Endocrine System WHO IS IN CONTROL?

Endocrine System WHO IS IN CONTROL?

Objectives Explain how the endocrine and nervous system work together to regulate bodily functions Describe the basic anatomy of the endocrine system Describe the functions of hormones and explain how hormones move through t he body Identify t he two classifications of hormones Explain how hormones help maintain homeostasis Identify the organs and glands of the endocrine system Know the location and function of the thyroid, parathyroid, thymus, pineal, and adrenal glands and hormones produced by each of these glands Explain endocrine and exocrine functions of the pancreas

Endocrine System The endocrine system includes the endocrine glands and their hormones The function of the endocrine system is to secrete hormones into the bloodstream. Hormone: A Chemical messenger which targets a specific group of cells, in order to cause that group of cells do some activity or stop doing an activity

Endocrine System Endocrine system is made of ductless glands called endocrine glands that include hypothalamus, pancreas, pituitary gland, adrenal gland, thyroid gland, pineal gland, testes and ovaries. Endocrine glands secrete hormones; chemical messengers into the bloodstream Exocrine Glands are glands of external secretion.

Endocrine System Exocrine glands release their secretions into ducts, or tubes Liver Bile released into the gallbladder, then through a duct into the small intestine Pancreas releases pancreatic juice into the small intestine via a duct Endocrine Glands are called ductless glands Release hormones directly into the bloodstream Blood transports hormones throughout the body Each hormone acts on only a certain kind of tissue called its target tissue Pancreas also releases hormones that regulate blood glucose levels in the body

Hormone Receptors Hormones are transported throughout the body by the blood, blood comes into contact with all body tissues and organs. However, hormones affect ONLY the tissues and organs that have receptors specific to those particular hormones.

Major Organs- Pituitary Pituitary gland is a round organ about the size of a pea (~1 cm in diameter), located behind the bridge of the nose at the base of the brain Secretes 9 different hormones, which affect many different areas of the body, including: Growth Blood pressure Regulation of Pregnancy Breast milk production Sex organ functions in both men and women Thyroid gland function Metabolism Water regulation in the body (kidneys) Temperature regulation

A Few Pituitary Hormones Hormone Growth Hormone (GH) Thyroid Stimulating Hormone (TSH) Follicle Stimulating Hormone (FSH) Luteinizing Hormone (LH) Function To increase body size during childhood and adolescence; to maintain body size during adulthood To stimulate the thyroid to produce thyroxin Regulate puberty, development, and reproductive processes Stimulates the production of estrogen and testosterone

Thyroid Located in the neck Releases hormone thyroxin Function is to regulate rates of metabolism in the body Essential for normal physical and mental development Oversecretion of thyroxin: Results in nervousness and weight loss Undersecretion of thyroxin: Results in cretinism (mental retardation, small size) in children Not of Iodine in diet can lead to enlarge thyroid(goiter)

Parathyroid Function is to control metabolism of calcium Necessary for normal nerve and muscle function, blood clotting, healthy bones and teeth Located in back of thyroid gland (in neck) Hormone released is parathormone Undersecretion of parathormone results in nerve disorders, brittle bones and clotting problems

Adrenal Glands (Kidney Hats) Located at the top of each kidney Hormones released are cortisone and adrenaline Function of cortisone is to regulate carbohydrate, protein and fat metabolism promotes conversion of fats and proteins to glucose Function of adrenaline is to raise blood sugar levels and increases heartbeat and breathing rates Under secretion of adrenaline may cause inability to deal with stress

Pancreas-located posterior to the stomach in the upper part of the abdominal cavity. Control blood glucose levels Islet of Langerhans Located on the pancreas Hormones secreted are insulin and glucagon; Glucagon is secreted by alpha cells that increase blood glucose levels Insulin stimulates glucose uptake by cells and secreted by beta cells Glucagon promotes conversion of glycogen (animal-based carbohydrate) to glucose Normal range of blood glucose levels 70 and 105mg/dL.

Pituitary glands

Endocrine glands

Thymus gland, Pineal gland, Adrenal Glands Thymus-Secretes thymosin a hormone for the development of white blood cells called T lymphocytes or T cells Pineal Gland- pinecone shaped gland in the brain. When exposed to darkness it releases the hormone melatonin causing us to feel sleepy. Adrenal glands- pair of glands that sit on top of the kidneys. Consist of the adrenal cortex functions as a gland; secrets steriods and the adrenal medulla secretes adrenaline and epinephrine hormones into the blood during time of stress.

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