. Text-book of normal histology: including an account of the development of the tissues and of the organs. nnerthat a single meduUatedaxis-cylinder passes to each muscle-fibre. At the point where thenerve pierces the sarcolemma the medullary substance abruptly ends, while the neurilemma, blendedwith the sarcolemma, joins the peri-neuria! (Henles) sheath in forming thetelolemma, or the sheath investingthe end-organ. The axis-cylinder, nowbeneath the muscle-sheath, continuesupon the surface of the sarcous sub-stance, and, later, breaks up into anumber of somewhat tortuous ultimatefibrillae, whic
. Text-book of normal histology: including an account of the development of the tissues and of the organs. nnerthat a single meduUatedaxis-cylinder passes to each muscle-fibre. At the point where thenerve pierces the sarcolemma the medullary substance abruptly ends, while the neurilemma, blendedwith the sarcolemma, joins the peri-neuria! (Henles) sheath in forming thetelolemma, or the sheath investingthe end-organ. The axis-cylinder, nowbeneath the muscle-sheath, continuesupon the surface of the sarcous sub-stance, and, later, breaks up into anumber of somewhat tortuous ultimatefibrillae, which irregularly unite andend in thickened bulbous terminations of the nerve areembedded in a flattened nucleatedmass—the sole-plate—composed ofsoft faintly granular protoplasm, whichresembles sarcoplasm and is closelyapplied to the surface of the muscularsubstance; this mass, together with the embedded nerve-fibrillae,constitutes the motor disk, or end-plate. Each muscle-fibre possesses usually but a single end-plate; inexceptional cases, however, there may be two or more ; likewise,. Motor end-plate of voluntary musclefrom rabbit: n, meduUated nerve-fibrepassing to muscle (>«), on the surface ofwhich the axis-cylinder ends in the darkarborescent figure; the latter lies em-bedded within the nucleated sole-plate(j) composed of granular protoplasm. THE PERIPHERAL NERVE-ENDINGS. 91 several nerve-fibres insteadof a single one may supplythe end-plate. The nerve-endings inthe voluntary muscle ofamphibians and bony fishesdiffer from the foregoing inthe absence of the granularprotoplasmic disk, and inthe more diffuse disposi-tion of the terminal nerve-fibres. The axis-cyhnders,in these cases, branch intofibrillse which extend forsome distance parallel tothe axis of the muscle-fibre and end in slightbulbous expansions ; gran-ular pyriform nuclei alsooccur along the course ofthese fibrillce. The muscle-spindlesdescribed by Kiihne, andconsidered by some(Kerschner) as
Size: 1691px × 1477px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherphiladelphiajblipp
