Term
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Definition
"fight, flight or fright"
Activated during exercise, excitement and emergencies
-blood vessel walls receive only sympathetic stimulation, so at rest, sympathetic is responsible for maintenance of blood pressure |
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Term
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Definition
"rest, digest"
-concerned with conserving energy |
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Term
| Anatomical differences in sympathetic vs. parasympathetic divisions |
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Definition
length of postganglionic fibers
-Sympathetic long fibers
-Parasympathetic short fibers
Branching of axons
- Sym.- highly branched, influences many organs
- parasym.- few branches, localized effect |
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Term
| Neurotransmitter released by preganglionic axons |
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Definition
Acetylcholine for both branches
- receptor is cholinergic |
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Term
| Neurotransmitter released by postganglionic axons |
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Definition
Sympathetic- most release norepinephrine, the receptor is adrenergic
Parasympathetic- release acetylcholine |
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Term
| Adrenergic Receptor subtypes- Alpha |
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Definition
- excitatory except in the gut
-alpha 1- (postsynaptic)- blood vessels, eye, sphinter, genitals, bladder, gut, liver, heart
-alpha 2-( presynaptic in PNS, pere- and postsynaptic in CNS)- blood vessels, pancreas, platelets |
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Term
| Adrenergic receptor subtypes- Beta |
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Definition
inhibitory except in the heart
- Beta1- heart, kidney
-Beta 2- lungs, vascular, gastrointestinal, genitourinary smooth muscle
-Beta 3- adipose |
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Term
| Cells of the Nervous System |
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Definition
Neurons- excitable cells that transmit electrical signals
-variable in size
- Microtubules, neurofibrils, microfilaments
Supporting Cells- cells that surround and wrap neurons |
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Term
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Definition
(Neuroglia or glial cells)
-provide supportive for neurons
-segregate and insulate neurons
-guide young neurons to the proper connections
-promote health and growth |
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Term
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Definition
schwann cells
satellite cells |
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Term
| In the CNS the neuroglial cells include- |
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Definition
Astrocytes
oligodendrites
microglia
epindymal cells |
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Term
| General Functions of Supporting cells |
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Definition
-protect the neuron
-Mylinate the cytoplasmic extentions of the neurons (oligodendrites and schwann cells) |
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Term
| Similarity and Differences between neuroglia and neurons |
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Definition
Similarity- they have fibrous cellular extentions
differences- They cannot generate or transmit nerve impulses |
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Term
|
Definition
highly branched glial cells
functionally- support neurons, anchor neurons to their nutrient supplies
- guide migration of young neurons
- control chemical environment |
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Term
|
Definition
small, ovoid cells with spiny processes
-Phagocytes that monitor the health of neurons |
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Term
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Definition
range in shape from squamous to columnar
-they line the central cavities of the brain and spinal column |
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Term
| define Oligodendrocytes, Schwann cells, and Satellite cells |
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Definition
Oligodendrocytes- branched cells that wrap CNS nerve fibers
Schwann cells- (neurolemmocytes)- surround fibers of the PNS. forms the myelin sheath
Satellite cells - surround neuron cell bodies with ganglia |
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Term
| The Neurons- identify the structural units of the nervous system |
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Definition
| Answer is in slide show titled as The Neurons ( nerve Cells) |
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Term
| What is the 3 components of the neuron? |
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Definition
| Cell body, dendrites, Axons |
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Term
Cell body?
Also what is the densely packed bodies in the PNS and CNS called? |
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Definition
-located mainly in the CNS
-Densely packed bodies in the CNS are nuclei
_Densely packed bodies in the PNS are ganglia |
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Term
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Definition
| receptive portion of the neuron |
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Term
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Definition
| -carry nerve impulses away from the cell body |
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Term
Axons-
Explain what is?- Axon hillock, Initial segment of the axon, myelin, Endoneurium, and Neurilemma |
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Definition
Axon hillock- cone shaped, nissl free ara, where the axon leaves the cell body
Initial segment of the axon- area of the axon that has the lowest threshold for stimulation, so the action potentials start at this point
myelin- segmented layer of lipid material, insulating substance, formed and maintained by the schwann cell
Endoneurium- delicate layer of connective tissue around each axon
Neurilemma- thin layer between the myelin sheath and the endoneurium |
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Term
| Explain what the nodes of Ranvier is, which is located within the axon? |
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Definition
| regular interruptions of the myelin sheath |
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Term
| Explain the 3 different characteristics that takes place within the the neuron? (i.e. convergence) |
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Definition
Saltatory conduction- the flow of ions between segments of the myelin rather than along the entire length of the axon
Divergence- ability of branching axons to influence many neurons
Convergence- branches of numerous neurons converging on one or a few neurons |
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Term
| Nerve cell body (Perikaryon or Soma) |
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Definition
- contains te nucleus and a nucleolus
no centrioles
well developed nissl bodies (rough ER)
contains an axon hillock |
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Term
|
Definition
-Generate and transmit action potentials
-secrete neurotransmitters from the axonal terminals |
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Term
| How does movement occur in the axon? |
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Definition
Antegrade- toward axonal terminal
Retrograde- away from axonal terminal |
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Term
| Myelin Sheath- what is it? what is the function? how was it formed? |
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Definition
-whitish, fatty, segmented sheath around most long axons
function- protect the axon, electrically insulate fibers from one another, increase the spend of nerve impulse transmission
-formed b schwann cells in PNS |
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Term
|
Definition
-envelopes an axon in a trough
-encloses the axon with its plasma membrane
Neurilemma- remaining nucleus and cytoplasm of a schwann cell |
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Term
| Nodes of Ranvier (Neurofibral nodes) |
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Definition
-gaps in the myelin sheath between adjacent schwann cells
- they are the sites where axon collaterals can emerge |
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Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
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Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
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Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
|
Term
|
Definition
-both myelinated and unmyelinated fibers are present
-no neurilemma
myelin sheaths are formed by oligodendrocytes
- nodes of ranvier are widely spread |
|
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Term
| Regions of the brain and spinal cord |
|
Definition
white matter- dense collections of myelinated
gray matter- mostly soma and unmyelinated fibers |
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Term
|
Definition
Multipolar- 3 or more processes
Bipolar- 2 processes (axon dendrite) attached to cell body
Unipolar- single, short process that divides to form peripheral and central processes
Pseudounipolar- single, short process that divides to form 2 or more axon like processes |
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Term
| Neuron functional classification |
|
Definition
Sensory (afferent)- transmit impulses toward the CNS
Motor (efferent)- carry impulses away from the CNS
Interneurons (association neurons)- shuttle signals through CNS pathways |
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