UNIT 1: Biological Bases of Behavior

Neuron Structure:

• Dendrites: Receive messages.

• Cell Body (Soma): Processes signal.

• Axon: Sends impulse.

• Myelin Sheath: Speeds transmission.

• Axon Terminal: Releases neurotransmitters.

Neural Communication:

• Resting Potential: Negative inside.

• Action Potential: Fires when threshold reached.

• Refractory Period: Resets.

• Reuptake: Reabsorbing unused neurotransmitters.

Neurotransmitters:

• Acetylcholine (ACh): Muscle movement, memory.

• Dopamine: Reward, emotion, motor.

• Serotonin: Mood, hunger, sleep.

• Norepinephrine: Arousal, alertness.

• GABA: Main inhibitory.

• Glutamate: Main excitatory.

• Endorphins: Pain relief.

Nervous System:

• Central NS (CNS): Brain + spinal cord.

• Peripheral NS:

  • Somatic: Voluntary.

  • Autonomic:

    • Sympathetic: Fight or flight.

    • Parasympathetic: Rest and digest.

Brain Structures:

• Brainstem: Basic functions.

• Medulla: Heartbeat, breathing.

• Pons: Sleep, arousal.

• Thalamus: Sensory switchboard.

• Cerebellum: Balance, coordination.

• Limbic System: Emotions, memory.

  • Amygdala: Fear, anger.

  • Hippocampus: Memory formation.

  • Hypothalamus: Drives (hunger, sex).

• Cerebral Cortex:

  • Frontal Lobe: Planning, judgment.

  • Parietal Lobe: Sensory.

  • Temporal Lobe: Auditory.

  • Occipital Lobe: Vision.

Endocrine System:

• Hormones: Chemical messengers.

• Pituitary Gland: Master gland.

• Adrenal Gland: Fight or flight.

• Thyroid: Metabolism.

Genetics:

• Genotype: Genetic makeup.

• Phenotype: Observable traits.

• Twin Studies: Nature vs nurture.

Other Key Concepts:

• Electrochemical process: Electrical impulse + neurotransmitters.

• Neuroplasticity: Brain's ability to rewire.

• Lateralization: Left = language, Right = spatial.

• Split-brain studies: Corpus callosum cut; left/right hemisphere function.