The dermis is tightly connected to the epidermis through a basement membrane. Structural components of the dermis are collagen, elastic fibers, and extrafibrillar matrix. It also contains Mechanoreceptors that provide the sense of touch and thermoreceptors that provide the sense of heat.part from these cells, the dermis is also composed of matrix components such as collagen (which provides strength), elastin (which provides elasticity), and extrafibrillar matrix, an extracellular gel-like substance primarily composed of glycosaminoglycans (most notably hyaluronan), proteoglycans, and glycoproteins.
Ischemia is a condition in which the blood flow (and thus oxygen) is restricted or reduced in a part of the body. Cardiac ischemia is the name for decreased blood flow and oxygen to the heart muscle. What is ischemic heart disease? It's the term given to heart problems caused by narrowed heart arteries.
Untreated heart attacks may slow blood flow enough that blood may start to clot and prevent the flow of blood to the brain or other major organs. Extremely low blood pressure can also result from drug overdose and reactions to drugs. Therefore, brain ischemia can result from events other than heart attacks.