. Elementary physiology . Fig. 122.—Section through the orbit and its contents. a, frontal bone ; b, superior maxillary bone ; r, eyebrow ; d, eyelids ; e, conjunctiva; f, the muscle which raises the upper lid ; ^and g , recti muscles ; h, inferior oblique muscle cut across ; i, optic nerve; 2, cornea ; 2', sclerotic ; 3, aqueous chamber; 4, crystalline lens ; 5, vitreous chamber. Four of these muscles run straight forward from the posterior part of the orbit to be inserted to the eyeball in front. They are hence called the recti muscles, and according to position are known as the superior, in
. Elementary physiology . Fig. 122.—Section through the orbit and its contents. a, frontal bone ; b, superior maxillary bone ; r, eyebrow ; d, eyelids ; e, conjunctiva; f, the muscle which raises the upper lid ; ^and g , recti muscles ; h, inferior oblique muscle cut across ; i, optic nerve; 2, cornea ; 2', sclerotic ; 3, aqueous chamber; 4, crystalline lens ; 5, vitreous chamber. Four of these muscles run straight forward from the posterior part of the orbit to be inserted to the eyeball in front. They are hence called the recti muscles, and according to position are known as the superior, inferior, external, and internal rectus, respectively. Their action corre- sponds to these names; thus, the superior rectus raises, while the inferior depresses, the front part of the eyeball; the external rectus turns it outwards in front, and the internal turns it inwards. The other two muscles are called the superior and inferior oblique, from their mode of attachment. The superior oblique muscle is attached to the posterior part of the orbit on the inner side, and passing forward ends in a tendon, which loops round a kind of pulley of fibres attached to the frontal bone, and then passes backward and outward to become fixed to the eyeball at its outer and back portion. When this muscle contracts, it turns the front of the eyeball obliquely outward and downward. The
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Keywords: ., bookcentury1800, bookdecade1890, bookpubli, booksubjectphysiology
