HISTOMORPHOLOGY OF MUSCLE-SPINDLE OF MASTICATORY MUSCLES IN THE GOAT

Muscle spindles of 5 different regions of the masticatory muscles from 5 goats, aging 1 year were studied. Typical muscle spindles were obse rved in the buccinator, masseter, pterigoideus, temporalis and digastr icus muscles. The capsule of the muscle spindle contained elastic fibr es in addition to collagenous fibres. Two types (nuclear bag fibres an d nuclear chain fibres) of intrafugal fibres were observed in each spi ndle and fibres were associated with 3 kinds of nerve endings, viz. pr imary sensory ending, secondary sensory ending and polar nerve endings . The density of spindles in the masticatory muscles was compared with that of other skeletal muscles from different body regions. The muscl e spindles in this study were of simple category with relatively small er size. Each spindle contained 3 to 5 nuclear bag fibres with 18 to 2 4 mu in diameter. Nuclear chain fibres varied from 4 to 10 mu spindle. Minor salivary glands among the fasciculi of the buccinator and masse ter muscles were recorded. it is concluded that the masticatory muscle s were fatigue resistant and less dependent on strech sensitivity in t he goat.