fissure

Frequently several structures are fissured: the choroid (the pigmented middle layer of the wall of the eye), the retina (the light-sensitive layer of tissue that lines the back and sides of the eye), the ciliary body (the source of the aqueous humour and the site of the ciliary muscle,…

…deep horizontal and an oblique fissure. The left lung, smaller in volume because of the asymmetrical position of the heart, has only two lobes separated by an oblique fissure. In the thorax, the two lungs rest with their bases on the diaphragm, while their apexes extend above the first rib.…