VIDEO CLIP

ENDOCRINE V. EXOCRINE

ENDOCRINE• “into”• Releases substance

(hormone) into the bloodstream

EXOCRINE• “out of”• Releases substance into a

duct to exit the body

• Controlling system of the body; regulates homeostasis– Similar to nervous system

• Slower than nervous systems; uses chemical messengers released into blood (hormones)

• Organs small in size

Examples of major processes controlled by hormones

•Reproduction, growth/development, maintenance of electrolyte/water/nutrient balance of blood

HORMONES• Greek: “to arouse”• Def: chemical substances secreted by cells that

regulate the activity of other cells.• Circulate in blood• binds to specific

receptor (in cell or on cell membrane) and triggers a response

Q: What primarily prompts glands to release their hormones?

a. Negative feedback mechanismb. The kidneys c. Nothing; they are continuousd. Secondary responses

Negative feedback mechanisms

• Glands are triggered by some stimulus (internal or external) and release hormones.

• Then rising hormone levels in the blood are detected by the gland and tell it to quit releasing the hormone

Examples of stimuli that cause an endocrine gland to secrete a

hormone

1. Hormonal – a hormone from another gland

2. Humoral– chemical changes in blood

3. Neural – signals from nervous system

Endocrine glands

1. Pituitary gland2. Hypothalamus3. Pineal gland4. Thyroid5. Parathyroid

6. Adrenal gland7. Thymus8. Pancreas9. gonads (ovaries/testes)10. Placenta