chapter 2

Vocabulary-style flashcards covering key concepts from neuroscience notes: neurons, nervous systems, brain structures, plasticity, and endocrine interactions.

Interneurons

Neurons that carry messages between other neurons within the central nervous system.

Neuron

The basic cell of the nervous system that transmits information via electrical impulses.

Myelin sheath

A fatty coating around some axons that speeds the transmission of neural impulses.

Action potential

An electrical impulse that travels along the neuron, enabling the neuron to fire.

Stimulus threshold

The minimum stimulus required to trigger an action potential.

Resting potential

The neuron's baseline electrical charge when it is not firing.

Refractory period

A brief period after an action potential when the neuron cannot fire again.

Presynaptic neuron

The neuron that sends a signal across the synapse.

Postsynaptic neuron

The neuron that receives a signal across the synapse.

Synapse

The junction between two neurons across which neurotransmitters are released.

Neurotransmitter

Chemical messengers released by neurons to transmit signals across the synapse.

Acetylcholine (ACh)

A neurotransmitter involved in muscle activation and various brain functions.

Glutamate

The major excitatory neurotransmitter in the brain that increases neural activity.

Dopamine

A neurotransmitter involved in reward/motivation; excess is linked to schizophrenia.

Norepinephrine (noradrenaline)

A neurotransmitter involved in arousal and the fight-or-flight response.

Agonist

A substance that activates receptor sites, mimicking a neurotransmitter.

Antagonist

A substance that blocks receptor sites and prevents neurotransmitter binding.

Central nervous system (CNS)

The brain and spinal cord; the main processing center.

Peripheral nervous system (PNS)

All nerves outside the CNS that connect the CNS to the body.

Somatic nervous system

Subdivision of the PNS that controls voluntary movements and sensory input.

Autonomic nervous system

Subdivision of the PNS that regulates involuntary functions; includes sympathetic and parasympathetic.

Sympathetic nervous system

Part of the autonomic system that prepares the body for fight-or-flight.

Parasympathetic nervous system

Part of the autonomic system that conserves energy and facilitates rest/digestion.

Hypothalamus

Brain region linking the nervous and endocrine systems; regulates hormonal release.

Pituitary gland

Small gland beneath the brain; releases hormones that regulate growth and other glands.

Adrenal glands

Glands that release adrenaline and other hormones in response to stress.

Endocrine system

Glands that secrete hormones to regulate body processes.

Hormone

Chemical messengers released by glands that travel through the bloodstream.

Neuroplasticity

The brain's ability to change its function or structure in response to experience.

Functional plasticity

Brain can shift functions to different areas after injury.

Structural plasticity

Physical changes in brain structure due to learning and experience.

Neurogenesis

Growth of new neurons; occurs in the olfactory bulb and in some adult areas.

Olfactory bulb

Brain structure involved in smell; a site of adult neurogenesis.

Brainstem

Lower brain area that includes the medulla, pons, and cerebellum; regulates basic life functions.

Medulla

Brainstem region that controls breathing, heart rate, and other autonomic functions.

Pons

Brainstem structure involved in relaying signals and contributing to sleep and arousal.

Cerebellum

Brain region coordinating movement, balance, and motor precision.

Cerebral cortex

Outer layer of the brain responsible for higher-order thinking.

Gray matter

Brain tissue consisting mainly of neuron cell bodies; appears gray.

White matter

Brain tissue composed mainly of myelinated axons; appears white.

Hindbrain

Lower part of the brain including the medulla, pons, and cerebellum; controls basic functions.

Spinal reflexes

Involuntary, automatic responses mediated by the spinal cord.

Dendrite

Branching extension of a neuron that receives signals.

Axon

Long projection that transmits electrical impulses away from the cell body.

Axon terminal

End of the axon where neurotransmitters are released into the synapse.

Synaptic cleft

The narrow gap across which neurotransmitters cross to reach the postsynaptic neuron.

Receptor site

Location on the dendrite where neurotransmitters bind to elicit a response.

Endocrine-pituitary axis

The regulatory relationship between the hypothalamus and the pituitary gland controlling hormone release.