7.2: Physiology of the Integumentary System: RepairThe smallest unit of life is a cell. Cells come together to formtissues.Tissuesare comprised of cells, which are similar in structure andfunction. Tissues are comprised of cells andmatrix. Matrix is alsocalledextracellular material, made up of ground substance (extracellularfluid), protein, and collagen fibers. When the skin is damaged, both tissueand matrix need to be repaired.Tissue RepairIn the case of tissue damage, the body needs to respond quickly to preventblood loss in and microorganisms from entering the bloodstream. Tissues,such as the skin, can be repaired by the body through a multi-stepprocess(Figure 7.10). Bloodplatelets(Figure 7.11)from the broken bloodvessel start to accumulate in the area where the tissue was damaged,forming aclot, secreting a mesh-like substance around it to prevent bloodloss(Figure 7.11).Figure 7.10 Tissue damage: Skin is cut by a foreign object.
Figure 7.11 Tissue repair:Platelets gather in the broken blood vessel andform a clot.