video clip. endocrine v. exocrine endocrine “into” releases substance (hormone) into the...

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