Organization of the Nervous System Flashcards
(80 cards)
Consists of the brain and spinal cord
Integration and correlation center of nervous information
Central Nervous System
Consists of the cranial and spinal nerves and their associated ganglia
Conducts info to and from the central nervous system
Peripheral Nervous System
Functional units of the nervous tissue
Highly specialized cells that exhibit irritability and conductivity
Neurons
Also known as nerve cell body
Contains cytoplasm with a nucleus embedded on it
Perikaryon
Elongated processes that receive stimuli from the environment
Diameter tapers as they extend from the cell body
Branch profusely
Dendrites
Small projections found in the finer branches of the dendrites
Dendritic spines
Single, tubular process that conducts impulses away from the body
Axon
More than two processes arising from perikaryon
Neurons of the brain and spinal cord
Multipolar
Possess an elongated cell body where a process emerge at each end
Found in retina and vestibular region
Bipolar
Has a single process
Found in spinal ganglia, cranial ganglia and posterior root ganglion
Unipolar
With many dendrites but no true axon
Regulates electrical changes of adjacent neuron
Do not produce actin potentials
Anaxonic
Long axon that may be 1m or more in length
Form the long fiber tracts of the brain and spinal cord
Ex. Pyramidal cell, Purkinje cell, motor cells
Golgi Type I Neurons
Have a short axon
Star-shaped appearance
Inhibitory
Numerous in cerebral and cerebellum complex
Golgi Type II Neurons
Also called afferent neurons
Receive input from peripheral structures
Transmit sensory info to CNS
Sensory Neurons
Efferent neurons
Transmit impulses from CNS to effector organs
Motor Neurons
Association Neurons
Connect sensory to motor neurons
90% of neurons in CNS
Interneurons
Non-neuronal specialized cels which support the nerve cells of the NS
Non-transmitting
Glial cells
A kind of CNS neuroglia
Small cell bodies with branching processes that extend in all directions
Function: formation of blood-brain barrier, structural support
Astrocytes
Found mainly in the white matter where their processes pass between the nerve fibers
Fibrous astrocytes
Found mainly in the gray matter where their processes pass between the nerve cell bodies
Protoplasmic astrocytes
A kind of CNS Neuroglia
Possess cell bodies and few delicate processes
No filaments in their cytoplasm
Found in rows along myelinated nerve fibers
Surround nerve cell bodies
Responsible for the formation of the myelin sheath
Oligodendrocytes
Smallest of the CNS neuroglia lol cells
Derived from macrophages
Function: engulfing debris resulting from injury or disease
Microglia
A kind of CNS neuroglia
Line the cavities of the brain and central canal of the spinal cord
Assists in the circulation of CSF by movement of the cilia
Ependymal cells
3 groups: ependymocytes, tanycytes, choroid all epithelial cells
A kind of PNS Neuroglia
aka capsular cells
Surround neuron cell bodies in ganglia
Regulate nutrients and transmitter levels
Satellite cells