Week 2 Flashcards
cells
the smallest structural unit of living matter, 100 trillion cells in the human body!
Cells group together to form a tissue
four basic tissues
epithelial, connective, nerve and muscle tissues
extracellular matrix
gel-like substance contains interwoven protein fibers that surrounds most cells.
*mesh like material
epithelial tissue
-Makes up outer surface of body
-Lines body cavities
Mouth, stomach and –intestines
Composed of stratified squamous epithelium
-Characterized by plentiful cells; sparse extracellular matrix.
composition of epithelial tissue
Plentiful cells closely packed, bound together
-basal lamina
basal lamina
Thin mat of extracellular matrix secreted by epithelial cells supports overlying epithelium
-Similar to the foundation of a building
-The basal lamina separates epithelial sheets from the underlying connective tissue
keratinization of epithelial cells
Epithelial cells on the surface of the skin become stronger and waterproof
-Keratinized epithelial cells
-Have no nuclei
-Form a tough, -resistant layer on skin
Palms of hands and soles of feet most heavily keratinized epithelium of the body
non-keratinized epithelial cells
Have nuclei
-Act as cushion against stress and wear of tissue
-Softer and more flexible than keratinized cells.
-Example: Lining of cheeks (buccal mucosal) permits the ability to speak, chew, and make facial expressions
blood supply to epithelial tissues
Avascular – meaning there is no blood vessels in the epithelial tissues!
Oxygen and nourishment received from blood vessels in underlying connective tissue – process is known as DIFFUSION.
connective tissue
-Fills spaces between tissues and organs in body
-Supports or binds other tissues
-Consists of sparse cells and abundant extracellular substance
-Includes cementum, dentin, alveolar bone, pulp.
connective tissue is made up of
-sparse cells
-extracellular matrix
-all dental tissue: dentin, cementum, alveolar bone, pulp
sparse cell
-Fibroblasts – fiber-builders
-Macrophages and neutrophils – phagocytes – “cell eaters” that devour dying cells and invading microorganisms.
-Lymphocytes – immune cells that play an essential role in host defense
Extracellular matrix of connective tissue
A rich, gel-like substance containing a network of strong fibers.
The fibers, rather than cells, give connective tissue its strength to withstand mechanical forces.
dental tissues of the epithelium
enamel
blood supply of connective tissue
Connective tissue has a rich blood supply that brings nourishment to both connective tissue and to the epithelial tissue that covers it
epithelial connective tissue interface
Site where epithelial and connective tissues meet in either a wavy or a smooth boundary
In most places in the body, these tissues meet in an uneven, wavy boundary
-epithelial ridges
-connective tissue papillae
epithelial ridges of connective tissue
extensions of epithelium that reach down into connective tissue.
connective tissue of papillae
fingerlike extensions of connective tissue that extend up into the epithelium
functions of wavy boundary
-Provides greater adhesion of epithelium to connective tissue by increasing surface area at the boundary where these tissues meet.
-The wavy junction increases the area from which epithelium can receive nourishment from connective tissue.
epithelial cell junctions
Cellular structures that mechanically “lock” cell to its neighbor or basal lamina
Binding cells form structurally strong unit
Gingival epithelium
A type of stratified squamous epithelium designed to function in the wet environment of the oral cavity.
-Microscopic anatomy is similar to the skin.
-Three anatomical areas
*Oral epithelium (OE)
*Sulcular epithelium (SE)
*Junctional epithelium (JE)