Write short notes on :-
1) squamous epithelial tissue
2) cuboidal epithelial tissue
3) columnar epithelial tissue
4) ciliated epithelial tissue
Answers
2 Simple cuboidal epithelia are found on the surface of ovaries, the lining of nephrons, the walls of the renal tubules, and parts of the eye and thyroid. On these surfaces, the cells perform secretion and absorption
3 Sometimes these cells secrete mucus, gastric juices or tears into different ducts within the body. These are known as exocrine glands because the secretions affect the surrounding tissue. Columnar epithelial cells can also be found in endocrine glands, which make hormones which are then secreted into the blood.
4 Ciliated epithelium performs the function of moving particles or fluid over the epithelial surface in such structures as the trachea, bronchial tubes, and nasal cavities. It often occurs in the vicinity of mucus-secreting goblet cells.
Squamous epithelial tissue: the cells of this tissue are larger flattened and elongated width of the cell is Greater than the length nucleus are flattened and oven the cells remain arranged one above another like tiles they are distributed in alveoli peritoneum pleura henle's loop of kidney in bowman's capsule the tissue helps in exchange of gaseous and liquid substance infiltration and protects the body from the attack of microorganisms.
Cuboidal epithelial tissue: the cells of this tissue are equal in length and breadth nucleus is oval in upper surface is polygonal the cells are distributed in Renal tubule salivary gland thyroid gland etc. Helps in secretion and defence.
Columnar epithelial tissue: length of the cell is greater than the breadth cells are remain arranged on the basement membrane hence called columnar tissue nucleus is large in size oval and cytoplasm is reticular the cells a distributed in stomach small intestine large intestine and in certain glands the tissue participate mainly in secretion difference this tissue is modified in different parts of the body according to need than this tissue is called modified columnar epithelium there are two types brush border columnar epithelium and Goblet cell.
Ciliated epithelial tissue: the cells of this tissue is somewhere columnar somewhere cuboidal from the free end of cell 28-30 hair like structure is extended they are known as Cilia Cilia arise from the Basal particle the cells are distributed in alveoli and some adjacent part uterus oviduct ependymal cells of spinal cord the tissue clear mucus dust particles different types of microbes in the respiratory tract the cells helps to expel ovum and spermatozoa.