ANAT 9999 Lecture Notes - Lecture 5: Basement Membrane, Serous Membrane, Salivary Gland
4 Nov 2016
School
Department
Course
Professor
Document Summary
A tissue is composed of cells and a matrix. In muscle and epithelium, the cells are so close together that the matrix is scarcely visible, but in connective tissues, the matrix usually occupies more space than the cells do. The matrix is composed of fibrous proteins and a clear gel known as ground substance, tissue fluid, ecf, or interstitial fluid. The first tissues appear when cells begin to organize into layers called the primary germ layers. Ectoderm- outer layer that gives rise to the epidermis and nervous system. Endoderm- inner most layer that gives rise to the mucous membranes of the digestive and respiratory tracts. Mesoderm- loosely organized cells in between these two layers, which eventually turns to gelatinous tissue called mesenchyme, composed of collagen and gives rise to muscle, bone, and blood. Cells are very close together and avascular- no room between cells for blood vessels. Usually lie on vessel-rich layer of connective tissue, high rate of mitosis.
