Pre-Lab Reading Introduction Connective tissue is a term used to describe the tissue of mesodermal origin that that forms a matrix beneath the epithelial layer and is a connecting or supporting framework for most of the organs of the body. This lab will focus on the so-called connective tissue proper and cartilage; the next lab will focus on bone. Overview of Connective Tissue In contrast to epithelia, connective tissue is sparsely populated by cells and contains an extensive extracellular matrix consisting of protein fibers, glycoproteins, and proteoglycans. The function of this type of tissue is to provide structural and mechanical support for other tissues, and to mediate the exchange of nutrients and waste between the circulation and other tissues.
June 1, 0 Comments Epithelial Tissue Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity. Two forms occur in the human body: Covering and lining epithelium— forms the outer layer of the skin; lines open cavities of the digestive and respiratory systems; covers the walls of organs of the closed ventral body cavity.
Glandular epithelium— surrounds glands within the body. Characteristics of epithelium Epithelial tissues have five main characteristics.
Polarity— all epithelia have an apical surface and a lower attached basal surface that differ in structure and function. For this reason, epithelia is described as exhibiting apical basal polarity. Most apical surfaces have microvilli small extensions of the plasma membrane that increase surface area.
For instance, in epithelia that absorb or secrete substances, the microvilli are extremely dense giving the cells a fuz zy appearance called a brush border. Examples of this would include epithelia lining the intestine and kidney tubules.
Other epithelia have motile cilia hairlike projections that push substances along their free surface. Next to the basal surface is the basal lamina thin supporting sheet.
The basal lamina acts as a filter allowing and inhibiting certain molecules from passing into the epithelium. Specialized contacts— epithelial cells fit close together and form continuous sheets except in the case of glandular epithelia.
|Blood Coagulation: Hemostasis||The aim of these lab classes is to provide students with educational resources to acquire basic practical skills of each subject, recognize, locate and describe cell types and basic tissues. Each of these practical sessions are structured around three main elements:|
|Classification of Epithelia||The intrinsic cascade which has less in vivo significance in normal physiological circumstances than the extrinsic cascade is initiated when contact is made between blood and exposed negatively charged surfaces.|
They do this with tight junctions and desmosomes. Tight junctions form the closest contact between cells and help keep proteins in the apical region of the plasma membrane. Desmosomes connect the plasma membrane to intermediate filaments in the cytoplasm.
Supported by connective tissue— all epithelia are supported by connective tissue. For instance, deep to the basal lamina is reticular lamina extracellular material containing collagen protein fiber which forms the basement membrane. The basement membrane reinforces the epithelium and helps it resist stretching and tearing.
Regeneration— epithelium have a high regenerative capacity and can reproduce rapidly as long as they receive adequate nutrition.
Classification of Epithelia Epithelium has two names. The first name indicates the number of cell layers, the second describes the shape of its cell. Based on the number of cell layers, epithelia can either be simple or stratified.In biology, tissue is a cellular organizational level between cells and a complete organ.A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function.
Organs are then formed by the functional grouping together of multiple tissues. The English word is derived from the French tissu, meaning something that is woven, from. Epithelial Tissue.
Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity. Two forms occur in the human body: Covering and lining epithelium– forms the outer layer of the skin; lines open cavities of the digestive and respiratory systems; covers the walls of organs of the closed ventral body cavity.; Glandular epithelium– surrounds glands within the body.
Epidermis, the epithelial layer of skin, is primarily protective. This layer, consisting of keratinized stratified squamous epithelium, is tough, relatively impermeable, and ashio-midori.com functional qualities are conferred by the epidermis' principal cell type, the keratinocyte..
The quality of the epidermis differs from place to place in the body (see regional differences). Tissue definition, an aggregate of similar cells and cell products forming a definite kind of structural material with a specific function, in a multicellular organism. See more. The ability of the body to control the flow of blood following vascular injury is paramount to continued survival.
The process of blood clotting and then the subsequent dissolution of the clot, following repair of the injured tissue, is termed ashio-midori.comasis comprises four major events that occur in a set order following the loss of vascular integrity.
Glands are single cells or groups of cells which secrete protein, mucous, or lipid. These products can be secreted internally (endocrine) or into the external environment (exocrine).