background preloader

Topic 8: The endocrine system

Facebook Twitter

The Endocrine System. Endocrine System, part 1 - Glands & Hormones: Crash Course A&P #23. Endocrine System, part 2 - Hormone Cascades: Crash Course A&P #24. Endocrine System: Discover the Anatomy and Function of Glands. The endocrine system includes all of the glands of the body and the hormones produced by those glands. The glands are controlled directly by stimulation from the nervous system as well as by chemical receptors in the blood and hormones produced by other glands.

By regulating the functions of organs in the body, these glands help to maintain the body’s homeostasis. Cellular metabolism, reproduction, sexual development, sugar and mineral homeostasis, heart rate, and digestion are among Continue Scrolling To Read More Below... Continued From Above... The many processes regulated by the actions of hormones. Anatomy of the Endocrine System Hypothalamus The hypothalamus is a part of the brain located superior and anterior to the brain stem and inferior to the thalamus.

Thyrotropin-releasing hormone (TRH) Growth hormone-releasing hormone (GHRH) Growth hormone-inhibiting hormone (GHIH) Gonadotropin-releasing hormone (GnRH) Corticotropin-releasing hormone (CRH) Oxytocin Antidiuretic hormone (ADH) Human endocrine system | Description, Function, Glands, & Hormones. Feedback regulation mechanisms of endocrine signaling A constant supply of most hormones is essential for health, and sustained increases or decreases in hormone production often lead to disease. Many hormones are produced at a relatively constant rate, and in healthy individuals the day-to-day serum concentrations of these hormones lie within a rather narrow normal range.

However, hormone concentrations in the circulation may change in response to stimulatory or inhibitory influences that act on the hormone-producing cells or to increases or decreases in the degradation or excretion of the hormones. Hormone production and serum hormone concentrations are maintained by feedback mechanisms. Target glands, such as the thyroid gland, adrenal glands, and gonads, are under distant feedback regulation by the hypothalamic-pituitary-target gland axis.

Other hormonal systems, however, are under direct feedback regulation mechanisms. Growth and development Endocrine-related developmental disorders. 18 04 Local and Circulating hormones. Endocrine gland hormone review | Endocrine system physiology | NCLEX-RN | Khan Academy. Hormone concentration metabolism and negative feedback | NCLEX-RN | Khan Academy.

The hypothalamus and pituitary gland | Endocrine system physiology | NCLEX-RN | Khan Academy. Human endocrine system | Description, Function, Glands, & Hormones. Endocrine gland secretion is not a haphazard process; it is subject to precise, intricate control so that its effects may be integrated with those of the nervous system and the immune system. The simplest level of control over endocrine gland secretion resides at the endocrine gland itself. The signal for an endocrine gland to secrete more or less of its hormone is related to the concentration of some substance, either a hormone that influences the function of the gland (a tropic hormone), a biochemical product (e.g., glucose), or a biologically important element (e.g., calcium or potassium). Because each endocrine gland has a rich supply of blood, each gland is able to detect small changes in the concentrations of its regulating substances.

Some endocrine glands are controlled by a simple negative feedback mechanism. In the hypothalamic-pituitary-target gland axis, a second negative feedback loop is superimposed on the first negative feedback loop. Paper 12 19247 806. Homeostasis and Negative/Positive Feedback. Insulin and Glucagon: How Do They Work? Introduction Insulin and glucagon are hormones that help regulate the levels of blood glucose, or sugar, in your body. Glucose, which comes from the food you eat, moves through your bloodstream to help fuel your body. Insulin and glucagon work together to balance your blood sugar levels, keeping them in the narrow range that your body requires. These hormones are like the yin and yang of blood glucose maintenance. Read on to learn more about how they function and what can happen when they don’t work well. How insulin and glucagon work together Insulin and glucagon work in what’s called a negative feedback loop. How insulin works During digestion, foods that contain carbohydrates are converted into glucose.

The insulin tells cells throughout your body to take in glucose from your bloodstream. Read more: Simple vs. complex carbs » How glucagon works Glucagon works to counterbalance the actions of insulin. This whole feedback loop with insulin and glucagon is constantly in motion. Type 1 diabetes. Hormone Regulation ( Read ) | Biology. On or off? Hormones alter conditions inside the cell, usually in response to a stimulus. That means they are activated at specific times. So they must be turned on and then turned back off. What turns these hormones and their responses on or off?

Hormone Regulation: Feedback Mechanisms Hormones control many cell activities, so they are very important for homeostasis. Negative Feedback Negative feedback occurs when a product feeds back to decrease its own production. The thyroid gland is regulated by a negative feedback loop. Here’s how thyroid regulation works. Negative feedback also controls insulin secretion by the pancreas. Positive feedback Positive feedback occurs when a product feeds back to increase its own production. Summary Most hormones are controlled by negative feedback, in which the hormone feeds back to decrease its own production.

Review What is negative feedback? Oxytocin | You and Your Hormones from the Society for Endocrinology. Alternative names for oxytocin Alpha-hypophamine; manufactured versions – carbetocin, syntocinon and pitocin What is oxytocin? Oxytocin is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland. Secretion depends on electrical activity of neurons in the hypothalamus – it is released into the blood when these cells are excited. The two main actions of oxytocin in the body are contraction of the womb (uterus) during childbirth and lactation. More recently, oxytocin has been suggested to be an important player in social behaviour.

In the brain, oxytocin acts as a chemical messenger and has been shown to be important in human behaviours including sexual arousal, recognition, trust, anxiety and mother–infant bonding. Many research projects are undertaken, looking at the role of oxytocin in addiction, brain injury, anorexia and stress, among other topics. How is oxytocin controlled? There is also a positive feedback involved in the milk-ejection reflex. 2-Minute Neuroscience: Pineal Gland. Somatostatin | biochemistry. Advanced endocrine system physiology | Health and medicine. Hacking Into Your Happy Chemicals: Dopamine, Serotonin, Endorphins, & Oxytocin | The Utopian Life.

You might not have a money tree, but you can have a happiness tree. Dopamine, Serotonin, Oxytocin, and Endorphins are the quartet responsible for your happiness. Many situations can trigger these neurotransmitters, but instead of being in the passenger seat, there are ways you can intentionally cause them to flow. Being in a positive state has significant impact on your motivation, productivity, and wellbeing.

Here are some simple ways to hack into your positive neurochemicals: [Download the free infographic below!] Dopamine Dopamine motivates you to take action toward your goals and gives you a surge of reinforcing pleasure when achieving them. Break big goals down into little pieces. And avoid the dopamine hangover — when you slump after a massive high. Serotonin Serotonin flows when you feel significant or important. Reflecting on your past achievements allows your brain to re-live the experience. Oxytocin The release of oxytocin creates intimacy, trust, and strengthens relationships.

Thyroid, Parathyroid, Adrenal, Endocrine Surgery, The Connection between the Pituitary and Hypothalamus? The hypothalamus is the part of the brain that monitors many aspects of the state of the body systems, integrating a large amount of information from many sensory pathways. The connection between the hypothalamus and the pituitary gland results from hormones released from the hypothalamic neurones. The hypothalamus has two different connections with the pituitary gland. The connection to the adenohypophysis (the anterior lobe) is via a special portal blood system, whereas the connection to the neurohypophysis (the posterior lobe) is directly via neurones.

The hypothalamus is located underneath the thalamus and consists of many nerve cells (hypothalamic nuclei). The hypothalamic nuclei send their axons to the pituitary gland into two distinct areas: The Median Eminence - the axons terminate close to the primary capillary network The Neurohypophysis - the axons travel through the pituitary stalk into the posterior of the pituitary gland (the neurohypophysis).

Performance-enhancing drugs: Know the risks. Performance-enhancing drugs: Know the risks Hoping to gain a competitive edge by taking performance-enhancing drugs? Learn how these drugs work and how they can affect your health. By Mayo Clinic Staff Most serious athletes will tell you that the drive to win is fierce. Besides the satisfaction of personal accomplishment, athletes often pursue dreams of winning a medal for their country or securing a spot on a professional team. But using performance-enhancing drugs (doping) has risks.

Anabolic steroids What are they? Some athletes take a form of steroids — known as anabolic-androgenic steroids or just anabolic steroids — to increase their muscle mass and strength. Testosterone has two main effects on your body: Anabolic effects promote muscle building. Some athletes take straight testosterone to boost their performance. These hormones have approved medical uses. Why are these drugs so appealing to athletes? Designer steroids Risks Men may develop: Women may develop: Androstenedione What is it?