Q.3 Short Answers (Answer 7 out of 9) (7 x 5 = 35) A) Write a note on epithelial tissue. B) Explain the physiology of skeletal muscle contraction. C) Write a note on cell signalling. D) Summarize in short the renin-angiotensin-aldosterone system. E) Describe the ABO and Rh systems of blood groups. F) Draw a neat labeled diagram of a lymph node and discuss its structure and function. G) Explain the physiology of smell. H) Define and classify joints. Write a note on synovial joints with its labelled diagram. I) Explain in detail the mechanism of blood coagulation.

A) Epithelial tissue is a type of animal tissue that forms the covering of all body surfaces, lines body cavities and hollow organs, and is the major tissue in glands. It is characterized by closely packed cells with little extracellular matrix, forming continuous sheets. Epithelial tissues are avascular (lack blood vessels) and are anchored to underlying connective tissue by a basement membrane. Their primary functions include protection, secretion, absorption, excretion, and filtration.