vein
1. Blood vessel that returns blood from the microvasculature to the heart, walls thinner and less elastic than those of artery.
2. In leaves, thickened portion of leaf containing vascular bundle, the pattern, venation, is characteristic for each species.
Leaves are the major photosynthetic organ of a plant. Apart from that, they are also crucial to water movement. In this tutorial, various plant processes are considered in more detail. It also includes topics on leaf arrangements, leaf types, leaf structure, leaf color, abscission, and importance to humans...
Ferns and their relatives are vascular plants, meaning they have xylem and phloem tissues. Because of the presence of vascular tissue, the leaves of ferns and their relatives are better organized than the mosses and liverworts. ..
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...
The circulatory system is key to the transport of vital biomolecules and nutrients throughout the body. Learn about the different components and functions of the human circulatory system dealt with in detail in this tutorial. The lymphatic system is also elucidated elaborately here...
