1. Indiana Standard: 8
Endocrine System
Title
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2. The Endocrine System The Endocrine System
Unlike the nervous system, the endocrine system does not have its own connected network of tissues.
Instead, it sends chemical messages throughout the body in the blood stream from glands to target cells.
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3. The Endocrine System Hormones
The chemicals made by the endocrine system are called hormones. Hormones are made in organs called glands found in many different areas of the body. Glands release hormones into the bloodstream.
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4. The Endocrine System Hormones
As hormones move through the body in the bloodstream, they come into contact with many different cells however they only bind with cells that have matching receptor cells, called target cells.
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5. The Endocrine System Hormones
When the hormones come into contact with target cells they bind to the matching receptor and signal the cell to make certain proteins.
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6. The Endocrine System Hormones
All hormones belong to one of two categories:
Steroid or non-steroid hormones.
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7. The Endocrine System Hormones Steroid
Steroid hormones are made of cholesterol, a type of lipid. Steroid hormones enter the cell by diffusing through the cell membrane. They are able to enter this way since they are made of cholesterol.
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8. The Endocrine System Hormones Steroid
Remember from biology: cell membranes are made of lipid
bi-layers, this is why a steroid hormone can easily pass through the cell membrane.
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9. The Endocrine System Hormones Steroid
Once inside the cell, the steroid hormone attaches to a receptor protein inside the cell which transports the steroid hormone into the nucleus. After it is inside, it binds to the cell’s DNA causing the cell to produce proteins coded by that portion of the DNA.
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10. The Endocrine System
Hormones
Steroid
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11. The Endocrine System Hormones Nonsteroid Hormones
Nonsteroid hormones are made of amino acids that cannot pass through a cell membrane. Instead, they bind to protein receptors located on the cell membrane.
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12. The Endocrine System Hormones Nonsteroid Hormones
Once bound to the receptor, the receptor changes chemically sending a message into the cell. This chemical message activates DNA within the nucleus causing the production of proteins coded by that portion of DNA.
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13. The Endocrine System
Hormones
Nonsteroid Hormones
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15. The Endocrine System Glands
The endocrine system has many glands. Each gland makes hormones that have target cells in various places throughout the body. These are some of the major glands of the endocrine system:
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16. The Endocrine System Glands Pineal Gland- 1
Structure: Small area in the middle of the brain.
Hormones:
Melatonin that regulates sleep patterns
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17. The Endocrine System Glands Pituitary Gland - 2
Structure: Small pea-like structure in the middle of the brain.
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18. The Endocrine System Glands Pituitary Gland - 2 Hormones:
Growth Hormone (GH) stimulates cell division, protein synthesis and bone growth in multiple tissues.
Antidiuretic hormone (ADH) causes the blood to absorb water from the kidneys.
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19. The Endocrine System Glands Thyroid - 3
Structure: Wraps around the windpipe on three sides.
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20. The Endocrine System Glands Thyroid - 3 Hormones:
Thyroxin (T4) and Triiodothyronine (T3) increase metabolism, digestion and a person’s energy levels.
Calcitonin causes the body to remove calcium from the blood and increase bone formation.
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21. The Endocrine System Glands Thymus - 4
Structure: Located in the chest.
Hormones:
Thymosin causes white blood cells to reproduce and mature.
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22. The Endocrine System Glands Adrenal Glands - 5
Structure: Located above the kidneys.
Hormones:
Epinephrine causes the heart to increase its strength and number of contractions, circulating blood more quickly.
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23. The Endocrine System Glands Pancreas - 6
Structure: Located between the stomach and intestines.
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24. The Endocrine System Glands Pancreas - 6 Hormones:
Insulin removes sugar from the blood stream and increases sugar metabolism.
Glucagon increases sugar production and adds sugar to the bloodstream.
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25. The Endocrine System Glands Ovaries - 7
Structure: Located in female pelvic area.
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26. The Endocrine System Glands Ovaries - 7 Hormones:
Estrogen causes sexual maturation, including egg production, influences female characteristics such as fat distribution & widening of hips.
Progesterone causes menstruation.
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27. The Endocrine System Glands Testes - 8
Structure: Located in male pelvic area.
Hormones:
Testosterone causes sexual maturation including sperm production and male characteristic such as facial hair and a deep voice.
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28. References
Holt McDougal Biology
By Stephen Nowicki

29. Endocrine System Part 1

30. Endocrine System Part 2