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BIOS-1140
Ch 02 - Cells and Tissues
Term | Definition |
---|---|
Definition of Tissues | Collection of specialized cells and cell products that are organized to perform a relatively limited number of functions. |
primary tissue types | (1) Epithelial tissue (2) Connective tissue (3) Muscle tissue, (4) neural tissue |
Definition of Epithelium | The covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. It is classified into types on the basis of the number of layers deep and the shape of the superficial cells. |
Functions of Epithelial tissue | This tissue will provide physical protection, control permeability, provide sensation, and produce specialized secretions. |
Epithelial tissue | Glands fall into this tissue type. |
Basement membrane | Extracellular matrix characteristically found under epithelial cells. |
layers of the basement membrane | (1) basal lamina, immediately adjacent to the cells, is a product of the epithelial cells themselves and (2) reticular lamina is produced by fibroblasts of the underlying connective tissue. |
simple epithelium | An epithelium having one layer of cells. |
stratified epithelium | An epithelium composed of multiple layers of cells, only the basal layer being in contact with the basal lamina. |
squamous epithelium | An epithelium in which the cells are flattened. May be simple or stratified. Often located on the surface of the skin and the inside lining of the mouth. |
cuboidal epithelium | Simple epithelium with cells appearing as short hexagonal boxes. These cells make up the lining of the urinary tubules and some glands. |
columnar epithelium | Epithelium formed of a single layer of prismatic cells taller than they are wide. Often located on the inside lining of the trachea and small intestine. |
pseudostratified columnar epithelium | An epithelium that gives a superficial appearance of being stratified because the cell nuclei are at different levels, but in which all cells reach the basement membrane, hence it is classed as a simple epithelium. |
Definition of connective tissue | An internal tissue with many important functions, including establishing a structural framework; transporting fluids and dissolved materials; protecting delicate organs; supporting, surrounding, and interconnecting tissues; storing energy reserves; and de |
Connective tissue proper | Composed of extracellular fibers, a fiscous ground substance and fixed or wandering cells. |
Types of connective tissue fibers, how they look and move | (1) collagen fibers - long, straight, strong, most common, (2) reticular fibers - branched, tough but flexible, and (3) elastic fibers - branching stretch |
categories of the fiber matrix | (1) loose connective tissue and (2) dense connective tissue |
examples of loose connective tissue | (1) areolar tissue, (2) adipose tissue, (3) reticular tissue |
areolar tissue | Loose, irregularly arranged connective tissue that consists of collagenous and elastic fibres, a protein polysaccharide ground substance, and connective tissue cells (fibroblasts, macrophages, mast cells, and sometimes fat cells, plasma cells, leukocytes, |
adipose cells | A connective tissue cell specialized for the synthesis and storage of fat. Such cells are bloated with globules of triglycerides, the nucleus being displaced to one side and the cytoplasm seen as a thin line around the fat droplet. |
reticular cells | A cell with processes making contact with those of other similar cell's to form a cellular network; These cells are found making up the main portions of the liver, spleen, appendix, tonsils, and lymph nodes. |
dense cells | these cells are found making up our tendons, ligaments, and aponeurosis |
fluid connective tissue | consists of a distinctive collection of cells in a watery matrix. |
examples of fluid connective tissue | blood and lymph |
types of matrix in supporting connective tissue | gel and solid |
Cartilage | Connective tissue dominated by extracellular matrix containing collagen type II and large amounts of proteoglycan, particularly chondroitin sulphate. It is produced by chondrocytes that come to lie in small lacunae surrounded by the matrix they have secre |
Types of cartilage and where they are located. | (1) Hyaline - ends of long bones, trachea, nose (2) Fibrocartilage - intervertebral discs, symphysis pubis, and menisci (3) Elastic Cartilage - ears |
bone (osseous tissue) | A connective tissue, the matrix of which consists of collagen fibres and ground substance and in which are deposited calcium salts (phosphate, carbonate, and some fluoride) in the form of an apatite. |
osteocytes | Osteoblasts that have become embedded within the bone matrix, occupying a flat oval cavity and sending, through the canaliculi, slender cytoplasmic processes that make contact with processes of other similar cells. |
canaliculi | In bone, channels that run through the calcified matrix between lacunae containing osteocytes. |
Muscle tissue | consists primarily of cells that are specialized for contraction |
types of muscle tissue | (1) skeletal muscle tissue, (2) cardiac muscle tissue, (3) smooth muscle tissue |
skeletal muscle | striated muscle of vertebrates that is under voluntary control. |
cardiac muscle | striated but involuntary muscle responsible for the pumping activity of the vertebrate heart. The individual muscle cells are joined through a junctional complex known as the intercalated disc and are not fused together |
smooth muscle | involuntary muscle found particularly in blood vessel walls, surrounding the intestine and in the uterus. |
neural tissue | A highly differentiated tissue composed of nerve cells, nerve fibres, dendrites, and a supporting tissue (neuroglia). This tissue is specialized to conduct electrical impulses from one area of the body to another |