connective tissue types. connective tissue it is a type of tissue that connect and support other...
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CONNECTIVE TISSUEIt is a type of tissue that connect and support other body tissues, also called supporting tissue.CLASSIFOCATION:Classified on the basis of following four criteria1. Relative proportion of various fibers2. Compactness and arrangements of these fibers3. Nature of matrix4. Types of cell present
• On the basis of factors mentioned above connective tissue is grouped into two main categories
1. Embryonal C.T2. Adult C.T
EMBRYONAL C.T
• Developmentally the C.T are derived from mesoderm• Immature C.T derived from mesoderm is called
mesenchyma,it is composed f roughly star-shaped cells.• As the development progress the mesenchyme gradually
assumes the characteristics of adult C.T• The first change is the appearance of fibers and the
embryonal connective tissue of this stage is called mucous tissue.
• The umbilical cord contains considerable amount of mucous tissue which in this location is called warton’s jelly.
ADULT C.T
It is further divided into following three main varieties1. Connective tissue proper2. Cartilage3. bone
Types of Connective Tissue
2:CARTILAGE:
I. Hyaline Cartilage
II. Elastic Cartilage
III. Fibrocartilage Cartilage
3: BONE
A: EMBRYONAL C.T:I. Mesenchyme II. Mucous tissue
B: ADULT C.T1: connective tissue properLoose Connective Tissue
I. areolarII. reticularIII. adipose
DENSE CONNECTIVE TISSUEIV. regularV. irregular
CONNECTIVE TISSUE PROPERClassified into further following two subtypes:
1. loose connective tissue2. Dense connective tissue
1: LOOSE CONNECTIVE TISSUE:• In Loose Connective Tissue, the fibers in the extracellular matrix are
loosely arranged. • Lots of ground substance. • The ground substance is semifluid (viscous). Cells are scattered
throughout the tissue.• Not very cellular.
LOOSE CONNECTIVE TISSUE INCLUDES:I. Areolar Connective TissueII. Adipose TissueIII. Reticular Connective Tissue
LOOSE AREOLAR CONNECTIVE TISSUE
• Areolar is the most abundant type of connective tissue.• All kind of fibers and cells are present.• It is the packing and anchoring material of the body.• It binds other tissues, organ components, and organs together
and allow flexibility and mobility between such parts.• form the supporting frame work (stroma) of most of the
organs.
examples:1. Superficial and deep fascia2. Mesentery3. omentum
LOCATION:1. Found in the subcutaneous layer deep to skin and in
superficial part of dermis2. mucus membranes3. around blood vessels4. nerves and body organs
FUNCTION: supports glandular epithelium and mesothelial layers of mesentery, supports immune cells
RETICULAR CONNECTIVE TISSUE
DESCRIPTION:• R.C.T consists of reticular cells and reticular fibers.• Reticular cells have stellate shape and possess long
processes which pass in different directions to make contact with the neighboring cells.
• The dominant fiber is reticular fiber. • Reticulocytes are fibroblasts that produce reticular fiber . • The ground substance is semifluid.
LOCATION:• Found in lymph nodes and other non-muscular organs• Provides a support structure for macrophages and other
cells involved in immunity.
FUNCTION :• forms the framework (stroma) of liver, spleen,
bone marrow, and lymphoid organs.• Produce reticular fibers• Can also act as phagocytes• May also give rise to precursors of
erythrocytes and leukocytes
ADIPOSE TISSUE
• Consists almost entirely of fat cells arranged into lobules that are separated from each other by fibrous septa.
Depending on its color, location and morphology of component cells, the adipose tissue is subdivided into two verities
1. WHITE OR UNILOCULAR ADIPOSE TISSUE• Widely distributed in the body includes most of the adipose
tissue of adult man.• On naked eye it appears whitish or light yellow in color.• Under L/M fat cells of white adipose tissue shows a single
large fat droplet in the cytoplasm that is why they are called unilocular fat. The fat droplet is not membrane bound.
• These cells give a typical signet ring appearance in ordinary H%E stained sections
ADIPOSE TISSUE
2: BROWN OR MUTILOCULAR ADIPOSE TISSUE• On naked eye it appears brown• The fat cells here have fat in the form of many small droplets
instead of one droplet, that is why they are also called multilocular fat.
• In adult this tissue is absent or restricted in distribution but in fetus and child it is common
The brownish appearance is due to two reasons 1. This tissue has a very rich capillary blood supply2. These cells contain numerous mitochondria and are rich in
cytochrome enzymes which have colored component
ADIPOSE TISSUE
NOTE: as compared to other varieties of connective tissues the adipose tissue consist of cells and not intercellular substance. In other words the cell-intercellular substance ratio is ratio resemble that of the epithelium.
Function: 1. Act as important food reserve of the body and chief site of
energy storage (this function is restricted to white fat)2. Mechanical function of acting as shock absorbing pads, in
buttocks, soles etc.3. Plays important role in temperature regulation which is
accomplished by two following waysI. By heat production as a result of fat metabolism(function of
brown adipose tissue)II. Acting as insulator to prevent heat loss from the body
Dense Connective Tissue
• The extracellular matrix consists of tightly packed parallel bundles of collagen fibers with less cells as compared to loose connective tissue and very little ground substance.
• It is less flexible and far more resistant to stress.According to its arrangement of component fibers it is
divided into two categories1. Regularly arranged dense C.T2. Irregularly arranged dense C.T
REGULARLY ARRANGED DENSE C.T
• Fibers are densely packed and are parallel to each other• Usually occur in the form of cords and bands• Examples: tendons, aponeurosis and ligamentsTendons:• Composed entirely of collagen fibers• Fibers run parallel and closely packed in the form of
bundles separated by a small quantity of intercellular substance.
• Fibroblasts are the only cells present• The whole tendon is surrounded by a layer of
fatty ,coarse connective tissue sometimes called as epithelium
REGULARLY ARRANGED Dense C.T
Apo-neurosis:• Apo-neurosis have the same structure as tendon but these
are broad and relatively thin.• The fibers may be arranged in several superimposed layers,
those of one layer running at an angle to fibers of the adjacent layer.
Ligaments:• Ligaments are bands of dense connective tissue.• Structurally they resemble tendons because they are
predominantly composed of collagenous fibers.• A few ligaments consists entirely of elastic fibers, these are
called yellow elastic ligaments.
IRREGULARLY ARRANGED DENSE C.T
• This variety of C.T occur in the form of sheets.• Consist mainly of collagenous fibers but elastic and reticular
fibers are also present.• The components fibers interlace to form a network.• Fibroblasts and some macrophages are found between the
fibers . Location:• Found in the dermis of the skin• capsule of some organs (liver, testes, lymph nodes) • Fibrous sheaths of cartilage (perichondrium) and bone
(periosteum)
Function: Provides strength and support to organs