Understanding the Endocrine System and Hormone Function

The endocrine system consists of specialized glands that secrete hormones directly into the bloodstream to regulate various bodily functions. The pituitary gland acts as the master control center, producing multiple hormones that direct other glands to release their specific hormones.

Definition: Hormones are chemical messengers released into the blood that affect specific target organs and cells.

Example: Adrenaline from the adrenal glands increases heart rate and breaks down liver glycogen stores during stress responses.

Highlight: While neurons provide rapid, precise, and short-term responses, hormones work more slowly but have longer-lasting, broader effects throughout the body.

Vocabulary:

• Glycogen: Stored form of glucose in the liver
• Endocrine glands: Specialized organs that produce and secrete hormones
• Target organs: Specific body parts that respond to particular hormones

The major endocrine glands and their functions include:

• Pituitary gland: Controls other glands and produces multiple regulatory hormones
• Thyroid gland: Produces thyroxine to regulate metabolism and heart rate
• Pancreas: Secretes insulin to control blood glucose levels
• Adrenal glands: Release adrenaline for fight-or-flight response
• Reproductive glands (testes/ovaries): Produce sex hormones controlling reproduction and development

Quote: "Hormones are chemicals released directly into blood and are carried to other parts of the body - but only affect particular cells in organs (target organs)."