Flashcards in Nervous Tissue Deck (81):
Describe the basics of the neural tissue (cells, ECM, & vascularization)
- abundance of cells
- scarcity of ECM
Neurons are supported by a small amount of what CT?
Neurons are also closely associated by what supporting cells?
Schwann cells, satellite cells, gila
Clusters of the cell bodies of neurons in the CNS
Clusters of the cell bodies of neurons in the PNS
Bundles of neuronal processes in the CNS
Bundles of neuronal processes in the PNS
Areas of the CNS containing predominantly myelinated neuronal processes
Whit matter of the CNS
Areas of the CNS containing predominantly neuronal cell bodies (they may be aggregated to form nuclei; they may form layers; or, as in the spinal cord, a mass of tissue which shows a butterfly-shaped image in cross sections of the spinal cord.)
Gray matter of the CNS
the neuron is composed of a cell body, referred to as the ..., and one or more cell processes.
soma or perikaryon
Cell processes are classified on the basis of function, Those which function in the reception of stimuli are termed ...
If the neuronal soma functions as a receptor site it is included in the ...
The single process that conducts an impulse away from the dendritic zone is termed the ...
What is the effector portion of the neuron?
Unipolar neurons have a single process. They are common in ...
sensory ganglia; sensory modality
Bipolar neurons have two processes. They are associated with ...
special senses of sight, and smell
Multipolar neurons have three or more processes. They are common in the CNS, ..., also in the PNS in the ...
PNS in the sympathetic ganglion
The supportive cell of the CNS
The supportive cell of the PNS
Neurilemma (Schwann cells)
The supportive cell of the ganglia
What is the most abundant type of gila cell?
Neurogila cell that anchor neurons to their blood supply
What 2 things do Astrocytes do to regulate the external chemical environment of neurons?
- remove excess ions, notably Potassium
- Recycle NTs released during synaptic transmission
What neurogila cell coats axons of the CNS with their cell membrane, called myelin, producing the myelin sheath?
These neurogila cells line the cavities of the CNS and make up the walls of the ventricles
What are the 2 functions of the ependymal cells?
Secrete CSF & beat their cilia to help circulate that CSF
These supportive cells of the CNS are not technically neurogila, but they are specialized .... capable of ... that protect neurons of the CNS.
macrophages capable of phagocytosis
CT proper forms what three things?
- meninges of the CNS
- capsules of ganglia
- fibrous storm of the PNS
Where are neuronal cells bodies found?
- nuclei & gray matter of the CNS
- within the ganglia in the PNS
What is the euchromatin content of the nucleus of a neuron?
there is abundant euchromatin
- nucleoplasm is typically pale
What appears as basophilic granules or clumps of material in cells prepared for LM?
Nissl substance represents concentrations of ..., which may extend into the ...
- may extend into the dendrites but not the axon
Abundance of Nissl Substance suggests ...
active synthesis of proteins
Neurofibrils are made up of ..., like those seen in other cells
intermediate filaments and microtubules
Intermediate filaments and microtubules of neurofibrils may function in the transport of materials ...
out of the SOMAL region and distally in CELLULAR PROCESSES
What accumulates in the soma as a neuron ages?
lipofuscin pigment (yellow-brown)
Lipofuscin pigment can be seen confined within vesicles , which may have been lysosomes at an earlier time. The pigment represents an ...
indigestible end-product by lysosomal activity
What is the only organelle not present in dendrites?
The site of axon origin from the cells body is made conspicuous by the abrupt disappearance of ...
the origin of the axon, is called the ..., and is seen as an area of pale cytoplasm
The axon gives off occasional branches, along its course, called....
The axoplasm has no ...
GA, rER, or ribosomes
The axoplasm has no mechanism for ...., therefore is is dependent on flow of materials from the cell body.
Bidirectional transport of molecules and selected organelles along the axon.
Moves materials from the soma to axon and dendrite terminals.
What er the microtubule associated proteins for anterograde transport?
Kinesin & ATP
Transport relies on the microtubule-associated protein ... to move materials from the periphery of axons and dendrites to the soma.
Which axoplasmic transport system only employs the fast method of conveyance?
In both forms of axoplasmic transport, ... establish a system of "rails" extending the length of the axon or dendrite.
what % of the myelin is represented by lipid?
What % of the myelin is represented by protein?
The amount of myelin surrounding an axon is directly proportional to the axon's ...
Myelination in the CNS is accomplished by ....
oligodendrocytes, a type of glial cell
During conduction of an excitatory impulse, generation of the AP occurs sequentially at each node (the impulse "skips" from node to node). This is called ...
Encircling the myelin when it is present, is the Schwann cell. The embrace of the Schwann cell constitutes the ...
The neurilemma can't be seen at the LM level but its presence may be indicated by a ...
Synapse located between axon & dendrite
Synapse located between axon & cell body
Synapse where one axon contacts another axon near its beginning or end. (comparatively infrequent)
Connections between the ANS and .... are unusual in that no special junctions (synaptic clefts) are formed. Instead bulbous enlargements of the axon, with aggregates of synaptic vesicles, are seen adjacent to the muscles cells
Heart muscle & Smooth muscle
The peripheral nerves are composed of ... & ...
nerve fibers (axons & their ensheathments) & CT
Nerve fibers (axons) occur in bundles, or ...
Fascicles are gathered together by a surrounding layer of ... to form a nerve
The sleeve of dense CT enclosing the entire nerve is termed the ..., and extensions of this may penetrate between the enclosed fascicles.
Immediately surrounding each fascicle is a thin layer of concentrically arranged dense CT, the ...
Within the fascicle and around each nerve fiber is a meshwork of fine collagen fibers with occasional fibroblasts. The fibrous framework is called the ...
Blood vessels and lymphatics course in the ... and supply capillaries within the ....
epineurium; endoneurial tissue
A collection of nerve cell bodies in the PNS
Each cell body is enclosed by a single layer of ...
flattened satellite cells
Satellite cells are homologous to and continuous with
Schwann cells which invest axons
Immediately superficial to the satellite cell layer are ...
fine collage fibers & fibroblasts
Fine collagen fibers & fibroblasts are continuous distally with ...
the endoneurium of associated nerve fibers
The ganglion is encapsulated by ..., which is continuous distally with the ... of the associated nerve
moderately dense CT; Epineurium
Where is the sensory or dorsal root ganglia found?
roots of spinal & cranial nerves
where are the nuclei of sensory ganglia located?
What type of neurons are sensory ganglia composed of?
Sensory ganglia have abundant ... cells
Where are parasympathetic ganglia found?
in the walls of organs
Autonomic ganglia nuclei are ...
What type of neurons are autonomic ganglia?