The Endocrine system Glands and hormones

Hormones- chemical messengers carried by blood- May stimulate other glands Regulate growth, development, metabolism, sex processes

Hormones need a specific receptor on a specific cell to do their job

Major Glands of the Endocrine system

Pituitary gland Produces many hormones that affect other glands thyroid stimulating hormone (TSH) Somatotropin- growth hormone (GH) stimulates protein synthesis and growth in cells Lutenizing (LH)- causes ovulation Melanocyte stimulating- distribution of melanin in skin ADH- antidiuretic hormone; stimulates kidneys to reabsorb water

Problems with the Pituitary Gigantism- oversecretion of somatotropin (GH) before puberty

Pituitary Dwarfism

Acromegaly results when the anterior pituitary gland produces excess growth hormone (GH) after epiphyseal plate closure at puberty

Acromegaly

Hypothalamus Controls secretion of the pituitary gland Activity influenced by other hormones and central nervous system

Thyroid produces hormones (Thyroxine) that control metabolism and calcium in blood. Thyroid gland must have a source of iodine

Goiter Too little iodine in the diet needed for proper thyroid function All you need is a pinch per day of salt. If you can’t have salt, you can take iodine drops.

HYPERTHYROIDISM Most commonly caused by Graves Disease, which is an autoimmune disease Signs include thinness, eyes that stick out like a bug (exophthalmoses) Leads to nervousness, weight loss, sweating, and rapid heart rate.

Hypothyroidism Before and After Treatment Decreases metabolism, causes obesity

Adrenal Glands Located just above the kidney Secretes many hormones Epinephrine Norepinephrine Many steroid hormones, inc estrogen and androgens. Steroids have a three ring chemical structure

Excessive Adrenal Hormones Cushing’s Disease- pituitary tumor (excess ACTH) Signs/symptoms: buffalo hump, moon face, muscle loss/weakness, thin skin with striae, hyperglycemia, immune suppression

Cushing’s Syndrome

Pancreas pancreatic juices into the intestine Alpha cells secrete glucagon- increases glucose in bloodstream by signaling liver to breakdown glycogen Beta cells secrete insulin, a hormone that allows glucose into cells. Promotes storage of glucose as glycogen in liver

Diabetes Mellitus Cause- decreased secretion of insulin or decreased insulin sensitivity Symptoms Excessive thirst, excessive urination, hyperglycemia, slow healing of skin infections, lethargy, vision problems, nerve issues Affects 21 million in US: 7% of population Estimated 1/3 of people who have diabetes don’t know it 225,000 die each year from complications 132 billion/year- 10% of our health care spending

Insulin Facts Insulin was the first hormone identified (late 1920's) which won the doctor and medical student who discovered it the Nobel Prize (Banting and Best) 1982 - Human Insulin- First ever approved genetically engineered human therapeutic by Genentech

Diabetes Mellitus Type I diabetes (insulin dependent, usually develops in children) Destruction of pancreatic Beta islet cells by immune system Need insulin injections daily throughout life. Type II diabetes (not insulin dependent in the beginning, usually develops in adults) consequence of obesity: cells are less sensitive to insulin. Initially treated with diet and exercise. Oral medicines or injected insulin may be needed.