Biological Bases of Behavior

Central Nervous System: Brain, spinal cord
Peripheral Nervous System: Voluntary (Somatic), involuntary (Autonomic)
Parasympathetic: Rest and digest
Sympathetic: Fight or flight

Neuron Components:

• Soma: Cell body

• Dendrites: Receive signals

• Receptor sites: Bind neurotransmitters

• Axon: Transmit signals

• Myelin sheath: Insulates axon

• Axon terminal branches/buttons: Release neurotransmitters

• Synaptic vesicles: Store neurotransmitters

• Synapse: Gap between neurons

Cells/Neurons:

• Glial cells: Support neurons

• Sensory neuron: Receive stimuli

• Motor neuron: Initiate movement

• Brain plasticity: Neural adaptability

Neurotransmitters:

• Dopamine: Reward, movement

• Serotonin: Mood, sleep

• Norepinephrine: Alertness

• Glutamate: Excitatory

• GABA: Inhibitory

• Endorphins: Pain relief

• Substance P: Pain signals

• Acetylcholine: Muscle action, memory

• Ghrelin: Hunger

• Leptin: Satiety

• Melatonin: Sleep

• Oxytocin: Bonding

• Adrenaline: Stress response

Brain Regions:

• Brain stem: Survival functions

• Medulla: Breathing, heart rate

• Reticular Activating System: Arousal

• Cerebellum: Coordination

Cerebral Cortex:

• Hemispheres: Left/right brain

• Lobes: Frontal, Parietal, Temporal, Occipital

• Corpus callosum: Connects hemispheres

Lobe Functions:

• Occipital: Vision

• Temporal: Hearing, memory

• Parietal: Sensory processing

• Frontal: Decision-making

Key Areas:

• Wernicke’s: Language comprehension

• Broca’s: Speech production

• Somatosensory: Touch

• Prefrontal: Planning

• Motor cortex: Movement

Limbic System:

• Thalamus: Sensory relay

• Hypothalamus: Homeostasis

• Hippocampus: Memory

• Amygdala: Emotion

• Pituitary gland: Hormones

Consciousness & Sleep:

• Circadian rhythms: 24-hour cycles

• EEG Sleep Patterns:

  • Beta: Awake

  • Alpha: Relaxed

  • Theta: Light sleep

  • Delta: Deep sleep

• Sleep stages:

  • NREM 1: Light sleep

  • NREM 2: Spindles/K-complexes

  • NREM 3-4: Deep sleep

  • REM: Dreams

• Dream theories:

  • Activation-synthesis: Random brain activity

  • Information-processing: Memory consolidation

• Sleep theories: Restorative, evolutionary

• Disorders: Insomnia, narcolepsy, apnea, sleepwalking

Sensation:

• Absolute threshold: Minimum stimulus

• Just-noticeable difference: Detect change

• Weber’s law: Proportionate detection

Vision:

• Retina: Image processing

• Rods: Low light

• Cones: Color

• Fovea: Sharp vision

• Lens: Focuses light

• Optic nerve: Sends visual info

• Blindspot: No receptors

• Bipolar/ganglion cells: Signal transmission

Color Vision Theories:

• Trichromatic: RGB cones

• Opponent-Process: Opposing colors

Hearing:

• Wavelength: Pitch

• Amplitude: Volume

• Eardrum/ossicles: Vibrate with sound

• Oval window: Transfers vibrations

• Cochlea: Sound processing

• Basilar membrane: Sound frequency

• Auditory cilia: Detect sound

• Conduction deafness: Outer/middle ear

• Sensorineural deafness: Inner ear

Smell & Taste:

• Olfactory bulb: Smell relay

• Gustatory: Taste processing

• 5 Tastes: Sweet, salty, sour, bitter, umami

Touch:

• Gate control: Pain modulation

• Phantom limb: Sensation in missing limb