Plasma cells are mature B lymphocytes that produce large quantities of antibodies. They are abundant wherever antigens may enter the body, such as the gastrointestinal tract and the respiratory system. Eosinophils are involved in many inflammatory processes, including parasitic infections, allergic diseases, and asthma. Chapter 3 - Connective Tissue Connective tissue provides support, binds together, and protects tissues and organs of the body.
Connective Tissue Fibers The three types of connective tissue fibers are: Collagen fibers - most are type I collagen most abundant protein in the body Tensile strength - resistance to stretching Elastic fibers - contain elastin and fibrillin Elasticity - can be stretched, yet still, return to its original length Reticular fibers - contain type III collagen Support - network of thin fibers Different stains can be used to visualize each type of fiber.
MH Mesentery. MH Lymph Node. MHS Spleen. Fig Types of Connective Tissue. MH Connective Tissue. MH a Tendon. MH Thick Skin. MH a Fetal Pig Snout. MHS Umbilical Cord. MHS b Eye. MHS Lymph Nodes. Davis AT Collection. Davis PT Collection. Murtagh Collection. About Search. Enable Autosuggest. You have successfully created a MyAccess Profile for alertsuccessName. Home Books Junqueira's Basic Histology, 14e. Previous Chapter. Next Chapter.
In: Mescher AL. Mescher A. Anthony L. Junqueira's Basic Histology, 14e. McGraw Hill; Accessed November 11, APA Citation Connective tissue. Mescher AL. McGraw Hill. Download citation file: RIS Zotero. Reference Manager. Shortly before Kollar and Baird published their account of epithelio-mesenchymal interactions, Alexander Friedenstein discovered mesenchymal stem cells in mice Mus musculus. In publications from through , Friedenstein, in conjunction with his peers at the University of Moscow in Moscow, Russia, provided evidence from transplantation experiments that stem cells taken from bone marrow can differentiate into mesenchymal tissues, such as fat, bone, and cartilage.
These cells came to be known as mesenchymal stem cells , and have subsequently been found in blood, cartilaginous, skeletal, and fatty tissues. Mesenchymal stem cells provide a reservoir of reserve cells that the body can use for normal or pathological tissue regeneration and repair. The abilities of mesenchymal stem cells to differentiate into different tissues, known as cell potency, has been a cause of debate in recent years, leading researchers to question whether these cells are truly multipotent, and can give rise to multiple cells types.
The potential multipotency of mesenchymal stem cells , in conjunction with their presence in adult organisms, has made them an attractive alternative to embryonic stem cells for research on tissue regeneration.
Current research on mesenchyme spreads across many biological fields. The focus of mesenchyme research, however, divides between two general interests: the role and expression of mesenchyme -specific genes during development, including pathological processes, and the locations and capabilities of mesenchymal stem cells.
While some still investigate mesenchyme at the tissue level, the two current focuses reflect a trend towards the analysis and understanding of molecular-level mechanisms by which mesenchyme functions during development. Beginning with the definition by the Hertwig brothers, mesenchyme research has moved from anatomical investigations in developing embryos, to cellular contributions for organ formation and tissue level interactions, and now to the genetic mechanisms of development and tissue repair.
There is historical continuity within mesenchyme research, but there remain vestiges of the controversy that surrounded this tissue in the late nineteenth century. In her article in which she introduced the biological community to the ectodermal origins of mesenchyme in the head region, Julia Platt also suggested a change in terminology. Mesenchyme of ectodermal origins she specified by the term mesectoderm, while mesodermal mesenchyme she called mesendoderm.
The medical community, especially pathologists, still employs this distinction between mesenchymal sources, only referring to a tissue as mesenchyme if it is derived from mesoderm. Pathologists maintain the distinction because the mesenchymal source determines the type and behavior of a disease. Meanwhile, developmental biologists tend to recognize mesenchyme by a single name, regardless of source. The study of mesenchyme has a long history, from mesenchyme 's recognition within the framework of germ-layer theory, to controversy about mesenchyme 's origins, to uncovering mesenchyme 's roles in morphogenesis and its capacity to produce stem cells.
This history is in part due to the fact that mesenchyme is crucial for embryonic growth and development, as well as maintenance of connective tissues in adulthood. The loose nature of cells within mesenchyme allows the tissue to move and to be molded. Meanwhile, nearly every organ forms through epithelio-mesenchymal interactions, in which mesenchyme provides both the inductive stimulus and determines the path of differentiation. Although little mesenchyme remains in the body during adulthood, the final remnants of this tissue, mesenchymal stem cells , allow connective tissues to repair and regenerate.
Mesenchyme By: Kate MacCord.
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