A hair is found at a crime scene and you are asked to evaluate whether it is of human origin. Which of the following attributes indicates that the hair will be of human origin?: (A) Medullary index of 0.5, (B) Cuticle completely covers hair shaft, (C) Pigment granules present in coex and medulla, (D) Medullary index of 1
Answer is B. The cuticle completely covers the hair shaft in human hair. It only paly covers the hair shaft in animal hair. Human hair has 3 pas: Cuticle - outermost layer; Coex - middle layer; Medulla - innermost pa. Coex is thick (4 - 10 times that of medulla) such that the medullary index is <0.3 (Medullary index=diameter of medulla/diameter of hair). The pigment in human hair is present only in the coex, where it is evenly distributed. Reference The Synopsis of FORENSIC MEDICINE and Toxicology 29th Edition