Section 18.1 The Endocrine System Slide 1 of 18 Objectives Describe the general roles of the endocrine system. Identify the glands of the endocrine system. Section 18.1 The Endocrine System

Section 18.1 The Endocrine System Slide 2 of 18 Health Stats What trends in growth rate does this graph show? Does your observation of classmates support the trends shown in the graph? Explain.

Section 18.1 The Endocrine System Slide 3 of 18 The endocrine system regulates long-term changes in the body such as growth and development. What Is the Endocrine System? It also controls many of your body’s daily activities.

Section 18.1 The Endocrine System Slide 4 of 18 Your endocrine (EN duh krin) system is made up of a group of organs, called endocrine glands. Endocrine Glands An endocrine gland produces and releases chemical substances that signal changes in other parts of the body. Endocrine glands release substances directly into the bloodstream.

Section 18.1 The Endocrine System Slide 5 of 18 A chemical substance produced by an endocrine gland is known as a hormone. Hormones You can think of a hormone as a chemical messenger. The endocrine system is kept in balance by the coordinated action of various hormones.

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Section 18.1 The Endocrine System Slide 9 of 18 The endocrine glands include the Functions of the Endocrine Glands hypothalamus pituitary gland thyroid and parathyroid glands thymus gland adrenal glands pancreas reproductive glands

Section 18.1 The Endocrine System Slide 10 of 18 Thyroid Gland The thyroid gland regulates the body’s overall metabolic rate and controls calcium levels in the bloodstream. Parathyroid Glands Four tiny parathyroid glands regulate levels of calcium and phosphorus––minerals that are necessary for proper bone and tooth formation and for muscle and nerve activity. Pancreas The pancreas is a large gland, located behind the stomach, that controls sugar levels in the blood. The Endocrine System

Section 18.1 The Endocrine System Slide 11 of 18 The Endocrine System Hypothalamus The hypothalamus links the nervous system and the endocrine system and controls many of the pituitary gland functions. Pituitary Gland The pituitary gland controls other endocrine glands and regulates growth rate, reproduction, and metabolism. Thymus Gland Hormones released by the thymus gland help the immune system develop during childhood. By adolescence, this gland has shrunk considerably in size. Adrenal Glands These glands release several hormones. Adrenaline triggers the body’s response to sudden stress. Other hormones affect salt and water balance in the kidneys and general metabolism.

Section 18.1 The Endocrine System Slide 12 of 18 The Endocrine System Ovaries The female reproductive glands release sex hormones that regulate egg maturation and control changes in a female’s body at puberty. Testes The male reproductive glands release a sex hormone that regulates sperm production and control changes in a male’s body at puberty.

Section 18.1 The Endocrine System Slide 13 of 18 The hypothalamus (hy poh THAL uh mus), an endocrine gland located in the brain, is actually part of both the nervous and the endocrine systems. Hypothalamus Nerve signals from the hypothalamus control body temperature and feelings of sleep and hunger. Hormones from the hypothalamus control the body’s water levels.

Section 18.1 The Endocrine System Slide 14 of 18 “Releasing hormones” from the hypothalamus signal the release of hormones from a pea-sized endocrine gland in the brain, called the pituitary gland (pih TOO ih tehr ee). Pituitary Gland The pituitary controls many of your body’s functions. These functions include growth reproduction metabolism

Section 18.1 The Endocrine System Slide 15 of 18 The reproductive glands are an important part of the endocrine system. Other Endocrine Glands Puberty is the period of sexual development during which a person becomes sexually mature and physically able to reproduce.

Section 18.1 The Endocrine System Slide 16 of 18 Vocabulary endocrine glandA gland that produces and releases chemical substances that signal changes in other parts of the body. hormoneA chemical substance produced by an endocrine gland. hypothalamusAn endocrine gland in the brain that is part of both the nervous and endocrine systems. pituitary glandAn endocrine gland in the brain that controls many of the body’s functions, including growth, reproduction, and metabolism. pubertyThe period of sexual development during which a person becomes sexually mature and physically able to reproduce.

Section 18.1 The Endocrine System Slide 17 of 18 QuickTake Quiz Click to start quiz.

Section 18.1 The Endocrine System Slide 18 of 18 End of Section 18.1 Click on this slide to end this presentation.