This book has been written for the benefit of undergraduate students to acquire knowledge and guide them to give appropriate answers to questions in their examinations and to help them clear the exams. Answers are given in three forms: Essays, Short notes and Short answers. The contents presented in this book are taken from my lecture notes and updates from standard Physiology textbooks. This question-answer book in Physiology is first of its kind and has been prepared with utmost care and concern for the students.