1. Endocrine System

2. ENDOCRINE SYSTEM
The endocrine system is made up of the cells, tissues, and organs that secrete hormones into body fluids such as the blood stream.

3. Hormones diffuse into the bloodstream, and eventually act on cells called target cells.

4. General Characteristics of the Endocrine System
Glandular cells of the endocrine system release hormones into the bloodstream, which carries these messenger molecules everywhere.
The endocrine system is precise because only target cells can respond to a hormone. Target cells have specific receptors that other cells do not have.

5. The endocrine system helps regulate metabolic processes by:
Controlling the rates of certain chemical reactions
Aid in the transport of substances across membranes
Help regulate water and electrolyte balances
Playing a vital role in reproduction, development, and growth

6. Major Endocrine Glands
Pituitary gland
Thyroid gland
Parathyroid gland
Adrenal gland
Pancreas
Pineal gland
Reproductive glands
Kidneys
Thymus

8. Pituitary Gland
Located at the base of the brain, where a pituitary stalk attaches it to the hypothalamus.

9. Growth hormone (GH)
Stimulates cells to increase in size and divide more frequently
Pituitary dwarfism insufficient secretion of growth hormone; body parts normally proportioned, mental development is normal

10. Gigantism oversecretion during childhood; usually a result of a tumor which can cause oversecretion of other pituitary hormones; often has several metabolic disturbances

11. Acromegaly oversecretion during adulthood; enlarged heart, bones, thyroid gland, facial features, etc

12. Prolactin (PRL)
Milk production in lactating women

13. Thyroid stimulating hormone (TSH)
Controls thyroid gland secretions

14. Adrenocorticotropic hormone (ACTH)
Controls the hormones of the adrenal gland

15. Follicle stimulating hormone (FSH)/ Luteinizing hormone (LH)
Exert their actions on the gonads

16. Antidiuretic hormone (ADH)
Decreases urine formation.
Regulates the water concentration of body fluids.

17. Diabetes insipidus (too little ADH) person may produce as much as liters of very dilute urine per day, and solute concentrations in body fluids rise.

18. Oxytocin (OT)
Causes contraction of the uterine walls during childbirth
Contracts specialized cells associated with the milk- producing glands and their ducts.
May be given to ‘induce’ labor (Pitocin) and/or following childbirth to minimize risk of hemorrhage

19. Thyroid Gland Located below the larynx, anterior to the trachea
Consists of two broad lobes connected by an isthmus
Made of many secretory parts called follicles.

20. Thyroxine (T4) & Triiodothyronine (T3)
Regulate metabolism of carbohydrates, proteins, and lipids
Basal metabolic rate how many calories the body must consume at rest in order to maintain life
Required for normal growth and development
Essential to nervous system maturation

21. Calcitonin Lowers blood calcium and phosphate ion concentration
Inhibits release of calcium and phosphate ions from the bones
Increases excretion of calcium and phosphate ions by kidneys

22. HYPOthyroidism
Common among older adults
Fatigue and weight gain

23. HYPERthyroidism Elevated metabolic rate, restlessness, and overeating
Eyes protrude because of swelling behind them
Produces a bulge in the neck because the thyroid gland enlarges

24. 11.9 Pancreas
Endocrine (secretes hormones) and exocrine (digestive juices) gland
Located posterior the stomach

25. Hormones of the Pancreatic Islets
Glucagon
Stimulates the liver to break down glycogen and convert certain noncarbohydrates, such as amino acids, into glucose
Raises blood sugar concentration

26. Insulin
Stimulates the liver to form glycofen from glucose and inhibits conversion of noncarbohydrates
Decreases blood glucose (sugar) concentration

27. 11.10 Other Endocrine Glands
Pineal Gland
Located deep between the cerebral hemispheres, attached to the thalamus
Produces Melatonin:
Produced in response to light conditions received by the retinas of the eyes.
Involved in regulation of circadian rhythms of the body
Thymus
Located posterior to the sternum between the lungs
Thymosin- important in immunity
Reproductive Glands
Testes  produces testosterone
Ovaries  produces estrogen & progesterone
Placenta produces estrogen, progesterone & gonadotropin

28. 11.11 Stress and Health
Physical factors include extreme heat or cold, decreased oxygen, infections, injuries, prolonged heavy exercise, and loud noises.
Psychological factors include thoughts about real or imagined dangers, personal losses, and unpleasant social interactions or feelings of anger, fear, grief, anxiety, depression, and guilt.
Responses to Stress
USE FIGURE 11.18
Hypothalamus
helps prepare the body for “fight or flight” by triggering sympathetic impulses to various organs
stimulates epinephrine release, intensifying the sympathetic responses
secretes corticotropin-releasing hormones, which sets into motion more lasting responses to stress