Nervous Tissue Flashcards
What is the Neural Tissue function?
Detect and respond to continuous changes in external and internal environment.
The CNS is derived embryonically from [] []
Neural Tube
- Ganglia/Neurons are derived embryonically from [] []
- Except: …..?
- Neural Crest
- Olfactory neurons and spirl aganglia of the cochlea
- Neurons carrying information to the CNS are []
- Neurons carring information from the CNS are []
- Afferent
- Efferent
Neurons are specialized to transmit information to other [] and excitable tissues like []
Neurons and excitable tissues like muscle
- The most common type of neurons in vertebrates is the [] neuron
Multipolar
- [] Neurons have a single axon and multiple dendrites.
- [] Neurons have a singel axon and single dendrite
- [] Neurons have single process at the soma which branches
- Multipolar
- Bipolar
- Pseudounipolar/Unipolar
Functional Classification of Neurons:
- Sensory Neurons: receive [] and [] stimuli and conduct information to appropriate [] centers
- [] Neurons: integrate [] and [] neurons
- Motor Neurons: transmit information from the CNS to other [], [], and []
- Internal and External; CNS
- Integrative Neurons; sensory and motor
- Neurons, Muscles, and Glands
- Sensory neurons include these types of Neurons:…
- Integrative neurons include these types of Neurons:….
- Motor neurons include these types of neurons:….
- Pseudounipolar, Bipolar
- Internuerons, Pyramidal Cells, Pukinje Cell
- Motor neurons, presynaptic/postsynaptic ANS neurons.
What are other names for the neuronal cell body?
Soma or Perikaryon
Neuronal Cell Body:
- Large [] with promients [] nucleolus
- rER is arranged into a basophilic [] []
- Prominent [] apparati and numerous []
- Characteristic of cells with high [] rate and lots of [] transport
- Nucleus; basophillic
- Nissl Body
- Golgi; mitochondria
- metabolic rate; vesicular transport
Neuronal cell body has a significant cytoskeleton containing [] and []
neurofibrils
microtubules
[] spines are small provesses which serve to increase synaptic surface area
Dendritic Spines
T/F
Dendrites cannot make proteins
FALSE
Dendrites CAN make proteins.
T/F
- Distally dendrites have many microtubules; Golgi, ribosomes, and Nissl Body
False
- Distally dendrites have many microtubules; Golgi, ribosomes, and Nissl decreases with distance…
- Proximally dendrites have similar cytological features as soma.
The Axon:
- [] Diameter throughout axon
- Limited by plasma membrane called the []
- Begins at the axon [], Contains no [] or []like the soma.
- Has [], abundant microtubules and []
- Uniform
- Axolemma
- Hillock; Golgi and rER
- Mitochondria; neurofilaments
Where would you find the following cytological structures in a neuron cell? (Soma, Dendrites, Axon)
rER, Golgi, Mitochondria, Microtubules, Neurofilaments, Dendritic Spines
-
Soma:
- Tons of rER, Golgi, Mitochondria, Microtubules, Neurofilaments
-
Dendrites:
- Proximally - same cytological featues as Soma
- Distally - no Golgi, Nissle substance decreases (so rER amounts decrease). Has microtubules, Dendritic spines…probably has neurofilaments
-
Axon
- Has mitochondria and a lot of microtubules and neurofilaments….no organelles
What is the most common form of neuronal synapse?
Chemical
(using neurotransmitters)
Define the following Morphologic Types of Synapses:
- Axodendritic Synapse:
- Axosomatic Synapse:
- Axoaxonic Synapse:
- Dendrodendritic Synapse:
- Functional contact between an axon and a dendrite
- Contact between axon and cell soma
- Contact between 2 axons
- Electric synapses between retina amacrine inte-neurons.
What are the 2 functional types of synapses?
Chemical Synapse (neurotransmitters)
Electrical Synapse (Connected by Gap junctions)
T/F
Amino Acids can act as Nuerotransmitters?
True
Examples: glutamic acid (excitatory), GABA, dopamine, serotonin, glycine
Which neurotransmittes are primarily inhibitory in function?
GABA
Glycine
T/F
Dendrites have a smooth surface that is covered by myelin and have no ribosomes and ER in the cytosol.
FALSE
- Axons are smooth, covered by myeling and have no ribosomes/ER
- Dendrites are the opposite.
Axonal Anterograde Transport entails:
Axonal Retrograde Transport entails:
- Anterograde - Moves materials from the soma, to the terminal buoton
- Fast - used to move vesicles/mitochondria
- Slow - Used for regeneration and carries proteins, enzymes
- Mediated by Kinesin
- Retrograde - Moves materials from the terminal buoton to the soma
- Intermediate rate - recycling and viral transport
- Mediated by Dynein
What protein mediates anterograde transport in an axon?
What protein mediates retrograde transport in an axon?
Kinesin
Dynein
What are the supporting cells of the PNS?
What are the supporting cells of the CNS?
- Schwann Cells and Satellite Cells
- Astrocytes, Oligodendrocytes, Microglia, Ependymal Cells
Myelin Sheath:
- Formed by several layers of the [] [] of the myelinating cell
- the sheath is [] continuous along the entirety of the axon
- Commonly visualized using [] staining.
- plasma membrane
- not
- osmium
T/F
An internode is another name for the Node of Ranvier, or the place between myelin sheaths.
FALSE
The internode is the myelin sheaths in between each Node of Ranvier.
What are the three different types of axon fibers?
Type A
Type B
Type C
T/F
Type A axons are efferent in nature
False
Type A are afferent, sensory type neurons.
Type B Fibers:
- Smaller diameter than [] Fibers
- Thinner myelin than [] Fibers
- Conduct at a [] velocity (3-14 m/sec)
- Normally found in [] [] nervous systems
- A Fiber
- A Fiber
- moderate
- post ganglionic Autonomic nervous systems
Type C Nerve Fibers:
- [] Fiber
- [] Myelin
- Conduct at the [] velocity, (.5 - 2 m/sec)
- Ensheathed by [] []
- Normally found in the [] [] of the CNS and functions in [], [], and []
- Thinnest Fiber
- Lack Myelin
- Slowest
- Schwann Cells
- Dorsal Root; Pain, temperature, mechanoreception
Type A Nerve Fibers:
- [] and myelinated
- Exhibit long [] regions
- [] velocity, (15-100 m/sec)
- Acts as main [] reception nerves throughout the body
- Thick
- Internodal
- Highest
- Sensory
What type of inputs do Type A Nerve Fibers recieve?
- Proprioception
- Somatic Motor touch
- pressure Motor to Spindle
- Pain, cold, Touch
What are the 4 types of neuroglial cells?
Astrocytes
Oligodendrocytes
Microglia
Ependymal Cells
[] are a layer of small cuboidal cells surround neurons, providing electrical insulatino and metabolic exchange.
Satellite Cells
Astrocyte:
- [] neurglial cell type
- [] in response to injury/disease
- This can unfortunately generate []
- Buffers [] and []
- Supports [] formation and efficiency
- Forms the [] [] []!
- Largest
- Proliferates
- Tumors
- K+ and Neurotransmitters
- Synapse
- Blood brain barrier
Oligodendrocyte:
- Produces [] in the CNS to insulate and protect axons
- This is similar to [] cells in the PNS
- One oligodendrocyte produces [] myelin sheaths
- Found in both [] and [] matter
- Stains very []
- Myelin
- Schwann cells
- many
- white and grey
- Dark
Microglia:
- Derived from [] origin
- Microglia then become []
- [] of the neuroglia support cells
- At rest, exhibit a small, elongated [] and discrete []
- [] and become [] in response to CNS injury and disease
- monocytic origin
- Phagocytic
- Smallest
- nucleus, with discrete processes
- Proliferate and becom Phagocytic
Ependymal Cells:
- Simple []/[] epithelial cells lining the ventricles of the [] and central canal of the [] []
- [] nuclear location
- Possess both [], for movement of CSF, and []
- cuboidal/columnar; ventricles of brain and central canal of the spinal cord
- Basal
- Cilia; microvilli
- What produces cerebro spinal fluid?
- What type of specialized CNS support cell is this composed of?
- Choroid plexus
- Ependymal
- Group of Neuronal Bodies in the PNS vs CNS
- Bundle of Nerve Fibers in PNS vs CNS
- Group of Neuronal Bodies
- PNS - Ganglia
- CNS - Nuclei
- Bundle of Nerve Fibers
- PNS - Nerve
- CNS - tract
White Matter vs Gray Matter
- White - contain predominately [] fibers and associated [] cells
- Gray - location of [] cell bodies, many [] fibers
- [] Bodies = Gray matter
- White - myelinated fibers, neuroglial cells
- neuronal, unmyelinated Fibers
- Nissl
The Cerebral Cortex is a thin layer of [] matter on the surface of the cerbral hemispheres
Gray Matter
Functions of the Cerebral Cortex include:
- Response to sensory signals from internal/external environment
- Associate, analysis, and consolidation of information to memories
- Initiate motor response
1 is incorrect.
It should be integration of sensory signals from internal/external environment
What are the 6 layers of the cerebral cortex (From outer –> Inner)?
- Molecular Layer (synaptic field of cortex)
- External Granular Layer (interneuron granules)
- External Pyramidal Layer
- interneurongs/pyramidal cells
- Internal Granular Layer
- narrow band of small/large interneurons
- Internal Pyramidal Layer
- Multiform Layer
T/F
Grey matter is exterior to white matter in the Spinal cord?
FALSE
- Grey Matter is inside of white matter in the spinal Cord
T/F
Grey matter is outside of white matter in the brain?
True
Spinal Cord:
Where are Dorsal Roots located and what is in them?
Where are Ventral Roots located and what is in them?
- Dorsal roots are on the “backside” of the horn. The afferent nerves from dorsal root ganglia synapse with interneurons here
- Ventral roots are on the “front” of the horn. The fibers and large perikaria of multipolar motor neurons are found here.
[] [] are fromed from the union of ventral and dorsal roots
Peripheral nerves
What are the 2 types of sensory peripheral Ganglia in the PNS?
Autonomic Ganglia
Cranial Ganglia
Caniospinal Ganglia:
- These ganglia are associated with most [] nerves and the [] roots of spinal nerves
- round, [] cell bodies
- Contain the cell body of [] neurons
- Proccesses have the morphology of []
- Cranial nerves and the dorsal roots of spinal nerves
- pseudounipolar cell bodies
- sensory neurons
- axons
Ganglia are defined as….
Encapsulated collection of neuronal cell bodies located outside of the CNS.
Autonomic Ganglia:
- Located [] the organs they innervate
- [] cell bodies with eccentric nucleus
- Surrounded by [] []
- How are synapses communicated to autonomic ganglia in the body?
- Help regulate: visceral [], [] secretion, control of [] and [] muscle
- near
- multipolar
- satellite cells
- Preganglionic nerves from teh CNS synapse with the ganglia/postsynaptic nerve
- Visceral motility, glandular secretion, control of smooth and cardiac muscle
T/F
Is there a connective tissue layer around nerves?
If so, what cell makes this CT
Yes!
Fibroblasts
What are the 3 layers of a peripheral nerve?
Epineurium
Perineurium
Endonuerium
This is the outermost layer of a nerve…
Epineurium
What CT layer breaks up a nerve into different fascicles?
Perineureum
The [] is a thin layer of reticular fibers produced by Schwann Cells that surround individual nerv fibers
Endoneurium
What forms the blood-nerve barrier and how does it accomplish this?
Perineurium
Squamos epithelial cells are connected by tight junctions that prevent the passive movement of macromolecules
What are the different layers of the Nerve fiber’s outer sheath? What type of CT makes up each layer?
- Epineurium - Dense Irregular CT
- Perineurium - Irregular CT
- Endoneurium - squamos epithelial cells
T/F
If a nerve is severed from an organ there is no way to regenerate the nerve.
False - kinda
- This is true in the CNS - axons cannot regenerate in the CNS
- But the can in the PNS
T/F
Myelin inhibit axon regrowth?
True
