Tissue in the Human Body

Connective Tissue

Connective tissues are found all over our bodies. Generally, they are located in blood, fat, and between muscles and bones. The matrix is the substance that surrounds the cell. Matrices can be fluid or solid, depending on where they are found. They also are found to have varying degrees of vascularity. For example, a bone would be very vascular while cartilage is avascular. Two good property the cells of connective tissue have is that they can divide and repair themselves. The functions of these tissues are: to bind structures, support, protect, serve as framework, store fat, produce blood cells and repair damage.

Cell Types

There are three major cell types of connective tissue: Fibroblasts, Macrophages, and Masts. Fibroblasts are the most common type. They are large and star-shaped, and they are fixed in position. The function of fibroblasts is to produce fibers. Macrophages are phagocytic cells (they eat other cells), and they are wandering. Their purpose is to defend the body and help the immune system. Masts are fixed (like fibroblasts) and their function is to release herapine and histamine for allergic responses.

Fibers

There are also three types of connective tissue fibers: Collagenous, Reticular, and Elastic. Collagenous tissue fibers are thick so that they can hold structures together. They are located in the tendons and ligaments. Reticular tissue fibers are very thin and highly branched so that they can form supportive networks. Reticular tissue fibers are located in the spleen. Elastic tissue fibers are somewhat thin so that they can allow stretching. They are found in the vocal chords and air passages.

Types of Connective Tissue: Proper and Specialized

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...down into endocrine, exocrine, unicellular, and multicultural. Endocrine is ductless glands which secrete into the blood stream. Exocrine glands have ducts. Unicellular is one cell (like goblet cells) and is exocrine. Multicellular has many cells and is exocrine also (like sweat glands or salivary glands). The structural types of glandular epithelium are either simple (one duct) or compound (more than one duct). There are three types of glandular secretion: merocrine, apocrine, and holocrine. Merocrine has a fluid product which secretes through the membrane of the cell. It is found in the pancreas and sweat glands. Apocrine has a cellular product and is secreted by half of the cell. It is found n mammary glands and ceruminous glands (ear wax). Holocrine has secretory products which are secreted by the entire cell. It is found in sebaceous glands (oil).