Explain the role of receptors, sensory neurons, relay neurons, motor neurons, synapses and effectors in the response of animals to stimuli.
Give two examples of how animal responses are affected by natural selection.
Outline the diversity of stimuli that can be detected by sensory neurons.
- More sensitive to light, function well in dim light
- Only one type of rod is found in the retina, absorbs all wavelength of visible light
- Impulses from a group of red cells pass to a single nerve fibre in the optic nerve.
Explain processing of visual stimuli.
Edge enhancement: Ganglion cell is stimulated when light falls on the receptive field. If it it falls on the centre (grey) & if it falls on the periphery (white).
Perception of sound.
Sound makes eardrum vibrate. Transmits vibration t middle ear. Ossicles transmit the vibrations to the oval window (reduces amplitude & increases force).
Distinguish between innate and learned behaviour.
- Inherited, Devloped by natural selection, increases chances of survival/reproduction, controlled by genes, develops independebtly of the enviromental context.
Outline Pavlov's experiments into classical conditioning of dogs.
Inheritance and learning of birdsongs
Decision making in the CNS
Explain how psychoactive drugs increase or decrease postsynaptic transmission.
Explain THC & Cocaine in terms of their actions at the synapses in the brain.
THC - (inhibitory) THC affects transmission where the postsynaptic neurone can release a signalling chemical that can bind to receptors in the membrane of the presynaptic neurone. It binds to cannabinoid receptors, blocks the release of the excitatory neurotransmitter.
Discuss the causes of addiction.
#1: Dopamine secretion - The first factor affecting whether the drug is addicting itself. Many addictive drugs feature a transmission that's stimulated at the synapse where there is dopamine as a neurotransmitter (Euphoria). Hard to stop, they're dependent on the feelings that dopamine promotes.
Medulla oblongata - Controls automatic and homeostatic activities, eg. swallowing, vomiting, breathing.
Cerebellum - Coordinates unconscious functions, eg. balance, movements.
Hypothalamus - Maintains homeostasis using both nervous & endocrine systems, produces hormones that are secreted by the posterior pituitary gland.
Identification of brain parts involved in specific functions.
Lesions - Accidents, strokes, tumour can damage different parts of the brain. These areas are called lesions and from the particular brain functions can be located. eg. lesions in the Broca's area led to the inability to speak.