Flashcards in MCM 2-25 Microanatomy of Epithelial Tissue Deck (12)
tissues consist of groups of cells with varying amounts of extracellular matrix that perform specific functions
two or more tissues combine to form larger functional units called organs
organs may be divided into 2 components
parenchyma - cells responsible for the main organ function
Stroma - supporting elements or matrix of the organ
4 basic types of tissues
epithelial, connective, muscular, nervous
Basic steps in preparing tissue for light microscopy
1. fixation - prevents structural organization, formalin cross-links proteins to each other, osmium fixes lipids. prevents post-mortem changes
2. sectioning - steel blade on rotary microtone, cuts 3-10um sections of specimen embedded in parafin. Paraffin removed prior to staining after section is mounted on glass slide
3. Staining - used to localize/distinguish cell and tissue components. Acidic Eosin (-) binds cytoplasmic structures and components .
basic strain (+) (hemotoxylin) binds structures such as nucleic acids. H&E stain distinguishes nucleus from cytoplasm
closely coherent cells that form cellular sheets that cover and line many surfaces and lumens of the body. one can distinguish between covering epithelia and glandular epithelia
functions of epithelia (4)
covers surfaces, provides protection, secretes/adsorbs various substances, transports particles
types of epithelia
simple, pseudostratified, stratified
what is the basal lamina?
structure composed of Type IV collagen, laminin, enactin, and proteoglycans that separates epithelial cells from connective tissue.
what connects the basal lamina to connective tissue?
anchoring fibrils made of type 7 collagen
1. number of cell layers (simple, pseudostratified, stratified)
2. shape of cells at most superficial layer furthest from basal lamina (squamous, cuboidal, or columnar)
3. If the free surface has cilia or keratin (or neither)