Nervous and hormonal control

Question 1

Stimulus

Answer 1

Detectable alteration in the internal/external environment of an organism that produces some change in the organism

Question 2

Receptor

Answer 2

Cells/organs that can detect a change in the environment and convert the energy from the stimulus into a form processed by the organism

Question 3

Co-ordinator

Answer 3

Connects info from receptor to appropriate effector

Question 4

Effectore

Answer 4

Organ that responds to stimulation by a nerve impulse, resulting in a change/response

Question 5

Response

Answer 5

The action that an organism takes to a stimulus

Question 6

Describe what a taxis is

Answer 6

When an organism moves towards/ away from a directional stimulus. EG. earthworm away from light= negative phototaxis

Question 7

Describe what a kinesis is

Answer 7

Non-directional movement in response to a stimulus- the more unpleasant the stimulus the fasteer the random movement. eventually brings organism back into favourable environment. Eg. woodlice- moist air

Question 8

Describe what a tropism is

Answer 8

The growth of a plant in response to a directional stimulus. Positive=towards. Negative= away

Question 9

What are the advantages of an organism being able to respond to a stimuli?

Answer 9

Detecting changes allows organism to respond appropriatley to internal/ external environmentalchanges promoting survival by avoiding harmful environemtns/ ensuring conditions optimal for their metabolism

Question 10

Main components of the nervous system

Answer 10

• Made up of neurones. Organised into larger structures-nerves, spinal cord and brain.-
• Two major divisions- CNS (brain and spinal cord) PNS (pairs of nerves originating from either brain or spinal cord)
• PNS divides into- Sensory NS (nerve impulses to muscles, under voluntary control) Autonomic NS 9 nerve impulses to glands and cardiac muscle- involuntary)
• ANS divides into sympathetic NS (fight or flight responses- neurotransmitter= noradrenaline) parasympathetic NS ( resting responses, acetylcholine)

Question 11

Neurone is…

Answer 11

a nerve cell which carries a electrical impulse

Question 12

Sensory neurone

Answer 12

Transmits electrical impulses from receptors to CNS

Question 13

Motor Neurone

Answer 13

Transmits electrical impulses from CNS to effectors

Question 14

Relay neurone

Answer 14

Transmits electrical impulses between sensory and motor neurones

Question 15

Simple nerve impulse transmission

Answer 15

Stimulus detected by receptor cells
Electrical impulse sent along sensory neurones to CNS
CNS processes info, decides what to do next
CNS sends impulses from motor neurone to effector