Biology glossary - Homeostasis and response

Antidiuretic hormone (ADH)

A hormone made in the pituitary gland to control the water excreted by the kidneys

Urea

a metabolic waste product made in the liver and excreted from the kidneys

Excretion

Removing waste products from your body (CO2 and Urea)

Endocrine gland

Releases a hormone (chemical messenger) into the bloodstream

Negative feedback

When a corrected measure is switched off when the condition returns to the set point

Menstrual cycle

The regular cycle of events regulated by hormones in a female

Positive tropism

A response towards a stimulus

Hydrotropism

a response to water

Negative tropism

A response away from a stimulus

Phototropism

A response to light

Geotropism / Gravitropism

A response to gravity

Homeostasis

Regulation of the internal environment

Nerve

A bundle of neurones, usually wrapped in a sheath for protection

Neurone

A single cell which transmits electrical impulses along its length

Accomodation

The process of changing the shape of the lens to focus on near or distant objects

Auxin

A plant hormone which causes a change in growth rates in plant roots and shoots

Tropism

A growth response to a stimulus detected by plants. May be positive or negative

Dialysis

a treatment for kidney failure, artificially cleaning the blood

IVF

In-vitro fertilisation. The artificial fertilisation of eggs in a lab. It is a treatment to help couples have a baby

Contraception

a method used to prevent a pregnancy from occurring

Reflex

A fast, automatic response to a stimulus that occurs without conscious thought

Gibberellin

A type of plant hormone that stimulates seed germination, stem growth and flowering

Synapse

The connection between two neurones

Vasodilation / Vasoconstriction

When blood vessels supplying the capillaries dilate (get wider) or constrict (get narrower)

Diabetes

A condition that affects the body’s ability to control its blood glucose level