Because of the many causes of transient visual disturbance, a structured approach to both the assessment and the management of these patients is essential. The likely causes of transient vision loss (TVL) vary according to the age of the patient.
The mantle cavity is a central feature of molluscan biology. This cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space. This space contains the mollusc's gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity functions as a respiratory chamber in most molluscs.In bivalves it is usually part of the feeding structure. In some molluscs the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a locomotory organ.The mantle is highly muscular.he mantle cavity is a central feature of molluscan biology. This cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space. This space contains the mollusc's gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity functions as a respiratory chamber in most molluscs.
Two functions of a clam's gills are to extract oxygen from the water and separate sand particles from food particles and water when being digested.he gill filaments are the hair-like structures on the gills which absorb the oxygen from the lamallae. The gill arch, on the other hand, acts as a form of muscle which holds â¦ the structures of the gills together. ~Sincerely, A Smarty pants :). + 21 others found this useful.