Different intrafusal fiber composition of spindles in sheep and pig extraocular muscles

1989 ◽  
Vol 45 (6) ◽  
pp. 563-567 ◽  
Author(s):  
G. Lalatta Costerbosa ◽  
P. A. Scapolo ◽  
A. M. Barazzoni ◽  
M. L. Lucchi ◽  
R. Bortolami
Keyword(s):  
Extraocular Muscles ◽  
Intrafusal Fiber ◽  
Fiber Composition

Structural Organization and Distribution of Fiber Types in Extraocular Muscles of Cats

1972 ◽  
Vol 30 ◽  
pp. 34-35
Author(s):  
Asish C. Nag ◽  
Lee D. Peachey
Keyword(s):  
Fiber Type ◽  
Light And Electron Microscopy ◽  
Small Diameter ◽  
Extraocular Muscles ◽  
Fiber Types ◽  
Distinctive Features ◽  
Superior Rectus ◽  
Adult Cats ◽  
Different Diameters ◽  
Orbital Region

Cat extraocular muscles consist of two regions: orbital, and global. The orbital region contains predominantly small diameter fibers, while the global region contains a variety of fibers of different diameters. The differences in ultrastructural features among these muscle fibers indicate that the extraocular muscles of cats contain at least five structurally distinguishable types of fibers.Superior rectus muscles were studied by light and electron microscopy, mapping the distribution of each fiber type with its distinctive features. A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the carotid arteries of anesthetized adult cats and applied locally to exposed superior rectus muscles during the perfusion.

Intramuscular Nerve and Neuromuscular Junction Alteration In Extraocular Muscles of Diabetic Mice

1985 ◽  
Vol 43 ◽  
pp. 682-683
Author(s):  
Bruce R. Pachter
Keyword(s):  
Diabetes Mellitus ◽  
Peripheral Nerves ◽  
Sudden Onset ◽  
Extraocular Muscles ◽  
Diabetic Patients ◽  
Oculomotor Palsy ◽  
Third Nerve Palsy ◽  
Patients With Diabetes ◽  
Intramuscular Nerve ◽  
Oculomotor Nerves

Diabetes mellitus is one of the commonest causes of neuropathy. Diabetic neuropathy is a heterogeneous group of neuropathic disorders to which patients with diabetes mellitus are susceptible; more than one kind of neuropathy can frequently occur in the same individual. Abnormalities are also known to occur in nearly every anatomic subdivision of the eye in diabetic patients. Oculomotor palsy appears to be common in diabetes mellitus for their occurrence in isolation to suggest diabetes. Nerves to the external ocular muscles are most commonly affected, particularly the oculomotor or third cranial nerve. The third nerve palsy of diabetes is characteristic, being of sudden onset, accompanied by orbital and retro-orbital pain, often associated with complete involvement of the external ocular muscles innervated by the nerve. While the human and experimental animal literature is replete with studies on the peripheral nerves in diabetes mellitus, there is but a paucity of reported studies dealing with the oculomotor nerves and their associated extraocular muscles (EOMs).

THE HEXOSAMINE CONTENT OF THE ORBIT IN RELATION TO ANTI-THYROTROPHIN ANTIBODY TITRES IN SERA OF THYROTROPHIN-TREATED RABBITS WITH AND WITHOUT CORTISONE ADMINISTRATION

1962 ◽  
Vol 41 (3) ◽  
pp. 474-480 ◽  
Author(s):  
Otto Wegelius ◽  
E. J. Jokinen
Keyword(s):  
Connective Tissue ◽  
Guinea Pigs ◽  
Antibody Formation ◽  
Direct Proof ◽  
Significant Rise ◽  
Extraocular Muscles ◽  
Concomitant Treatment ◽  
Antibody Titres ◽  
Hexosamine Content ◽  
Synergetic Action

ABSTRACT In all previous investigations on experimental exophthalmos, heterologous thyrotrophic pituitary extracts have been used. These protein hormones stimulate antihormone formation in the test animals. Cortisone has been reported to effectively block antibody formation. In addition, it has been shown to potentiate TSH-induced exophthalmos in guinea-pigs. With rabbits as test animals, the hexosamine content of the orbital tissues was determined and used as an index of exophthalmos development and at the same time the antibody titres in the sera were followed. TSH injections for six weeks led to a highly significant accumulation of hexosamine in the retrobulbar connective tissue and in the extraocular muscles, i. e. an increase of up to 400% as compared with the control animals. At the same time a significant rise in antihormonal titres was detectable in the sera. Concomitant treatment with cortisone brought about an equal or higher accumulation of hexosamine but significantly lower antibody titres. The known opposite peripheral actions of TSH and cortisone can be reconciled with the synergy in producing experimental exophthalmos by attributing the synergetic action of cortisone to the blocking of antihormone formation. If less antihormones are produced, the effect of TSH is enhanced. Our experiments do not provide direct proof for this hypothesis. High hexosamine values in the orbit and low antihormone titres in the serum are, however, concomitant phenomena.

RESULTS OF POLARIZED LIGHT USE FOR STUDY OF STRESS-STRAIN STATE OF CORNEA IN PATHOLOGY OF EXTRAOCULAR MUSCLES

2020 ◽  
pp. 65-69
Author(s):  
Nataliia Mykhailivna Kovtun ◽  
Ihor Volodymyrovych Kaplin
Keyword(s):  
Interference Pattern ◽  
Optical Anisotropy ◽  
Extraocular Muscle ◽  
Strain State ◽  
Polarized Light ◽  
Attachment Site ◽  
Rectus Muscle ◽  
Extraocular Muscles ◽  
Asymmetric Distortion ◽  
Interference Picture

The parameters of interference patterns observed on the cornea in a polarized light in pathology of extraocular muscles were quantitatively evaluated. A study of the shape of 147 interference patterns observed on the cornea in a polarized light showed that the horizontal deviation of an eye in 56 % of cases was caused by the displacement of the attachment of the upper rectus muscle towards the inner rectus muscle. During illumination of the cornea of a live eye with polarized light, a specific interference pattern in the form of a rhombus formed by rainbow stripes (isochromes) is observed. It is established that such an interference pattern is the result of the influence of extraocular muscles on the cornea. The findings showed that the weakening of the force of one of muscles leads to asymmetric distortion of the shape of the interference rhombus, which is manifested with a reduced length of the corresponding section of the diagonal. On the contrary, as the force of the muscle increases, the corresponding section of the diagonal enhances. The displacement of the attachment site of direct extraocular muscle along the line of action is equivalent to a change in effort on its part, indicated appropriately by the shape of the interference rhombus. As the muscle moves away from the line of action, the angle of the interference rhombus is shifted away from the corresponding meridian. Key words: polarized light, optical anisotropy, cornea, extra−ocular muscles, interference picture.

Sign in / Sign up

Export Citation Format

Share Document