Biology in Psychology Notes

BIOLOGY IN PSYCHOLOGY

  • The study of biology provides insights into psychological processes, particularly through the examination of the brain and neurons.

NEURONS

  • Neurons are basic units of the nervous system, transmitting signals through electrical impulses and neurotransmitters.

Structure of Neurons

  • Major components:

    • Dendrites: Receive signals

    • Cell Body: Contains nucleus and organelles

    • Axon: Transmits impulses to other neurons

    • Synapses: Facilitate communication between neurons

NEURONAL SIGNALLING

  • Neurons communicate via electrical currents and neurotransmitters.

  • Signal direction: Dendrite → Cell Body → Axon.

  • When signal is sent: Presynaptic cell (sending), Postsynaptic cell (receiving).

ACTION POTENTIAL

  • Resting potential: −70mV-70 mV

  • Steps in action potential generation:

    1. Threshold is reached

    2. Sodium channels open; sodium rushes in (depolarization)

    3. Potassium channels open; potassium leaves (repolarization)

    4. Cell returns to resting state (hyperpolarization).

SYNAPTIC TRANSMISSION

  • Sequence of events:

    1. Action potential reaches axon terminal

    2. Calcium ion channels open, allowing Ca2+Ca^{2+} influx

    3. Synaptic vesicles release neurotransmitters into the synaptic gap.

  • Neurotransmitters bind to receptors on the postsynaptic neuron, influencing its activity (excitatory or inhibitory).

COMMON NEUROTRANSMITTERS

  • Acetylcholine: Muscle control, cognition

  • Glutamate: Learning, memory

  • GABA: Inhibition, anxiety regulation

  • Dopamine: Pleasure, movement

  • Serotonin: Mood, sleep, appetite

  • Norepinephrine: Arousal, alertness

  • Endorphins: Pain management.

BRAINSTEM FUNCTIONS

  • Connects spinal cord to brain; responsibilities include respiration and motor/sensory information processing.

  • Components include Medulla, Pons, and Midbrain.

FOREBRAIN STRUCTURE

  • Includes cerebral cortex and subcortical structures (thalamus, hypothalamus, amygdala, hippocampus) essential for various cognitive and emotional functions.