APHY 102 Ch 17: Endocrine System Ivy Tech

APHY 102 Ch 17: Endocrine System Ivy Tech endocrinology Study of hormones and endocrine organs functions of the endocrine system 1. control reproduction, development and growth 2. prepare the body to combat stress 3. maintain electrolyte and water balance and blood pressure 4. maintain nutrient balance (glucose) 5. regulate cell metabolism 6. increase or decrease cellular activity by changing: plasma membrane permeability, synthesis of proteins, enzyme functions, cellular secretions, rate of cell reproduction. characteristics of the endocrine system includes cells, tissues, and organs that secrete hormones. These organs and tissues are scattered in different regions of the body. Endocrine glands have no ducts so hormones are transported through blood and lymphatic vessels. hormones chemical messengers produced by endocrine tissues that alter the function of target cells target cells tissues with receptors for specific hormone How are hormones specific? act on specific target cells/target organs because each hormone binds to protein receptors present on/in its target cell. Hormone binds to proper receptor like a key in a lock. exocrine glands -have ducts to transport their secretion -action: extra cellular effect (enzyme on food) endocrine glands -release secretion into blood or lymph vessels to travel to target cells and induce an action: intracellular effect. Major endocrine organs hypothalamus (neuro-endocrine gland), pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pineal gland, thymus gland, pancreas, ovaries and testes Other organs contain cells or tissues that secrete hormones -liver (IGF) -small intestine- (secretin, CCK) -placenta (estrogen, progesterone, hCG) -stomach (gastrin) -kidneys (EPO, renin, vitamin D) -heart (ANP)