31
the pairs of spinal nerves
12
the pairs of cranial nerves
Afferent
includes somatosensory portion and visceral sensory portion
Efferent
includes somatic nerves and autonomic nerves, which also includes the PNS and SNS
Somatosensory portion
monitors skeletal muscles, joints, and skin
Visceral sensory portion
monitors smooth muscles, cardiac muscle, and other internal organs
Somatic Nerves
controls skeletal muscle contractions
Autonomic Nerves
controls internal organ activities
Parasympathetic Nerves
pupil constriction, decrease HR, and tense the urinary bladder
Sympathetic Nerve
pupil dilation, increase HR, and relax urinary bladder
Neuroglia
supporting cells and protects the neuron
Neurons
nerve cells that are responsible for the transfer and processing of information in the nervous system. consists of soma, axon and dendrites. specialized for rapid communication of information received in the form of electrochemical signals from one neuron
Neurons can be classified based on what?
Structure (placement of cell body or the number of processes extending from the cell body) and Function (sensory or motor or interneuron/association neurons)
Another name for interneurons
Association Neurons
Interneurons
involved with both sensory and motor pathways and are present only in the CNS. analyze sensory input and coordinates motor outputs. can be excitatory or inhibitory
What are the structural classifications of neurons? (4)
Anaxonic, Bipolar, (Pseudo)unipolar, and Multipolar
What are the functional classifications of neurons? (3)
Sensory, Motor, Interneurons
Anaxonic
has many processes but cannot differentiate between axons and dendrites. one of the structural classifications of neurons
Bipolar
sensory. when the cell body is between 2 "axon-alike" processes. restricted to a few special sensoe organs such as the retina for vision (also in olfactory pathway). one of the structural classifications of neurons
(Pseudo)unipolar
when the cell body is off to one side of the axon. one of the structural classifications of neurons
Multipolar
typically has a single axon and multiple dendrites. one of the structural classifications of neurons. most common of all structures for neurons. includes interneurons and motor
Upper Motor Neuron
part of a neuron that can have excitatory and inhibitory effects.
Lower Motor Neuron
part of a neuron that is always activating. it always has excitatory effects on skeletal muscle fibers.
Unipolar
peripheral somatic sensory neurons such as from skin and muscles
Synapse
junction between the axon of one neuron and the dendrite of another, the some of another, the axon of another, muscle, or gland. (a single neuron would not innervate all three)
Are motor neurons somatic and/or automatic?
Motor neurons are both somatic and automatic
Where is the ganglia found?
PNS
Where is the nuclei found?
CNS
Ganglia
collections of neuron cell bodies
Nerves
bundles of axons
What are the white and gray matters of the PNS composed of?
Gray Matter: Ganglia
White Matter: Nerves
What are the white and gray matters of the CNS composed of?
Gray Matter: Centers, Nuclei, Neural Cortex
White Matter: Tracts, Columns
What are in the gray matters of the human body?
PNS: Ganglia
CNS: Neural Cortex, Centers, Nuclei
What are in the white matters of the human body?
PNS: Nerves
CNS: Tracts, Columns
Gray Matter
contains cell bodies and some axons
White Matter
contains myelinated axons
Tracts
bundles of CNS axons that share a common origin and destination
Columns
several tracts that form an anatomically distinct mass
Centers
collections of neuron cell bodies. each have specific processing function. higher ones are more complex
Nuclei
collections of neuron cell bodies in the interior of the gray matter of the CNS
Neural Cortex
located on the surface of the gray matter of the CNS
What are the functions of a neuroglia?
1. provide framework for the neural tissues
2. maintain the intercellular environment
3. act as phagocytes
4. has the ability to reproduce unlike neurons
5. can alter the composition of ions
6. different in CNS and PNS
7. 5 times the number of neurons
8.
Oligodendrocytes
type of neuroglia that myelinates CNS axons and provides structural framework
Astrocytes
type of neuroglia that:
-maintain blood-brain barrier
-structural support
-regulate ion, nutrient, and dissolved gas concentrations
-absorb and recycle neurotransmitters
-form scar tissue after injury
-can lead to CNS degeneration
Microglia
type of neuroglia remove cell debris, waste and pathogens by phagocytosis
Ependymal Cells
type of neuroglia that lines ventricles (brain) and central canal (spinal cord);assists in producing, circulating, and monitoring cerebrospinal fluid (CSF). some secrete CSF
Satellite Cells
surround neuron cell bodies in ganglia; regulate O2, CO2, nutrient, and neurotransmitter levels around neurons in ganglia
Schwann Cells
surround all axons in PNS. responsible for myelination of peripheral axons; participate in repair process after injury
Cerebrospinal Fluid (CSF)
produced by choroid plexus that is located in the 4th ventricles. found in cymoid space and surround CNS and inside ventricles and canals
Neurolemmocytes
another name for schwann cells
Nerve
bundles of neuron axons forming discrete white flat or circular threads visible to naked eye in PNS (usually large ones contain both sensory and motor fibers)
Tract
comparable structure except runs within CNS, either ascending or descending, and composed of bundles of axons of interneurons. they are usually ascending or descending thus all fibers within are carrying action potential impulses the same direction.
What are the three pathways in the autonomic nervous system.
1. Hypothalamus
2. Brain Stem/Spinal Cord
3. Ganglia
Epineurium
Perinuerium
Endoneurium
are the three connective tissue layers of the peripheral nerve
Epineurium
outer layer that becomes continuous with the dura mater
Perineurium
layer surrounding a fascicle (bundle of axons)
Endoneurium
layer surrounding a single axon
Where will you find neurons?
CNS and PNS
Soma
cell body of the neurons
Axons/Dendrites
one or more specialized, slender processes of the neuron
Dendrites/Soma
a "receptive" or input region of the neuron
Axon
a "conducting" component of the neuron
Axon Terminal
a "secretory" (output) region of the neuron
What is this type of neuron?
Bipolar Neuron
What is this type of neuron?
Pseudounipolar Neuron
What is this type of neuron?
Multipolar Neuron
What is this image of?
Oligodendrocytes
What is this image of?
Astrocyte
What is this image of?
Microglia
What is this image of?
Ependymal Cells
What is this image of?
Schwann Cells
Describe the bottom cell.
Satellite cells are part of the peripheral nervous system. They surround neuron cell bodies in the ganglia, regulate O2, CO2, nutrient, and neurotransmitter levels around the neurons in ganglia.
...
Be able to label parts of this image!
...
Be able to label parts of this image!
What is the arrow pointing to?
White Matter
What is the arrow pointing to?
Gray Matter
Which glial cell in the CNS is analogous to Schwann's?
Oligodendrocytes
Compare the myelination in the CNS vs the PNS.
Schwann cells (PNS) myelinated around ALL axons of the cell bodies while Oligodendrocytes (CNS) myelinated around each axon separately.
Are nerves part of the CNS or PNS? How about tracts?
Nerves=PNS
Tracts=CNS
Select the correct statement(s) about tracts in the nervous system:
1. usually have ascending and descending fibers
2. are part of the gray matter in PNS
3. are part of the white matter in the CNS
4. all of the above
Are Part of the White Matter in CNS
Label #8 and what flows through the little arrows
Dura
CSF
What type of neuron is multipolar in structure and is located entirely within the CNS?
Interneuron
What type of commands carry the corticospinal tract?
Somatic Motor
Which of the following divisions of the nervous system carries motor commands to muscles and glands?
1. afferent division of the CNS
2. afferent division of the PNS
3. efferent division of the CNS
4. efferent division of the PNS
Efferent division of the PSN
Which of the following structures provide pressure, pain, and temperature sensations?
1. special sensory receptors
2. visceral sensory receptors
3. sympathetic division of the autonomic nervous system
4. somatic sensory receptors
Somatic Sensory Receptors
Sensory neurons of the PNS, which may be myelinated, are usually:
1. multipolar
2. anaxonic
3. pseudounipolar
4. bipolar
Pseudounipolar
Which of the following is a function of astrocytes?
1. they perform repairs in damaged neural tissue and contribute to the selective permeability of CNS vasculature
2. they are usually phagocytic cells of the CNS, which engulf cellular debris, waste produ
They perform repairs in damaged neural tissue and contribute to the selective permeability of CNS vasculature
A synapse between neurons may involve a synaptic terminal and which of the following?
1. dendrite
2. axon
3. cell body
4. all of the above
All of the Above