PHS 3504 Chapter Notes - Chapter 4: Dense Irregular Connective Tissue, Connective Tissue, Basal Lamina
Document Summary
Tissues are: collections of specialized cells and cell products organized to perform a limited number of functions: histology is the study of tissues. 4 tissue types: epithelial, connective, muscular & nervous: epithelial: always found covering or lining all body surfaces, internal or external. Includes glands and epithelium: glands are secretory, avascular: no direct blood supply. Epithelial tissues receive nutrients and oxygen through diffusion, which takes place in lower layer of tissue beneath epithelia. Functions: physical protection, control permeability, provides sensation & produce specialized secretions. Specializations: perform secretory functions, perform transport functions, maintains physical integrity & ciliated epithelia move materials across the surface: maintaining the integrity of epithelium: Cells attach at specialized cell junctions: tight junctions: fusion of membranes. Basal lamina (basement membrane) attaches to underlying surface. Lamina lucida: acts as a barrier that restricts the movement of proteins and other large molecules from underlying connective tissue.