Edexcel Biology Gcse - Coordination and Control - The Human Endocrine System Part 1

Glands located on top of the kidneys which produce adrenaline.

Hormone produced by the adrenal gland and is released in times of fear or stress.

Food belonging to the food group consisting of sugars, starch and cellulose. Carbohydrates are vital for energy in humans and are stored as fat if eaten in excess. In plants, carbohydrates are important for photosynthesis.

An organ or tissue that makes a substance for release, such as a hormone.

Animals store glucose as glycogen in their liver and muscle tissues.

The maintenance of steady conditions. The ability of the body to maintain a constant internal environment, eg temperature and blood glucose concentration.

Chemical messenger produced in glands and carried by the blood to specific organs in the body.

Part of the brain which controls water balance, temperature and secretion of hormones by the pituitary gland.

A mechanism where changes to conditions cause an action to reverse the change, to keep conditions stable.

Mechanism to lower raised levels of something, and to raise reduced levels of something.

Large gland located in the abdomen near the stomach which produces digestive enzymes and the hormone insulin.

An endocrine gland that is located just below the centre of the brain. It releases a number of important hormones.

The chemical change that takes place inside living cells, which uses glucose and oxygen to release the energy that organisms need to live. Carbon dioxide is a by-product of respiration.

The organ with receptor molecules on its cell surfaces which recognise a specific hormone.

Gland located at the base of the neck which controls metabolic rate by releasing the hormone thyroxine.

Hormone produced by the thyroid to control metabolism.

Thyrotropin releasing hormone produced by the hypothalmus in response to a lack of thyroxine in the blood.

Thyroid stimulating hormone produced by the pituitary gland in response to TRH.

A hormone is a chemical substance, produced by a gland and carried in the bloodstream, which alters the activity of specific target organs. An example of this is the release of the hormone adrenaline, which is released by the adrenal glands. One of its target organs is the heart, where it increases the heart rate.

Like the nervous system, hormones can control the body. The effects are much slower than the nervous system, but they last for longer.

Once a hormone has been used, it is destroyed by the liver.

Nervous: Electrical (chemical at synapses)

Hormonal: Chemical

Nervous: By nerve cells (neurones)

Hormonal: By the bloodstream

Nervous: Muscles or glands

Hormonal: Target cells in particular organs

Nervous: Muscle contraction or secretion

Hormonal: Chemical change

Nervous: Very rapid

Hormonal: Slower