Endocrine: Chemical Messages Hormones coordinate activities in different parts of the body Hormones coordinate activities in different parts of the body regulate energy use, metabolism, and growth regulate energy use, metabolism, and growth also maintain homeostasis also maintain homeostasis Endocrine glands secrete hormones Endocrine glands secrete hormones chemical signals that are carried by blood and cause specific changes in target cells chemical signals that are carried by blood and cause specific changes in target cells

Endocrine: vs Nervous Both communication but: Both communication but: Endocrine take longer for effect b/c needs to be made and travels through blood stream throughout body and causes protein synthesis Endocrine take longer for effect b/c needs to be made and travels through blood stream throughout body and causes protein synthesis longer lasting because hormones can trigger protein production that lasts long time longer lasting because hormones can trigger protein production that lasts long time

Endocrine: vs Exocrine No hormones – release chemicals through ducts instead of hormones through blood stream No hormones – release chemicals through ducts instead of hormones through blood stream ex. Pancreas release enzymes into small intestine via duct ex. Pancreas release enzymes into small intestine via duct

Endocrine: Glands

Endocrine: Hormones Hormone released by glands and travel through bloodstream to target cells Hormone released by glands and travel through bloodstream to target cells Target cells have SPECIFIC receptors Target cells have SPECIFIC receptors

Endocrine: Hormones Protein vs Steroid

Endocrine: Hormones Proteins - Most hormones are amino acids Proteins - Most hormones are amino acids bind to receptor proteins in target-cell plasma membrane bind to receptor proteins in target-cell plasma membrane Initiate signal- transduction pathways, cause changes inside target cell Initiate signal- transduction pathways, cause changes inside target cell Steroid hormones bind to intracellular receptors Steroid hormones bind to intracellular receptors steroid-receptor complex binds to DNA, turning specific genes on or off steroid-receptor complex binds to DNA, turning specific genes on or off Desired outcome takes longer than protein hormone Desired outcome takes longer than protein hormone Only the sex glands and the adrenal cortex secrete steroid hormone Only the sex glands and the adrenal cortex secrete steroid hormone

Table 26.3

Table 26.3, part 2

Endocrine: Hypothalamus Hypothalamus - master control center of the endocrine system Hypothalamus - master control center of the endocrine system Regulates posterior and anterior pituitary gland Regulates posterior and anterior pituitary gland

Endocrine: Pituitary Glands Both Pituitary Glands release when they receive message from the Hypothalamus Both Pituitary Glands release when they receive message from the Hypothalamus Posterior Pituitary Glands: stores and releases hormones made by hypothalamus Posterior Pituitary Glands: stores and releases hormones made by hypothalamus Anterior Pituitary Glands: makes own hormones Anterior Pituitary Glands: makes own hormones

Endocrine: Posterior Pituitary Gland Oxytocin Oxytocin ADH: anti- diuretic hormone ADH: anti- diuretic hormone

Endocrine: Anterior Pituitary Gland FLAT PEG FLAT PEG FSH: follicle stimulating FSH: follicle stimulating LH: lutenizing LH: lutenizing ACTH: adrenocorticotropic ACTH: adrenocorticotropic TSH: thyroid stimulating TSH: thyroid stimulating Prolactin Prolactin Endorphins Endorphins Growth Hormone Growth Hormone

Endocrine: Negative Feedback Mechanism Normal Negative Feedback Normal Negative Feedback Abnormal (Goiter) Abnormal (Goiter)

Endocrine: Thyroid Thyroid gland releases Thyroxine Thyroid gland releases Thyroxine Regulates development and metabolism Regulates development and metabolism

Endocrine: Regulating Calcium Levels Calcitonin Calcitonin Parathyroid Hormone Parathyroid Hormone

Endocrine: Regulating Blood Sugar Levels Insulin Insulin Glucagon Glucagon

Endocrine: Regulating Blood Sugar Levels Blood glucose levels controlled by two hormones secreted by pancreas Blood glucose levels controlled by two hormones secreted by pancreas Insulin: lowers blood sugar level Insulin: lowers blood sugar level - signals cells to use and store glucose as glycogen in liver Glucagon: raises blood sugar level Glucagon: raises blood sugar level - signals cells to release stored glycogen from liver into blood

Endocrine: Diabetes Diabetes (2 types): body cells unable to absorb glucose from blood Diabetes (2 types): body cells unable to absorb glucose from blood Type I (insulin-dependent) diabetes Type I (insulin-dependent) diabetes Autoimmune disease: pancreatic beta cells destroyed, not enough insulin produced Autoimmune disease: pancreatic beta cells destroyed, not enough insulin produced Often develops before age 15 Often develops before age 15 Patient requires insulin supplement, often by injection Patient requires insulin supplement, often by injection

Endocrine: Diabetes Body cells unable to absorb glucose from blood Type I (insulin- dependent) diabetes Type I (insulin- dependent) diabetes Autoimmune disease: pancreatic beta cells destroyed, not enough insulin produced Autoimmune disease: pancreatic beta cells destroyed, not enough insulin produced Often develops before age 15 Often develops before age 15 Patient requires insulin supplement, often by injection Patient requires insulin supplement, often by injection Type II (non-insulin- dependent) diabetes Type II (non-insulin- dependent) diabetes Pancreatic cells function properly; sufficient amounts of insulin produced Body cells fail to respond to insulin Accounts for 90% of diabetes cases in the United States Associated with obesity Often develops after age 40

Endocrine: Stress Hormones (Adrenal Gland) Adrenal gland hormones - maintain homeostasis when body under stress Adrenal gland hormones - maintain homeostasis when body under stress Adrenal Medulla: Short Term Stress Adrenal Medulla: Short Term Stress Adrenal Cortex: Long Term Stress Adrenal Cortex: Long Term Stress

Endocrine: Stress Hormones Adrenal medulla Adrenal medulla Nervous signals from hypothalamus stimulate secretion of epinephrine and norepinephrine Nervous signals from hypothalamus stimulate secretion of epinephrine and norepinephrine Trigger quickly fight or flight response Trigger quickly fight or flight response Adrenal cortex Adrenal cortex Chemical signals (ACTH) stimulate secretion of corticosteroids glucocorticoids and mineralocorticoids Corticosteroids boost blood pressure and energy in response to long-term stress Stimulates ADH production

Endocrine: Stress Hormones (Adrenal Glands)

Endocrine: Stress Hormones Athletes often take glucocorticoids Athletes often take glucocorticoids Relieve pain and inflammation Relieve pain and inflammation But they also mask injury and suppress immunity But they also mask injury and suppress immunity Example: cortisone Example: cortisone

Endocrine: Sex Hormones Gonads – secrete sex hormones (steroid hormones) Gonads – secrete sex hormones (steroid hormones) Secretion controlled by hypothalamus and pituitary Secretion controlled by hypothalamus and pituitary Steroid hormones found in both sexes but in different proportions Steroid hormones found in both sexes but in different proportions estrogens estrogens progestins progestins androgens androgens

Endocrine: Sex Hormones Estrogen and progestins Estrogen and progestins maintain the female reproductive system maintain the female reproductive system stimulate the development of female characteristics stimulate the development of female characteristics Androgens, such as testosterone, Androgens, such as testosterone, trigger the development of male characteristics In male elephant seals, androgens account for bodies weighing 2 tons or more, a thick hide, and aggressive behavior