AP2+Endocrine

1. Indicate important differences between hormonal and neural controls of body functioning. endocrine system acts IN CONCERT with nervous system to coordinate activity of all body cells
 * Review**

Major Differences: nervous signals take milliseconds to occur and last of milliseconds. hormonal signals can take seconds to days to transmit and their effects can be seen for up to years. Hormones can change DNA. Nervous signals are local-- having only to cross a synapse. Hormones must travel through the blood to whichever target cell it intends to influence. Neural control is limited to muscle, other neurons, and glands while hormonal influence reaches every cell in the body. 2. List the major endocrine organs, and describe their body locations. **Pineal Gland**-small cone-shaped gland in the roof of the third ventricle of the brain. MELANIN


 * Hypothalamus ** - located below the thalamus, capping the brainstem and forming inferolateral walls oft he third ventricle. Etends from optic chiasma to posterior margin of the mammillary bodies. connects to the pituitary via the infundibulum. It is the main visceral control center of the body. It is the autonomic control center, center for emotional response, temperature regulation, food intake, regulating thirst, sleep/wake cycles, and control of endocrine system functioning. pg. 445 ADH, OXYTOCIN


 * Pituitary Gland ** - attached via infundibulum to hypothalamus. Cradled hypophyseal fossa of the sella turcica of the sphenoid bone. Consists of two lobes, the adenohypophysis (anterior) and neurohypophysis (posterior). TSH, ACTH, FSH, LH, PRL, GH

**Thyroid**- two lobes joined by an isthmus. located in the throat inferior to the larynx. TH, CALCITONIN

**Parathyroid**-- embedded in the posterior surface of the thyroid gland. Can be additionally located in neck. PTH

**Pancreas**--partially behind stomach in the abdomen. Endocrine and exocrine gland. DIGESTIVE ENZYMES, INSULIN, GLUCAGON. Contains alpha cells to synthesize glucagon and beta cells to make insulin arranged in islets of Langerhans, surrounded by acinar cells which perform the exocrine work of the gland.

**Thymus**-- bilobed gland in the superior thorax posterior to the sternum and anterior to the heart and longs. Conspicuous in infant, inconspicuous in older adults. THYMULIN, THYMOSINS, THYMOPOIETINS poorly understood--thought to aid in the development of T lymphocytes and immune resoponse

**Adrenal Glands**-- located atop or close to the kidnes. Adreneal medulla develops from neural crest tissue and is directly controlled by the sympathetic nervous system. EPINEPHRINE 80%, NOREPINEPHERINE 20% (fight or flight) Adrenal corte produces corticosteriods. Mineralocorticoids (Aldesterone) regulate water and electrolyte balance. Glucocorticoids (Cortisol (hydorcortisone), cortisone, and corticosterone) increase blood glucose levels to enable resistance of long term stressors. Gonadocorticoids (androgens--male sex hormones) and some estrogens. 3. Distinguish between hormones, paracrines, and autocrines. 4. Describe how hormones are classified chemically. 5. Describe the two major mechanisms by which hormones bring about their effects on their target tissues. 6. List three kinds of interaction of different hormones acting on the same target cell. 7. Explain how hormone release is regulated. 8. Describe structural and functional relationships between the hypthalamus and the pituitary gland. the hypothalamus is the most direct connection between the two systems (a neuroendocrine organ) as it produces oxytocin and ADH in its neurosecretory cells located in the paraventricular nucleus and the supraotpic nucleus which are transported down the axons to the axon terminals in the posterior pituitary for storage. 9. List and describe the chief effects of anterior pituitary hormones. *Anterior- TROPIC hormones-- stimulate another glad to secrete hormones. (all peptide/protein based/ amino acid derived, CAMP--except GH). These are controlled by neurosecretions, releasing or inhibiting hormones produced by neurons of the ventral hypothalamus. They are liberated into the hypophyseal portal system and carried to cells of the anterior pituitary where they control release of anterior pituitary hormones. (lab manual, pg. 406) ....................TSH Thyroid Stimulating Hormone. (glycoprotein, thyrotroph). Stimulated by TRH Thyrotropin-Releasing Hormone, indirectly by pregnancy, and cold temperatures for infants. Inhibited by beedback inhibition by thyroid hormones on anterior pituitary and hypothalamus and by growth hormone inhibiting hormone GHIH.Targets the Thyroid Gland to release Thyroid Hormones. HYPO: cretinism in children, myxedema in adults ....................ACTH Adenocorticotropic Hormone (polypeptide of 32 amino acids, corticotroph) Stimulated by CRH corticotropin Releasing Hormone-- caused by fever, hypoglycemia, and stress. Inhibited by feedback inhibition from glucocorticoids. Targets Adrenal Cortex to promote release of glucocorticoids and androgens. HYPO: rare. HYPER: Cushing's disease, mostly caused by prescription drugs. buffalo hump of fat on upper back. muscles weaken ....................FSH Follicle Stimulating Hormone (glycoprotein, gonadotroph) Stimulated by GnRH Gonadotropin-Releasing Hormone. Inhibited by feedback inhibition exerted by inhibin, and estrogen in females and testosterone in males. Targets Ovaries to produce estrogen and mature ovarian follicle. In males, stimulates sperm production. HYPO: failure to sexually mature. HYPER: nada ....................LH Lutenizing Hormone (glycoprotein, gonadotroph) Stimulated by GnRH Gonadotropin-Releasing Hormone. Inhibited by feedback inhibition exerted by estrogen and progesterone in females and testosterone in males. Targets ovaries--triggers ovulation and stimulates ovarian production of estrogen and progesterone, in males--testosterone. HYPO: failure to sexually mature. HYPER: nada.
 * Ovary**
 * Testis**
 * Hormones**
 * The Pituitary Glad and Hypothalamus**

Anterior NON TROPIC Hormones .....................GH Growth Hormone (protein, somatotroph--formed by somatotroph, can promote growth and metabolic actions.Stimulated by GHRH Growth Hormone Releasing Hormone which is triggered by low blood levels of GH as well as hypoglycemia, increases in blood levels of amino acids, low levels of fatty acids, estrogens, exercise, and other stressors. Inhibited by feedback inhibition from GH and IGFs (Insulin-like Growth factors --growth promoting proteins produced by liver, skeletal muscle, bone, etc.-- and by hyperglycemia, gyperlipidemia, obesity, emotinal deprivation vai either increased GHIH (somaotostatin or decreased GHRH release. Targets liver, muscle, bone, cartilage, and other tissues. Anabolic hormone. Stimulates somatic growth, mobilizes fats, spares glucose. Growth promoting effects mediated indirectly by IGFs. HYPO: pituitary dwarfism. HYPER: gigantism in children, acromegaly (enlarged extremities) in adults .....................PRO Prolactin (protein, produced by lactotrophs) Stimulated by decreased PIH Prolactin Inhibiting Hormone (DOPAMINE), release enhanced by estrogens, birth control pills, breast-feeding, and dopamine-blocking drugs. Inhibited by PIH (dopamine). Targets breast secretory tissue--promotes lactation. HYPO: poor milk production HYPER: galactorrhea--too much milk production, cessation of menses in females, impotence in males 10. Discuss the structure of the posterior pituitary, and describe the effects of the two hormones it releases. ....................ADH. Antidiuretic Hormone (peptide/protein based, CAMP) Made in supraoptic nucleus of hypothalamus. has a direct effect on blood volume. stimulated by hypothalamic neurons in response to osmolality of blood or decreased blood volume. Targets kidneys tubule cells to reabsorb water. Inhibited by caffeine and alcohol. HYPO: Diabetes Insipidus (glucose lost in urine, blood becomes concentrated), HYPER: Syndome of inappropriate ADH secretion (SIADH) ....................OXYTOCIN. (peptide/protein based, CAMP) made in paraventricular nucleus of hypothalamus. Stimulated by hypothalamic neurons responding to cervical stretching and suckling. Inhibited by neural stimuli. Targets uterus to stimulate contractions and breast to initiate milk ejection. Mobilized via second messenger system to mobilize CA2+. 11. Describe important effects of the two groups of hormones produced by the thyroid gland. ...................TH Thyroid Hormone made up of two active iodine-containing amine hormones: T4 Thyroxine &T3 Triodothronine. Affects virtually every cell in body. CAMP. Increases basal metabolic rate and body heat production--calorigenic effect. Secreted by thyroid follicles after production on the ribosomes of the thyroid's follicle cells. Negative feedback loop controls release and inhibition. Rising TH inhibit thypthalamic anterior pitutary axis, temporarily shutting off stimulus for TSH Thyroid Stimulating Hormone release. Target: basal metabolic rate, temperature regulation, carbohydrate/lipid/protein metabolism, nervous system, cardiovascular system, muscular system, skeletal system, gastrointestinal system, reprodutive system, integumentary system. HYPO: Myxedema, endemic goiter, cretinsim. HYPER: Graves Disease
 * The Thyroid Gland**

12. Follow the process of thyroxine formation and release. SYNTHESIS NOT REQUIRED 13. Indicate general functions of parathyroid hormone. ....................PTH Parathyroid Hormone. The organ contains oxyphil and cheif cells. Chief cells secrete parathyroid hormone. (Protein) Most important hormone for calcium balance in the blood. Stimulated by falling blood Ca2+ levels in the blood to stimulate three target organs00 skeleton-- by stimulating osteoclasts, kidneys--by enhancing resorbption of Ca2+ and excretion of phosphate, and intestine to activate vitamin D, increasing absorption of Ca2+ by intestinal mucosal cells. HYPO: leads to hypocalcemia and tetany HYPER: Rickets
 * The Parathyroid Gland**

14. List hormones produced bny the adrenal gland, and cite their physiological effects. ....................Epinephrine/Norepinephrine. Made in Adrenal Medulla. Direct connection to sympathetic nervous system. Most potent. Stimulated by decreasing blood volume and blood pressure, rising blood levels of K+. Reverse conditions inhibit. Renin-angiotensin mechanism. ....................Mineralocorticoids (ALDOSTERONE) regulates sodium ion in kidney tubules. Zona Glomerulosa ....................Glucocorticoids (Cortisol, cortisone, corticosterone) increase blood glucose levels to combat long term stressors Zona Fasciculata ....................Gonadocorticoids (androgen, estrogen) Zona Reticularius 15. Briefly describe the importance of melatonin. ...................produces MELATONIN. diurnal cycle, biological rhythms, some inhibitory effect on reproductive system that prevents precocious sexual maturation. 16. Compare and contrast the effects of the two major pancreatic hormones. ...................Insulin-- ( amino acid protein linked by disulfide bonds. Purpose is to lower blood glucose levels. Influences protein and fat metabolism. . Insulin enhances membrane transport of glucose into body cells--esp muscle and fat. It inhibits the breakdown of glycogen to glucose. It inhibits the conversion of amino acids or fats to glucose. HYPO:Diabetes mellitus and lipemia. HYPER: low blood glucose leels or Hypoglycemia. Weakness, anxiety, etc. ...................Glucagon (29 amino acids polypeptde) Super potent hyperglycemic action-- one molecule releases 100million molecules of glucose into blood. it breaks down glycogen to glucose, synthesises glucose from lactic acid and noncarbohydrate molecules (glyconeogenesis) and releases glucose to the blood from liver cells. Antagonist to insulin. Assisted by cortisol. Stimulated by falling blood glucose levels and some sympathetic nervous signals. Targets: liver, bloodstream 17. Describe the functional roles of hormones of the testes, ovaries, and placenta. 18. Name a hormone produced by the heart. 19. State the location of enteroendocrine cells. 20. Briefly explain the hormonal functions of the kidney, skin, adipose tissue, bone, and thymus. 21. Describe the effects of aging on endocrine system functioning.
 * The Adrenal (Suprarenal) Glands**
 * The Pineal Gland**
 * The Pancreas**
 * The Gonads and Placenta**
 * Hormone Secretion by Other Organs**
 * Developmental Aspects of the Endocrine System**

1. To identify and name the major endocrine glands and tissues of the body when provided with an appropriate diagram. 2. To list the hormones produced by the endocrine glands and discuss the general function of each. 3. To indicate the means by which hormones contribute to body homeostasis by giving appropriate examples of hormone actions. 4. To cite mechanisms by which the endocrine glands are stimulated to release their hormones. 5. To describe the structural and functional relationship between the hypothalamus and the pituitary. 6. To describe major pathological consequence of hypersecretion and hyposecretion of several of the hormones considered. 7. To correctly identify the histologic structure of the thyroid, parathyroid, pancreas, anterior and posterior pituitary, adrenal cortex, and adrenal medulla by microscopic inspection or when presented with an appropriate photomicrograph or diagram. 8. To name and point out the specialized hormone-secreting cells in the above tissues as studied in the laboratory.
 * LAB Exercise 27**


 * Other points not listed here which seemed important in lecture:**