1. Unit 12: Human Regulation and Reproduction
Assignment 2: The Nervous and Endocrine Systems

2. Starter Activity Complete the anagrams…
Write a definition of each word!

3. Lesson Objectives
To understand the basic structure of sensory, relay and motor neurons.
To be able to describe the function of each part of a neuron.
To revise the function of a synapse.

4. Draw a Nerve Cell
On your mini whiteboards, draw a labelled diagram of a nerve cell.
(Nerve cell = Neuron / Neurone)

5. Did it look like this?

7. Neurons Specially adapted cells
(can you remember how they are adapted?)
Carry electrochemically charged impulses
(this needs energy from ATP so there are lots of mitochondria to carry out respiration)
Use Neurotransmitters (cells feature a large amount of endoplasmic reticulum to make these proteins)

8. Sensory Receptors
Respond to an environmental stimulus with an electrical change.
The resulting signal is conducted to a sensory neuron.

9. Sensory Receptors: Sense Sense Organ Sensory Receptor Cells
Sensitive to…
Sight
Eye
Rod and Cone cells in the retina
Changes in light
Smell
Hearing
Taste
Touch

10. Sensory Receptors: Sense Sense Organ Sensory Receptor Cells
Sensitive to…
Sight
Eye
Rod and Cone cells in the retina
Changes in light
Smell
Nose
Olfactory Cells
Chemicals in the air
Hearing
Ear
Hair cell receptors (inner ear)
Vibrations in the air particles
Taste
Tongue
Chemoreceptors on the taste buds
Chemicals in food and drink.
Touch
Skin
Pressure /Thermo receptors
Changes in temperature and pressure

11. Stimulus
Receptor
Sensory Neuron
Inter neuron
Motor neuron
Effector
Response

12. Types of Neuron
Sensory
Relay
Motor

13. Sensory Neurons

14. Sensory Neurons
These cells transmit an electrical impulse from a sensory receptor to a relay neuron (interneuron).
Long cells
Cell body is located away from the dendrites. Why?

15. Relay Neurons (interneurons)

16. Relay Neurons
Transmit a nerve impulse from a sensory neuron to a motor neuron in the reflex arc.
Found in the central nervous system (spinal cord / brain)

17. Motor Neurons

18. Motor Neurons Transmit electrical impulses from sensory/relay neurons.
Cause a change in an effector (e.g. muscle movement)

20. Neuron Structure
Complete the handout using your notes and the biology text books.

21. Synapses
Draw a synapse on your mini whiteboard

22. Did it look like this?

23. Neuromuscular Junctions

24. What do synapses do? A Synapse is where two nerve cells meet
There is a tiny gap between the pre synaptic membrane (synaptic knob) and the post synaptic membrane.
An electrical impulse is converted into a chemical messenger
(neurotransmitter) to pass over the synaptic gap, this is then converted into an electrical signal again.

25. Neurotransmitters
Acetylcholine
Noradrenaline
Serotonin
Dopamine
GABA

26. Acetylcholine (ACH) 1st Neurotransmitter to be discovered
Also present in the CNS and PNS (Neuromuscular junctions)
Most common NT
Vital in the transmission of nerve impulses

27. Noradrenaline Mostly involved in stimulating heart rate
Sympathetic Nervous System
Involved in the ‘’fight or flight’’ response.

28. Serotonin Found in the brain synapses Responsible for mood balance
Involved in mood, emotion, sleep and appetite.
High levels make us feel really good
Low levels linked to depression
Chocolate can increase the production of serotonin. (Tryptophan)
Drugs like ecstasy increase serotonin.

29. Dopamine Focus, movement, co-ordination, memory.
Parkinson's = loss of dopamine
Reward system in pleasurable behaviour) (when eating, having sex or carrying out addictive behaviour)
Disruption to the dopamine system is linked to psychosis (schizophrenia)

30. Complete the handout ‘Synapses’
Class / Home Work
Complete the handout ‘Synapses’

31. Lesson Objectives
To understand the basic structure of sensory, relay and motor neurons.
To be able to describe the function of each part of a neuron.
To revise the function of a synapse.