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Medicinal plants (PG 101)                                        Level 1                              Clinical Pharmacy-PharmD



                                                             B) Vessels

                                Vessels are narrow or wide water conducting tubes, formed from                           B) Xylem parenchyma
                                  number of cells, by a partial or complete disintegration of their end                   ▪  Living            cells,
                                  walls. (perforated end walls)                                                              scattered      among

                            They may be:                                                                                     tracheary  elements
                                a-Protoxylem (narrow) (annular-    spiral)                                                   and      fibers      or
                             b-Metaxylem(wide) (reticulate - bordered pitted)                                                aggregate into rays.
                                                                                                                          ▪  Thin walled but often
                                                                                                                             with lignified walls.

                                                               Reticulate                                                 ▪  Function:      storage
                                                                                                                             and  conduction  of
                                               Spiral           vessels
                                                                                                                             materials  across  the
                                               vessels                                                                       tracheary elements.





                                                              Bordered
                                            Annular            pitted

                                             vessels           vessels







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