Neuroscience: Cellular Anatomy, Neurophysiology, and Neuropharmacology

Vocabulary practice flashcards covering cell types, neuroanatomy, electrical signaling, synaptic transmission, and neuropharmacology from Chapters 2, 3, and 4.

Input zone

The functional zone of a neuron, comprised primarily of dendrites, where the cell collects and processes information from other cells or the environment.

Integration zone

The functional zone of a neuron, centered at the cell body (or soma), where the decision to produce a neural signal is made and information is integrated.

Conduction zone

The functional zone of a neuron, consisting of a single axon (or nerve fiber), where information is electrically transmitted over great distances away from the cell body.

Output zone

The functional zone at the end of a neuron, made up of axon terminals, where the cell transfers information to other cells.

Multipolar neurons

The most common structural type of neuron, possessing a single axon and many dendrites.

Motor neurons

Large neurons with long axons that transmit signals from the central nervous system to stimulate muscles and glands.

Axon hillock

A cone-shaped region of the cell body that gives rise to the axon and converts incoming input into electrical signals.

Oligodendrocytes

Glial cells that form the myelin sheaths around axons within the brain and spinal cord (central nervous system).

Schwann cells

Glial cells that provide fatty myelin insulation to neurons located outside the brain and spinal cord (peripheral nervous system).

Astrocytes

Star-shaped glial cells with processes that stretch around neurons and blood vessels, assisting in secreting chemicals and forming the outer membrane around the brain.

Microglial cells

Tiny, mobile glial cells that function to engulf and destroy debris from injured or dead cells.

Somatic nervous system

The main anatomical division of the peripheral nervous system consisting of cranial and spinal nerves that interconnect the brain and the major muscles and sensory systems.

Autonomic nervous system

The main neural system responsible for controlling internal organs (viscera), divided into the sympathetic and parasympathetic divisions.

Cranial Nerves

Twelve pairs of peripheral nerves that innervate the head, neck, and visceral organs directly from the brain, classified into sensory, motor, or mixed functions.

Sympathetic nervous system

A division of the autonomic nervous system whose axons innervate sympathetic ganglia to prepare the body for action in a 'fight-or-flight' response.

Parasympathetic nervous system

A division of the autonomic nervous system with ganglia located near target organs that helps the body relax and recuperate.

Lobes of the Cerebral Cortex

The four main functional anatomical regions of each cerebral hemisphere: Frontal, Parietal, Occipital, and Temporal lobes.

Corpus callosum

A dense bundle of axons that connects the two cerebral hemispheres of the brain.

Basal ganglia

A group of forebrain nuclei important for motor control, consisting mainly of the caudate nucleus, putamen, and globus pallidus.

Limbic system

An interconnected network of brain structures—including the amygdala, hippocampus, fornix, cingulate gyrus, and olfactory bulb—that is crucial for emotion, learning, and memory.

Meninges

The three protective membranes surrounding the brain and spinal cord, consisting of the dura mater, arachnoid membrane, and pia mater.

Ventricular system

A series of fluid-filled internal chambers containing cerebrospinal fluid (CSF) produced by the choroid plexus.

Resting potential

The electrical charge difference across the membrane of an unstimulated neuron, typically measuring between $-50$ and $-80\,\text{mV}$.

Sodium-potassium pump

A membrane protein mechanism that actively expels three sodium ions ($\text{Na}^+$) out of the cell for every two potassium ions ($\text{K}^+$) pumped inside.

Hyperpolarization

An increase in membrane potential where the interior of the cell becomes more negative and moves farther away from zero.

Depolarization

A decrease in membrane potential where the interior of the cell becomes less negative and moves closer to zero.

Absolute refractory phase

A brief period following an action potential during which voltage-gated sodium channels are unresponsive and no subsequent action potential can be triggered.

Relative refractory phase

A period following the absolute refractory phase during which an action potential can only be triggered by an abnormally strong stimulus.

Saltatory conduction

The rapid form of action potential propagation along a myelinated axon, where the electrical signal jumps from one node of Ranvier to the next.

Excitatory postsynaptic potential (EPSP)

A small, local depolarizing potential in the postsynaptic membrane caused by the opening of $\text{Na}^+$ channels, bringing the cell closer to threshold, increases the likelihood of a neuron firing an action potential.

Inhibitory postsynaptic potential (IPSP)

A hyperpolarizing local potential caused by the influx of chloride ions ($\text{Cl}^-$), pushing the postsynaptic neuron further away from threshold.

Spatial summation

The integration of multiple postsynaptic potentials originating from different physical locations across the cell body at the axon hillock.

Temporal summation

The integration of postsynaptic potentials arriving at the axon hillock at different times; potentials arriving closer together exert a greater effect.

Synaptic Connection Types

The structural classification of chemical synapses based on contact sites: Axo-dendritic, Axo-somatic, Axo-axonic, and Dendro-dendritic.

Ionotropic receptors

Fast-acting receptor proteins that open or close an integrated ion channel directly when bound by a matching neurotransmitter molecule.

Metabotropic receptors

Receptor proteins that do not contain an ion channel directly, but instead alter chemical reactions inside the cell using a G protein and second messenger system.

Dopaminergic Pathways

Major dopamine projection systems in the brain including the Mesostriatal pathway (substantia nigra to basal ganglia) and the Mesolimbocortical pathway (VTA to nucleus accumbens and cortex).

Retrograde transmitter

A neurotransmitter, such as a gas (nitric oxide or carbon monoxide), that is produced in the postsynaptic cell and diffuses backward across the synapse to affect the presynaptic neuron.

Binding affinity

The degree of chemical attraction between a ligand (such as a drug or neurotransmitter) and its specific receptor.

Efficacy (intrinsic activity)

The ability of a bound ligand to activate its receptor and produce a functional response in the target cell.

Functional tolerance

A form of drug tolerance where target tissues alter their sensitivity by down-regulating receptors in response to agonists or up-regulating receptors in response to antagonists.

Antipsychotics (neuroleptics)

A class of psychoactive drugs used to treat schizophrenia by blocking dopamine $\text{D}_2$ receptors.

Selective serotonin reuptake inhibitors (SSRIs)

Antidepressant drugs, such as Prozac or Celexa, that act specifically by blocking the reuptake of serotonin at presynaptic terminals.

Benzodiazepines

Anxiolytic medications that bind as agonists to $\text{GABA}_A$ receptors, enhancing GABA's inhibitory effects in the nervous system.

Positive reward model

A model of drug abuse asserting that addiction is driven by behaviors controlled by positive reinforcement, mediated by dopamine release in the nucleus accumbens.

sensory neurons

have various shapes that best respond to specific types of stimuli, such as light, sound, or touch, and transmit sensory information to the central nervous system.

interneurons

have tiny axons and analyze input from one set of neurons and communicate with others

bipolar neurons

one axon, one dendrite

unipolar neurons

a single extension branches in two directions, forming an output and input zone

presynaptic membrane

on the axon terminal of the presynaptic neuron

postsynaptic membrane

on the dendrite or cell body of the postsynaptic neuron

synaptic cleft

the gap that seperates the membranes

synaptic vesicles

small spheres in presynaptic axon terminals that contain a neurotransmitter, a specialized chemical

neurotransmitter receptors

in the postsynaptic membrane are specialized proteins that react to neurotransmitter molecules.

neural plasticity

refers to the continual remodeling of neuronal connections

axon collateral

a branch of an axon that also ends in terminals

axonal transport

the bidirectional movement of materials within an axon

glial cells

assist neuronal activity by providing raw materials, chemical signals, and structure and also participate in information processing.

nodes of ranvier

gaps between sections of myelin where the axon is exposed

central nervous system

consists of the brain and spinal cord

peripheral nervous system

includes all other parts of the nervous system outside the brain and spinal cord

motor nerves

transmit information from the spinal cord and brain to muscles and glands

sensory nerves

convey info from the body to the CNS

spinal nerves

connect to the spinal cord, each one consists of a group of motor fibers that project from the spinal cord and a group of sensory fibers that enter the spinal cord

autonomic nervous system

the main system for controlling the body’s organs

frontal lobe

the largest region of the human brain, located directly behind the forehead, and it manages higher-level thinking, voluntary movement, and emotional control

parietal lobe

a major region of the cerebral cortex located near the top and back of the head that processes sensory input and spatial awareness

occipital lobe

the smallest of the four main lobes in the human brain's cerebral cortex and serves as the primary visual processing center

temporal lobe

one of the four main regions of the cerebral cortex, located behind the temples and ears on both sides of the brain, responsible for processing sound, understanding language, and forming long-term memories, has the sylvian fissure (boundary of the lobe)

central sulcus

divides the frontal lobe from the parietal lobe

gray tissue

brain tissue that cointains more cell bodies and dendrites, which lack myelin

white matter

brain tissue that consists mostly of axons with white myelin sheaths

neural tube

develops three subdivisions: the forebrain (develops into the telencephalon and diencephalon), midbrain, and hindbrain (develops into the cerebellum, pons and medulla)

Pyramidal cells

are the most prominent neurons in cerebral cortex, layer III or V

thalamus

cluster of nuclei that relay sensory information

hypothalamus

contains nuclei with many functions, also contains the pituitary, keeps the body in a balanced state called homeostasis

computerized axial tomography (CAT)

a measure of X-ray absorption at several positions around the head

magnetic resonance imaging (MRI)

higher resolution images, fewer damaging effects than CT

Functional MRI

detects small changes in brain metabolism, such as oxygen use, in actie brain areas

Positron emission tomography (PET)

gives images of brain activity, emissions of radioactive chemicals in the bloodstream indicate their destination, identifies which brain regions contribute to specific functions

transcranial magnetic stimulation (TMS)

briefly stimulates discrete cortical regions. Scientists can then record observed changes in behavior.

Magnetoencephalography (MEG)

measures the tiny magnetic fields given off by active neurons during cognitive processing.