HORMONES & THE ENDOCRINE SYSTEM Ashley Gutierrez, Divya Khullar Ms. Said AP Biology, per.6,7

CONCEPT 45.1 THE ENDOCRINE SYSTEM AND THE NERVOUS SYSTEM ACT INDIVIDUALLY AND TOGETHER IN REGULATING AN ANIMALS PHYSIOLOGY  The endocrine system of an animal is the sum of all its hormone-secreting cells and tissues.  Endocrine glands are ductless and secrete hormones directly into body fluids  Hormones are chemical signals that cause a response in target cells

REVIEW OF HORMONES  Hormones can be polypeptides, amines, or steriods and can be water –soluble or lipid-soluble.  Peptide/protein hormones and most hormones derived from amino acids bind to receptors embedded in the plasma membrane. Steriod hormones and thyroid hormones enter target cells and bind to specific protein receptors in the cytosol and the nucleus.  Hormones in the body can affect one tissue, a few tissues or most of tissues in the body, or they may affect other endocrine glands

4.1 CONTINUED  Positive and negative feedback regulates most endocrine secretion.

CONCEPT 4.2 HORMONES AND OTHER CHEMICAL SIGNALS BIND TO TARGET CELL RECEPTORS, INITIATING PATHWAYS THAT CULMINATE IN SPECIFIC CELL RESPONSES  Two mechanisms of hormone action: Cell-surface receptors bind the hormone, and signal transduction pathway is triggered. A signal transduction pathway consists of a series of molecular events that initiate a response to the signal Example: The binding of epinephrine to liver cells causes a cascade that leads to the conversation of glycogen to glucose Intracellular receptors are bound by hormones that are lipid- soluble. The receptor then acts as a transcription factor, causing a change in gene expresion. Example: Testerone and estrogen enter the nuclei of target cells, bind the DNA, and stimulate transcription of certain genes.

Cell surface receptorsIntracellular receptors

INSULIN AND GLUCOGEN: CONTROL OF BLOOD GLUCOSE  Insulin (from beta cells of the pancreas) reduces blood glucose levels by promoting cellular uptake of glucose, glycogen formation in the liver, protein synthesis, and fat storage  Glucagon (from the alpha cells of the pancreas) increases blood glucose levels by stimulating conversion of glycogen to glucose in the liver and breakdown of fat and protein to glucose.  Diabetes mellitus, which is marked by elevated blood glucose levels, results from inadequate production of insulin (type 1) or loss of responsiveness to target cells to insulin(type 2)

CONCEPT 45.3 THE HYPOTHALAMUS AND PITUITARY INTERGRATE MANY FUNCTIONS OF THE VERTEBRATE ENDOCRINE SYSTEM  The hyothalamus receives information from the nerves throughout the body and from other parts of the brain and then initiates endocrine signals in response.

CONTINUE OF 45.3:POSTERIOR PITUITARY  The posterior pituitary is an extension of the hypothalamus that stores and secretes two hormones: 1. Oxytocin causes contraction of the uterine muscles in childbirth and ejection of milk and nursing 2.Antidiuretic hormone (ADH) makes the collecting tubules of the kidney more permeable to water, increasing water retention

CONTINUE OF 45.3:ANTERIOR PITUITARY  The anterior pituitary consist of endocrine cells that synthesize and secrete several hormones. Some of these are tropic hormones, which means they stimulate the activity of other endocrine tissues (FSH, LH, TSH, and ACTH). Follicle-stimulating hormone(FSH) stimulates development of the ovarian follicles in females and promotes spermatogenisis in males by acting on the cells in the seminiferous cells Luteinizing hormone triggers ovulation in females and stimulates the production of testosterone by the interstitial cells of the testes

COORDINATION OF ENDOCRINE AND NERVOUS SYSTEMS IN INVERTEBRATES  Diverse hormones regulate different aspects of homeostasis in vetebrates  In insects, molting and development are controlled by prothoracicotropic hormone (PTTH), a tropic nuerohormone; ecdysone, whose relesase is triggered by PTTH; and juvenile hormone

COORDINATION OF ENDOCRINE AND NERVOUS IN VERTEBRATES  The hypothalamus, on the underside of the brain, contains sets of neurosecretory cells. Some produce direct-acting hormones that are stored in and released from the posterior pituitary.  Other hypothalamic cells produce hormones that are transported by portal blood vessels to the anterior pituitary. These hormones either promote or inhabit the release of hormones from the anterior pituitary

CONCEPT 45.4 NONPITUITARY HORMONES HELP REGULATE METABOLISM, HOMEOSTASIS, DEVELOPMENT, AND BEHAVIOR  The maintenance of blood calcium level is one example of how homeostasis is maintained by negative feedback. Remember, in negative feedback, more gets you less.

A REVIEW OF THE ENDOCRINE SYSTEM  &feature=related &feature=related Endocrine System

QUIZ All of the following are endocrine glands EXCEPT: A. adrenal glands B. sebaceous glands C. pineal glands D. pituitary glands 2. Hormones that enter target cells and bind to receptors in the nucleus are called A. steroid hormones B. water soluble hormones. C. peptide hormones. D. second messengers. 3. The hormones regulating blood calcium levels are A. insulin and glucagon. B. glycogen and parathyroid hormone. C.parathyroid hormone and calcitonin. D.estrogen and progesterone.

4. All of the following are hormones of the anterior pituitary EXCEPT A. human growth hormone (GH). B. follicle-stimulating hormone (FSH). C. parathyroid hormone(PTH). D. thyroid-stimulating hormone (TSH). 5. Antidiuretic hormone and oxytocin are stored and released by the A. posterior pituitary gland. B. anterior pituitary gland. C.thyroid gland. D. adrenal gland.