Brain Structure, Nervous Tissue, and Functional Divisions

Comprehensive vocabulary flashcards covering neuroanatomy, glial cell types, the ventricular system, and functional divisions of the nervous system based on lecture transcripts.

Brain

The nervous tissue contained within the cranium, located in the cranial cavity of the skull.

Regions of the Brain

The five regions consisting of the telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon.

Meninges

A series of membranes composed of connective tissue that cover the outer surface of the CNS and protect the brain.

Dura Mater

A thick fibrous layer and strong protective sheath over the entire brain and spinal cord, attached to the inner surface of the cranium; the outer covering.

Arachnoid Mater

A membrane of thin fibrous tissue forming a loose sac around the CNS; the middle layer.

Arachnoid Trabeculae

A thin, filamentous mesh located beneath the arachnoid in the subarachnoid space.

Arachnoid Granulations

Outpouchings of the arachnoid membrane into the dural sinuses where CSF is filtered back into the blood.

Pia Mater

A thin fibrous membrane adjacent to the surface of the CNS that follows the convolutions of gyri and sulci.

Lumbar Puncture

A procedure where a needle is inserted through the dura and arachnoid layers to withdraw CSF.

Cerebrospinal Fluid (CSF)

Fluid that circulates throughout the CNS providing protection, nourishment, and waste removal; mostly water with oxygen, carbon dioxide, and electrolytes.

Ventricles

Four open spaces within the brain, developed from the central canal of the neural tube, through which CSF flows.

Lateral Ventricles

The first and second ventricles located deep within the cerebrum.

Third Ventricle

The space between the left and right sides of the diencephalon, bounded by the hypothalamus and thalamus.

Fourth Ventricle

The space between the cerebellum and the pons/upper medulla that narrows into the central canal of the spinal cord.

Choroid Plexus

A specialized structure in the ventricles where ependymal cells filter blood from capillaries to produce CSF.

Ependymal Cells

A type of glial cell that helps make CSF and lines the ventricles.

Glial Cells

Supportive cells that provide a framework of tissue for neurons and their activities, capable of undergoing mitosis.

Neuron

The neural tissue cell responsible for generating and propagating electrical signals.

Soma

The cell body of a neuron, containing the nucleus and major organelles.

Axon

The fiber that connects a neuron with its target and propagates nerve impulses away from the cell body.

Dendrite

Highly branched processes that receive input from other neurons at synapses.

Gray Matter

Regions of nervous tissue predominantly containing cell bodies and dendrites.

White Matter

Regions of nervous tissue composed mainly of axons, appearing white due to lipid-rich myelin.

Myelin

A lipid-rich insulation for axons provided by oligodendrocytes in the CNS and Schwann cells in the PNS.

Axon Hillock

The tapering of the cell body toward the axon fiber where the axon emerges.

Axoplasm

The gel-like fluid inside a nerve fiber that helps carry signals and nutrients.

Node of Ranvier

The gaps in the myelin sheath along the length of an axon.

Synaptic End Bulb

The ending of the axon terminal that makes a connection with the target cell at the synapse.

Unipolar Neuron

Neurons with only one process; in humans, these are pseudo-unipolar sensory neurons with cell bodies found in ganglia.

Bipolar Neuron

Neurons with two processes (one axon and one dendrite) extending from each end, such as in the olfactory epithelium and retina.

Multipolar Neuron

Neurons with one axon and two or more dendrites, including Purkinje and pyramidal cells.

Astrocyte

Star-shaped CNS glial cells that maintain chemical concentrations, react to tissue damage, and contribute to the blood-brain barrier (BBB).

Oligodendrocyte

CNS glial cells with few branches that reach out to insulate multiple axon segments with myelin.

Microglia

Small CNS-resident macrophages that ingest and digest diseased or damaged cells and pathogens.

Satellite Cell

PNS glial cells that provide support for neurons in the sensory and autonomic ganglia.

Schwann Cell

PNS glial cells that insulate a single axon segment with myelin.

Central Nervous System (CNS)

The division of the nervous system comprised of the brain and spinal cord.

Peripheral Nervous System (PNS)

The division of the nervous system encompassing all neural tissue outside the brain and spinal cord, such as cranial and spinal nerves.

Nucleus (CNS)

A localized collection of neuron cell bodies in the Central Nervous System.

Ganglion

A cluster of neuron cell bodies in the Peripheral Nervous System.

Tract

A bundle of axons located in the Central Nervous System.

Nerve

A bundle of axons located in the Peripheral Nervous System.

Integration

A function of the nervous system that combines sensory perceptions with higher cognitive functions to produce a response.

Somatic Nervous System (SNS)

The division responsible for conscious perception and voluntary motor responses, such as skeletal muscle contraction.

Autonomic Nervous System (ANS)

The division responsible for involuntary control of the body, usually for homeostasis, regulating smooth and cardiac muscle and glands.

Enteric Nervous System

A region of the PNS responsible for autonomic control of gastrointestinal functions.

Afferent

Neural pathways that carry sensory information from the site of perception to the brain.

Efferent

Neural pathways that carry motor information outward from the brain to the moving parts.

Multiple Sclerosis

An autoimmune disease where antibodies attack oligodendrocytes and the myelin sheath in the CNS.

Circle of Willis

A confluence of arteries that maintains blood perfusion to the brain even if flow is limited in one part.

Superior Sagittal Sinus

A dural sinus running in the longitudinal fissure that absorbs CSF and drains into the confluence of sinuses.