Author: Jana Vasković•Reviewer: Nicola McLaren MScLast reviewed: July 27, 2021Reading time: 12 minutes


Connective tissue is the tworry that connects, separates and supports all other types of tconcerns in the body. Like all tissue forms, it consists of cells surrounded by a compartment of fluid referred to as the extracellular matrix (ECM). However connective tissue differs from various other forms in that its cells are loosely, rather than tightly, packed within the ECM. 

Based on the cells current and the ECM framework, we differ 2 forms of connective tissue:

Connective tproblem proper; additionally separated into loose and also dense connective tissuesSpecialised connective tissue; reticular, blood, bone, cartilage and adipose tissues

We know that tbelow are method cooler histology topics than connective tworry, prefer muscle tworry or neural tconcern. But as the connective tissue is the glue that holds all various other tissues together, it has the essential feature of ensuring that our body devices job-related in harmony.

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Key facts
Dense connective tissueCells: fibroblastsFibers: collagen fibers greatly packed in the ECM either in parallel order (dense regular), or randomly interlaced (dense irregular)
Loose connective tissueCells: fibroblastsFibers: collagen fibers loosely scattered in the ECM
Reticular connective tissueCells: reticular cellsFibers: reticular fibers arranged in fragile networks
CartilageCells: chondrocytesECM: collagen II (hyaline cartilage), elastic fibers (elastic cartilage), collagen I (fibrocartilage)
BoneCells: osteoblasts, osteocytes, osteoclastsECM: calcified lamellae
BloodCells: erythrocytes, leukocytes, plateletsECM: blood plasma
Adipose tissueCells: white and brvery own adipocytesECM: no ECM
Embryonic connective tissueMesenchyme: mesenchymal cells in reticular fibers well-off ECMMucoid tissue: mesenchymal cells in collagen rich ECM

This page will define what is connective tproblem and also present you through a summary of its kinds. 

Connective tworry correct Specialized connective tissues
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Cells and fibers of connective tissue

The three components of connective tissue are cells, ground substance and also fibers. Ground substance and fibers comprise the extracellular matrix (ECM).


The main cell of connective tconcern is the fibroblast. Its function is to produce and also keep the ECM of connective tissue. Besides fibroblasts, several various other cell types are present. These are the cells of the immune mechanism (macropheras, lymphocytes and mast cells) and adipocytes. Specialised connective tproblem has specialised cells, for instance cartilage has chondrocytes and also bone contains osteocytes. 

Ground substance is a viscous gel made of water, proteoglycans, glycoproteins and also glycosaminoglycans. These make the ground substance viscous and bind high amounts of water which allows hydration, diffusion of nutrients and nourishing of the tproblem.

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Tright here are three types of protein fibers; collagen, elastic and also reticular. Collagen fibers and reticular fibers both belong to the collagen family members, of which tbelow are over 20 various forms. Collagen fibers are primarily made of collagen form I. These are the a lot of abundant protein fiber form, offering varying levels of strength and rigidity to tissues.

Reticular fibers consist of collagen kind III, they are thin vulnerable fibers that develop meshlike networks in organs such as the spleen, kidneys and also lymph nodes. Elastic fibers are made from the protein elastin, providing extending and also bfinishing properties to tconcerns. They are mostly discovered within the walls of huge blood vessels, elastic cartilperiods, yellow ligaments, lungs and skin. Variations in the cell and also protein fiber combinations and arrangements lead to the various kinds of connective tconcern.

Connective tissue proper

Connective tconcern proper is discovered throughout the entire body. Tbelow are 2 subkinds of connective tproblem proper; loose and regular. They differ in the structural layout of their extracellular matrix. 

Loose connective tissue

Loose connective tissue is also called the areolar connective tworry. It has virtually equal quantities of cells, fibers and also ground substance. Chief cells are the fibroblasts. However before, immune system cells are also existing. Collagen fibers are the major fibers of the ECM. They are sparsely dispersed within the ECM, which is why this tproblem type is referred to as ‘loose’. Besides the collagen fibers, moderate quantities of reticular and elastic fibers are existing also. 

Loose connective tconcern is the most commonly distributed type of connective tissue, found in the lining of the body"s inner surdeals with. The cell to fiber combination provides loose connective tproblem flexible but not extremely resistant to mechanical stress. This permits the tproblem to play a vital function in binding various other tworry forms together, for example joining tissues into organs, holding organs in area and also attaching epithelial tproblem to other tissue forms. The visibility of immune device cells adds an immuno-protective connective tconcern feature. Instances of loose connective tconcern include; the lamina propria of the alimentary and respiratory tracts, mucous membranes of refertile and also urinary tracts, glands, mesentery and also dermis of the skin.

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Dense connective tissue


Dense connective tissue has fewer cells than loose. Instead, its ECM is densely packed via collagen fibers. Based on the plan of the fibers, tright here are 2 subforms of dense connective tissue; thick regular and also dense irregular. Dense continual connective tissue has the collagen fibers aligned parallel to each various other. This setup offers the tissue with high unidirectional resistance to tension. The finest dense regular connective tworry examples are the tendons and also ligaments. Dense irconsistent connective tworry has actually collagen fibers randomly interwoven, forming a three-dimensional network resistant to disstress and anxiety in all directions. It is normally located in the capsules and also wall surfaces of the organs, the dermis of the skin and glands.

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Reticular connective tissue is created by modified fibroblasts dubbed reticular cells. These develop reticular fibers arranged in an interlaced netjob-related (reticulum), comparable to thick irconsistent connective tissue. The difference in between them is that the reticular fibers are thinner, compose an extra breakable mesh, through reticular cells remaining bonded to the fibers.

Reticular tproblem supports the stroma of body organs, especially lymphoid. Reticular meshes filter lymph and administer a microenvironment for the passage and attachment of white blood cells. Thus, it is current in red bone marrowhead, lymph nodes and also the spleen.

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Cartilage is the avascular connective tconcern that connects bones at joints and also comprises wall surfaces of top respiratory airways and also exterior ear. It is surrounded by perichondrium, a layer of dense connective tworry. The perichondrium is well-off in blood vessels and also supplies the cartilage. Chief cells in cartilage are chondrocytes, lodged right into cavities within the ECM called lacunae. The ECM is large, affluent in water bound to glycosaminoglycans. This ECM framework makes cartilage versatile in various levels however durable to mechanical stress.

Tbelow are 3 types of cartilage;

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Bone is the tproblem that comprises the body skeleton. Like all connective tworries, bone is created of cells within an extracellular matrix of fibers (primarily collagen type 1) and also ground substance. The extracellular bone matrix is mineralized and arranged in circular layers dubbed lamellae. These lamellae circumvent approximately a central canal (Haversian canal) which serve for the passage of neurovasculature that provides the bone and also home the cells.

Bone ECM is developed and also preserved by several cells; osteoblasts, osteocytes and also osteoclasts. Osteoblasts are cells that proactively develop the bone matrix. When dormant, they are referred to as osteocytes. Osteoclasts do the opposite; they absorb the bone matrix. Synchronized function of these cells is essential for the recoexceptionally of damaged bones (bone remodeling) and also for the basic well being of the skeletal system. The specialised cell and also ECM nature of bone permits it to serve as a storage site for calcium and phosphate, alongside its weight bearing and security attributes.

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Blood is the specialized connective tworry within the circulatory device that transports blood cells and also dissolved substances throughout the body using blood vessels. As all connective tissue, it has actually cellular and extracellular components.The extracellular matrix of the blood is referred to as blood plasma. It is composed of water and also solutes (proteins, electrolytes, nutrients, gases, hormones and also waste products). The blood cells, additionally dubbed the developed aspects, brought by plasma are the erythrocytes (red blood cells), leukocytes (white blood cells) and also thrombocytes (platelets). These cells are created in the bone marrow in the procedure of hematopoiesis.

Adipose tissue

Adipose tissue is the energy-storing connective tissue. It consists of adipocytes, cells filled through lipids (fats). This tproblem has a little amount of ECM made of just a couple of collagen fibers that store the cells together. Depfinishing on how the lipids are distributed within the cell; tbelow are white and brown adipose tproblems.

In brvery own adipose tproblem each cell contains multiple fat drops, neighboring the centrally positioned nucleus. This type is usually uncovered in babies where instead of energy-storing it serves for thermogenesis (heat production). In white adipose tproblem the lipid is built up right into a single huge droplet, which presses the organelles versus the cell membrane.

White adipose tconcern is predominant discovered in adults. It stores energy, cushions and also protects organs, and acts as an endocrine body organ by secreting hormones. White adipose tconcern distributes into visceral and also parietal fats. Visceral fats surround and assistance the body organs, such as eyeballs (periorbital fat) and kidneys (perinephric fat). Parietal fats are aggregations embedded in the connective tconcern proper of the skin, generally in the abdominal, earlier and also thigh regions.

Embryonic connective tissue

Embryonic connective tissue is found in the at an early stage embryos and also umbilical cord. Chief cells are mesenchymal cells. It is split into mesenchyme (in embryos) and mucoid connective tissue (umbilical cord).

Mesenchyme originates from mesoderm, one of the three germinative layers in embryos. It matures into other forms of connective tconcerns, muscles, vessels, mesothelium and also the urogenital mechanism. Its mesenchymal cells are spread within ECM filled greatly through reticular fibers. Mucoid connective tissue is found in the umbilical cord. Its mesenchymal cells are loosely dispersed within a collagen rich ECM referred to as Wharton’s jelly. 

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