BIOL 2100 Lecture Notes - Lecture 2: Dense Irregular Connective Tissue, Integumentary System, Epithelium
Document Summary
Skin is composed of the epidermis and the dermis. Often we share the hypodermis as well, although the hypodermis is not officially considered part of the integumentary system. Skin is also called the cutaneous membrane which means that the subcutaneous, or sub-q space is the hypodermis. The dermis is made of connective tissue that anchors the epidermis to the deeper tissues. The dermis itself is subdivided into 2 layers. Papillary layer made of areolar loose connective tissue. Reticular layer made of dense irregular (fibrous) connective tissue. The papillary layer forms hills and valleys that sandwich together with corresponding hills and valleys of the epidermis. Dorland"s medical dictionary defines papilla as " a small nipple shaped projection, elevation, or structure. in other words, the tiny hills are papillae (the plural for of papilla) and this layer is known as the papillary layer. Filling these papillae, we find loose connective tissue in the form of areolar connective tissue.
