Neurotransmitters, Hormones, and Nervous System Divisions

Vocabulary flashcards covering key excitatory and inhibitory neurotransmitters, endocrine hormones, neural firing principles, and functional divisions of the nervous system.

Dopamine

An excitatory neurotransmitter associated with reward and motivation.

Norepinephrine

An excitatory neurotransmitter associated with alertness and energy.

Glutamate

The most common excitatory neurotransmitter, involved in learning and memory.

Substance P

The pain messenger; an excitatory neurotransmitter released by sensory neurons in response to injury or stress.

GABA

An inhibitory neurotransmitter that calms the nervous system.

Serotonin

An inhibitory neurotransmitter that regulates mood and sleep.

Endorphins

Inhibitory neurotransmitters that act as natural painkillers.

Acetylcholine

A neurotransmitter that is attacked in myasthenia gravis, causing muscle weakness.

Hormones

Chemical messengers of the endocrine system that travel through the bloodstream and are slower but longer-lasting.

Adrenaline

A hormone that raises heart rate and energy during fight-or-flight responses.

Oxytocin

A hormone that regulates bonding and social behavior.

Leptin

A hormone that signals fullness, regulating hunger and fat storage.

Ghrelin

A hormone that stimulates hunger.

Melatonin

A hormone responsible for regulating sleep-wake cycles.

Action potential

A brief electrical charge traveling down the axon, triggered at the threshold, which follows the all-or-nothing principle.

Peripheral nervous system (PNS)

All nerves outside the brain and spinal cord, which splits into the somatic and autonomic systems.

Somatic nervous system

A division of the peripheral nervous system controlling voluntary movement of skeletal muscles.

Autonomic nervous system (ANS)

A division of the peripheral nervous system controlling involuntary actions like heartbeat, digestion, and breathing, which splits into the sympathetic and parasympathetic systems.

Sympathetic nervous system

The division of the autonomic nervous system responsible for fight or flight; raises heart rate, dilates pupils, and inhibits digestion.

Parasympathetic nervous system

The division of the autonomic nervous system responsible for rest and digest; lowers heart rate and stimulates digestion.

Reuptake inhibitor

A substance that prevents neurons from reabsorbing neurotransmitters, allowing them to remain in the synaptic cleft.

Endocannabinoid

A lipid-based neurotransmitter produced naturally by the body that helps regulate mood, pain sensation, appetite, and memory to maintain homeostasis.