This topic summary covers Knowledge Organiser within Human Endocrine System for GCSE Biology. Topic 4: Human Endocrine System It is section 10 of 11 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Knowledge Organiser
Key Glands and Hormones
- Pituitary — FSH, LH, ADH; "master gland"
- Thyroid — thyroxine; metabolic rate
- Pancreas — insulin (lowers glucose), glucagon (raises glucose)
- Adrenal — adrenaline; fight or flight
- Ovaries — oestrogen, progesterone; female reproduction
- Testes — testosterone; male reproduction
Nervous vs Hormonal Comparison
- Nervous: electrical impulses → fast → short-lasting → specific target
- Hormonal: chemical in blood → slower → long-lasting → widespread
- Target organ responds because it has specific receptor proteins for that hormone
- Pituitary = master gland — controls thyroid, adrenal glands, ovaries, testes
- Both systems work together; hypothalamus links nervous and endocrine
Common Mistakes
- Saying "the brain releases FSH": The pituitary gland releases FSH — it is a separate gland attached beneath the brain, controlled by the hypothalamus.
- Saying hormones travel along neurones: Hormones are chemicals secreted into the bloodstream and travel dissolved in plasma — they do not travel through nerves.
- Vague target organ explanations: "The hormone goes to the right organ" scores no marks — always state that the target organ has receptor proteins complementary in shape to the hormone.
- Confusing insulin and glucagon actions: Insulin lowers blood glucose; glucagon raises blood glucose — both from the pancreas but with opposite effects. These must not be swapped.
- Incomplete nervous vs hormonal comparisons: State a point about the nervous system AND the corresponding hormonal point for each mark — never describe only one system.
Practice questions for Human Endocrine System
Which gland is known as the 'master gland' because it controls other endocrine glands?
Compare how the nervous system and the endocrine system coordinate responses in the body. [3 marks]
Quick recall flashcards
What is the endocrine system?
The endocrine system is a network of glands that produce and release hormones directly into the bloodstream. Hormones travel to target organs to trigger a response.
What is a hormone?
A hormone is a chemical messenger produced by a gland, released into the blood, and carried to a target organ where it causes a response.