1. Nicotine – stimulates receptors that usually respond to acetylcholine, causing adrenaline to increase in the sympathetic nervous system, which elevates heart rate, blood pressure, and blood glucose levels. Cocaine – blocks the re- uptake of dopamine, causing it to accumulate in the synapse, which results in a “good” feeling. Amphetamines (Ecstacy/methylenedioxymethamphetamine) – release noradrenaline and dopamine into synapses and inhibit re-uptake, which leads to increase in concentration and alertness. Excitatory drugs excite EPSPs or inhibit IPSPs

2. Benzodiazepines (Valium) – these drugs hyperpolarize the post- synaptic membrane, which cause a “fading out” of impulses Alcohol – keeps GABA receptors open longer so further hyperpolarization of post-synaptic membrane occurs THC (tetrahydrocannabinol) – binds to endorphin receptors Inhibitory drugs inhibit EPSPs or promote IPSPs

3. THE EYE

4. MOVEMENT OF LIGHT THROUGH THE EYE Light passes through the nerve cells and reaches the rods and cones. Unabsorbed light strikes a pigment layer so it’s not reflected internally in the eye. The light is refracted (bent) by the cornea and the lens. Once it passes through the vitreous humour, it then reaches the retina. Rods and cones of retina contain a photosensitive pigment called rhodopsin, that is catabolized by light, causing one or more impulses to be sent to the brain – they reform once light is absent.

5. CONTRALATERAL PROCESSING This means that objects in the right side of the visual field are processed by left side of the brain and the objects in the left side of the visual field are processed by the right side of the brain

6. Compare rod and cone cells.

7. Label a diagram of the ear.

8. Explain how sound is perceived by the ear, including the roles of the eardrum, bones of the middle ear, oval and round windows, and the hair cells of the cochlea.