Lumen
(Science: anatomy) The cavity or channel within a tube or tubular organ.
You will also like...
Kidneys and Regulation of Water and Inorganic Ions
The kidneys are responsible for the regulation of water and inorganic ions. Read this tutorial to learn about the different parts of the kidneys and its role in homeostasis...
Digestion and Absorption of Food
The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and then transferred to the internal environment by absorption. Find out more about these processes carried out by the gastrointestinal system through this tutorial...
Plant Cells vs. Animal Cells
Plant cells have plastids essential in photosynthesis. They also have an additional layer called cell wall on their cell exterior. Although animal cells lack these cell structures, both of them have nucleus, mitochondria, endoplasmic reticulum, etc. Read this tutorial to learn plant cell structures and their roles in plants...
Movement of Molecules Across Cell Membranes
Molecules move within the cell or from one cell to another through different strategies. Transport may be in the form of simple diffusion, facilitated diffusion, active transport, osmosis, endocytosis, exocytosis, epithelial transport, or glandular secretion. This tutorial provides elaborate details on each of these mechanisms. Find out how. ..
Genetic Information and Protein Synthesis
Genes are expressed through the process of protein synthesis. This elaborate tutorial provides an in-depth review of the different steps of the biological production of protein starting from the gene up to the process of secretion. Also included are topics on DNA replication during interphase of the cell cycle, DNA mutation and repair mechanisms, gene pool, modification, and diseases...
Cell Structure
A typical eukaryotic cell is comprised of cytoplasm with different organelles, such as nucleus, endoplasmic reticulum, Golgi apparatus, mitochondria, and so on. The cellular contents are surrounded by a double layer, cell membrane. These cellular structures and cell junctions are elaborated in this tutorial...