Yixuan He ENDOCRINE SYSTEM

 Collection of all of an animal’s hormone-secreting cell  Secretes hormones to maintain homeostasis FUNCTION

 Regulation of an internal environment  Maintains a stable, relatively constant condition  Temperature  PH  Main job in endocrine system is to maintain homeostasis by balancing hormones.  If homeostasis is not maintained, the basic physical and chemical parameters of the body can become disordered, which can lead to cell death or illness of the entire body. HOMEOSTASIS

 A primary mechanism of homeostasis. Whereby a change in a physiological variable that is being monitored triggers response that counteracts the initial fluctuation.  Example:  secretion of more aldosterone, a hormone, to absorb more mineral salt during reabsorption in kidney if the osmotic pressure in blood is low. NEGATIVE FEEDBACK MECHANISM

 Cell signaling is a complex system of communication that governs basic cellular activities and coordinates cell actions.  The ability of cells to perceive and correctly respond to their microenvironment  Basis of development, tissue repair, and immunity as well as normal tissue homeostasis.  Insulin and glucagon are hormones that regulate the concentration of glucose in the blood.  When blood glucose exceed level of 90/100mg, insulin is released. Its effects lower glucose concentration.  When blood glucose drops below set level, glucagon is released. Its effects rise glucose concentration. CELL SIGNALING MECHANISM

DIABETES Diabetes I Diabetes II Body is not producing insulin Body destroys insulin producing beta cells 15% of all diabetic patients have Diabetes I Not preventable Usually occurs before age 40 Body is not responding properly to insulin Usually developed because the patient is overweight or unfit Usually occurs later in life Metabolism disorder the glucose in the blood- stream does not enter cell

 A condition in which the thyroid gland makes too much thyroid hormone.  Symptom:  Difficulty concentrating, fatigue, diarrhea, thyroid nodules, heat intolerance, increased appetite, increased sweating, nervousness, restlessness weight loss  Signs:  High systolic blood pressure (the first number in a blood pressure reading), hyperactive reflexes, increased heart rate, thyroid enlargement, tremor  Treatment:  Anti-thyroid medications, radioactive iodine, surgery to remove the thyroid  Prevalence  Estimated at 2% for women and 0.2% for men. HYPERTHYROIDISM

 Medscape.org   AP Biology Textbook  Campbell, Neil A., Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, and Robert B. Jackson. AP Edition: Biology. New York: Benjamin/Cummings,  PubMed Health  disease.symptoms  Turnbridge WM, Evered DC, Hall R, Appleton D, Brewis M, Clark F, et al. The spectrum of thyroid disease in a community: the Whickham survey. Clin Endocrinol (Oxf). 1977;7:481–93.  Image  tem.jpg BIBLIOGRAPHY