Nervous systemm Flashcards
What are the two main cell types in the nervous system?
Neurons and neuroglia
Name the composition of a neuron, it has 4 elements
It has a cell body, with extensions called dendrites, and axons which carry the impulses to and away from the cell body. Some axons are surrounded by a myelin sheath
Name the two elements of the CNS
The brain and spinal cord
What part of the nerves lie in the gray matter?
The nerve cell bodies
What part of the nerves lie in the white matter?
The interconnecting fiber tract system
Which three layers constitute the meninges?
pia mater, arachnoid mater, dura mater
Which two things surround and protect the CNS?
Meninges and cerebrospinal fluid (CSF)
The brain and spinal cord is covered by what layer?
The pia mater
Where is the CSF located?
Between the pia and arachnoid mater
What layer surrounds the arachnoid mater?
Dura mater
In the PNS, there are two classes of nerve fibers. Name them and describe their characteristics
Myelinated nerve fiber, which have a myelin sheath that enwrap an individual axon.
Unmyelinated nerve fibers, in which multiple axons are embedded in a Schwann cell
Peripheral nerves are supported and protected by three connective tissue layers. Name them from inside to outside
Endoneurium, perineurium, epineurium
What does the endoneurium enclose from a nerve fiber?
The neurolemma cells and axons
What does the perineurium enclose from a nerve fiber?
It encloses a bundle of peripheral nerve fibers
What does the epineurium enclose?
A bundle of nerve bundle fibers
A collection of nerve cell bodies outside the CNS is called ….
Ganglion
Peripheral nerves are either …. or …. nerves
cranial or spinal
How many pairs of cranial nerves are there?
12 pairs
There are 31 pairs of spinal nerves, name the number of nerves per category according to the vertebrae
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
The somatic nervous sytem provides …………………. to all parts of the body except the viscera in the body cavities, smooth muscle, and glands
sensory and motor innervation
The autonomic nervous sytem is divided into two systems. Name them
Sympathetic and parasympathetic nervous system
Name the two roots of a nerve and what they consist of
The anterior/ventral root consists of motor/efferent fibers
The posterior/dorsal root consists of sensory/afferent fibers
Name three structures that the posterior rami supply to
Synovial joints of the vertebral column, deep muscles of the back and the overlying skin of the back
Name the four major areas the anterior rami supply to
Anterior and lateral regions of the trunk, and the upper and lower limbs
Name the four main components of a typical spinal nerve
Somatic sensory fibers and motor fibers, visceral motor fibers, connective tissue coverings, and the vasa nervorum
What type of nerve fibers does the autonomic nervous system consist of?
Visceral efferent/motor fiberss
Where is the cell body of the first and second neuron located?
The gray matter of the CNS, and the axon synapses
What are the two locations the cell bodies of postsynaptic neurons of the sympathetic nervous system occur in?
The paravertebral ganglia and the prevertebral ganglia
Presynaptic fibers of the sympathetic nervous system have four possible courses to take. Name them.
Ascend and then synapse
Descend and then synapse
Synapse at the level of exit
Pass through the sympathetic trunk without synapsing to enter the abdominopelvic splanchnic nerve
What does splanchnic nerves convey?
Visceral efferent autonomic and afferent fibers to and from the viscera of the body cavities
Where do the fibers of the parasympathetic nervous system exit?
At the cranial parasympathetic outflow and the sacral parasympathetic outflow
The sympathetic and parasympathetic nervous system set the body up for two different situations. Name them
Sympathetic prepares for fight or flight, parasympathetic prepares for quiet and orderly body processes
