As the name suggests a connective tissue in animals, acts as a connecting medium, with some specialized functions. In animals, the connective tissue is very complex has a vital role to play. They provide internal support as well as give and maintain form to the body. Let us learn about some connective tissues – Blood, Cartilage, Bones etc.
Types of Connective Tissue
Loose Connective Tissue
The areolar tissue and the adipose tissue are classified under the loose connective tissue. This tissue has cells and fibres that are loosely arranged in the semifluid ground substance. The areolar tissue has fibrous extracellular molecules and a number of different cell types. These include a ground substance, the matrix, fibroblasts, mast cells, and macrophages.
The areolar tissue is a loose connective tissue that can be seen between the skin and muscles; in the bone marrow as well as around the blood vessels and nerves. This tissue fills the spaces between the different organs and connects the skin to the underlying muscles. And therefore, it provides support to the internal organs as well as help in the repair of tissues.
The adipose tissue is also a loose connective tissue that is found beneath the skin. The cells of the adipose tissue store fats. It is in these cells that fat is stored in the form of fat globules. Due to the storage of fat, the adipose tissue acts as an insulator.
Dense Connective Tissue
In the dense connective tissue, the fibres and fibroblasts are compactly packed. The dense connective tissue can be further classified into dense regular and dense irregular connective tissue, depending on the regularity/irregularity of the collagen fibres.
The collagen fibres are present in rows, in between many parallel bundles of fibres in a dense regular tissue. Tendons and ligaments fall under this tissue category. In a dense irregular connective tissue, the fibroblasts and collagen fibres are oriented differently, as seen in the tissue present in the skin.
Specialized Connective Tissue
The three specialized connective tissues are Blood, bones, and cartilage.
Blood is a fluid connective tissue. It consists of a liquid matrix called as the plasma, in which blood cells are present. It travels all around the body in blood vessels. So blood helps in the transport of gases, nutrients, hormones as well as the elimination of the waste materials.
There are three types of blood cells that are found in the plasma. They are the Red blood cells (RBC) or Erythrocytes; White blood cells or Leucocytes (WBC) and Thrombocytes or Blood Platelets. The RBCs and the WBC’s are the living components of the blood.
The RBCs have a pigment called hemoglobin, due to which blood appears red in color. The WBCs help in protecting the body by attacking any foreign body that enters into the body, while the blood platelets are responsible for clotting of blood.
Bones are the hard connective tissue. They give support and framework to the body. They protect the internal organs and the muscle tissue attached to the bones helps in movement. The bone tissue is strong and non-flexible. The cells are embedded inside a hard matrix, which is made up of proteins, calcium and phosphorous. And bones are rich in calcium salts and collagen fibres, giving them the strength.
Cartilage is another type of connective tissue that has a solid matrix. It contains proteins and sugars. The cartilage tissue has widely spaced cells. Cartilage is also an important connective tissue as it helps in smoothening the bone surfaces at the joints. Cartilage is also present in the trachea, nose, ears, and larynx.
Solved Questions For You
Question: Pick the odd one out.
1] Areolar tissue, squamous epithelium, bones, blood
Ans. Squamous epithelium, since all the others are connective tissues)
2] Ligament, exocrine glands, salivary glands, endocrine glands
Ans. Ligament – It is a connective tissue (all the others are glandular epithelial tissue)