Biological Bases of Behaviour: Nervous System, Brain and Endocrine Influences
Nervous system organisation
The nervous system divides into central (brain and spinal cord) and peripheral. Peripheral divides into somatic (voluntary) and autonomic, and autonomic into sympathetic (arousal, fight-or-flight) and parasympathetic (rest, digestion). Know the neuron: dendrites receive, soma integrates, axon conducts, myelin speeds conduction, terminal buttons release neurotransmitters across the synapse. Key transmitters include acetylcholine (muscle and memory), dopamine (reward and movement), serotonin (mood), norepinephrine (alertness), GABA (inhibition), and endorphins (pain relief).
Brain structures and function
Know the hindbrain (medulla, pons, cerebellum), midbrain, and forebrain. The limbic system includes the amygdala (emotion, fear), hippocampus (memory consolidation), and hypothalamus (homeostasis, endocrine control). The cerebral cortex has four lobes: frontal (planning, motor, Broca's area), parietal (somatosensory), temporal (hearing, Wernicke's area), occipital (vision). Lateralisation and split-brain findings are commonly examined.
Endocrine influences
Glands release hormones into blood: pituitary (master gland), thyroid (metabolism), adrenal (cortisol, adrenaline), pancreas (insulin), gonads (sex hormones). The hypothalamic-pituitary-adrenal axis underlies stress response.
Traps and rule of thumb
Questions often swap Broca and Wernicke, or attribute memory to the amygdala. A useful rule: damage to Broca impairs speech production; Wernicke impairs comprehension. Sympathetic activation raises heart rate and dilates pupils; parasympathetic reverses it. Do not confuse neurotransmitters (synaptic, fast) with hormones (blood-borne, slower, longer-lasting).