Co-ordination and Control Revision

What we are learning about today:

Know the names of the various neurones involved the nervous system

Know the difference between a reflex action and a conscious action.

Know the roles of the hormones used in the menstrual cycle.

Know about the role of hormones in plant growth.

Neurones and the Nervous System

• Neurones are cells that can transmit electrical _________.

• A __________ picks up a change in the environment.• This sends a signal along a ________ neurone. • The signal reaches the CNS, where it enters a

_______ neurone.• The signal is sent back along a ________ neurone.• An __________ then changes something to do with

the body.

Synapse• Neurones do not

directly touch each other. There is a gap between them called a synapse. So how does the signal get passed along this gap?

Reflexes• Reflexes are

fast/slow reactions. They normally involve/do not involve the brain. Reflexes are designed to avoid damaging/improving the body.

A person steps on a pin. Can you describe the pathway of the impulse through the nervous system in this reflex action? (6 marks)

A receptor is stimulated in the skin when the pin is stepped on. This sends signal along a motor neurone to the spine. This riaction is dead quick to avoid harm. The signal is picked up by a relay neurone in the spine. The signal is then sent to an effector which is the leg muscle. This raises up to avoid the pin going proper in the foot. Ouch.

What mark would you give this? How could it be improved?

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The menstrual cycle

• Hormones control the menstrual cycle. The goal of the menstrual cycle is to produce an egg ready for fertilisation.

What do these hormones do?• FSH: • LH:• OESTROGEN:

Controlling Fertility• Hormones can be taken

in the form of a pill.• In order to stop the

menstrual cycle, which hormone would you give and why?

• In order to promote fertility, which hormone would you give and why?

• What option is available if hormones cannot help pregnancy to happen?

Plant hormones

• Plant hormones are called auxins. They control the growth of the plant, but how?