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Lab 9: Endocrine System. Review. Where does pepsinogen come from? Why doesn’t the stomach digest itself? Why can Veggans not eat meat anymore?. Function. Maintain Homeostasis (Balance) Communicates and coordinates physiological responses Example of Imbalance?. DVD clip Battling A Giant.
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Review • Where does pepsinogen come from? • Why doesn’t the stomach digest itself? • Why can Veggans not eat meat anymore?
Function • Maintain Homeostasis (Balance) • Communicates and coordinates physiological responses • Example of Imbalance?
Hormones • Chemical messengers • Stimulate physiological responses in other cells • Target Cells • Tropic (Trophic) Hormones • Hormone whose target is another endocrine gland. • How do hormones travel?
Hormone Production and Distribution • Production • Endocrine Glands • Gland: an organ specialized to produce secretions • Distribution • Relies on blood circulatory system • How does this compare to nervous system?
Hypothalamus Pituitary Thyroid Parathyroid Pancreas Adrenal Gonads Endocrine Glands
Hypothalamus • Location- Base of brain case • Functions- Regulation of Primitive or Basal activities such as sex drive and water balance • 9 hormones- • 7 act on anterior lobe of pituitary gland (Tropic) • 2 stored in posterior lobe
Hypothalamo-hypophyseal portal system • What type of vessels comprise a portal system? • What is unique about a portal system?
Hypothalamo-hypophyseal portal system and tract • Location- • Pituitary Stalk (Infundibulum) • Link the hypothalmus to the pituitary gland • Portal- Capillary beds connect to anterior lobe • Tract- Neurons connect to posterior lobe
Pituitary gland • Location- Sphenoid bone of the skull • Anterior Lobe • Produces Six hormones that Regulate • Reproduction • Growth • Activity of the Thyroid Gland • Posterior Lobe • No hormone production only storage of hypothalamic hormones
Thyroid • Largest endocrine gland • Location- Wrapped around anterior and lateral sides of Trachea, just below Larynx • Hormone- Thyroid Hormone • Function- Increases Metabolic Rate
Parathroid Glands • Location- Four glands imbedded on posterior surface of Thyroid • Hormone- Parathyroid Hormone • Function- Calcium Regulation
Cortex Zona Glomerulosa: Outer layer Zona Fasciculata: Middle Layer Zona Reticularis- Inner Layer Medulla Location- 2 glands one superior to each Kidney. Adrenal Glands
Cortex- Zona Glomerulosa Mineralocorticoids- Regulate Kidney Na+ and K+ excretion Zona Fasiculata Glucocorticoids- Stress and immune supression Zona Reticulata- Sex steroids- androgens precursor to sex hormones Medulla- (Fight or Flight Response) Epinepherine and Norepinephrine Adrenal Glands
Location- Inferior and posterior to Stomach Pancreatic Islets Clusters of endocrine cells Function- Glucose Regulation Pancreas
Gonads • Male- Testes • Secrete Androgens such as Testosterone • Female- Ovary • Secrete Estrogen and Progesterone
Homeostatic Control • Metabolic Rate • Growth Hormone • Blood Glucose Levels • Blood Calcium Levels • Water Retention • Stress
Metabolic Rate • Hormones released in response to a decrease in T3 blood levels • Affects: All cells in the body except brain, spleen, testes, uterus and the thyroid gland • Results: Increase in basal metabolic rate, oxygen consumption and heat production
Hypothyroidism (Creatinism) Children: mental retardation, development abnormalities Adults: lethargy, obesity Goiter Hyperthyroidism (Graves’ Disease) Weight loss, sweating, nervousness, sleeplessness Goiter -----a hypertrophy of the thyroid gland resulting from iodine deficiency Disorders
Growth • Gland- Pituitary Gland • Hormone- • Growth Hormone: increases mitosis and cellular differentiation. • Secreted in response to Sleep, Trauma, Exercise, High protein meals, and Low blood sugar • Effects • Directly: Liver • Indirectly: Bone, Muscle, and Cartilage
Pituitary Dwarfism- Insufficient secretion of Growth Hormone Gigantism- Over-secretion of Growth Hormone Disorders
Blood Glucose Levels • Gland- Pancreas • Hormones • Insulin- increases uptake of glucose by cells • Glucagon- increases release of glucose by cells and increases liver glucose production • Released in response to… • Insulin: high blood glucose levels • Glucagon: low blood glucose levels • Effects- • Systemic • Liver
Disorders • Diabetes Mellitus- Disruption of Metabolism due to lack of insulin or lack of response to insulin. • Symptoms- Excessive Urine, Intense Thirst, and Ravenous Hunger • Type I- (Juvenile of Insulin Dependant) Destruction of Insulin Producing Cells • Type II- (Adult or Noninsulin Dependant) Target cells resistant to Insulin
Blood Calcium Levels • Gland- Parathyroid • Hormone- Parathyroid hormone • Released in response to low calcium levels • Effects • Kidneys- Retain Calcium • Bones- Release Calcium
Disorders • Hyper- or Hypo-parathyroidism • Hyper-parathyroidism: Over Secretion • Soft, Fragile Bones • Kidney stones • Hypo-parathyroidism: Under Secretion • Rapid Decline of Blood Calcium • Fatal
Water Retention • Gland- Hypothalamus • Stored and released by posterior pituitary • Hormone- ADH • Released in response to Dehydration and High Osmolarity (thickening) of blood • Effects?
Stress • Gland- Adrenal Cortex • Hormones • Glucocorticoids • Effect- Systemic
Disorders • Cushing Syndrome • Cause: Excess Glucocorticoids • Disrupts Protein and Fat Metabolism • Symptom is abnormal fat deposits, fatigue and exhaustion
Cushing Syndrome (cont.) After Surgery
Dissection & Review • Cat Questions- • You won’t need to find the specific glands • You will need to know region of the body where found • You will need to know location of organs affected • Lab Notes at Library on Reserve • Research Papers Next Week Due • Reviews for final exam will be in Two Weeks.