Chapter 7 Anatomy Vocab

Nervous System

the network of nerve cells and fibers which transmits nerve impulses between parts of the body.

Sensory input

the process by which sensory receptors detect stimuli and send information to the central nervous system.

Integration

the process by which the nervous system processes and interprets sensory input to make decisions and coordinate responses.

Motor output

the response generated by the nervous system that activates muscles or glands to produce a reaction.

CNS

Central Nervous System, which includes the brain and spinal cord, responsible for processing and transmitting neural signals.

PNS

peripheral nervous system, consisting of sensory and motor neurons.

Sensory or afferent division

the part of the peripheral nervous system that transmits sensory information from the body to the central nervous system.

Motor or Efferent division

the part of the peripheral nervous system that transmits motor commands from the central nervous system to the muscles and glands.

Somatic/Voluntary Nervous system

the part of the motor division that controls voluntary movements by activating skeletal muscles.

Autonomic/Involuntary system

the part of the motor division that regulates involuntary bodily functions, such as heart rate and digestion, without conscious control.

Neuroglia or glia

supporting cells in the nervous system that protect and maintain neurons, providing structural and functional support.

Astrocytes

Star-shaped glial cells in the brain and spinal cord that support neurons and maintain the blood-brain barrier.

Microglia

a type of neuroglia that acts as the immune defense in the central nervous system, removing waste and pathogens.

Ependymal cells

ciliated glial cells that line the ventricles of the brain and the central canal of the spinal cord, involved in the production and circulation of cerebrospinal fluid.

Oligodendrocytes

a type of glial cell in the central nervous system that produces myelin, insulating axons to enhance the speed of electrical impulses.

Schwann cells

glial cells in the peripheral nervous system that produce myelin, insulating neuronal axons to enhance signal transmission.

Satellite cells

glial cells in the peripheral nervous system that support neuronal cell bodies in ganglia and regulate their environment.

Neurons or nerve cells

the fundamental units of the nervous system responsible for transmitting information throughout the body via electrical and chemical signals.

Cell body

the part of a neuron that contains the nucleus and organelles, responsible for maintaining the cell's functions and processing information.

Nissl bodies

clusters of ribosomes and rough endoplasmic reticulum in the cell body of neurons, involved in protein synthesis.

Neurofibrils

fine, thread-like structures in neurons that provide support and transport materials within the cell.

Process/fibers

extensions of the neuron that transmit signals, including axons and dendrites.

Dendrites

extensions of neurons that receive signals from other neurons and transmit them toward the cell body.

Axons

long, cable-like projections that transmit signals away from the cell body to other neurons or muscles.

Axon hillock

the part of a neuron where the axon begins, integrating signals from the cell body and initiating action potentials.

Axon terminals

the endpoints of axons that release neurotransmitters to communicate with other neurons.

Neurotransmitters

chemical messengers that transmit signals across synapses between neurons.

Synaptic cleft

the small gap between the axon terminals of one neuron and the dendrites or cell body of another neuron, where neurotransmitters are released and received.

Synapse

the junction between two neurons where neurotransmitters are released and received, facilitating communication.

Myelin

a fatty substance that surrounds and insulates axons, facilitating faster signal transmission in the nervous system.

Myelin sheath

a protective layer that surrounds nerve fibers, facilitating faster transmission of electrical signals.

Neurilemma

The outermost layer of the myelin sheath that surrounds nerve fibers, providing protection and support.

Nodes of Ranvier

gaps in the myelin sheath along the axon that facilitate rapid signal conduction by allowing ions to flow in and out of the neuron.

Multiple Sclerosis (MS)

A chronic autoimmune disorder that affects the central nervous system, characterized by the deterioration of the myelin sheath, leading to disrupted nerve signal transmission.

Nuclei

Clusters of neuron cell bodies in the central nervous system.

Ganglia

clusters of neuron cell bodies located in the peripheral nervous system.

Tracts

Bundles of axons in the central nervous system that connect different regions of the brain and spinal cord.

Nerves

Bundles of axons in the peripheral nervous system that transmit signals between the central nervous system and the rest of the body.

White matter

regions of the central nervous system consisting mainly of myelinated axons, which facilitate communication between different brain areas.

Gray matter

Regions of the central nervous system containing neuronal cell bodies, dendrites, and unmyelinated axons, primarily involved in processing information.

sensory/afferent neurons

Neurons that carry signals from sensory receptors to the central nervous system, enabling the perception of stimuli.

Receptors

specialized structures that detect and respond to sensory stimuli, converting them into neural signals for processing by the nervous system.

Cutaneous sense organs

Specialized structures that detect changes in the environment, such as touch, temperature, and pain, located in the skin and other tissues.

Proprioceptors

sensory receptors located in muscles, tendons, and joints that provide information about body position and movement.

motor/efferent neurons

neurons that transmit signals from the central nervous system to muscles and glands, facilitating movement and response.

interneurons/association neurons

neurons that connect sensory and motor neurons within the central nervous system, playing a critical role in reflexes and processing information.

Multipolar neuron

a type of neuron characterized by multiple dendrites and a single axon, commonly found in the brain and spinal cord.

Bipolar neuron

neurons with one axon and one dendrite that extend from opposite sides of the cell body.

Unipolar neurons

a nerve cell with one process extending from its cell body

Polarized

a state where a cell or tissue has a difference in electrical charge between its inner and outer surfaces