1. What is the endocrine system?

2. Endocrine System
Chapter 10

3. Regulating Body Function
Working closely with your nervous system is the endocrine system, a chemical communication system that regulate many body functions.
Keeps you in your happy place

4. not Exocrine vs Endocrine Exocrine Glands Endocrine
secrete their products into ducts that empty onto a surface or into a cavity.
Ex: Sweat glands and salivary glands
Ductless glands.
They secrete chemicals (hormones) into intracellular spaces.
not

5. Regulating Body Function
A gland is a group of cells, or an organ, that secretes a chemical substance.
The endocrine glands secrete chemicals called hormones directly into the bloodstream.
The blood carries the hormones directly to the tissue they are targeted to affect.
Some hormones are produced continuously, while others are produced only at certain times.

6. Regulation of Hormone Secretion
Negative Feedback
Positive Feedback
Homeostatic control mechanism that reverses what is happening in the body
More common than positive feedback.
Ex: Insulin, Body Temperature, Blood Pressure
Amplifies changes rather than reverses them.
Ex: Labor – amplified contractions.
Discuss target cells

7. Mechanisms of Hormone Action
Nonsteroid Hormones
Steroid Hormones
Protein
Second messenger mechanism:
nonsteroid hormones serve as 1st messenger between gland and cells;
Another molecule will then act as a 2nd messenger providing communication within the target cell
Lipid-soluble
Can pass through cell membrane of target cell
Bind with receptors on the nucleus and act on DNA

8. Meet the Glands
Endocrine System

9. But first….

10. Pituitary
The pituitary gland at the base of the brain is a gland that signals other endocrine glands to produce hormones when needed.
It is also known as the “Master Gland” and is located at the base of the brain.
It secretes several hormones.
These regulate the thyroid gland, adrenal glands, and kidneys- plus your growth and development. It produces growth hormones.

11. Pituitary Anterior Posterior ADH TSH Oxytocin ACTH FSH LH GH Prolactin
Anti-duretic
Oxytocin
TSH
Thyroid stimulating
ACTH
Adrenocorticotropic
FSH
Follicle-stimulating LH
luteinizing GH
growth
Prolactin

12. Hypothalamus
The hypothalamus is a vital neuroendocrine and autonomic control center beneath the thalamus.
Secretes:
Releasing hormones
Anterior pituitary
Inhibiting hormones
Posterior pituitary

13. Parathyroid
The parathyroid glands direct the distribution of certain minerals in your body.
Increase Ca+ in blood
Secretes
Parathyroid hormone or PTH

14. Calcium Reabsorption

15. Pancreas
The pancreas is part of two body systems- the digestive system and the endocrine system.
It is located behind the stomach and supplies the small intestine with digestive juice.
It produces insulin and contains small clusters of cells called the islets of Langerhans, which control blood sugar levels.
It produces insulin.

16. Pancreas

17. How Insulin Works

18. Thymus The thymus gland is located in the mediastinum.
It is a vital part of the body’s immune system.
Produces thymosin

19. Pineal Gland
The pineal gland is located in the third ventricle of the brain.
It produces melantonin.

20. Thyroid
The thyroid gland is located where the larynx and trachea meet.
It regulates the chemical reactions of nutrients in the cells.
It produces thyroxine.

22. Adrenal The adrenal glands are located on your kidneys.
They secrete hormones that help the body maintain its levels of sodium and water, aid the digestive process, and control your body’s response to emergencies.
It produces adrenaline.

23. Adrenal

24. The Body’s Response to Stress
When your brain recognizes a stressful situation, your adrenal glands responds by releasing the hormone adrenaline. This hormone prepares your body to respond to stress.

25. Reproductive
During adolescence, the endocrine system plays an important role in growth and development.

26. Ovaries The ovaries are the female reproductive glands.
They control the development of secondary sex characteristics during adolescence.
It produces estrogen.

27. Placenta
The placenta anchors the developing fetus to the uterus and provides a “bridge” for the the exchange of nutrients and waste products between the mother and the developing baby.

28. Testes The testes are the male reproductive glands.
They control the development of secondary sex characteristics during adolescence.
It produces testosterone.

29. Problems or Abnormalities
Endocrine System

30. Secretions of Hormones
Hyposecretion
Hypersecretion
Production of too little hormone by a diseased gland
Production of too much hormone by a diseased gland

31. Diabetes
Diabetes mellitus is a disease that may be caused by inadequate insulin production by the pancreas.
Symptoms include:
lack of energy
weight loss
extreme thirst
frequent urination

32. THYROID HYPOTHRYOIDISM HYPERTHYROIDISM
Underactive thyroid gland can cause a dull facial expression, hoarse voice, facial puffiness, coarse, dry skin and hair, and weight gain.
Goiter- caused by low dietary iodine intake
Cretinsim- when hyposecretion occurs in infants/toddlers
Overactive thyroid gland produces symptoms that may include protrusion of eyeballs, warm, moist skin, trembling hands, nervousness, increased sweating, disturbed sleep, and weight loss.

33. Growth Hormone hyposecretion hypersecretion Dwarfisim Gigantism
Acromegaly results when GH is secreted too much after adolescents.

34. Parathyroid
Parathyroid hormone (PTH) and vitamin D help manage calcium balance in the body
Calcium is important to many body functions, including:
Bone formation
Hormone release
Muscle contraction
Nerve and brain function

35. Parathyroid and Nerve Cells

36. Parathyroid hypersecretion hyposecretion Results in hypercalcemia
Causes several abdominal, muscle, kidney and psychological symptoms
Results in hypocalcemia
Symptoms include:
Petechiae (red spots on skin)
Strong muscle contractions of the hand (cramping)
Life threatening
ECG changes