This definitions covers Key Definitions within Human Endocrine System for GCSE Biology. Topic 4: Human Endocrine System It is section 6 of 11 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 6 of 11
Practice
15 questions
Recall
20 flashcards
Key Definitions
Endocrine system: The system of glands that produce and secrete hormones directly into the bloodstream to regulate body functions.
Hormone: A chemical messenger produced by an endocrine gland, secreted into the blood, and transported to target organs where it produces a specific effect.
Endocrine gland: A ductless gland that secretes hormones directly into the bloodstream (e.g. pituitary, thyroid, adrenal glands, pancreas).
Pituitary gland: The "master gland" located at the base of the brain that secretes multiple hormones, many of which control the activity of other endocrine glands.
Target organ: An organ that responds to a specific hormone because its cells possess the complementary receptor proteins that bind to that hormone.
Adrenaline: A hormone produced by the adrenal glands (above the kidneys) in response to stress or danger; prepares the body for "fight or flight" by increasing heart rate and blood glucose.
Thyroxine: A hormone produced by the thyroid gland that regulates the body's metabolic rate (how quickly cells carry out chemical reactions).