Untitled Flashcards Set

3rd Ventricle

Thin, vertical pocket of fluid inferior and medial to the lateral ventricles.

4th Ventricle

Tiny, diamond-shaped space where the cerebellum attaches to the back of the brainstem.

Absolute Refractory Period

Time during which the local area of the membrane has surpassed the threshold potential and will not respond to any stimulus.

Action Potential

Nerve impulses; membrane potential fluctuation of an actively conducting axon.

Active Transport

Movement of a substance of a molecule that reacts with another molecule.

All-or-Nothing

Principle that a process, once it begins, will occur at its maximum or not at all.

Arachnoid Mater

Weblike middle layer of the meninges.

Arachnoid Villi

Finger-like projections of the arachnoid mater into the brains venous sinuses, absorb blood.

Arbor Vitae

Internal white matter of the cerebellum.

Ascending Tract

Spinal cord tract that conducts impulses up the cord to the brain.

Association Area

Region of the cerebral cortex that integrates information from different sensory modalities.

Astrocyte

Star shaped neuroglial cell.

Autonomic Division

Part of the peripheral nervous system controlling involuntary bodily functions.

Axon

Single process in a neuron extending from the axon hillock, transmitting impulses away from the cell body.

Axon Hillock

Portion of the cell body from which the axon extends.

Basal Nuclei

Islands of gray matter deep inside the white matter of each hemisphere.

Bipolar Neuron

Neuron with only one dendrite and one axon.

Brainstem

Part of brain containing the midbrain, pons, and medulla oblongata.

Broca’s Area

Region of brain plays a crucial role in speech production and language processing.

Cerebellum

Part of the human brain; plays an essential role in the production of typical movements.

Cerebrospinal Fluid

Plasma-like fluid filling the subarachnoid space in the brain and spinal cord.

Cerebrum

Largest and uppermost part of the human brain.

Cholinesterase

An enzyme in the nervous system that breaks down acetylcholine.

Dendrite

Branching nerve cell process that receives input from other neurons.

Depolarization

Electrical activity that triggers contraction of heart muscles.

Descending Tract

Bundle of axons in the spinal cord conducting impulses down from the brain.

Diencephalon

Parts of the brain between cerebral hemispheres and the midbrain.

Ependymal Cell

Cell type lining the ventricles of the brain.

EPSP

Excitatory postsynaptic potential; temporary depolarization of the postsynaptic membrane after stimulation.

Frontal Lobe

A major subdivision of the cerebral cortex at the anterior.

Graded Potential

Local potentials that vary according to strength of the stimulus.

Gyri

Ridges or folds on the brain.

Homunculus

Visual representation of body parts within the brain.

Hypothalamus

Autonomic and neuroendocrine control center located inferior to the thalamus.

Inhibitory Postsynaptic Potentials (IPSP)

Temporary hyperpolarization making the membrane more negative than its resting potential.

Lateral Ventricles

Pair of structures located in each hemisphere of the cerebrum.

Myelin

A fatty substance that insulates axons.

Pons

Part of the brainstem involved in sleep, respiration, and sensory motor functions.

Relative Refractory Period

Period following the absolute refractory period during which a neuron can generate an action potential if the stimulus is stronger.

Resting Membrane Potential

The electrical potential difference across a cell membrane when the cell is at rest.

Saltatory Conduction

Rapid conduction of action potentials along myelinated axons.

Sodium / Potassium Pump

Active transport pump that maintains a gradient across the plasma membrane.

Somatic Division

Division of the nervous system made up of afferent pathways from somatic sensory receptors.

Synapse

Membrane-to-membrane junction between a neuron and another cell.

Temporal Summation

When synaptic knobs stimulate a postsynaptic neuron in rapid succession.

Thalamus

Mass of gray matter located in the diencephalon.

Unipolar Neuron

Neurons that appear to have only one extension from the cell body.

Ventricle

A cavity, such as the large, fluid-filled spaces within the brain.

Wernicke’s Area

Region of the brain crucial for language comprehension.

3rd Ventricle

A narrow, vertically oriented cavity in the brain located between the two halves of the thalamus, involved in the production and circulation of cerebrospinal fluid.

4th Ventricle

A diamond-shaped cavity situated between the brainstem and cerebellum, responsible for the flow of cerebrospinal fluid and containing important brainstem structures.

Absolute Refractory Period

The period immediately following an action potential during which a neuron cannot fire again, regardless of the strength of the incoming stimulus, due to the state of the sodium channels.

Action Potential

A rapid and temporary change in membrane voltage that enables the transmission of electrical signals along a neuron, resulting from a series of ion channel activations.

Active Transport

The process of moving molecules across a cellular membrane against their concentration gradient, requiring energy, typically from ATP, for substances involved in physiological functions.

All-or-Nothing

A fundamental principle of neuronal action potential generation, stating that an action potential either occurs fully or not at all, with no intermediate states.

Arachnoid Mater

The middle layer of the meninges that envelops the brain and spinal cord, characterized by a web-like structure that cushions and protects the central nervous system.

Arachnoid Villi

Tiny, finger-like projections of the arachnoid mater that protrude into the dural sinuses, allowing for the absorption of cerebrospinal fluid back into the bloodstream.

Arbor Vitae

The distinctive tree-like structure formed by white matter within the cerebellum, facilitating communication between the cerebellar cortex and other parts of the brain.

Ascending Tract

Bundles of nerve fibers in the spinal cord that transmit sensory information from the body to the brain, playing a critical role in reflex actions and sensory perception.

Association Area

Regions within the cerebral cortex responsible for integrating information from various sensory modalities and higher cognitive functions, thus allowing for complex behaviors.

Astrocyte

Star-shaped glial cells in the brain that support neurons by maintaining the blood-brain barrier, providing nutrients, and assisting in the repair of brain injuries.

Autonomic Division

A subdivision of the peripheral nervous system that regulates involuntary physiological functions, such as heart rate, digestion, and respiratory rate, divided into sympathetic and parasympathetic branches.

Axon

A long, slender projection of a neuron that conducts electrical impulses away from the cell body to transmit signals to other neurons or muscles.

Axon Hillock

The cone-shaped region of a neuron where the axon begins, playing a critical role in the initiation of action potentials based on input received from dendrites.

Basal Nuclei

Clusters of gray matter located deep within the cerebral hemispheres that are involved in regulating voluntary motor control, procedural learning, and routine behaviors.

Bipolar Neuron

A type of neuron characterized by having two extensions: one axon and one dendrite, commonly found in sensory pathways like vision and olfaction.

Brainstem

The lower part of the brain that connects the cerebrum with the spinal cord, crucial for autonomic functions like breathing, heart rate, and conscious states.

Broca’s Area

An area in the frontal lobe primarily associated with language production, speech motor control, and the formulation of grammatical structures.

Cerebellum

A major structure of the hindbrain that coordinates voluntary movements, balance, and fine motor skills, ensuring smooth and precise muscle activity.

Cerebrospinal Fluid

A clear fluid that surrounds and cushions the brain and spinal cord, playing essential roles in protection, buoyancy, and nutrient transport to nervous tissues.

Cerebrum

The largest part of the brain, comprising two hemispheres, responsible for higher brain functions such as thought, action, emotion, and sensory perception.

Cholinesterase

An enzyme found in the synapses that breaks down the neurotransmitter acetylcholine, thus terminating synaptic transmission and enabling muscle relaxation.

Dendrite

Short, branching extensions of a neuron that receive signals and information from other neurons or sensory receptors, essential for synaptic communication.

Depolarization

A phase in action potential generation where the membrane potential becomes less negative, allowing sodium ions to enter the cell, which contributes to neuronal firing.

Descending Tract

Bundles of nerve fibers in the spinal cord that transmit motor commands from the brain to the muscles, facilitating voluntary movement and reflexes.

Diencephalon

A region in the brain situated between the cerebral hemispheres and the midbrain, encompassing structures like thalamus and hypothalamus that are vital for sensory and endocrine functions.

Ependymal Cell

Ciliated cells lining the ventricles of the brain, involved in the production and circulation of cerebrospinal fluid.

EPSP

Excitatory postsynaptic potential; a small depolarization of the postsynaptic membrane that increases the likelihood of neuron firing after synaptic input.

Frontal Lobe

The largest lobe of the brain situated at the front, associated with executive functions such as reasoning, planning, problem-solving, and impulse control.

Graded Potential

A change in membrane potential that varies in size relative to the strength of the stimulus, integral in initiating action potentials when sufficient.

Gyri

The elevated ridges or folds on the surface of the brain that increase its surface area and accommodate more neurons, contributing to cognitive abilities.

Homunculus

A visual representation of the human body that maps sensory and motor functions within the brain, illustrating the areas of the cortex dedicated to different body parts.

Hypothalamus

A small but critical region of the brain located below the thalamus, involved in regulating vital bodily functions, including temperature control, hunger, and hormone secretion.

Inhibitory Postsynaptic Potentials (IPSP)

A temporary hyperpolarization of the postsynaptic membrane, making the neuron less likely to fire an action potential by opening potassium or chloride channels.

Lateral Ventricles

A pair of large, C-shaped chambers within the cerebral hemispheres that produce cerebrospinal fluid and connect to other ventricles in the brain.

Myelin

A protective fatty sheath that surrounds axons, improving the speed and efficiency of electrical signal transmission along the nerve cells.

Pons

A section of the brainstem that is key for regulating sleep cycles, respiration, and relaying signals between the cerebellum and the rest of the brain.

Relative Refractory Period

The phase following the absolute refractory period during which a neuron can only fire again if a stimulus is strong enough to overcome the hyperpolarization.

Resting Membrane Potential

The stable, negative electrical charge across the neuronal membrane in a resting state, essential for the generation of action potentials when stimuli are applied.

Saltatory Conduction

A rapid form of action potential propagation along myelinated axons, wherein impulses 'jump' between the nodes of Ranvier for faster communication.

Sodium / Potassium Pump

An active transport mechanism that uses ATP to move sodium ions out of and potassium ions into the cell, crucial for maintaining the resting membrane potential.

Somatic Division

Part of the peripheral nervous system that governs voluntary movements by controlling skeletal muscles and processing sensory information from the body.

Synapse

The gap between neurons or between a neuron and another cell where neurotransmitter release and reception occur, facilitating communication throughout the nervous system.

Temporal Summation

The process by which multiple electrical synaptic inputs to a neuron occur in rapid succession, leading to a greater cumulative effect on the postsynaptic membrane.

Thalamus

A central brain structure that acts as a relay station for sensory and motor signals, processing information before it reaches the cerebral cortex.

Unipolar Neuron

A type of neuron characterized by a single process that branches into two extensions, typically found in sensory pathways related to touch and pain.

Ventricle

Fluid-filled cavities in the brain, including four primary ventricles, responsible for the production and circulation of cerebrospinal fluid that cushions the brain.

Wernicke’s Area

A region in the dominant hemisphere of the brain, typically the left, crucial for language comprehension and processing, allowing for meaningful communication.

White Matter

: nerves covered with white myelin sheath