Endocrine System What you must know The endocrine

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Endocrine System

Endocrine System

What you must know: • The endocrine system is one of two body systems

What you must know: • The endocrine system is one of two body systems for communication and regulation. • How hormones are transported, bind to specific target cells, and trigger cellular responses. • The secretion, target, action, and regulation of at least two hormones. • An illustration of both positive and negative feedback in the regulation of homeostasis by hormones.

 • Endocrine System = Hormone-secreting cells and Tissues • Endocrine Glands: ductless; secrete

• Endocrine System = Hormone-secreting cells and Tissues • Endocrine Glands: ductless; secrete hormones directly into body fluids • Hormones: chemical signals that cause a response in target cells (receptor proteins for specific hormones) • Affects 1 tissue, a few, or most tissues in body • OR affect other endocrine glands • Regulation by Positive & Negative Feedback

Pheromones Hormones Local Regulators Chemical signal from 1 individual to another individual Chemical signal

Pheromones Hormones Local Regulators Chemical signal from 1 individual to another individual Chemical signal from endocrine gland through blood to target cell Chemical signal from one cell to an adjacent cell Eg. cytokines, Eg. ant trail; sex Eg. peptide, growth factors, phermones steroid hormones nitric oxide (NO)

Discovery Video: Endocrine System

Discovery Video: Endocrine System

Ø Negative feedback systems: • Thyroid hormones • Blood Ca 2+ levels • Blood

Ø Negative feedback systems: • Thyroid hormones • Blood Ca 2+ levels • Blood glucose levels Ø Positive feedback system: • Oxytocin (birthing process; release of milk/suckling)

Types of Hormones Peptide Steroid • Water-soluble • Bind to receptors on plasma membrane

Types of Hormones Peptide Steroid • Water-soluble • Bind to receptors on plasma membrane & triggers signal transduction pathway • Affects protein activity already present in cell • Rapid response • Short-lived • Eg. oxytocin, insulin, epinephrine • Lipid-soluble • Enters cell & binds to intracellular receptors • Causes change in gene expression (protein synthesis) • Slower response • Longer life • Eg. androgens (testosterone), estrogen, progesterone, cortisol, thyroid hormone

Fight or Flight Response

Fight or Flight Response

Epinephrine: One hormone Many effects! a) Liver cells break down glycogen and release glucose

Epinephrine: One hormone Many effects! a) Liver cells break down glycogen and release glucose b) Blood vessels to skeletal muscles dilate c) Blood vessels to intestines constrict

Master Glands Hypothalamus Pituitary Gland

Master Glands Hypothalamus Pituitary Gland

Master Glands Hypothalamus • Receives info from nerves and brain • Initiates endocrine signals

Master Glands Hypothalamus • Receives info from nerves and brain • Initiates endocrine signals Posterior pituitary gland: • Oxytocin: contract uterine muscles, eject milk in nursing Pituitary Gland • Antidiuretic hormone (ADH): promote H 2 O retention by kidneys Anterior pituitary gland: • Follicle-stimulating hormone (FSH): development of ovarian follicles (eggs); promote sperm production • Luteinizing hormone (LH): trigger ovulation; stimulate testosterone production in testes

Hypothalamus Posterior Pituitary

Hypothalamus Posterior Pituitary

Hypothalamus Anterior Pituitary

Hypothalamus Anterior Pituitary

BIOFLIX: HOMEOSTASIS – BLOOD SUGAR

BIOFLIX: HOMEOSTASIS – BLOOD SUGAR

Insulin & Glucagon

Insulin & Glucagon

High blood glucose Liver breaks down glycogen and releases glucose into blood Insulin released

High blood glucose Liver breaks down glycogen and releases glucose into blood Insulin released from pancreas Body cells take up glucose Liver stores glucose as glycogen Glucagon released from pancreas Blood glucose drops

Diabetes Mellitus • Type I diabetes (10%): deficiency of insulin • Insulin-dependent • Autoimmune

Diabetes Mellitus • Type I diabetes (10%): deficiency of insulin • Insulin-dependent • Autoimmune disorder beta cells of pancreas destroyed • Type II diabetes (90%): failure of target cells to respond to insulin • Non-insulin dependent • Insulin produced cells don’t respond (defect in insulin receptor or response pathway) • Risk factors: obesity, lack of exercise

Homeostatic Imbalance: Graves Disease • Hyperthyroidism

Homeostatic Imbalance: Graves Disease • Hyperthyroidism

Homeostatic Imbalance: Hashimoto’s Thyroiditis • Autoimmune disorder • Antibodies destroy thyroid gland • Low

Homeostatic Imbalance: Hashimoto’s Thyroiditis • Autoimmune disorder • Antibodies destroy thyroid gland • Low levels of thyroid hormone • TSH levels rise • Hypothyroidism • Low temp, gain weight, sluggish, low heart rate

Stress and the Adrenal Gland

Stress and the Adrenal Gland