Biopsych

Central nervous system

portion of the nervous system that consists of brain and spinal chord

Spinal chord

a collection of neurons and supportive tissue running from the base of the brain down to the centre of back

Reflex

an automatic response to a stimulus, requiring no conscious efforts

Peripheral nervous system

all nerves outside CNS, contains somatic and autonomic nervous systems,

Somatic nervous system

subdivision of peripheral NS that connects to sensory receptors and to skeletal muscles

Autonomic nervous system

subdivision of the PNS that regulates the internal organs and glands

Sympathetic NS

mobilizes bodily resources and increases the output of energy during emotion and stress

What does the adrenal gland secrete in the sympathetic NS

epinephrine and norepinephrine

Parasympathetic NS

operates during relaxed states and conserves energy

Biofeedback

monitoring devices track the bodily processes in question and deliver a signal whenever a person makes the desired response

Neurons/nerve cells

cells that conduct electrochemical signals

Arborization

branching, treelike formation

Cell assemblies

Collections of neurons working together in pathways

Glial cells

Support, nourish, and insulate neurons

Nerve

Bundle of axons and dendrites in the PNS

Dendrites

Branches receiving information from other neurons and transmitting it to the cell body.

Cell body (soma)

Keeps neuron alive; determines whether it will fire.

Axon

Extending fiber conducting impulses away from the cell body.

Myelin sheath

Fatty insulation around some axons; increases speed; develops in order: sensory, motor, prefrontal cortex.

Synapse

Junction where impulses pass from one neuron to another; includes axon terminal, synaptic cleft, receptor sites.

Action potential

Electrical impulse traveling down axon; unmyelinated = smooth flow; myelinated = jumps between nodes.

Synaptic end bulb

Contains synaptic vesicles that release neurotransmitters

Neurotransmitter

Chemical released by transmitting neuron that alters activity of receiving neuron.

Acetylcholine

Muscle activation, REM sleep (pons), memory, learning.

Dopamine

Reward, movement, learning, emotion; involved in schizophrenia and Parkinson’s.

Serotonin

Sleep, dreaming, mood, arousal, emotion.

GABA

Major inhibitory transmitter; regulates anxiety.

Receptor sites

Lock‑and‑key binding sites for neurotransmitters.

Excitatory signal

Increases probability of neuron firing.

Inhibitory signal

Decreases probability of neuron firing.

Neuromodulators

Chemicals that increase/decrease neurotransmitter action; drugs act on these systems (e.g., cocaine blocks dopamine reuptake).

Endorphins

Natural opiate‑like chemicals; pain reduction, pleasure, memory

Hormones

Chemical substances secreted by glands affecting distant organs.

Endocrine glands

Internal organs producing hormones released into bloodstream.

Melatonin

Pineal hormone regulating daily biological rhythms (sleep cycles, jet lag).

Brain stem

Automatic, ritualistic, territorial functions.

Limbic system

Emotional processing.

Cortex

Mammalian brain; higher cognition.

Lesion method (extirpation)

Removing/cutting brain parts to study effects on function.

Electrode method

Inserting electrodes to record or stimulate brain activity.

Microelectrodes

Measure activity of single neurons.

Surface electrodes

Taped to scalp to record brainwaves.

EEG

Records neural activity via scalp electrodes.

Evoked potentials

Brain activity patterns in response to specific events.

PET scan

Measures biochemical activity using radioactive glucose.

MRI

Uses magnetic fields and radio waves to image brain tissue.

Localization of function

Specific brain areas specialize in specific tasks.

Brain stem

Medulla, pons, midbrain.

Medulla

Automatic functions: breathing, heart rate.

Pons

Sleep, waking, dreaming; relays info from cerebrum to cerebellum.

Reticular Activating System (RAS)

Arouses cortex; screens incoming information.

Midbrain

Eye movement, auditory/motor relay; includes tectum (superior/inferior colliculi) and substantia nigra.

Cerebellum

Movement, balance, timing, simple learning.

Forebrain

Emotion, memory, thought.

Thalamus

Relays sensory messages to cortex; tracks visual/auditory info; movement execution.

Hypothalamus

Hunger, thirst, fear, sex; regulates ANS via pituitary.

Pituitary gland

Master endocrine gland controlling others.

Limbic system

Emotion, motivation, reward; Olds & Milner rat “pleasure center.”

Amygdala

Emotional arousal/regulation; evaluates sensory info; linked to anxiety/depression.

Hippocampus

Formation of new memories; HM case (anterograde amnesia).

Cerebrum

Largest brain region; sensory, motor, cognitive processing.

Cerebral hemispheres

Left and right halves of cerebrum.

Corpus callosum

Connects hemispheres.

Cerebral cortex

Thin layers of grey matter covering cerebrum; white matter = myelinated axons.

Occipital lobe

Visual cortex; lower back of brain.

Parietal lobe

Somatosensory processing; larger areas = more sensory function.

Temporal lobe

Memory, perception, emotion, language, auditory; damage

Frontal lobe

Motor cortex, planning, creativity, initiative.

Prefrontal cortex

Personality, decision‑making; Phineas Gage case.

Split brain

Two minds in one head due to severed corpus callosum.

Left hemisphere

Language (Broca + Wernicke), logic, right‑hand control, sees right visual field, speech production.

Right hemisphere

Spatial skills, facial recognition, music, art, nonverbal sounds; cognitive level inferior to chimp in some domains.

Plasticity

Young brains (under ~6–7) can reorganize functions; hemispherectomy cases show right hemisphere can take over left‑hemisphere functions.