Lesson 8.2 Major Endocrine Organs Chapter 8: The Endocrine System

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Major Endocrine Organs 1. Hypothalamus 2. Pituitary Gland 3. Thyroid Gland 4. Parathyroid Gland 5. Thymus Gland 6. Pineal Gland 7 Adrenal Glands 8. Pancreas 9. Gonads Figure page 269

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. The Endocrine System is run by the Hypothalamus - Buried deep within the brain (4 grams) - Collects information from each body system + integrate response with the NS + maintains homeostasis by regulating »metabolism »heart rate »energy level »body temperature »Thirst The Hypothalamus The Hypothalamus controls by releasing hormones to stimulate/inhibit Pituitary Hormones.

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Pituitary Gland - pea shaped, two lobes - located in the depression of the Sphenoid bone - suspended underneath the Hypothalamus by a short stalk. infundibulum

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Hormones of the Anterior Pituitary Figure 8.6 – page 277 Anterior Pituitary secretes two types of hormones: - act directly on targeted tissue - stimulate other endocrine glands Tropins - lastly, stores hormones of the hypothalamus

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. growth hormone (GH) - directly affect –growth of bone and muscles prolactin (PRO) – directly affect –growth of mammary glands –milk production in a nursing mother Hormones of the Anterior Pituitary adrenocorticotropin hormone (ACTH) - Tropin –release of steroid hormones from adrenal cortex thyroid-stimulating hormone (TSH) - Tropin –release of T 4 and T 3 from thyroid gland

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. follicle-stimulating hormone (FSH) - Tropin –in females estrogen production egg production –in males sperm production luteinizing hormone (LH) - Tropin –in females ovulation –in males testosterone Hormones of the Anterior Pituitary

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Produced in the Hypothalamus, stored in the posterior Pituitary antidiuretic hormone –acts on kidney, decreases urine output oxytocin –acts on uterus, causes contractions –acts on breast, causes secretion of milk Hormones of the Posterior Pituitary Figure 8.7 – page 278

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Thyroid gland - inferior to the larynx, two inches long, butterfly shaped, lies front and sides of the trachea –Secrete two hormones Thyroid hormone (needs iodine) - thyroxine T 4 and triiodothyronine T 3 - controls rate of metabolism Calcitonin -removes calcium from blood, puts into bones Major Endocrine Glands - Thyroid

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Parathyroid gland –parathyroid hormone (PTH) – increases blood calcium levels Three ways: 1.removes calcium from bones (breakdown osteoclasts), puts into blood 2.Increase calcium absorption in intestines 3.Stimulate kidney reabsorption of calcium from urine Major Endocrine Glands - Parathyroid

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Thymus gland –Both part of endocrine and lymphatic system –Lies under sternum and anterior to heart –Large during childhood, shrinks with age –Thymosin development of immune system – T lymphocytes (white blood cells) aka T Cells Pineal gland –Pine cone shaped in brain – unclear how it works –Melatonin produces sleepiness Major Endocrine Glands – Thymus & Pineal

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Thyroid and Parathyroid Glands

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. adrenal medulla –epinephrine and norepinephrine adrenaline rush adrenal cortex –mineralocorticoids aldosterone sodium and water reabsorbed in kidneys –glucocorticoids cortisone and cortisol promote gluconeogenesis –sex hormones estrogen and androgens maintains sexual characteristics Adrenal Glands

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Adrenal Glands

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. islets of Langerhans –alpha cells glucagon increase blood glucose level –beta cells insulin decrease blood glucose level Pancreas

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. testes –testosterone sperm production ovaries –estrogen secondary sexual characteristics progesterone menstrual cycle Gonads

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Fill in the blanks with: ADH, thyroxine, thymosin, or adrenal cortex. 1. The thymus gland produces _______________. 2. The posterior pituitary gland produces oxytocin and _______________. 3. Mineralocorticoids are produced by the _______________. 4. T 4 is also called _______________. Review and Assessment