This tube is organized into a series of four distinct layers which are fairly consistent throughout its length. Click on a link for more detail, or scroll down. Terms such as inside and outside are potentially confusing when used to describe tubular organs.
Characteristic connective tissue cell types include both resident cells and immigrant or wandering cells.
Fibroblasts which secrete the fibers and ground substance of the extracellular matrix. Adipocytes which store fat. Macrophages which ingest and remove foreign material or damaged cells. Fibroblasts are responsible for secreting collagen and other elements of the extracellular matrix of connective tissue.
In microscopic appearance, fibroblasts lack obvious specialized features. And fibroblasts throughout the body all appear similar to one another, wherever they occur in ordinary connective tissues. There is thus little about fibroblasts to attract the attention of an observer.
However, fibroblasts are essential for normal development and repairand recent research PLoS Genetics has shown that fibroblasts from different regions display extensively differentiated patterns of gene expression which may guide differentiated patterns of tissue organization, such as different types of skin and hair in different areas.
Indeed, the single cell type called "fibroblast" Tissue study guide for anatomy properly represent many distinctly but invisibly different cell types, including "mesenchymal stem cells" which retain capacity to differentiate into other cell types see Science The name "fibroblast" is something of a misnomer, since most cells with "blast" in their name are embryonic precursor cells which subsequently differentiate into specialized cell types.
Fibroblasts are already a mature, differentiated cell type although some may have the capacity to differentiate into other mesenchymal cell types as well. Resting fibroblasts typically have so little cytoplasm that the cells commonly appear, by light microscopy, as "naked" nuclei.
Fibroblast nuclei appear dense heterochromatic and are usually flattened or spindle-shaped. The pink material in this thumbnail image is extracellular collagen.
Fibroblasts are active during growth but are normally quiescent in the adult. When active, fibroblasts are actively secretory, manufacturing the collagen and other components of the extracellular matrix of connective tissue. Active fibroblasts appear larger than resting ones, with more cytoplasm and with nuclei that are more euchromatic less densely stained.
Resting fibroblasts retain the ability to become active and to multiply when necessary, as during healing after injury. Scars are formed by fibroblast activity during tissue repair.
The substance of the scar is collagen deposited by fibroblasts to replace damaged tissue. For an image of scar formation, see WebPath. For recent research on fibroblast involvement in scar formation, see Science Closely related to fibroblasts are the chondroblasts which produce the matrix of cartilage and the osteoblasts which produce the matrix of bone.
The appearance of "blast" in a cell name normally indicates an embryonic cell that transforms into a mature cell type e. However, in the case of "fibroblast", "chondroblast" and "osteoblast", this designation indicates a cell which secretes fibers, cartilage or bone.
Adipocytes are large connective tissue cells which contain a substantial amount of lipid stored in the form of conspicuous round droplets.
Adipocytes function primarily as warehouses for reserve energy. En masse, they also assist in thermoregulation maintaining body temperature and in a few sites offer some cushioning capacity e. Since most loose connective tissue contains scattered clusters of adipocytes, the term adipose tissue is usually reserved for large masses grossly visible of these cells.
The most common type of adipocyte is called the unilocular adipocyte or white fat.
Each cell contains one single fat droplet hence, unilocular surrounded by a thin rim of cytoplasm. Under the light microscope, the appearance of an adipocyte is that of a conspicuous clear space with a very thin border. The lipid droplet which comprises the bulk of each adipocytes is not stained by ordinary aqueous stains, and may even be removed by solvents during specimen preparation.
Furthermore, adipocyte cytoplasm itself is inconspicuously thin, and the nucleus of any particular adipocyte is unlikely to be included in any given section see Viewing Tissues.CliffsNotes study guides are written by real teachers and professors, so no matter what you're studying, CliffsNotes can ease your homework headaches and help you score high on exams.
The internal anatomy of the human vulva, with the clitoral hood and labia minora indicated as lines. The clitoris extends from the visible portion to a point below the pubic bone. Since , rutadeltambor.com has provided high quality information about health, wellness, and the science behind the human body.
Topics we cover include: Nutrition, Fitness, Diseases & Conditions, DNA Testing, Home Health Testing, and more. All content on our site is written by subject matter experts. Mucous connective tissue is a temporary tissue formed during embryonic development. An epithelial membrane is a combination of epithelial and connective tissues working together to perform a .
Outlines the steps of a cat dissection. Students of anatomy learn by studying a variety of specimens. Freshman start on the frog, advanced students might experience a rat, rabbit or a bullfrog.
Continued From Above Cardiovascular System Anatomy The Heart. The heart is a muscular pumping organ located medial to the lungs along the body’s midline in the thoracic region. The bottom tip of the heart, known as its apex, is turned to the left, so that about 2/3 of the heart is located on the body’s left side with the other 1/3 on right.