Search results
Results From The WOW.Com Content Network
The Purkinje fibers are further specialized to rapidly conduct impulses (having numerous fast voltage-gated sodium channels and mitochondria, and fewer myofibrils, than the surrounding muscle tissue). Purkinje fibers take up stain differently from the surrounding muscle cells because of having relatively fewer myofibrils than other cardiac cells.
Parallel fibers pass orthogonally through the Purkinje neuron's dendritic arbor, with up to 200,000 parallel fibers [6] forming a Granule-cell-Purkinje-cell synapse with a single Purkinje cell. Each adult Purkinje cell receives approximately 500 climbing fiber synapses, all originating from a single climbing fiber from the inferior olive. [ 7 ]
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...
One exception is that fibers from the flocculonodular lobe synapse directly on vestibular nuclei without first passing through the deep cerebellar nuclei. The vestibular nuclei in the brainstem are analogous structures to the deep nuclei, since they receive both mossy fiber and Purkinje cell inputs. [2]
Early in development, Purkinje cells are innervated by multiple climbing fibers, but as the cerebellum matures, these inputs gradually become eliminated resulting in a single climbing fiber input per Purkinje cell. These fibers provide very powerful, excitatory input to the cerebellum which results in the generation of complex spike excitatory ...
The parallel fibers are sent up through the Purkinje layer into the molecular layer where they branch out and spread through Purkinje cell dendritic arbors. These parallel fibers form thousands of excitatory Granule-cell-Purkinje-cell synapses onto the dendrites of Purkinje cells. This connection is excitatory as glutamate is released.
Muscle cells are grouped into muscle fascicles by enveloping perimysium connective tissue. [1] Fascicles are bundled together by epimysium connective tissue. [1] Muscle fascicles typically only contain one type of muscle cell (either type I fibres or type II fibres), but can contain a mixture of both types.
Each Purkinje cell receives excitatory input from 100,000 to 200,000 parallel fibers. Parallel fibers are said to be responsible for the simple (all or nothing, amplitude invariant) spiking of the Purkinje cell. Purkinje cells also receive input from the inferior olivary nucleus via climbing fibers. A good mnemonic for this interaction is the ...