Flashcards
Nervous Tissue
Flashcards do conjunto (54)
- 1These cells conduct electrical impulses.Neurons (nerve cells)
- 2What is the special relationship between glial cells and neurons?There can't be one without the other. Support cells for neurons aid in nerve cell function.
- 3What type of cells support, nurture, and protect neurons?Glial cells
- 4What are 3 types of neurons?bipolar, multipolar, and pseudounipolar
- 5These neurons have a single axon and a single dendrite. They are located in sense organs.Bipolar neurons
- 6What type of neurons have single axon and multiple dendrites?multipolar neurons
- 7The most common type of neurons.Multipolar neurons
- 8These neurons have a single process that extends from cell body and branches into an axon and dendrite. They first develop in the embryo as bipolar cells whose axon and dendrite later fuse into a single process.pseudounipolar neurons
- 9These neurons are located in spinal and cranial ganglia.pseudounipolar neurons
- 10These neurons are coined as the "workhorse" neuron. They aid in moving muscles at the neuromuscular junction.multipolar neurons
- 11What are the two divisions of the nervous system?anatomical divisions
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functional divisions - 12What are the two primary neurons of the functional division of the nervous system?afferent neurons
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efferent neurons - 13What are the two anatomical divisions of the nervous system?CNS
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PNS - 14What two body parts make up the CNS?brain and spinal cord
- 15The PNS consists primarily of _____ ______ and _____.peripheral nerves
ganglia - 16Efferent neurons involve what types of networks?somatic (voluntary)
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autonomic (involuntary) - 17_____ receive stimuli from sensory cells, axons, or other neurons. They convert these signals into small electrical impulses which are transmitted to soma.Dendrites
- 18______ often have arborized terminals which permit a neuron to receive very large number of stimuli.Dendrites
- 19What are two other names for neuronal cell bodies?soma, perikaryon
- 20This portion of the soma lacks rough ER and ribosomes. It also contains microtubules and neurofilaments.axon hillock
- 21These move organelles within a cell, projecting direct axonal flow.microtubules
- 22Part of cytoskeleton, ____ are intermediate filaments of the soma.neurofilaments
- 23This portion of the soma is large with dispersed chromatin and a large nucleolus.Nucleus
- 24Describe the stain of an axon.lack of staining because no Golgi or RER, indicating proteins (darkly stained); traveling down axon hillock cannot be seen also
- 25_____ conduct impulses away from the soma to the axon terminals. May also branch.Axons
- 26While dendrites taper, ____ retain a constant diameter along their course. The diameter is proportional with the size of a cell body, but length is highly variable.axons
- 27The name for neuronal cytoplasm, which is devoid of RER.axoplasm
- 28The term for the axonal plasma membrane.axolemma
- 29This structure of a neuron terminates in axon terminals from which impulses are passed to another neuron or other type of cell (muscle or gland).Axon
- 30An individual axon enveloped by a myelin sheath.nerve fiber
- 31How are myelin sheaths produced?Oligodendrocytes in the CNS
Schwann cells in the PNS - 32Where are oligodendrocytic myelin sheaths found?CNS
- 33Where are myelin sheaths produced by Schwann cells found?PNS
- 34How are lipoprotein sheaths formed?by several layers of plasma membrane of a Schwann cell wrapping around an axon
- 35Segments covered by one Schwann cell are separated by _____ ___ _____.Nodes of Ranvier
- 36How do lipids stain?Not well, so you must identify a lack of staining. Use a special stain that adds dark circles around the layers of Schwann cells being wrapped by lipoproteins.
- 37Describe the thickness proportion between axons and myelin sheaths.The thicker the axon, the thicker the myelin sheaths
- 38Which is faster impulse: a myelinated axon or unmyelinated axon?myelinated axon
- 39How are unmyelinated axons insulated?by astrocyte processes
- 40Where are unmyelinated axons located in the PNS?embedded in Schwann-cell cytoplasm
- 41The most common demyelinating disease.Multiple Sclerosis
- 42What is this disease? - Unknown etiology; immune/viral factors suspected - Multiple areas of demyelination in brain and spinal cord; progressive - Weakness of lower extremities, visual problems, sensory disturbances -CNS systemMultiple Sclerosis
- 43Which myelin disorder is found in the CNS? PNS?CNS = Multiple Sclerosis
PNS = Guillain-Barré Syndrome - 44What is this disease? - PNS system - Acute inflammatory demyelinating disease involving peripheral nerves - Often preceded by viral infection, immunization, or allergic reactions - autoimmune etiology - Ascending muscle weakness and paralysis (moving from lower extremity upward) - Most patients recover but respiratory failure may lead to deathGuillain-Barré Syndrome
- 45This connective tissue is fibrous, dense tissue that forms the external coat of nerves.Epineurium
- 46This layer of modified dense connective tissue surrounds each bundle (fascicle) of nerve fibers. Its inner surface consists of flattened epithelioid cells joined by tight junctions (barrier function).perineurium
- 47This thin layer of loose connective tissue surrounds individual nerve fibers.endoneurium
- 48This matter contains mainly myelinated but also some unmyelinated nerve fibers.white matter
- 49What is the function of pyramidal neurons in the brain?They give spatial recognition.
- 50What is the function of purkinje fibers/cells in the brain?proper movement in coordinated way; pain reception and awareness
- 51What are two important specialized receptors in the brain?Meissner's corpuscles
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Pacinian corpuscles - 52Name this specialized receptor. - Encapsulated receptors in dermis (skin) - fingertips - CT capsule enveloping nerve terminal and its Schwann cell - Fine touchMeissner's corpuscles
- 53Name this specialized receptor. - Encapsulated receptor in dermis, joints, and mesenteries - Multilayered capsule of fibroblasts, collagen, and fluid, surrounding a nerve terminal - Pressure, touch, vibrationPacinian corpuscles
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