Nervous Tissue
-the master integrating and coordinating system
-monitors and processes sensory info
-divided into central nervous system and peripheral nervous system
Central Nervous System
![card image](http://medicalterms.info/img/uploads/anatomy/central-nervous-system.jpg)
-consists of brain and spinal cord
Peripheral Nervous System
![card image](http://www.glutenfreevisalia.com/sample/wp-content/uploads/2012/09/nervous-systemv1.png)
-includes all nervous elements located outside the central nervous system
*ex: nerves, sensory receptors, and some cluster of nerve cells
Nervous Tissue
![card image](../uploads/837/81/_4c2d395_147e7781763__8000_00000115.jpg)
-made up of neurons and neuroglia cells
Neuroglia/ Glial Cells
![card image](http://www.mhhe.com/biosci/ap/ap_prep/anm1s1_7.jpg)
-serves the needs of the delicate neurons by bracing and protecting them
CNS: astrocytes, oligodendrocytes, microglial cells, and ependymal cells
PNS: Schwann cells and satellite cells
Microglial Cells
![card image](http://classconnection.s3.amazonaws.com/116028/flashcards/691844/jpg/microglial-cell.jpg)
-acts as phagocytes
Oligodendrocytes & Schwann Cells
-myelinate the cytoplasmic extensions of the neurons
Astrocytes
-play a role in capillary-neuron exchanges and control the chemical environment around neurons
Neuron/Nerve Cells
-basic functional units of nervous tissue
-transmit messages from one part of the body to another in the form of nerve impulses
Cell Body of Neuron
![card image](http://www.sd71.bc.ca/sd71/school/isfeld/graham/Bio%20page/brain-neuron.gif)
-slender processes extend
-both the biosynthetic center of the neuron and part of its receptive region
-make up the gray matter of the CNS and form clusters there called nuclei and ganglia in PNS
-contains a large round nucleus surrounded by cytoplasm
Nuclei
![card image](http://people.eku.edu/ritchisong/greymatter.jpg)
-cluster of neuron cell bodies in CNS
Ganglia
-cluster of neuron cell bodies in PNS
Two structures found in the cytoplasm
Neurofibrils and Chromatophilic Substance
Neurofibrils
![card image](../uploads/838/82/_4c2d395_147e7781763__8000_00000116.gif)
-provide support for the cell and a means to transport substances throughout the neuron
Chromatophilic Substance/Nissl Bodies
![card image](http://classconnection.s3.amazonaws.com/1557/flashcards/695051/png/picture-5.png)
-an elaborate type of rough endoplasmic reticulum involved in the metabolic activities of the cell
Two Types of Neuron Processes.
1.Dendrites
2.Axons
Dendrites
![card image](http://www.neurogenesis.com/images/dendrites.gif)
-receptive regions that bear receptors for neurotransmitters released by the axon terminals of other neurons
Axons/Nerve Fibers
![card image](https://student.societyforscience.org/sites/student.societyforscience.org/files/main/articles/a1830_3414.jpg)
-form the impulse generating and conducting region of the neuron
-the white matter of the nervous system
Tracts
-bundles of axons in the CNS
Nerves
-bundles of axons in PNS
Neurons may have several dendrites, but they only have a single _____________.
Axon
Axon Collaterals
![card image](http://visual.merriam-webster.com/images/human-being/anatomy/nervous-system/chain-neurons.jpg)
-branch off of the main axon forming more processes
Axon Hillock
![card image](http://0.tqn.com/d/psychology/1/S/H/axonhillock.jpg)
-conical area of origin of the axon from the nerve cell body
Axon Terminals
![card image](http://new.math.uiuc.edu/math198/MA198-2010/alesia_prakapenka/neuron_fig.jpg)
club-shaped endings by which axons make synaptic contacts with other nerve cells or effector cells
-stores the neurotransmitter chemical in tiny vesicles
Synaptic Cleft
![card image](http://thehippoandthecampus.files.wordpress.com/2010/12/sypnatic-cleft-doc-report.jpg)
- a narrow extracellular cleft between the presynaptic and postsynaptic membranes
Neuromuscular Junction
![card image](http://www.unm.edu/~lkravitz/MEDIA2/Neuro2.gif)
-specialized synapses between neurons and skeletal muscles
Myelinated Fibers
![card image](http://antranik.org/wp-content/uploads/2012/04/conduction-in-a-myelinated-nerve-fiber-saltatory-conduction.jpg?7ed0a5)
-long nerve fibers that are covered by fatty material (myelin)
Axons in the PNS are typically heavily myelinated by special supporting cells called ______________.
![card image](http://antranik.org/wp-content/uploads/2012/04/conduction-in-a-myelinated-nerve-fiber-saltatory-conduction.jpg?7ed0a5)
Schwann Cells
Schwann Cells
![card image](http://antranik.org/wp-content/uploads/2012/04/conduction-in-a-myelinated-nerve-fiber-saltatory-conduction.jpg?7ed0a5)
-wrap themselves tightly around the axon in jelly roll fashion, this wrapping is the myelin sheath
Nodes of Ranvier
![card image](http://antranik.org/wp-content/uploads/2012/04/conduction-in-a-myelinated-nerve-fiber-saltatory-conduction.jpg?7ed0a5)
-gaps or indentations in the myelin sheath
Within the CNS myelination is accomplished by neuroglia called ________________.
Oligodendrocytes
Unipolar Neurons
![card image](http://biologyonline.us/Online%20A&P/AP%202/Northland/AP2lab/Lab%201%20online/lab1/images/Picture16.jpg)
-one very short process which divides into peripheral and central processes, extends from cell body
Bipolar Neurons
![card image](http://biologyonline.us/Online%20A&P/AP%202/Northland/AP2lab/Lab%201%20online/lab1/images/Picture16.jpg)
-have two processes attached to the cell body
-rare
Multipolar Neurons
![card image](http://biologyonline.us/Online%20A&P/AP%202/Northland/AP2lab/Lab%201%20online/lab1/images/Picture16.jpg)
-many processes
Sensory (Afferent) Nerves
- conduct impulses only toward the CNS
Motor (Efferent) Nerves
-carry impulses only away from the CNS
Mixed Nerves
-nerves carrying both sensory and motor fibers
Endoneurium
![card image](http://classroom.sdmesa.edu/eschmid/F10.05.L.150.jpg)
-delicate connective tissue enveloping individual nerve fibers
Perineurium
![card image](http://classroom.sdmesa.edu/eschmid/F10.05.L.150.jpg)
-sheath of connective tissue enclosing a bundle of nerve fibers
-forming fascicles
Epineurium
![card image](http://classroom.sdmesa.edu/eschmid/F10.05.L.150.jpg)
sheath of connective tissue around all fascicles of nerve fibers