Histochemical Fibre Types in Human Extraocular Muscle
نویسنده
چکیده
It has long been known that the striated muscle fibres of which the extraocular muscles are composed differ in many respects from skeletal muscle in general. Their relatively small size, rich innervation, their small motor units and the presence of a proportion of fibres with multiple endplates are special characteristics which are recounted in most modern texts of ophthalmology. There are three sizes of extraocular muscle fibre, but pathologists called upon to examine biopsies of extraocular muscle are sometimes unaware of the normal fibre calibre variation and are tempted to make
منابع مشابه
Differentiation of fibre types in an extraocular muscle of the rat.
Mammalian extraocular muscles possess greater variation in structural and physiological properties than any other muscle. The superior rectus muscle of the adult rat contains five morphological fibre types. The differentiation of the muscle into these fibre types in embryonic and postnatal rats were studied by light and electron microscopy, and the distribution of each developing fibre type wit...
متن کاملHistochemical Differentiation of Skeletal Muscle in Foetal and Newborn Mice.
I N earlier investigations of muscle development, morphological criteria, such as diameter and staining with routine methods, have been used for classifying different fibre types. In human foetal muscle three fibre sizes are seen from the 15th week (Cuajunco, 1942). The largest fibres seem to be the centre of each primary muscle bundle. They were denoted as B fibres by Wohlfart (1937), who cons...
متن کاملThe histochemical profiles of fibre types in porcine skeletal muscle.
Using a variety of histochemical methods -mATPase staining after alkaline and acid preincubations, NADH-TR and alpha-MGPDH- we have investigated the fibre types in porcine skeletal muscle. The results reveal that four major fibre types -I, IIA, IIB and II*- can be separated histochemically in Longissimus lumborum muscle of Landrace pigs. The histochemical properties of the muscle fibre type II*...
متن کاملEffects of chronic denervation on the histology of canine extraocular muscle.
The histologic and enzyme histochemical characteristics of chronically denervated dog extraocular muscle (EOM) were studied. Our results show atrophy of coarse and granular fibers, with relative sparing of fine fibers. Thus experimentally denervated EOM does not demonstrate the familiar changes of denervated limb muscle but shows prominent atrophy of two of the three EOM fiber types. (INVEST OP...
متن کاملExtra- and intrafusal muscle fibre type compositions of the human masseter at young age In perspective of growth and functional maturation of the jaw-face motor system
Muscles control body posture and movement by extrafusal and intrafusal (muscle spindle) fibres. The purpose of this thesis was to provide insight into the muscular basis for human jaw function at young age. Extrafusal and intrafusal fibres in the young masseter, and for comparison young biceps, were examined for composition of fibre types and myosin heavy chain (MyHC) isoforms by means of morph...
متن کامل