1. Endocrine System Maintaining homeostasis

2. The Importance of the Endocrine System The body is composed of trillions of cells The body is composed of trillions of cells The body will not function properly if all cells work independently The body will not function properly if all cells work independently Cells must use chemicals to communicate with each other and coordinate their functions and maintain homeostasis. Cells must use chemicals to communicate with each other and coordinate their functions and maintain homeostasis. Hormones are chemical messengers produced in one part of the body to affect cells in another part of the body. Hormones are chemical messengers produced in one part of the body to affect cells in another part of the body.

3. Hormones Endocrine Hormone: a number of hormones produced in glands and secreted into the blood. The circulatory system carries them throughout the body to their target cells or organs. Endocrine Hormone: a number of hormones produced in glands and secreted into the blood. The circulatory system carries them throughout the body to their target cells or organs. Include: growth hormone, insulin, epinephrine, and thyroxine. Include: growth hormone, insulin, epinephrine, and thyroxine.

4. Hormones Cont… Exocrine Hormone: hormones produced in a gland and then excreted through ducts into a cavity or onto the body surface. Exocrine Hormone: hormones produced in a gland and then excreted through ducts into a cavity or onto the body surface. Includes: mucous, sebum, sweat. Includes: mucous, sebum, sweat. Exocrine glands are more common than endocrine glands. Exocrine glands are more common than endocrine glands. The pancreas is both a digestive gland and an endocrine gland. The pancreas is both a digestive gland and an endocrine gland.

5. Classification Non-target hormones: have no specific activation site, instead may affect a number of cells or systems. Non-target hormones: have no specific activation site, instead may affect a number of cells or systems. Ex: insulin affects most cells of the body by increasing the permeability of their membranes to glucose. Ex: insulin affects most cells of the body by increasing the permeability of their membranes to glucose. Target hormones: target specific cells. Target hormones: target specific cells. Ex: gastrin stimulates stomach cells to produce digestive enzymes. Ex: gastrin stimulates stomach cells to produce digestive enzymes.

6. Types Steroid Hormone: made from cholesterol in rings of carbon hydrogen and oxygen molecules. Not soluble in water but are soluble in fat. ex) sex hormones and cortisol Steroid Hormone: made from cholesterol in rings of carbon hydrogen and oxygen molecules. Not soluble in water but are soluble in fat. ex) sex hormones and cortisol Protein Hormone: are made of chains of amino acids and are soluble in water. Ex) insulin and growth hormone. Protein Hormone: are made of chains of amino acids and are soluble in water. Ex) insulin and growth hormone.

7. Source: AMA's Current Procedural Terminology, Revised 1998 Edition. CPT is a trademark of the American Medical Association.

8. Endocrine Glands Pineal body: located above the hypothalamus. Produces melatonin. Pineal body: located above the hypothalamus. Produces melatonin. Pituitary: located below the hypothalamus. Acts as a control center between the endocrine and nervous systems. Also produces Oxytocin and Antidiuretic hormone. Pituitary: located below the hypothalamus. Acts as a control center between the endocrine and nervous systems. Also produces Oxytocin and Antidiuretic hormone.

9. Glands Cont… Thyroid: 2 small lobes on either side of the neck at the base. Produces thyroxine and triodothytonine. Thyroid: 2 small lobes on either side of the neck at the base. Produces thyroxine and triodothytonine. Parathyroids: four much smaller glands located on the surface of the thyroid. Produce parathyroid hormone. Parathyroids: four much smaller glands located on the surface of the thyroid. Produce parathyroid hormone.

10. More Glands Thymus: Located in the center of the chest. Hormones produced aid in the maturation of t-cells and play an integral part in the production of infection-fighting cells. Thymus: Located in the center of the chest. Hormones produced aid in the maturation of t-cells and play an integral part in the production of infection-fighting cells.

11. Even More Glands Adrenal Glands: one located above each kidney. Each consists of 2 glands in one casing. Adrenal Glands: one located above each kidney. Each consists of 2 glands in one casing. Adrenal cortex: outer portion. Produces glucocorticoids and mineralcorticoids. Adrenal cortex: outer portion. Produces glucocorticoids and mineralcorticoids. Adrenal medulla: inner portion. Produces epinephrine and norepinephrine. Adrenal medulla: inner portion. Produces epinephrine and norepinephrine.

12. Glands… Pancreas: Closely associated with the stomach. Considered both exocrine and endocrine gland. Endocrine products are: insulin, glucagon and somatostatin. Pancreas: Closely associated with the stomach. Considered both exocrine and endocrine gland. Endocrine products are: insulin, glucagon and somatostatin. Ovaries: contain the immature egg cells. Produces estrogen and progesterone. Ovaries: contain the immature egg cells. Produces estrogen and progesterone. Testes: Produce sperm cells and the hormones testosterone and androsterone. Testes: Produce sperm cells and the hormones testosterone and androsterone.

13. Hormones Growth Hormone: protein hormone. Produced in pituitary. Stimulates growth of the long bones (legs, arms, fingers), increase in muscle production and calcium retention. Growth Hormone: protein hormone. Produced in pituitary. Stimulates growth of the long bones (legs, arms, fingers), increase in muscle production and calcium retention. Epinephrine: also known as adrenaline. Produced in the adrenal medulla. Increases heart rate and body reactions when under stress. Epinephrine: also known as adrenaline. Produced in the adrenal medulla. Increases heart rate and body reactions when under stress.

14. Hormones Insulin: Produced in the pancreas when blood sugar levels are high (often after a meal). Increases the permeability of cell membranes to glucose. Insulin: Produced in the pancreas when blood sugar levels are high (often after a meal). Increases the permeability of cell membranes to glucose. Cortisol: Produced in the adrenal glands. Stimulates the liver to create glucose, regulates blood pressure, and insulin release as well as a number of other functions. Cortisol: Produced in the adrenal glands. Stimulates the liver to create glucose, regulates blood pressure, and insulin release as well as a number of other functions.

15. Hormones Cyclic AMP: a secondary messenger created by the conversion of ATP. Activates enzymes and directs them to carry out their normal functions, often synthesis of proteins. Cyclic AMP: a secondary messenger created by the conversion of ATP. Activates enzymes and directs them to carry out their normal functions, often synthesis of proteins. Thyroxine: produced in the thyroid. Contains iodine and regulates growth and metabolism. Thyroxine: produced in the thyroid. Contains iodine and regulates growth and metabolism.

16. Hormones Glucagon: produced in pancreas. Increases blood sugar levels when they are low (between meals) by stimuating conversion of glycogen to glucose. Glucagon: produced in pancreas. Increases blood sugar levels when they are low (between meals) by stimuating conversion of glycogen to glucose. Norepinephrine: produced in the adrenal medulla. Initiates “fight or flight” reaction by increasing heart rate and blood sugar. Prepares the body to react quickly. Norepinephrine: produced in the adrenal medulla. Initiates “fight or flight” reaction by increasing heart rate and blood sugar. Prepares the body to react quickly.

17. Hormones Glucocortoids: A group of hormones (including cortisol) produced in the adrenal cortex that allow the body to adapt to stress. Glucocortoids: A group of hormones (including cortisol) produced in the adrenal cortex that allow the body to adapt to stress. Mineralocorticoids: Another group of hormones created in the adrenal cortex. Regulate water and electrolytes in the body. Mineralocorticoids: Another group of hormones created in the adrenal cortex. Regulate water and electrolytes in the body.

18. Hormones Calcitonin: Produced by the thyroid. Helps decrease the breakdown of bone cells to decrease the amount of calcium in the blood. Calcitonin: Produced by the thyroid. Helps decrease the breakdown of bone cells to decrease the amount of calcium in the blood. Parathyroid hormone: Produced in the parathyroid glands. Increases the amount of calcium in the blood by increasing the breakdown of bone as well as retention of calcium in the kidneys and intestines. Parathyroid hormone: Produced in the parathyroid glands. Increases the amount of calcium in the blood by increasing the breakdown of bone as well as retention of calcium in the kidneys and intestines.

19. Hormones Prostoglandins: 16 types which affect cells locally during stress. Can change blood flow and breathing rate. Prostoglandins: 16 types which affect cells locally during stress. Can change blood flow and breathing rate. Anabolic steroids: synthetic hormones made to mimic the muscle building affects of testosterone. Banned from competitive sports but are often still used illegally. Anabolic steroids: synthetic hormones made to mimic the muscle building affects of testosterone. Banned from competitive sports but are often still used illegally.

20. Hormones Oxytocin: stored and released by the anterior lobe of the pituitary gland but produced by the hypothalamus. Causes uterine contraction during labour. Oxytocin: stored and released by the anterior lobe of the pituitary gland but produced by the hypothalamus. Causes uterine contraction during labour. Antidiuretic hormone: stored and released by the anterior lobe of the pituitary gland but produced by the hypothalamus. Affects the kidneys and promotes proper water balance. Antidiuretic hormone: stored and released by the anterior lobe of the pituitary gland but produced by the hypothalamus. Affects the kidneys and promotes proper water balance.