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T Masegi

Publications and source records attributed to T Masegi.

At least 91 records · Page 5Linked to original sources
PubMed1978

Electron microscopic study of the snout muscle spindles of the mole following denervation.

The authors examined electron microscopically the daily effects of the muscle spindles of the mole snout muscles following unilateral facial neurotomy. The denervated muscle spindles show first a degenerative sign of the sensory end bulb 1 day after the operation and later a degenerative sign of the intrafusal muscle fibers one week after the operation. The muscle spindles on the untreated side show first a degenerative sign of the intrafusal muscle fibers 2 weeks after the operation and later a degenerative sign of the sensory end bulb 20 days after the operation. 40 to 90 days after the operation, the spindles on both sides show the same degenerative signs, the intrafusal muscle fibers having become much thinner than the control.

Animals↗
PubMed1977

Muscle spindle supply to the human jaw muscle.

Histological study of the human jaw muscle revealed that the temporal muscle displayed 342 muscle spindles, 208 in the horizontal and 134 in the vertical portion; the masseter muscle contained 114 spindles, 91 in the superficial and 23 in the profound portion; the medial pterygoid muscle had 59; and the lateral pterygoid muscle contained 6, four in the upper head and two in the lower head. These data suggest that the extensive mobility of the temporomandibular joint, and the maintenance of mandibular posture during mastication and speech are strongly influenced by proprioceptive mechanisms.

Fetus↗
PubMed1975

Muscle spindle supply to the snout musculature in moles (Talpidae).

To define the anatomical background of the neuromuscular mechanism involved in the movement of the snout of the moles (Talpidae) the present histological study was carried out on the snout muscles of this family including the Japanese shrew-mole (Urotrichus talpoides), Japanese lesser shrew-mole (Dymecodon pilirostris) and Temminck's mole (Mogera wogura). The snout musculature consists of five muscles: A) Zygomaticus major, B) Levator labii superioris, C) Levator alae nasi superioris, D) Levator alae nasi inferioris and E) Zygomaticus minor, the former two of which are the possessor of the muscle spindles and the latter three of which are not so, with the exception of the Zygomaticus minor having one spindle in the Japanese shrew-mole. Seventy-three spindles were counted on one side of the snout musculature in the Dymecodon pilirostris (12 g in weight), 120 spindles in the Urotrichus talpoides (19 g in weight) and the Mogera wogura (100 g in weight). The snout musculature was 0.015 g, 0.02 g and 0.1 g in weight, respectively. The number of spindles per milligram weight of the muscle was 4.9 in the Dymecodon, 6 in the Urotrichus and 1.2 in the Mogera. The density of the spindle distribution was much higher in the former two than in the latter one. Since the Dymecodon and Urotrichus actually search for food by moving their long snout vigorously over the ground and the Mogera, being a subterranean, searches for food by moving his snout not so vigorously under the ground, the pattern of the snout movement seems to be coincident with the morphological differentiation of the snout musculature and the density of the muscle spindle distribution in the moles (Talpidae).

Animals↗
PubMed1975

Topological distribution of muscle spindles in the human tongue and its significance in proprioception.

In order to obtain numerical data concerning the lingual muscle spindle distribution, the muscle spindles were histologically surveyed on the serial frontal and horizontal sections (stained by hematoxylin-eosin) from the apex to the radix of the tongue. On one side four hundred and sixty-six muscle spindles were counted in seven muscles, the superior longitudinal muscle containing 159 spindles, the genioglossus 80, the transverse 79, the styloglossus 75, the hyoglossus 37, the inferior longitudinal 22 and the vertical 14. The chondroglossus and the palatoglossus are devoid of the spindles. The question of whether the proprioceptive impulses from the lingual spindles lie in the hypoglossus nerve or in the lingual nerve has remained unsolved. This histological confirmation of the pathway and primary cell station of the lingual proprioceptive afferents is the subject in which the authors are greatly interested.

Humans↗