Question

question identify the structure indicated. lumen lipid ground substance cytoplasm

Explanation:

The lumen is the central cavity of a tubular structure. Lipids are molecules, ground - substance is the non - fibrous part of connective tissue matrix, and cytoplasm is the part of the cell between the cell membrane and the nucleus. The structure indicated appears to be a cavity within a tissue structure, which is consistent with the definition of a lumen.

Answer:

Lumen