Endocrine system

1. Endocrine system Chapter 13

2. Objectives: • Describe the vital function of the endocrine system • State the description and primary functions of the organs and structures of the endocrine system • Identify some of the hormones produced • Identify medical words • Introduce and review Root words, prefixes and suffixes in the endocrine system

3. Contd: • Endocrinology is the study of the endocrine system • Endocrinologist is a physician who specializes in the medical practice of endocrinology

4. Anatomy and Physiology: • the endocrine system influences almost every cell, organ, and function of our bodies. • It is instrumental in regulating mood, growth and development, tissue function, metabolism, and sexual function and reproductive processes.

5. Contd: • The vital function of the endocrine system involves the production and regulation of chemical substances called • Hormones • The word hormone is derived from the Greek language • Means to excite or urge on

6. Contd: • The foundations of the endocrine system are the hormones and glands. • hormones transfer information and instructions from one set of cells to another. • Each type of hormone is designed to affect only certain cells.

7. Contd: • Hyposecretion or hypersecretion of specific hormones can cause or be associated with many pathological conditions. • Too much or too little of any hormones can be harmful to the body • Controlling the production of or replacing specific hormones can treat many hormonal conditions

8. Parts of the Endocrine System: • The major glands that make up the human endocrine system are: • the hypothalamus, pituitary, thyroid, parathyroid's, adrenals, pineal body, and the reproductive glands, which include the ovaries and testes.

9. Glands: The Hypothalamus • a collection of specialized cells that is located in the lower central part of the brain • is the primary link between the endocrine and nervous systems. • The hypothalamus controls the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary.

10. The Pituitary Gland: • it is no bigger than a pea • located at the base of the brain just beneath the hypothalamus • is considered the most important part of the endocrine system • It's often called the "master gland" because it makes hormones that control several other endocrine glands.

11. Contd: • The tiny pituitary gland is divided into two parts: the anterior lobe and the posterior lobe. • The anterior lobe regulates the activity of the thyroid, adrenals, and reproductive glands. • also secretes endorphins, chemicals that act on the nervous system to reduce sensitivity to pain.

12. Contd: • The anterior lobe also secretes hormones that signal the ovaries and testes to make sex hormones. • also controls ovulation and the menstrual cycle in women.

13. Contd: • The posterior lobe of the pituitary releases antidiuretic hormone, which helps control body water balance through its effect on the kidneys and urine output; • Also releases oxytocin, which triggers the contractions of the uterus that occur during labor.

14. The Pineal Gland: • is located in the middle of the brain. • It secretes melatonin, a hormone that may help regulate the wake-sleep cycle. • Cone shaped structure attached by a stalk to the posterior wall of the cerebrum

15. The Thyroid: • located in the front part of the lower neck • is shaped like a bow tie or butterfly • produces thyroid hormones • These hormones (thyroxine and triiodothyronine) control the rate at which cells burn fuels from food to produce energy.

16. Contd: • Thyroid hormones also play a key role in bone growth and the development of the brain and nervous system in children. • The production and release of thyroid hormones is controlled by thyrotropin, which is secreted by the pituitary gland.

17. Parathyroid: • Are four tiny glands attached to the thyroid that function together • They release parathyroid hormone, which regulates the level of calcium in the blood with the help of calcitonin, which is produced in the thyroid.

18. Pancreas: • The pancreas produces (in addition to others) two important hormones, insulin and glucagon. • They work together to maintain a steady level of glucose, or sugar, in the blood to help maintain and store energy • Composed of three major types of cells: alpha, beta and delta • See page 447 of your text for each function

19. The Adrenal Glands: • The body has two triangular adrenal glands, one on top of each kidney. • The adrenal glands have two parts, each of which produces a set of hormones and has a different function.

20. Contd: • The outer part, the adrenal cortex, produces hormones called corticosteroids that influence or regulate salt and water balance in the body • Also influences the body's response to stress, metabolism, the immune system, and sexual development and function.

21. Contd: • The inner part, the adrenal medulla, produces catecholamines, such as epinephrine. • Also called adrenaline, epinephrine • It increases blood pressure and heart rate when the body experiences stress.

22. Gonads: • The gonads are the main source of sex hormones. • In males, they are located in the scrotum. • Male gonads, or testes, secrete hormones called androgens, the most important of which is testosterone. • These hormones regulate body changes associated with sexual development. • Working with hormones from the pituitary gland, testosterone also supports the production of sperm by the testes.

23. Contd: • The female gonads, the ovaries, are located in the pelvis. • They produce eggs and secrete the female hormones estrogen and progesterone. • Estrogen is involved in the development of female sexual features. • Both estrogen and progesterone are also involved in pregnancy and the regulation of the menstrual cycle.

24. Thymus: • is an organ located in the upper anterior portion of the chest cavity just behind the sternum. • The main function of the thymus is to provide an area for T cell maturation, and is vital in protecting against autoimmunity.

25. Abbreviations: • ADA American diabetes Association • BMR Basal metabolic rate • DI Diabetes insipidus • DM Diabetes mellitus • FBS Fasting blood sugar • GTT Glucose tolerance test

26. Contd: • IDDM Insulin-dependant diabetes mellitus (Type I) • NIDDM Non –insulin dependent diabetes mellitus (Type 2) • PRL Prolactin

27. Adenectomy • Aden gland • -ectomy surgical excision • Surgical excision of a gland