Boron Chapter 10 Organization of the Nervous System

Afferent neurons

Transmit sensory information from the periphery > CNS

Arachnoid mater

Composed of layers of cells that isolate the CSF from the blood

Astrocytes

Glial cells in the CNS that perform many functions including nourish and support of neurons,

maintain ion balance, & repair of tissue

Autonomic nervous system

Regulates & controls visceral fx including:

heart rate, blood pressure, digestion, body temperature, reproduction etc.

Axon

Projection of a neuron that usually carries a signal away from the cell body

Axoplasm

Cytoplasm within the axon of a neuron

Basal ganglia

Group of nuclei at the base of the forebrain and connected to the thalamus and cerebral cortex associated with:

voluntary motor control

Bipolar neurons

Neuron with two projections involved in the transmission of special senses

Cerebellum

Part of the brain concerned with coordination of movement

Cerebral cortex

Part of the brain responsible for higher mental f/x, perception, behavioral reactions, association and integration of functions etc.

visceral, motor, sensory fx

Cerebrocerebellum

receives sensorimotor portions from the cerebral cortex>

projections to _____ Co/->

motor behavior

Chromatolysis

After axonal injury, most neuron cell bodies swell and undergo a characteristic rearrangement of organelles

Dendrites

Projections of a neuron that receive info, and send to soma

Dermatome

cutaneous innervation by a single dorsal root and its ganglion (spine)

Diencephalon

Thalamus, subthalamus and hypothalamus

Dura mater

Thick, inelastic membrane, forms an outer protective envelope around the brain

Efferent neurons

CNS > motor signals > periphery

Endoneurium

CT surrounds individual axon

Epineurium

CT surrounds bundles of fascicles

Fasciculations

Small muscle twitches from spontaneous AP in dying/injured motor neurons or their axons

Fast Axoplasmic Transport

Transport of membranous organelles, including vesicles and mitochondria in neurons along microtubules

Fast Retrograde Transport

Transport of substances in a neuron > cell body

Fibrillation

Individual muscle fibers twitch spontaneously

Ganglia

Groups of nerve cells concentrated into small knots or clumps that are usually located outside of CNS

Hypothalamus

Main control center of the autonomic nervous system that synthesizes and transports hormones » pituitary gland or blood

Medulla

Part of the brain that contains ascending/descending tracts.

Along with the pons controls vital functions including respiration, circulation, digestion and special senses

Microglia

Phagocytes in CNS, derived from cells related to the monocyte-macrophage lineage

Midbrain

b//w cerebral cortex and the hindbrain associated with

vision, hearing, arousal

sleep/wake & temperature regulation

Multipolar neurons

Nuerons that have multi-dendrites & 1 axon

Nuclei

Neurons that share similar f/x are grouped into aggregations

Paresthesia

Tingling sensations

Perineurium

CT that surrounds fascicles

Pia mater

Thin layer of CT covers the brain & spinal cord

Pons

a/w mastication, eye movement, and facial muscles,

-receiving somatic sensory info from the face, scalp, mouth, and nose,

-processing information related to hearing and equilibrium,

-coordinating motor movements etc.

Pyramidal

Cells with a pyramid-shaped set of dendritic branches

Slow Axoplasmic Transport

Anterograde transport of

cytoskeletal proteins & soluble proteins

in the axon of a neuron

Somatic neurons

Provide motor innervation to muscle & skin

Spinocerebellum

Receives strong input from muscle stretch receptors thru connections in the

spinal cord & brainstem

fx: helps regulate muscle tone.

Stellate

Cells with a radial pattern of dendritic branches

Telencephalon

Cerebral cortex & basal ganglia

Thalamus

integrating station for sensory information in cerebral cortex,

Receives info from:

basal ganglia for motor function,

cerebellum for motor control,

control of arousal and certain aspects of memory function etc.

Unipolar neurons

Neurons=one projection that often have specialized structures for transducing

physical stimulus > electrical activity

via a single axon

Vestibulocerebellum

Sensors in inner ear

maintain the body's balance.

Visceral neurons

Provide motor innervation to

»

smooth muscle (internal organs), cardiac muscle and glands

very nervous small car must glide

Wallerian degeneration

segment of an axon is destroyed & removed slowly during a period of several weeks