Neurophysiology, Brain Anatomy, Glia, and Vertebrate Evolution Flashcards

Vocabulary practice flashcards generated from lecture notes covering neurophysiology, central nervous system anatomy, neuroglial cells, and vertebrate evolutionary lineages.

Resting Membrane Potential (RMP)

The potential difference in electrical charge across a neuron's plasma membrane at rest, which is equal to $-70\,mV$.

Sodium-Potassium Pump

A primary active transport membrane protein that maintains resting gradients by pumping $3\,Na^+$ out of the cell and $2\,K^+$ into the cell using ATP.

Action Potential Phases

The sequential electrical changes occurring during a nerve impulse: depolarization (driven by $Na^+$ influx), repolarization (driven by $K^+$ efflux), and hyperpolarization (temporary overshoot below resting potential).

Excitatory Postsynaptic Potential (EPSP)

A temporary local depolarization of the postsynaptic membrane potential caused by neurotransmitter binding.

Inhibitory Postsynaptic Potential (IPSP)

A temporary local hyperpolarization of the postsynaptic membrane potential caused by neurotransmitter binding.

Botulinum Toxin

A neurotoxin produced by Clostridium botulinum that inhibits synaptic transmission by decreasing the release of acetylcholine.

Tetrodotoxin

A toxin that selectively blocks voltage-gated $Na^+$ channels, preventing action potential generation and propagation.

Primary Brain Divisions

The four main functional regions into which the mature brain is categorized: cerebrum, diencephalon, cerebellum, and brainstem.

Lobes of the Cerebral Cortex

The four functional subdivisions of the cerebral gray matter: the frontal lobe, parietal lobe, temporal lobe, and occipital lobe.

Corpus Callosum

A prominent tract of white matter that physically connects the left and right cerebral hemispheres, enabling interhemispheric communication.

Thalamus

A major diencephalic center that functions as a relay station filtering sensory input destined for the cerebral cortex and regulating arousal and alertness.

Hypothalamus

A region of the diencephalon responsible for motivational behaviors like hunger and thirst, as well as maintaining body homeostasis via the endocrine system.

Pineal Gland

An epithalamic endocrine structure that synthesizes and secretes melatonin from tryptophan to regulate circadian sleep-wake cycles.

Cerebellum

The hindbrain division that coordinates, smooths, and corrects voluntary motor movements, maintaining balance and hand-eye coordination.

Brainstem Divisions

The brain stem regions comprising the midbrain (visual/auditory reflexes), pons (breathing, sleep/wake cycles), and medulla oblongata (cardiovascular/respiratory centers).

Cerebrospinal Fluid (CSF)

A protective fluid produced by ependymal cells in the choroid plexuses that fills ventricles and the subarachnoid space to nourish and cushion the CNS.

Blood-Brain Barrier

A selective barrier created by astrocytes and tight junctions between endothelial cells of capillary walls that limits solute movement from blood into brain extracellular fluid.

Reflex Arc

A neural circuit composed of sensory input detection by the PNS, central integration in the spinal cord or brainstem, and efferent motor output to target effectors.

Dendrites

Multiple thin, branched cellular extensions of a neuron that receive incoming electrical or chemical signals from other cells.

Axon Hillock

The specialized region connecting the neuron soma to the axon where incoming post-synaptic potentials summate to trigger an action potential.

CNS Neuroglia

The four types of supporting glial cells located in the central nervous system: astrocytes, oligodendrocytes, microglia, and ependymal cells.

Oligodendrocytes

Glial cells in the central nervous system that wrap around axons to form insulating myelin sheaths.

Schwann Cells

Neuroglial cells in the peripheral nervous system responsible for forming the myelin sheath around individual PNS axons.

Saltatory Conduction

The rapid mode of action potential propagation in myelinated axons, where depolarization jumps between unmyelinated Nodes of Ranvier.

Multiple Sclerosis

An autoimmune neurodegenerative disorder characterized by destruction of myelin sheaths in the CNS, resulting in impaired action potential conduction.

Gray Matter vs. White Matter

Unmyelinated regions containing neuron cell bodies, dendrites, and synapses appear gray, whereas myelinated axon tracts appear white.

Lancelets

Invertebrate chordates of the subphylum Cephalochordata that are bladelike, lack a cranium, and live buried in aquatic substrate as filter feeders.

Tunicates

Invertebrate chordates of the subphylum Urochordata (sea squirts) possessing motile larvae with chordate hallmarks and sessile, filter-feeding adults.

Neural Crest

A band of embryonic cells originating along the neural tube in craniates/vertebrates that gives rise to unique developmental structures.

Chondrichthyes

A class of jawed vertebrates consisting of cartilaginous fish, such as sharks, stingrays, and chimaeras.

Ray-Finned Fish

Bony aquatic vertebrates of Osteichthyes possessing fins supported by webbed bony spines and a swim bladder for buoyancy regulation.

Lobe-Finned Fish

Osteichthyan bony fish (including coelacanths and lungfish) featuring rod-shaped bone structures in their pectoral fins.

Amniotic Egg

A terrestrially adapted egg enclosed by specialized extraembryonic membranes (amnion, chorion, allantois, yolk sac) that protect and nourish the developing embryo.

Monotremata

An order of egg-laying amniote mammals (including platypuses and echidnas) that lack nipples.

Marsupialia

A clade of mammals whose offspring are born at an extremely early developmental stage and complete development attached to nipples inside a maternal pouch.