:19 physiological reactions. The endocrine gland is one organ, or group of cells, that secrete hormones directly into the bloodstream. For example, our pancreas is also considered an organ as well as an endocrine gland. A hormone is a chemical substance produced and released by the endocrine glands to help regulate bodily functions. 00:01:39 One reason we get tired is because the endocrine gland known as the pineal gland receives a signal from the brain to produce more melatonin, which makes us sleepy. Here are the structures of the endocrine system. The pituitary gland, thyroid gland, pineal gland, hypothalamus, thymus gland, adrenal glands, pancreas, ovaries, and testes. 00:02:00 Let's take a look at each one. The pituitary gland is found in the forebrain and is known as the master gland in the endocrine system. It controls all other endocrine glands and secretes chemicals that activate hormones and regulates our bodily growth. The pineal gland is located in the brain above the cerebellum. 00:02:21 It's known as the internal clock, and it controls our sleep and waking cycles. The thyroid gland is located in our neck. It regulates our metabolism, our body heat production, and our bone growth. If you're having problems with your thyroid gland, it might lead to weight gain or weight loss because it regulates our metabolism. 00:02:42 The adrenal glands are located above each kidney and regulate the salt and water levels in our body. They also control our stress response. Our reproductive glands, or gonads, are testes in males and ovaries in females. They affect sperm and egg formation, stimulate the development of sex characteristics, and control our reproductive cycle. 00:03:06 Here are other endocrine glands. The parathyroid gland regulates our blood calcium levels, whereas the thymus gland regulates the development of the immune system. Our pancreas regulates our blood sugar levels. So to review, we've talked about the endocrine system and how it's controlled by the hypothalamus. We've also talked about some of the endocrine glands, like 00:03:25 the pituitary, pineal, reproductive, adrenal, thymus, thyroid, pancreas, and parathyroid glands, and the hormones that they secrete. Next we're going to review the difference in communication styles between the endocrine and nervous system. Section 4 00:00:01 PROFESSOR: There are many different ways of communication. We can communicate through phone, letters, email, text messages, and so forth. It's easy to see how we communicate externally, but it's a little more difficult to see how our body sends messages internally. In this section, we are going to answer the question, what 00:00:18 are the different ways our bodies communicate internally? This is Section 2 of Functions of the Endocrine System. Our objectives are to describe the structure and functions of the endocrine system, to compare and contrast the communication process of the nervous and endocrine systems, and to describe how hormones influence internal and external behavior. In this section, we'll be comparing and contrasting the 00:00:41 communication process of the nervous and endocrine systems. Our body sends messages throughout the body and the brain by using both the endocrine and nervous system. The nervous system works through neurons and neural networks to communicate, whereas the endocrine system uses hormones. The nervous system connects the environment to the body and the body to the brain. 00:01:04 It regulates all bodily systems, including the endocrine system. The nervous system is a complex communication network which continuously receives, integrates, and transmit signals. It uses neurons and glia cells to communicate. Neurotransmitters send information from one neuron to another. 00:01:23 Neurons communicate by releasing these neurotransmitters and they attach to a neighboring neuron. The neural receptor is a protein structure on the surface of a neuron cell membrane, where neurotransmitters bind to initiate communication. So the neurotransmitters of one neuron are received by the receptor sites of a neighboring neuron. 00:01:43 The endocrine system is a system of glands that helps regulate physiological functioning. It uses the bloodstream to communicate. The bloodstream carries hormones to specific places in the body to perform specific functions. Hormones communicate by binding to other hormones. The hormone receptor is a receptor protein on the surface or interior of a cell that binds 00:02:04 to a specific hormone. Both neurons and hormones communicate by attaching to specific protein receptors in cells. This causes changes to occur within a cell, initiating specific functions. Hormones communicate with other hormones to perform specific functions by binding together, much like a lock and key. 00:02:24 If you have the correct key, the door will open. So a receptor binds with another and a change occurs, which triggers a specific reaction in the body. Neurons also communicate using the lock and key method. They communicate by releasing chemical messengers, or neurotransmitters. If the neurotransmitter doesn't fit in the receptor site, it won't enter the cell membrane. 00:02:48 The nervous system and the endocrine system both use chemical messengers for internal communication. They both receive communication commands from a hypothalamus. Just as a cell phone is used as a communication tool between individuals, both the endocrine and nervous systems use communication tools to help regulate the body. Like the symbol yin and yang represents the concept of 00:03:11 balance to the Chinese, both the nervous and the endocrine systems attempt to maintain balance in your body. They do this through homeostasis, which is the ability of a system or living organism to adjust its internal environment in order to maintain equilibrium. Here are some communication differences between the nervous system and endocrine system. Remember, the nervous system regulates 00:03:33 the endocrine system. It emits electrical and chemical signals, whereas the endocrine system only emits chemical signals. The nervous system has fast communication between cells, whereas the endocrine system has a slow communication between cells. Finally, the nervous system has a short-lived chemical effect, whereas the chemical effect of the endocrine system 00:03:54 can be long-lasting. The release point of the chemical messenger determines whether the chemical is a neurotransmitter or a hormone. If the chemical messenger is released at the synapse point, or the end of a neuron, it's a neurotransmitter. If the chemical messenger is released into the bloodstream, it's a hormone. Unlike neurotransmitters, hormones can spread all over 00:04:16 the body, so they can affect many organs. So to review, we've talked about the internal communication styles in your body. The nervous system uses neurons and neurotransmitters, whereas the endocrine system emits hormones into the bloodstream. Next we're going to review how hormones influence internal and external functioning. Section 7 00:00:01 PROFESSOR: Just as the gears on a steam engine work together to make a train move, our hormones work together to help our body function effectively. In this section, we're going to answer the question, how do hormones influence internal and external functioning? This is Section 3 of Functions of the Endocrine System. Our objectives are to describe the structure and functions of the endocrine system, to compare and contrast the 00:00:24 communication process of the nervous and endocrine systems, and to describe how hormones influence internal and external behavior. In this section, we'll be describing how hormones influence internal and external behavior. A hormone is a chemical substance produced and released by the endocrine glands that helps regulate bodily functions. 00:00:43 A hormone is released into the blood stream. There are over 30 hormones that our body produces. But in this section, we're going to talk about a few of the major hormones like epinephrine, norepinephrine, growth hormone, cortisol, thyroid hormones, testosterone and estrogen, and insulin. We're also going to talk about how hormones play an influence on our physical health. 00:01:04 Things like physical functioning, kidney functioning, heart functioning, immune functioning, metabolism, and blood sugar regulation are all affected by hormone levels in our bodies. Hormones also have an influence over our emotions. They can help us feel angry, sadness, excitement, happiness, fear, or anxiety. And hormones have an influence over our behavior. 00:01:27 They influence everything from sleeping patterns too assertive in mating behavior to cognitive ability and physical activity level. Epinephrine and norepinephrine are known as the stress hormones and are released by the adrenal glands. They play a role in preparing the body to react in stressful situations. Norepinephrine and epinephrine influence our heart and lung 00:01:49 functioning as well as the functioning of our nervous system and blood sugar regulation in our body. Emotions that norepinephrine epinephrine influence include excitement, fear, and anxiety. Excitement is linked to high levels of epinephrine. So you can see how it's also associated with fear and anxiety. Fear causes a spike in norepinephrine and 00:02:10 epinephrine. Cortisol is known as a major stress hormone, and it's also released by the adrenal glands. It influences almost every health and developmental behavior we'll need to discuss in this section. Cortisol influences our blood sugar regulation, as well as immune system functioning and metabolism, blood pressure regulation, muscle and bone formation, salt and water 00:02:33 balance in our body, and sleep patterns. It often serves as an anti-inflammatory which helps decrease the swelling in our body. That's why it's used to treat inflammatory diseases and allergies. Cortisol is connected to emotions like happiness, anger, excitement, anxiety, sadness, and fear. Levels of cortisol increase with stress and anger. 00:02:55 And sadness and depression are associated with decreased levels of cortisol in our body. Laughter is negatively correlated with cortisol levels in our body. So the more laughter or joy we're experiencing, the lower levels of cortisol we're going to have in our bodies. Growth hormone is released by the pituitary gland and also assists in immune functioning and other internal behaviors 00:03:16 like homeostasis and calcium retention. Growth hormone influences muscle growth and bone formation. It stimulates the growth of internal organs by promoting protein production and calcium retention. Growth hormone also influences our immune functioning and can lead to healthier bodies. Insulin is released by the pancreas and is a 00:03:37 vital source of energy. Insulin is released by the pancreas to help regulate blood sugar, our metabolism, and our physical activity level. Thyroid hormones are released by the thyroid glands which are found in our neck. A balance in thyroid hormones is vital to health and development. 00:03:55 Thyroid hormones influence our metabolism, protein production, bone growth, immune functioning, sleep patterns, and physical activity levels. The two sex hormones are testosterone and estrogen. Testosterone is released by the testes and ovaries and initiates the development of male sex characteristics. Estrogen is released by the ovaries and initiates the development of female sex characteristics. 00:04:20 Estrogen's main function is the development of reproductive organs. Both estrogen and testosterone influence bone and muscle formation and how we behave in romantic relationships. Testosterone is linked to assertive behavior, so things like competitiveness and aggression. And it's also linked to an increase in physical activity. Estrogen is associated with the amount of sleep woman get. 00:04:40 And both estrogen and testosterone are linked to cognitive ability, so things like our memory, attention, and mental clarity. Emotions that are linked to sex hormones are anxiety, anger, excitement, sadness, and happiness. High levels of testosterone are associated with anger, irritability, and frustration, but also excitement, like what you feel at the moment of triumph. 00:05:03 Low levels of estrogen are associated with despair and depression. The results of hormone imbalances are when hormone regulation fails. This is when we have too much or too little hormone produced in our body. An imbalance plays a large role in many health and developmental issues. 00:05:21 For example, diabetes has been linked to low levels of insulin or problems with our cortisol levels. Growth disorders are connected to too much or too little growth hormone. If we have too much, it can result in gigantism. If we have too little, it can produce stunted growths. High blood pressure is linked to an imbalance in cortisol, growth hormone, and norepinephrine. 00:05:41 Arthritis and osteoporosis are connected to adrenal hormones and testosterone imbalance. Allergies are linked to a cortisol imbalance. And weight issues can be connected to an imbalance in hormones like cortisol and thyroid hormones. Some behavioral problems associated with hormonal imbalance include attention deficit hyperactivity disorder, or ADHD, delinquent behaviors, family conflicts, 00:06:06 and some psychiatric disorders like mood disorders or schizophrenia. So to review, in this section, we've discussed how hormones work with the brain and glands to communicate internally. We've also talked about how hormone influences our behavior, health, and development, as well as how hormone imbalances affects our various health and developmental problems. 00:06:27 In this lesson, we've learned specifically the process of communication in the endocrine system. We've talked about both the endocrine and nervous systems and how they work together to regulate bodily functioning. Finally, we've talked about the different endocrine glands and how they assist with internal communication by producing hormones that influence internal and external behavior.

Cortisol, epinephrine, and norepinephrine are also known as stress hormones.

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The hypothalamus is a brain structure that controls the endocrine system.

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