HOMEOSTASIS DEFINITIONS

Question 1

Accommodation

Answer 1

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

Question 2

Adrenaline

Answer 2

A hormone produced by the adrenal glands in response to fear or stress which increases the heart rate and boosts the delivery of blood to the brain and muscles as part of the ‘fight or flight’ response.

Question 3

Antidiuretic hormone (ADH)

Answer 3

A hormone that increases the reabsorption of water in the kidney tubules.

Question 4

Contraception

Answer 4

Methods used to prevent pregnancy.

Question 5

Coordination centres

Answer 5

Areas of the body like the brain, spinal cord and pancreas that receive and process information from receptors.

Question 6

Deamination

Answer 6

A process occurring in the liver that removes the amino group from an amino acid to produce ammonia.

Question 7

Dialysis

Answer 7

A method of treating kidney failure or disease where the blood is artificially filtered to remove waste and toxins.

Question 8

Effectors

Answer 8

Muscles or glands which bring about responses which restore optimum levels.

Question 9

Ethene

Answer 9

A type of plant hormone which controls cell division and the ripening of fruits.

Question 10

Follicle stimulating hormone (FSH)

Answer 10

A female reproductive hormone that causes the maturation of an egg in the ovary.

Question 11

Geotropism/Gravitropism

Answer 11

A plant’s directional growth response to gravity.

Question 12

Gibberellins

Answer 12

A type of plant hormone which initiates seed germination.

Question 13

Gland

Answer 13

A group of cells that secrete chemicals called hormones directly into the bloodstream.

Question 14

Glucagon

Answer 14

A hormone produced by the pancreas that causes glycogen to be converted into glucose and released into the blood.

Question 15

Homeostasis

Answer 15

The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes.

Question 16

Hyperopia

Answer 16

A defect of the eye where nearby objects appear out of focus (also called long sightedness).

Question 17

In Vitro Fertilisation (IVF)

Answer 17

Fertilising a woman’s egg using sperm outside of the body.

Question 18

Luteinising hormone (LH)

Answer 18

A female reproductive hormone that stimulates the release of an egg.

Question 19

Myopia

Answer 19

A defect of the eye where distant objects appear out of focus (also called short sightedness).

Question 20

Negative feedback cycle

Answer 20

A regulatory mechanism that reverses a change.

Question 21

Oestrogen

Answer 21

The main female reproductive hormone which causes the uterus lining to grow and repair.

Question 22

Phototropism

Answer 22

A plant’s directional growth response to light.

Question 23

Receptors

Answer 23

Organs or cells that detect stimuli.

Question 24

Reflex action

Answer 24

A rapid and automatic response to a stimulus.

Question 25

Selective reabsorption

Answer 25

Reabsorbing certain useful molecules (like glucose, some ions and water) back into the blood after they have been filtered out.

Question 26

Stimuli

Answer 26

Changes in the environment.

Question 27

Target organ

Answer 27

The organ which a hormone acts on to produce an effect.

Question 28

Testosterone

Answer 28

The main male reproductive hormone produced by the testes and it stimulates sperm production.

Question 29

The brain

Answer 29

An organ made of billions of interconnected neurones which controls complex behaviour and has different regions that carry out different functions.

Question 30

The central nervous system (CNS)

Answer 30

The brain and spinal cord which coordinate the response of effectors.

Question 31

The eye

Answer 31

A sense organ containing receptors sensitive to light intensity and colour.

Question 32

Thermoregulatory centre

Answer 32

An area of the hypothalamus in the brain which contains blood temperature receptors and regulates body temperature.

Question 33

Thyroxine

Answer 33

A hormone produced by the thyroid gland that increases the metabolic rate in the body.

Question 34

Type 1 diabetes

Answer 34

A disorder in which the pancreas fails to produce sufficient insulin which is characterised by uncontrolled high blood glucose levels.

Question 35

Type 2 diabetes

Answer 35

A disorder where the body cells no longer respond to insulin produced by the pancreas.

Question 36

Vasoconstriction

Answer 36

The constriction of blood vessels.

Question 37

Vasodilation

Answer 37

The dilation of blood vessels.