Organization of the Nervous System, Part I

Comprehensive vocabulary flashcards covering nervous system divisions, cell types, comparative neuroanatomy, historical neuron doctrine principles, and cranial nerve functions based on lecture material.

Central Nervous System (CNS)

The structural division of the nervous system consisting of the brain and the spinal cord.

Peripheral Nervous System (PNS)

The structural division of the nervous system composed of nerves extending outside the brain and spinal cord, communicating sensory and motor signals with the CNS.

Hemorrhagic Stroke

A stroke caused by a rupture in an artery that allows blood to leak directly into brain tissue.

Ischemic Stroke

A stroke caused by blood clots or debris blocking an artery, preventing blood from reaching brain tissue and resulting in cell death.

Lissencephalic

Characterized by a smooth cerebral cortex lacking gyri and sulci, as seen in species like the brown rat (Rattus norvegicus).

Gyrencephalic

Characterized by a highly folded cerebral cortex featuring gyri and sulci, as seen in species like the capybara (Hydrochaeris hydrochaeris).

Golgi Stain

A silver staining technique invented by Camillo Golgi using potassium dichromate and silver nitrate that allows complete visualization of individual neurons.

Neuron Doctrine

The fundamental principle established by Santiago Ramón y Cajal that the nervous system is composed of discrete individual cellular units called neurons.

Dynamic Polarization

The law of unidirectional signaling in neurons stating that electrical transmission moves from dendrites to the cell body, and then down the axon.

Dale's Law

The principle that a single neuron releases a single type of neurotransmitter at all of its synaptic contacts.

Dendrites

Branching extensions of a neuron that serve as the input zone, receiving information from environment or other neurons.

Soma

The cell body region of a neuron that functions as the integration zone, combining incoming signals to decide whether to transmit a neural message.

Axon

The single long extension of a neuron that functions as the conduction zone, transmitting electrical impulses over long distances.

Axon Terminals

The specialized endings of an axon that serve as the output zone, transferring information across synapses to target neurons or tissues.

Multipolar Neuron

A neuron structurally categorized by having many dendrites and a single axon extending from the cell soma.

Bipolar Neuron

A neuron structurally categorized by having a single dendrite at one end of the cell body and a single axon at the opposite end.

Unipolar Neuron

A neuron with a single process leaving the cell body that branches into two directions, serving both as an input zone and an output zone.

Glutamate

The primary fast excitatory neurotransmitter in the central nervous system.

GABA (gamma-Aminobutyric Acid)

The primary fast inhibitory neurotransmitter in the central nervous system.

Ependymal Cells

Central nervous system neuroglia lining the walls of the lateral ventricles in direct contact with blood and cerebrospinal fluid.

Oligodendrocytes

Neuroglial cells that produce the myelin sheath around nerve cell axons in the Central Nervous System (CNS).

Astrocytes

Star-shaped CNS neuroglia that relay nutrients and signals from blood vessels to neurons, providing essential protection and support.

Microglia

Phagocytic CNS glial cells that become activated in response to brain infection or tissue damage.

Satellite Cells

Neuroglial cells in the Peripheral Nervous System (PNS) that surround neuron cell bodies, act similarly to astrocytes, and contribute to chronic pain.

Schwann Cells

Myelinating glial cells of the Peripheral Nervous System (PNS) that insulate peripheral axons and clear debris to allow neuron regrowth.

Synaptic Cleft

The narrow extracellular gap separating the presynaptic axon membrane from the postsynaptic dendritic or somatic membrane.

Grey Matter

Nervous tissue in the CNS predominantly composed of non-myelinated cell bodies and dendrites.

White Matter

Nervous tissue in the CNS predominantly composed of myelinated nerve axons.

Dorsal Root

The posterior root of a spinal nerve containing sensory nerve fibers carrying projections from the body into the spinal cord.

Ventral Root

The anterior root of a spinal nerve containing motor nerve fibers carrying commands from the spinal cord to target muscles.

Sympathetic Division

The branch of the autonomic nervous system responsible for 'fight or flight' responses, mediated primarily by the release of norepinephrine.

Parasympathetic Division

The branch of the autonomic nervous system responsible for 'rest and digest' activities, mediated primarily by acetylcholine release.

Olfactory Nerve (CN I)

Cranial Nerve I, dedicated to transmitting sensory smell input.

Optic Nerve (CN II)

Cranial Nerve II, dedicated to transmitting visual sensory input.

Oculomotor Nerve (CN III)

Cranial Nerve III, responsible for governing most eye movements and upper eyelid movement.

Trochlear Nerve (CN IV)

Cranial Nerve IV, responsible for controlling vertical eye movement.

Trigeminal Nerve (CN V)

Cranial Nerve V, providing sensory innervation to the face, sinuses, and teeth, and motor innervation to jaw muscles.

Abducens Nerve (CN VI)

Cranial Nerve VI, responsible for controlling outward horizontal movement of the eye.

Facial Nerve (CN VII)

Cranial Nerve VII, governing taste on the anterior tongue and soft palate, facial expressions, and tear and salivary glands.

Vestibulocochlear Nerve (CN VIII)

Cranial Nerve VIII, transmitting inner ear sensory input for hearing and balance.

Glossopharyngeal Nerve (CN IX)

Cranial Nerve IX, managing mouth taste sensations and motor control of throat muscles.

Vagus Nerve (CN X)

Cranial Nerve X, conveying visceral sensory and autonomic motor information to and from internal organs.

Accessory Nerve (CN XI)

Cranial Nerve XI, controlling spinal and neck muscles.

Hypoglossal Nerve (CN XII)

Cranial Nerve XII, controlling motor movement of tongue muscles.