Important Points for Competitive Exams
1.The most abundant tissue in animal body is the connective tissue.
2.The tissue which has minimum intercellular space is epithelial tissue and connective tissue has largest intercellular spaces.
3.The epithelial tissue has great regeneration power and it is the first evolved tissue.
4.Blubber of whale, hump of camel and thick tail of marino sheep mainly contain adipose tissue.
5.The abnormality characterised by gradual softening and bending of bones caused by failure of calcification due to lack of vitamin D is called osteomalacia (Gr. osteon = bone, malakia = softness)
6.The most abundant protein of the body is collagen, it accounts for about 40% of the total proteins. Wrinkling in old age is due to diminishing rigidity in collagen fibres.
7. Decalcification :- If a bone is kept in dilute acid like HCl, inorganic salts dissolves in acid and release CO2, while organic or protein part is left behind. Bone now becomes elastic and soft. This is called decalcification. In KOH solution muscles and connective tissue dissolve, but bone remains unaffected and it becomes clean. When a bone is burnt organic part (protein) burns and the remaining ash contains inorganic salts.
8. Dried bone :- When bone is exposed to high temperature it becomes dry. All cavities dry up and are emptied.
9. Clotting - Process by which the blood solidify and prevent haemorrhage.
10.Antigen - A foreign substance or toxin which when introduced in to the body of an organism stimulates the production of a specific antibody.
11. Antibody - A plasma protein [Gamma globulin] produced by an organism to counteract an antigen in the tissue or blood.
12. Glands - A group of cells which produces and secretes special chemicals.
13. Infection - Invasion of the body by a pathogen.
14. Matrix - The basic ground substance in which cells of a tissue are embedded.
15. Monocyte - A granular leucocyte with a large nucleus. It escapes from the blood by amoeboid movement through the capillary wall and in the tissue is transformed into either macrophages or histiocyte.
16. Fibroblast - Cells of connective tissue responsible for secretion of fibres.
17. Blood flows to all parts of the animal body and thus connects different parts of the body with one another.
18. Lymphocytes :- They secrete antibodies to destroy microbes and also help in healing of injuries.