Boron Chapter 10 Organization of the Nervous System

Afferent neurons

Transmit sensory information from the periphery to the 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, maintian ion balance, and repair of tissue

Autonomic nervous system

Regulates and controls visceral functions 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 forebrainand 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 menatl functions, visceral functions, motor and sensory functions, perception, behavioral reactions, association and integration of functions etc.

Cerebrocerebellum

Receives projections from sensorimotor portions of the cerebral cortex and coordinates 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 information and transmit it to the soma

Dermatome

Area of cutaneous innervation provided by a single dorsal root and its ganglion

Diencephalon

Thalamus, subthalamus and hypothalamus

Dura mater

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

Efferent neurons

Transmit motor output from the CNS to the periphery

Endoneurium

Connective tissue that surrounds individual axons

Epineurium

Connective tissue that surrounds bundles of fascicles

Fasciculations

Small muscle twitches from spontaneous action potentials in dying or 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 back toward the cell body

Fibrillation

Individual muscle fibers twitch spontaneously

Ganglia

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

Hypothalamus

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

Medulla

Part of the brain that contains ascending and descending tracts. Along with the pons controls vital functions including respiration, circulation, digestion and special senses

Microglia

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

Midbrain

Part of the brain located between the cerebral cortex and the hindbrain associated with vision, hearing, sleep/wake, arousal, temperature regulation etc.

Multipolar neurons

Nuerons that have many dendrites and a single axon

Nuclei

Neurons that share similar functions are grouped into aggregations

Paresthesia

Tingling sensations

Perineurium

Connective tissue that surrounds fascicles

Pia mater

Thin layer of connective tissue that covers the brain and spinal cord

Pons

Part of the brain associated with mastication, eye movement, and facial muscles, receiving somatic sensory information 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 and solubale protiens in the axon of a neuron

Somatic neurons

Provide motor innervation to muscle and skin

Spinocerebellum

Receives strong input from muscle stretch receptors through connections in the spinal cord and brainstem and helps regulate muscle tone.

Stellate

Cells with a radial pattern of dendritic branches

Telencephalon

Cerebral cortex and basal ganglia

Thalamus

Main integrating station for sensory information bound for the cerebral cortex, receives information from the basal ganglia important for motor function,iInput from the cerebellum important for motor control, control of arousal and certain aspects of memory function etc.

Unipolar neurons

Neurons with only one projection that often have specialized structures for transducing physical stimulus into electrical activity via a single axon

Vestibulocerebellum

Sensors are located in the inner ear and helps maintain the body's balance.

Visceral neurons

Provide motor innervation to smooth muscle (internal organs), cardiac muscle and glands

Wallerian degeneration

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