1. CHAPTER 16
CHEMICAL REGULATION

2. REGULATION involves the control and coordination
of life activities.

3. In all organisms, there are chemicals that regulate life activities.
Both chemical and nerve control aid in the maintenance of homeostasis in living organisms.
In all organisms, there are chemicals that regulate life activities.
For example, the human ENDOCRINE SYSTEM produces HORMONES.

4. In multicellular animals, there is nerve control
in addition to chemical control.

5. In both plants and animals, the life activities are controlled
by chemicals called HORMONES.

6. Plant growth hormones are produced in the growing parts, such as the tips of roots and stems.

7. Growth hormones cause responses called TROPISMS.
Tendril Video
Plants use specialized leaves called tendrils grasp and wrap around objects.
Tendrils help the race to the top of the forest. Click.

8. The growth of a plant toward a light source is called a PHOTOTROPISM.

9. growth, reproduction and metabolism are controlled by hormones.
In animals,
growth, reproduction and metabolism
are controlled by hormones.

11. In the human body there are two kinds of glands.
The EXOCRINE GLANDS secrete substances locally.
Ducts carry the materials directly to the place where they are used.

12. The organs affected by hormones are called the TARGET ORGANS.
The ENDOCRINE GLANDS secrete hormones directly into the blood. There are no ducts.
The hormones are transported throughout the whole body by the circulatory system.
The organs affected by hormones are called the TARGET ORGANS.

13. RECEPTORS on cell surfaces help hormones to recognize target organs.

15. Many hormones are secreted by the pituitary gland.
The pituitary is called the MASTER GLAND because of its effect on the other glands.

16. One of the many pituitary hormones is called GROWTH HORMONE (hGH).
Growth hormone regulates the physical growth of the body.

17. When too much growth hormone is released,
a person grows too much.

18. 7 feet 4 inches. 475 lbs. Died at age 46.
Andre the Giant
7 feet 4 inches lbs. Died at age 46.

19. This boy is 12 years old.

20. The world’s tallest woman, Yao Defen, is from China.

21. And when too little growth hormone is released, a person grows too little.

22. All these children have
primordial dwarfism.
It is rare for individuals affected by primordial dwarfism to live past the age of 30.
See video of Kenadie

23. At just 33 inches tall and 17 pounds, Kenadie Jourdin-Bromley is roughly the size of a one and a half-year-old toddler, but is 7 years old. She has an extremely rare form of dwarfism classified as primordial dwarfism -- which means unlike most little people, Kenadie's head and limbs are also proportionally small, giving her a doll-like appearance.

24. The THYROID gland secretes THYROXINE which regulates metabolism.

25. The thyroid gland is directly controlled by the pituitary gland.

26. When too little thyroxine is released,
a person suffers from slow metabolism.
hypothyroidism
Too much thyroxine increases the metabolism too much.

27. People with GOITER have an enlarged thyroid gland.
It’s usually a result of an iodine poor diet.
bad goiter pictures coming up…

31. The ADRENAL GLANDS produce ADRENALINE.

32. “fight or flight” response.
Adrenaline increases a person’s heart rate and breathing rate in emergency situations.
This produces the
“fight or flight” response.

33. It also produces an athletic “high” when you
exercise or participate in sports.

34. The PANCREAS has both endocrine and exocrine functions.
It produces both digestive enzymes and hormones.
REMEMBER THIS??
Bile is made in the liver.
It emulsifies fats.

35. The hormone producing cells are called the
ISLETS OF LANGERHANS.

36. The Islets of Langerhans are easy to distinguish from the rest of the pancreas.

37. The PANCREAS produces two important hormones
INSULIN and GLUCAGON.
Together, these hormones maintain a person’s blood sugar concentration.

38. If not properly managed,
When the pancreas cannot produce enough insulin, a person has DIABETES.
Diabetics need regular injections of insulin to help maintain their blood sugar at a constant level.
If not properly managed,
diabetes can lead to heart disease, blindness, nerve and kidney damage.

39. The OVARIES and TESTES are referred to as the human GONADS.
They produce specialized reproductive cells and hormones.

40. ESTROGEN stimulates the development of female reproductive organs and
secondary sex characteristics.
It also stimulates
egg production and the menstrual cycle.

41. TESTOSTERONE stimulates the development of male reproductive organs and secondary sex characteristics.
It also stimulates
sperm production.

42. There are many negative side effects of steriod use.
People use synthetic testosterone to increase the size of their bodies and their athletic performance.
There are many negative side effects of steriod use.
shrinking testes
stunted growth
acne and skin rashes
rage
baldness
heart disease

43. The endocrine system uses NEGATIVE FEEDBACK to regulate the body.
Negative feedback works to maintain homeostasis.

46. NEGATIVE FEEDBACK affect his body??
Remember
STEROID GUY??
How does
NEGATIVE FEEDBACK affect his body??

47. POSITIVE FEEDBACK causes a snowball effect.
Its biological applications are rare, but important!

49. See parasitic wasps laying eggs in aphids.
And what happens when similar parasites mess with a caterpillars normal growth hormone signals.