Unit 24 How Hormones Govern Body Activities 1.pptx

cvccfcf

1. Hormones and the Endocrine Glands

2. The endocrine system consists of glands that are capable of producing and secreting hormones. The Endocrine System Glands of the endocrine system

3. A hormone is a chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Endocrine glands are ductless glands that release hormones directly into the bloodstream. The Endocrine System Glands of the endocrine system

4. Main endocrine glands: pineal gland hypothalamus pituitary gland thyroid gland thymus adrenal glands pancreas ovaries testes The Endocrine System Glands of the endocrine system

5. Pineal Gland It is a pea-sized mass of tissue located in the epithalamus at the center of the brain, which is in between the brain hemispheres. It releases melatonin. Hormones and the Endocrine Glands Location of the pineal gland in the brain

6. Pineal Gland Melatonin is the hormone that regulates the sleep-wake cycle. It also controls reproductive cycles and beginning of puberty. Hormones and the Endocrine Glands The circadian rhythm or “biological clock”

7. Hypothalamus This is the control center in maintaining homeostasis It is important in regulating satiety and body temperature It also works with the pituitary gland. Hormones and the Endocrine Glands Location of hypothalamus in the brain

8. Hypothalamus Gonadotropin- releasing hormone (GnRH) stimulates the release of hormones connected to puberty, sexual maturation, and reproductive function. Somatostatin causes the pituitary gland to stop the release of growth hormone. Hormones and the Endocrine Glands

9. Pituitary Gland This is located at the base of the brain directly beneath the hypothalamus. It regulates many functions of the endocrine glands. Hormones and the Endocrine Glands Hypothalamus and pituitary gland

10. Pituitary Gland It works with the hypothalamus to command other endocrine glands when to release hormones. The pituitary is divided into two parts: anterior lobe posterior lobe Hormones and the Endocrine Glands Hypothalamus and pituitary gland

11. Pituitary Gland Hormones of the anterior lobe: Growth hormone is for bone and tissue growth. Thyroid-stimulating hormone (TSH) is for stimulating the thyroid gland. Hormones and the Endocrine Glands Structure of somatotropin , the growth hormone

12. Pituitary Gland Hormones of the anterior lobe: Adrenocorticotropic hormone (ACTH) stimulates the adrenal gland. Prolactin regulates milk production in females. Hormones and the Endocrine Glands Prolactin 3D structure

13. Pituitary Gland Hormones of the anterior lobe: Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) control sexual functions Hormones and the Endocrine Glands 3D structure of FSH

14. Pituitary Gland Hormones of the posterior lobe: Antidiuretic hormone (vasopressin) controls water loss. Oxytocin stimulates uterine contractions during childbirth. Hormones and the Endocrine Glands Structure of oxytocin

15. Thyroid Gland This is a butterfly-shaped gland located in the lower front part of the neck. It produces the hormone thyroxine. Hormones and the Endocrine Glands Location of the thyroid gland

16. Thyroid Gland Thyroxine is a hormone used to regulate metabolism. It plays a crucial role in digestion, muscle control, and bone development. Hormones and the Endocrine Glands Structure of the thyroid gland

17. Parathyroid Glands These are two pairs of tiny glands incorporated on the surface of the thyroid gland. They release parathyroid hormone to regulate the blood calcium levels and bone metabolism. Hormones and the Endocrine Glands Location of the parathyroid gland

18. Thymus This is a small gland with two lobes located in the upper anterior of chest. It decreases in size as a person ages. Hormones and the Endocrine Glands Location of the thymus in the chest

19. Thymus This the only organ for immunity that does not directly attack antigens It is a site for the maturation of T-cells. T cells are a major type of lymphocytes capable of producing an immune response Hormones and the Endocrine Glands Location of the thymus with reference to the heart

20. Adrenal Glands These are two triangular-shaped glands found above the kidneys They have two parts: adrenal cortex (outer) adrenal medulla (inner) Hormones and the Endocrine Glands Location of the adrenal glands

21. Adrenal Glands A drenal cortex produces corticosteroids that regulate metabolism, salt balance, and the immune system. A drenal medulla produces catecholamines that help the body cope with different kinds of stress. Hormones and the Endocrine Glands The kidney and the adrenal gland

22. Adrenal Glands These also release epinephrine or adrenaline during stress or strenuous activities They control the fight-or-flight response (increase blood flow to muscles, pupil dilation, and blood sugar). Hormones and the Endocrine Glands Location of the adrenal glands with respect to the torso

23. Pancreas This is an elongated organ located in the abdominal cavity behind the stomach It has both digestive and hormonal functions Hormones and the Endocrine Glands Location of the pancreas

24. Pancreas The exocrine pancreas secretes digestive enzymes. The endocrine pancreas is responsible for secreting hormones. insulin glucagon Hormones and the Endocrine Glands Parts of the pancreas

25. Reproductive Glands These are known as the gonads. They serve as the source of sex hormones: testes (male) ovaries (female) Hormones and the Endocrine Glands Male (left) and female (right) reproductive systems

26. Reproductive Glands The testes (male) are located in the scrotum. Testosterone promotes male secondary sex characteristics during puberty and affect sperm production. Hormones and the Endocrine Glands Location of the testis

27. Reproductive Glands The ovaries (female) are located on both sides of the uterus. Estrogen and progesterone control the development of female characteristics and reproductive functions. Hormones and the Endocrine Glands Location of the ovaries

28. Hormone-releasing cells: Endocrine cells pineal gland, thyroid gland, thymus, adrenal glands, pancreas, reproductive glands Neurosecretory cell s hypothalamus, pituitary gland Release of Hormones to the Bloodstream Types of hormone-releasing cells

29. T ypes of hormone-releasing cells: Endocrine cells produce and secrete hormones directly into the bloodstream. Neurosecretory cells are specialized nerve cells that produce and secrete hormones into the bloodstream. Release of Hormones to the Bloodstream

30. The pineal gland is a pea-sized mass of tissue located behind the third ventricle of the brain. It releases melatonin , a hormone that helps the body to set its “biological clock” during sleep and wake-up hours. 1 The hypothalamus , located in the brain, is the control center in maintaining homeostasis. It controls the production of hormones in the pituitary gland. 2

31. The pituitary gland releases several hormones. Some of these hormones affect other endocrine glands such as adrenal glands, testes, and ovaries. 3 The thyroid gland is a butterfly-shaped gland that releases thyroxine , a hormone used for the body’s metabolism. 4 The adrenal glands are found above the kidneys. They release epinephrine or adrenaline during stress or strenuous activities. 5

32. The pancreas is located in the abdominal cavity behind the stomach. It produces two important hormones, insulin and glucagon , which regulate the blood sugar level inside the body. 7 The thymus is a small gland located in the neck. It helps the immune system by releasing thymosin , a hormone that promotes maturation of T lymphocytes. 6

33. The ovaries are part of the female reproductive system. They produce hormones such as estrogen and progesterone that initiate female secondary sex characteristics, especially during puberty. 8 The testes are part of the male reproductive system. They produce testosterone that promotes male secondary sex characteristics during puberty. 9

34. Write the word true if the given statement is correct. Otherwise, write false. The endocrine system is important for maintaining homeostasis in the body. The glands of the endocrine system do not produce the hormones, they only excrete it to the bloodstream. The bloodstream serves as a pathway for the delivery of the hormones to the different parts of the body. All hormones are proteins that can be easily denatured when exposed to heat. Hormones do not help in any communication process in the body.

35. What will happen to the body if hormones are not secreted by the gland on time?