Mesenchymal connective tissue
Mesenchyme forms the undifferentiated "filling" of the early embryo. It consists of mesenchymal cells, which interconnect by slender cell processes. Mesenchymal cells have stem cell properties, i.e. they are able give rise to other cell and tissues types. The wide extracellular space between the mesenchymal cells is occupied by ground substance, which can be stained with dyes that also stain mucin - hence the alternative name of this tissue type: mucoid connective tissue. Collagen or reticular fibres may not be visible at all or form a loose network between the cells. With fetal development, mesenchyme forms the connective tissue between and within the developing tissues and organs. Mucoid connective tissue also forms a compliant cushion around the vessels of the umbilical cord, where it is also called Wharton's jelly.
In adult humans, mesenchymal connective tissue is only found in the dental pulp.
sections of umbilical cord, tooth (pulp), or sections of embryonic and early foetal development - H&E, Azan or Alcian blue & van Gieson
section usable for "intramembranous ossification" during foetal development will contain areas of mucoid connective tissue around the developing bone.
section usable for "intramembranous ossification" during foetal development will contain areas of mucoid connective tissue around the developing bone.
Umbilical Cord, Human - H&E and
Foetal Kidney, Human - H&E
Within the umbilical cord you will be able to identify three large vessels and their walls. Mucoid connective tissue fills the space between the vessels and the simple squamous epithelium lining the surface of the umbilical cord. Note the very fine appearance of the collagen fibres and the lack of apparent specialisations in this type of connective tissue.
The number of cells and appearance of the collagen fibres vary depending on the precise location of the tissue. In some locations, mucoid connective tissues will contain a large number of cells and only a few, very delicate collagen fibres. Examples are dental pulp and the mucoid connective tissue which is found between the developing tubuli and glomeruli of the foetal kidney.
A small drawing should be sufficient to capture the appearance of the tissue.
Foetal Kidney, Human - H&E
Within the umbilical cord you will be able to identify three large vessels and their walls. Mucoid connective tissue fills the space between the vessels and the simple squamous epithelium lining the surface of the umbilical cord. Note the very fine appearance of the collagen fibres and the lack of apparent specialisations in this type of connective tissue.
The number of cells and appearance of the collagen fibres vary depending on the precise location of the tissue. In some locations, mucoid connective tissues will contain a large number of cells and only a few, very delicate collagen fibres. Examples are dental pulp and the mucoid connective tissue which is found between the developing tubuli and glomeruli of the foetal kidney.
A small drawing should be sufficient to capture the appearance of the tissue.
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