Unit 1

Nervous System

Receptors - cells that can detect changes inside or outside the body

The Central Nervous System - CNS - the spinal cord and the brain

Effectors - organs in the body that cause a response - muscles/glands

Sense organs - organs that contain receptor cells

Stimuli - changes that receptor cells detect

Neurones - individual nerve cells specialised to transmit electrical impulses

Nerves - bundles of neurones that connect receptors and effectors to the CNS

Synapse - the gap between the two ends of two neurones

Chemical transmitters - chemicals that pass across a synapse and cause an electrical impulse to be generated in the next neurone

Voluntary/Reflex actions...Sensory/Relay/Motor neurones carry impulses.

1 of 2


The liver stores glucose and releases it when it is needed.

The pancreas releases insulin and glucagon.

The digestive system absorbs glucose into the blood.

Anti-Diuretic Hormone (ADH) - secreted from pituitary gland - transported in blood to kidneys - causes kidney to re-absorb more water into the blood if increased, causes them to leave more water in the urine if decreased.

Follicle Stimulating Hormone (FSH) - pituitary gland - causes an egg to mature in an ovary; stimulates the ovaries to produce oestrogen.

Luteinising Hormone (LH) - pituitary gland - stimulates the release of an egg from an ovary

Oestrogen - ovaries - inhibits further production of FSH; stimulates the pituitary gland to release LH; causes the lining of the womb to repair and thicken.

2 of 2


No comments have yet been made

Similar Biology resources:

See all Biology resources »