Electrical and chemical signals Science keywords
Terms
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- Accommodation
- Changes in the thickness of the lens in the eye to focus on near and far objects
- Artificial insemination
- Insertion of sperm from a donor into a woman to fertilise her egg
- Bacteria
- A type of microorganism. Most are useful, some cause disease
- Brain
- An organ that coordinates the actions of your body
- Brain tumour
- A mass of unnecessary cells growing inside the skull
- Central nervous system (CNS)
- The brain and spinal cord
- Cones
- Light-receptor cells in the retina of the eye that detect colour
- Contraception
- A method of preventing pregnancy
- Contract
- The shortening of muscles cells to make the muscle shorter
- Cornea
- The curved outer surface of the eye that focuses most of the light on the retina
- Diabetes
- A disease where your body is unable to control the level of sugar in the blood
- Effector
- Muscles that contract in response to impulses from the nervous system
- Electrical impulse
- A signal carried by the nerves in your body
- Endocrine system
- A system of glands in the body that make hormones
- Epilepsy
- A sudden burst of excess electrical activity in the brain causing a seizure
- Gland
- An organ that produces a hormone
- Glucose
- A simple sugar, a type of carbohydrate
- Grand mal
- A form of epilepsy where the person loses consciousness and makes uncontrolled jerky movements
- Hormone
- A chemical message produced by a gland to coordinate the body
- Infertility
- Where a couple are unable to have children. May be caused by blocked oviducts or not making enough sperms
- Insulin
- A hormone made in the pancreas to control the level of sugar in the blood
- In-vitro fertilisation (IVF)
- The fertilisation of a human egg outside the body
- Iris
- The coloured ring of muscle in the eye that controls the size of the pupil
- Iris reflex
- A reflex action that controls the amount of light entering the eye
- Menstrual cycle
- The cycle of preparing the uterus to receive a fertilised egg after ovulation
- Motor neurone
- A neurone that carries impulses to an effector
- Muscle
- Tissue made from cells which can contract, allowing movements to take place
- Nervous system
- The nerves, brain and spinal cord inside the body
- Neurone
- A single cell that carries impulses
- Oestrogen (Pronounced: E-strogen)
- A hormone that makes the lining of the uterus thicken and stops eggs from developing
- Pain sensor
- A receptor cell in the skin that responds to pain
- Pancreas
- An organ in your abdomen that produces insulin
- Parkinson's disease
- A disease where the brain is unable to coordinate muscle actions properly
- Pathway
- The route of an impulse between a receptor and an effector
- Pregnancy
- The development of an embryo from fertilisation until birth
- Progesterone
- A hormone that makes the uterus lining thicken after ovulation
- Pupil
- The hole in the centre of the iris that lets light enter through to the retina
- Reaction time
- The time between a sense organ detecting a stimulus and the muscles reacting
- Receptor
- A special cell that detects stimuli like light, sound and heat
- Relay neurone
- A neurone found in the central nervous system connecting a sensory neurone and a motor neurone as part of a reflex
- Reflex (Involuntary response)
- An automatic response to a stimulus
- Retina
- The inner lining of an eyeball containing light-detecting receptor cells called rods and cones
- Rods
- Light-detecting receptor cells in the retina of the eye that detect light intensity
- Sense organ
- An organ that contains receptors that detect stimuli
- Sensory neurone
- A neurone carrying impulses between a receptor cell and the central nervous system
- Spinal cord
- The bundle of neurones inside the backbone
- Stimulus
- Something you react to
- Stroke
- A blood clot or bleeding in the brain, which causes brain cells to die
- Synapse
- The gap between two neurones
- Target organ
- The organ a particular hormone works on
- Testosterone
- The male sex hormone
- Tumour
- Cells growing to form an abnormal tissue
- Voluntary response
- A response to a stimulus that you have to think about and can control