Lab Exercise Endocrine System Name Date Materials: Human torso model Compound light microscope Prepared slides of the pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus gland, adrenal gland, pancreas, testes and ovaries. Anatomical chart of the endocrine system 1. Hypothalamus and Pituitary Gland A. Using the microscope and histology slide of the pituitary gland as a guide, label the parts of the pituitary gland including the anterior pituitary and posterior pituitary and pituicytes in the picture below. B. Match the hypothalamic hormone with the appropriate hormone of the anterior pituitary. 1. GnRH 2. GHRH 3. TRH 4. CRH a. TSH b. ACTH c. GH d. FSH
C. Match the hormones below with their responses. 1. GH 2. FSH 3. PRL 4. LH 5. ACTH 6. TSH a. Production of gametes b. Production of sex hormones c. Secretion of hormones by the adrenal cortex d. Milk production by the mammary glands e. Secretion of thyroid hormones f. Growth of muscle and bone 2. Hormone Regulation a. Explain how a negative feedback mechanism can help maintain homeostasis. b. Explain how a positive feedback mechanism might be harmful.
3. Pineal Gland a. Using the microscope and a histological slide of the pineal gland, draw and label the tissue of the pineal gland in the space provided below. b. Using a brain model, locate the pineal gland. Describe its location in the brain. c. Describe the hormonal function of the pineal gland.
4. Thyroid Gland a. Using the microscope and a histological slide of the thyroid as a guide, label the microscopic structures of the thyroid gland including the follicles, colloid, follicular cells and parafollicular cells using the picture below. b. Locate and identify the thyroid on anatomic models. Describe its location in the body. c. What are the functions of the thyroid hormones synthesized and secreted by the follicular cells of the thyroid?
d. What are the functions of the hormone synthesized by the C (parafollicular) cells of the thyroid? e. What role does the thyroid play in maintaining the basal metabolic rate? f. A patient presents with signs and symptoms of hyperthyroidism. Blood tests indicate high T3, T4, and TSH levels; however, TRH levels are very low. What condition might explain these findings?
5. Parathyroid Gland a. Using the microscope and a histological slide of the parathyroid as your guide, draw and label the cells of the parathyroid gland in the picture below. b. Identify the parathyroid glands on lab models. Describe their location. c. A patient has had a thyroidectomy (surgical removal of the thyroid gland) during which the parathyroid glands were also removed. What changes might be expected in calcium levels found in the blood and urine? What changes would you expect to see in the vitamin D levels of this patient?
6. Thymus Gland a. Using the microscope and a histological slide of the thymus as a guide, label the structures of the thymus, lobules and Hassall s bodies in the picture below. b. Identify the thymus gland on the class models. Describe the physical changes that occur in the gland as one goes from infancy into late adulthood and into old age.
7. Adrenal Glands a. Using the microscope and a histological slide of the adrenal glands, draw and label the zones (glomerulosa, fasiculata and reticularis) and medulla of the gland in the space provided below. b. Describe the hormones that are secreted from each zone of the adrenal gland and their functions. c. During embryonic development, ectodermal tissues called the neural crests give rise to the ganglia of the sympathetic chain and the adrenal medulla. Discuss the functional relationship between the sympathetic nervous system and the adrenal medulla.
8. Pancreas a. Using the microscope and a histological slide of the pancreas as a guide, label the islets and the acini in the picture below. b. Explain why the pancreas is considered to be both an endocrine organ and an exocrine organ. c. List and describe the long term complications that arise with uncontrolled or poorly controlled diabetes mellitus type I and II.
9. Gonads a. Using a microscope and a histological slide of the ovary as a guide, label a follicle and ova in the picture below. b. Using a microscope and histological slide of the testis as a guide, label the seminiferous tubule, lobule and the interstitial cells in the picture below. c. During the reproductive life of woman, the estrogen produced during the reproductive cycle inhibits activity of the osteoclasts. Explain why post-menopausal women are more prone to osteoporosis than younger women.