The endocrine system is made up of glands that secrete hormones directly into the bloodstream to regulate many body activities. The major glands include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries, testes, pineal gland, and thymus gland. Each gland produces unique hormones that target specific organs to increase or decrease activity levels and regulate growth, metabolism, sexual development, and other bodily functions.

1. Endocrine System Chapter 11 Kristin Tomey Vallaly

2. The Endocrine System Brief Overview Function Secrete hormones that regulate many body activities (ie., metabolic rate, water and mineral balance, immune system reactions and sexual functioning) Organs involved: adrenal glands ovaries pancreas (islets of Langerhans) parathyroid glands pineal gland testes thymus gland thyroid gland

3. Anatomy & Physiology of the Endocrine System collection of glands that secrete hormones directly into the blood stream hormones are chemicals that act on their target organs to either increase or decrease activity levels two distinct types of glands: endocrine glands: release hormones directly into blood stream (ductless glands) exocrine glands: release secretions into a duct that carries them to outside of the body

4. Anatomy & Physiology of the Endocrine System (continued) Glands in the Endocrine System 2 adrenal glands 2 ovaries (female) 4 parathyroid glands pancreas pineal gland pituitary gland 2 testes (male) thymus gland thyroid

5. Glands of the Endocrine System & their hormones Adrenal Gland 2 located above kidneys each consists of 2 sections that secrete various hormones: Adrenal cortex glucocorticoids cortisol : regulates carbohydrate levels in the body mineralocorticoids aldosterone : regulates electrolytes and fluid volume in the body steroid sex hormones (androgen, estrogen, progesterone ): responsible for reproduction and secondary sexual characteristics Adrenal Medulla epinephrine (adrenaline) : intensifies response during stress: “fight or flight” response norepinephreine : chiefly a vasoconstrictor

6. Glands of Endocrine System Ovaries (female) 2 located in the lower abdominopelvic cavity female gonads (produce gamates or reproductive sex cells) also produce hormones: estrogen : stimulates development of secondary sex characteristics in females; regulates menstrual cycle progesterone : prepares for conditions of pregnancy

7. Glands of Endocrine System Pancreas located along lower curvature of stomach only organ in body with both endocrine and exocrine functions exocrine portion secretes digestive enzymes through a duct into duodenum endocrine portion (islets of Langerhans) produce 2 hormones: glucagon : stimulates liver to release glucose into the blood insulin : regulates and promotes entry of glucose into cells

8. Glands of Endocrine System Parathyroid Glands 4 tiny glands located on the dorsal surface of thyroid gland: produces one type of hormone: parathyroid hormone (PTH): stimulates bone breakdown; regulates calcium leve in the blood

9. Glands of the Endocrine System Pineal Gland small, pinecone-shaped gland that is part of the thalamus region of brain secretes melatonin that regulates the body's circadian rhythm (sleep-wake cycle)

10. Glands of the Endocrine System Pituitary Gland located underneath the brain, small, marble-shaped gland divided into two lobes that are controlled by the hypothalamus Anterior lobe Andrenocorticotropine Hormone (ACTH) : regulates function of adrenal cortex Follicle-stimulating Hormone (FSH) : stimulates growth of eggs in female and sperm in males Growth Hormone (GH) : stimulates growth of the body Luteinizing Hormone (LH) : Regulates function of male and female gonads and plays a role in releasing ova in females Melanocyte-stimulating Hormone (MSH) : stimulates pigment in skin Prolactin : stimulates milk production Thyroid-stimulating hormone (TSH) : regulates function of thyroid gland

11. Glands of the Endocrine System Pituitary Gland (continued) Posterior Lobe Antidiuretic hormone (ADH) : stimulates reabsorption of water by the kidneys Oxytocin : stimulates uterine contractions and releases milk into ducts

12. Glands of the Endocrine System Testes (male) 2, oval glands located in the scotal sac of the male male gonads that produce male gametes (sperm), produces male sex hormone: testosterone : promotes sperm production and development of secondary sex characteristics in males

13. Glands of Endocrine System Thymus Gland located in mediastinal cavity anterior and superior to the heat present at birth and grows to largest size during puberty then begins to shrink plays a part in the immune system, but is also part of endocrine system because it secretes the hormone: thymosin : promotes development of cells in immune system

14. Glands of Endocrine System Thyroid Gland resembles a butterfly in shape with right and left lobes located on either side of trachea and larynx produces 3 hormones: calcitonin : stimulates deposition of calcium into bone thyroxine (T 4 ) : stimulates metabolism in cells Triiodothyonine (T 3 ) : stimulates metabolism in cells