Nervous System I: Neurohistology Flashcards
what are the two components of the human nervous system?
- central nervous system (CNS)
- peripheral nervous system (PNS)
CNS components
- brain
- spinal cord
PNS components
- somatic (voluntary division)
- autonomic (involuntary division)
define neurons
- conducting elements (cells)
- makes up a part of the nervous system
define neuroglia
- accessory elements
- known as being supporting cells of the nervous system
define meninges
-coverings within the nervous system
neuron function
-responsible for receiving and transmitting information
classificational functions of neurons types
- sensory (afferent)
- motor (efferent)
- associative (interneuron)
neuron sensory function
-transmits impulse from periphery sensory recover to spinal cord or brain
neuron motor function
-transmits information from CNS to peripheral effectors
neuron motor function examples
- skeletal muscle
- smooth muscle
- cardiac muscle
- glands
neuron associative function
- located between sensory and motor neurons in CNS
- modifies responses of hormones
- relays information to other neurons
structural functions of neurons types
- multipolar
- bipolar
- unipolar
neuron multipolar structure
- has more than two processes attached to cell body
- most common type of neuron formed throughout CNS
neuron bipolar structure
- has two processes attached to cell body
- found in retina of eye and inner ear
neuron unipolar structure
- has only one process attached to cell body
- found in ganglia which are chapters of neurons adjacent to spinal cord
structure of typical neuron
- cell body
- processes (fibers) of a neuron
neuron cell body components
- most of the organelles typically found in cells (nucleus, mitochondria, golgi complex, etc)
- nissl bodies
- neurofibrils
neuron body: nissl bodies
- chomato philic bodies
- clusters of ribosomes of RER that module protein (neurotransmitters made of protein)
neuron body: neurofibrils
-cytoskeleton of neuron transport and maintain shape o neuron
neuron processes(fibers) of a neuron components
- dendrites
- axon (nerve fibers)
neuron fibers of a neuron: dendrites
- more than one per neuron
- receives impulse and transmits to cell body
neuron fibers of a neuron: axon
- only one per neuron
- transmits info away from the cell bud to another neuron or muscle
what are axons?
-nerve fibers
special characteristics of nerve fibers components
- myelin sheath
- neurolemma
- nodes of ranvier
- synaptic vesicles
special characteristics of nerve fibers: myelin sheath producer and location
produced by:
- oligodendrocytes in CNS
- schwann cells in PNS
special characteristics of nerve fibers: myelin sheath composition
-composed of primarily lipid(fat)
special characteristics of nerve fibers: myelin sheath function
-to increase transmission speed an electrical impulse
special characteristics of nerve fibers: neurolemma
-cell membrane of oligodendrocyte or schwann cell
special characteristics of nerve fibers: nodes of ranvier
- area of axon that’s not covered by myelin
- assists with rapid transmission of impulse
special characteristics of nerve fibers: synaptic vesicles
-structures that store neurotransmitters that are released at a synapse
allowers of communication in between neurons
- synapses
- conduction of nerve impulses