1 Endocrine System

2 Functions & Organs Endocrine System is made up of glands that act as the body’s master regulator. Regulates growth, metabolism, and sexual development. The glands and other tissue of the endocrine system secrete special chemical messengers called hormones into the bloodstream. Hormones work in specific target cells. Hormones-- These protein messengers control most major bodily functions, from simple basic needs like hunger to complex systems like reproduction, and even the emotions and mood.

3 Hormones and Glands Hormones transfer info and orders from a set of cells to another. Each type of hormone is designed to affect only certain cells. A gland is a bunch of cells that produce and gives off chemicals. A gland ‘selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body.’ Glands are small organs throughout the body. Some glands release substances like tears and sweat to the outside of the body. Others release substances directly into the bloodstream. Many glands produce hormones which help regulate many body functions.

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5 Endocrine vs Exocrine GlandsExocrine – release products (enzymes) into ducts Ex) Sweat, tears, digestive juices Endocrine – releases directly to bloodstream; NO DUCTS Ex) Hormones Endocrine glands release chemical substances directly into the bloodstream or tissues of the body.T he chemical substances released by the endocrine glands are known as hormones.  Exocrine glands release chemical substances through ducts to outside the body or onto another surface within the body

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8 Pituitary Gland The gland is no bigger than a pea and is located at the base of the brain, and the most important part of the entire endocrine system. AKA: The master gland because it makes hormones that control other endocrine glands. The production of hormones and secretions can be affected by emotions and seasons change. Divided into two parts: Anterior and Posterior Lobe Anterior produces and secretes 7 hormones which are regulated by the hypothalamus Posterior releases 2 hormones that are produced in the hypothalamus and stored in the posterior lobe. Controls other glands and stimulates growth. anterior lobe of the pituitary gland is controlled by the hypothalamus in the brain. This lobe produces seven hormones. Growth hormone (GH) is responsible for growth and development. It is also called somatotropic hormone (STH). Thyroid-stimulating hormone (TSH) stimulates the growth and secretion of the thyroid gland. Adrenocorticotropic hormone (ACTH) stimulates the growth and secretion of the adrenal cortex. Prolactin hormone (PRL) develops breast tissue and produces milk in females after childbirth. The function of this hormone for males is not known. Follicle-stimulating hormone (FSH) stimulates the growth of the ovarian follicle and estrogen production in females. It stimulates the production of sperm in males. Luteinizing hormone (LH) stimulates ovulation and the formation of corpus luteum to secrete progesterone in females. Interstitial cell-stimulating hormone (ICSH) stimulates the secretion of testosterone in males. The posterior lobe of the pituitary gland produces two hormones. Antidiuretic hormone (ADH) maintains water balance by increasing the absorption of water by the kidneys. It is also called vasopressin. Oxytocin stimulates contractions of the uterus in females during childbirth. It also stimulates milk flow during breastfeeding.

9 Hypothalamus Part of brain and attached to pituitaryResponsible for the production of many of the body’s essential hormones, chemical substances that help control different cells and organs.   Controls pituitary secretions The hormones from the hypothalamus govern physiologic functions such as temperature regulation, thirst, hunger, sleep, mood, sex drive, and the release of other hormones within the body.  The hypothalamus' primary function is homeostasis, which is to maintain the body's status quo system-wide.

10 Pineal Gland The pineal gland, or the pineal body is in the middle of the brain. It secretes melatonin, a hormone that regulates wake-sleep cycle of the body Typically, melatonin levels start to rise in the mid-to-late evening, after the sun has set. They stay elevated for most of the night while you’re in the dark. Then, they drop in the early morning as the sun rises, causing you to awaken

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12 Thyroid Gland Regulates metabolism, energy balance, and regulate the amount of calcium in the blood Thyroid hormones are important because they participate in the growth and development of kids’ and teens’ bones and the nervous system. Attached to the thryoid are four small glands called the parathyroids, which, with the help of calcitonin, control the calcium level. Controls rate of metabolism. Thyroxine- Regulates body energy usage Calcitonin- One hormones that regulates calcium and phosphate in blood These control the rate at which cells burn fuels from food to produce energy. Thyroid hormones are important because they participate in the growth and development of kids’ and teens’ bones and the nervous system. Attached to the thryoid are four small glands called the parathyroids, which, with the help of calcitonin, control the calcium level.

13 Parathyroid Gland Increases calcium, phosphate, and magnesium absorption in intestines. Causes bones to release calcium and phosphate Causes removal of calcium and magnesium from urine by kidneys Increases the making of Vitamin D in body Regulates calcium and phosphorus metabolism.

14 Thymus Gland Considered to be apart of the Endocrine system because it secretes a hormone and is ductless. But is also apart of the immune system. Releases stimulates the production of T cells and B cells, which are important to the development of an immune response. Location: Thoracic cavity below the neck; Primary Hormones: Thymosis; Functions: T-lymphocyte education center Major Disorders: Cancers (lymphomas)

15 Adrenal Gland Releases hormones to deal with stressThe outer part, or the Arenal Cortex, makes hormones (corticosteroids) that control the salt and water balance in the body, responses to stress, metabolism, the immune system, and sexual development/function. The inner part, or the Adrenal Medulla, makes hormones (catecholamines) that increases blood pressure and heart rate when there is stress. (ex. Epinephrine, or adrenaline)

16 Pancreas Functioning as an endocrine gland, the pancreas secretes the hormones insulin and glucagon to control blood sugar levels throughout the day. Regulates Glucose by eating regularly and hormone adjustments What did the pancreas do in digestion? Secreted Enzymes Between meals Blood glucose low Pancreas secretes glucagon Liver changes glycogen to glucose glucose sent to target tissues After a meal Blood glucose high Pancreas secretes insulin Glucose goes to the Liver(Glygogen) and goes to Target tissues Insulin causes cells to store glucose to reduce high blood sugar levels. Glucagon has the opposite effect and causes stored glucose to be released in response to low blood sugar levels. What did the pancreas do in digestion? Secreted Enzymes

18 Endocrine Hormone Release ProcessOnce a hormone is secreted, it travels from the endocrine gland that produced it through the bloodstream to the cells designed to receive its message. These cells are called target cells. Along the way to the target cells, special proteins bind to some of the hormones. These proteins act as carriers that control the amount of hormone that is available for the cells to use. The target cells have receptors that latch onto only specific hormones, and each hormone has its own receptor, so that each hormone will communicate only with specific target When the hormone reaches its target cell, it locks onto the cell's specific receptors and these hormone-receptor combinations transmit chemical instructions. When hormone levels reach a certain normal amount, the endocrine system helps the body to keep that level of hormone in the blood. EXAMPLE: Parathyroid hormone increases the level of calcium in the blood. When the blood calcium level rises, the parathyroid glands sense the change and reduce their secretion of parathyroid hormone. This turnoff process is called a negative feedback system.

19 Diseases and DisordersMost endocrine illnesses are the result of oversecretion or undersecretion. Dwarfism: stunted growth, caused by a undersecretion of growth hormone by the pituitary gland. Gigantism: caused by oversecretion of growth hormones by the pituitary gland.

20 Diseases and DisordersDiabetes mellitus: caused by undersecretion of insulin. Type 1: insulin-dependent. Result of underproduction of insulin by the pancreas. Type 2: noninsulin-dependent. Usually overweight adults whose responsive to insulin is abnormally low. Without insulin, cells cannot absorb sugar (glucose), which they need to produce energy. You either have too much or too little. TYPE 1: the body's immune system destroys the beta cells pancreas that release insulin, eventually eliminating insulin production from the body. Without insulin, cells cannot absorb sugar (glucose), which they need to produce energy. So they take insulin injections. TYPE 2: the body isn't able to use insulin the right way. This is called insulin resistance. As type 2 diabetes gets worse, the pancreas may make less and less insulin. This is called insulin deficiency. Low sensitivity to insulin: The more excess body weight we carry, the less sensitive we are to insulin. Being insensitive to insulin means insulin doesn't reduce blood glucose levels as much as it should. People with low insulin sensitivity often need to be injected with insulin to avoid hyperglycemia. Beta cell failure: If you develop insulin resistance, you need more of it to keep your blood glucose levels stable. More insulin production means more work for the pancreas. Over time, the beta cells can become burnt out by the constant strain, and stop producing insulin altogether. 

22 Jobs and Professions Endocrinologist- Physician who specializes in the endocrine system. Treat conditions that affect the glands and try to restore normal balances of the hormones.