Unit 1A: the nervous system

Central nervous system

Brain and spinal cord.

Peripheral nervous system

Part of the nervous system outside the central nervous system.

Autonomic nervous system

Controls involuntary bodily functions.

Sympathetic nervous system

Part of the autonomic nervous system; prepares the body for 'fight or flight'.

Parasympathetic nervous system

Part of the autonomic nervous system; promotes 'rest and digest' functions.

Somatic nervous system

Controls voluntary movements of skeletal muscles.

Neurons

Nerve cells that transmit information through electrical and chemical signals.

Glial cells

Supportive cells in the nervous system.

Reflex arc

The simplest type of neuron pathway, responsible for reflex actions.

Sensory neurons

Carry signals from sensory receptors to the central nervous system.

Motor neurons

Transmit signals to muscles from the central nervous system.

Interneurons

Connectors between sensory and motor neurons within the central nervous system.

Neural transmission

The process of transmitting signals along neurons.

Action potential

A rapid electrical charge that travels down an axon.

All-or-nothing principle

The principle that a neuron either fires completely or does not fire at all.

Depolarization

The process during the action potential when the inside of the cell becomes more positive.

Refractory period

The time following an action potential during which a neuron cannot fire again.

Resting potential

The electrical charge of a neuron when it is not firing.

Reuptake

The process of neurotransmitter reabsorption by the sending neuron.

Threshold

The level of stimulation required to trigger an action potential.

Multiple sclerosis

A disease that affects the central nervous system by damaging the myelin sheath.

Myasthenia gravis

An autoimmune disorder affecting communication between nerves and muscles.

Excitatory neurotransmitters

Chemical messengers that increase the likelihood of firing an action potential.

Inhibitory neurotransmitters

Chemical messengers that decrease the likelihood of firing an action potential.

Dopamine

A neurotransmitter associated with pleasure and reward.

Serotonin

A neurotransmitter involved in mood regulation.

Norepinephrine

A neurotransmitter that affects attention and responding actions.

Glutamate

The main excitatory neurotransmitter in the brain.

GABA

The main inhibitory neurotransmitter in the brain.

Endorphins

Neurotransmitters that act to relieve pain and promote pleasure.

Substance P

A neurotransmitter involved in the transmission of pain.

Acetylcholine

A neurotransmitter that plays a role in learning and memory.

Hormones

Chemical messengers produced in glands that regulate various bodily functions.

Adrenaline

A hormone released in response to stress; prepares the body for 'fight or flight'.

Leptin

A hormone involved in regulating energy balance and hunger.

Ghrelin

A hormone that stimulates appetite.

Melatonin

A hormone that regulates sleep-wake cycles.

Oxytocin

A hormone that plays a role in social bonding and reproduction.

Agonists

Substances that enhance or mimic the action of neurotransmitters.

Antagonists

Substances that block or inhibit the action of neurotransmitters.

Brain stem

The part of the brain that connects to the spinal cord; controls basic life functions.

Medulla

Part of the brain stem that controls breathing and heart rate.

Reticular activating system

A network of neurons that regulates arousal and sleep-wake transitions.

Reward center

Brain structures that are activated by rewarding stimuli.

Cerebellum

A brain structure that coordinates movement and maintains balance.

Cerebral cortex

The outer layer of the brain involved in complex functions like thought and action.

Limbic system

A set of brain structures involved in emotion, memory, and motivation.

Thalamus

The brain's relay station that directs sensory messages to the cortex.

Hypothalamus

Regulates basic bodily functions such as temperature, thirst, and hunger.

Pituitary gland

The 'master gland' that controls other endocrine glands.

Hippocampus

A brain structure involved in memory formation.

Amygdala

A brain structure involved in emotion processing.

Corpus callosum

A bundle of neural fibers that connects the two brain hemispheres.

Occipital lobes

Brain lobes that process visual information.

Temporal lobes

Brain lobes involved in processing auditory information and memory.

Parietal lobes

Brain lobes that process sensory information from the body.

Association areas

Regions of the cerebral cortex involved in higher mental functions.

Somatosensory cortex

The area of the parietal lobe that processes sensory input from the body.

Frontal lobes

Brain lobes involved in reasoning, planning, and movement.

Linguistic processing

The brain's ability to comprehend and produce language.

Higher-order thinking

Complex mental processes such as reasoning and problem-solving.

Executive functioning

Mental skills that include working memory, flexible thinking, and self-control.

Prefrontal cortex

Part of the frontal lobes involved in complex behaviors and decision making.

Motor cortex

The area of the frontal lobe that controls voluntary muscle movement.

Split brain research

Studies of patients with severed corpus callosum to understand hemispheric functions.

Hemispheric specialization

The distinct functions that each hemisphere of the brain performs.

Broca’s area

A language area in the frontal lobe involved in speech production.

Wernicke’s area

A language area in the temporal lobe involved in language comprehension.

Aphasia

Language impairment due to brain damage, affecting production (Broca's) or comprehension (Wernicke's).

Contralateral hemispheric organization

The brain's organizational structure where one hemisphere controls the opposite side of the body.

Plasticity

The brain's ability to reorganize and adapt throughout life.

EEG

A test that detects electrical activity in the brain.

fMRI

A brain imaging technique that measures brain activity by detecting changes in blood flow.

Lesioning

The intentional destruction of brain tissue to study its effects.