Hair Identification Lecture Notes 2024 PDF

Identification of Hair &Fibers By Dr. Nagwa M. Ghandour Professor of Forensic Medicine and Clinical Toxicology Faculty of medicine - Assiut University 2024 Table of contents 1 2 3 is the presented if hair...

Identification of Hair &Fibers By Dr. Nagwa M. Ghandour Professor of Forensic Medicine and Clinical Toxicology Faculty of medicine - Assiut University 2024 Table of contents 1 2 3 is the presented if hair, is it if human, is it the object hair or human or hair of a certain not? animal? person? 4 5 from what part of the body did the MLI of hair examination hair come? In the study of hairs and fibers, we shall be directed by the following questions:- 1- is the presented object hair or not? 2- if hair, is it human or animal? 3- if human, is it the hair of a certain person? 4- from what part of the body did the hair come?  HAIR Is a specialized epithelial outgrowth of the skin which occur 1 everywhere on the human body except on Is the presented the palm of the hands object hair or and the sole of the not? feet.  PARTS OF HAIR 1. Roots (portion embedded in the skin) 2. Shaft (portion above the surface of the skin). The most DISTINCTIVE part of the hair. 3. Tip (sometimes termed point). The distal end of an uncut hair. PARTS OF SHAFT 1. Cuticle – outermost covering of the hair. It is consisting of one layer of non-nucleated polygonal cells, which overlaps like the scales on a fish. 2. Cortex – the intermediate and the THICKEST layer of the hair and is composed of elongated, spindle-shaped fibrils which cohere. They contain pigment granules in varying proportion depending on the type of hair. 3. Medulla or Core – the most characteristics portion of the hair. It is the central canal of the hair that maybe empty or may contain various sorts of cells more or less pigmented. Textile Fibers – fibers that can be converted into yarns. Hair Fiber Cotton ✓ Flattened ✓ Twisted ✓ Tape –like Linen ✓ Jointed with swellings at the joints like Bamboo Silk ✓ Shining (Refractile) ✓ Straight line ✓ Regular (no twist, joints or swelling) Wool ✓ Animal (sheep) hair ✓ Imbricated surface(cuticle) ✓ Wide medulla ✓ Irregular  Human Animal Tr Animal hair General Fine and thin Coarse and thick Cuticle Thin layer of cells , Irregular cells , 2 undistinguished overlapping each other , easily if hair, is it recognized human or Cortex Broad , longitudinally striated Narrow, with animal? transverse striations Medulla Narrow , segmented or Broad and absent continuous Precipitin Specific for human Specific for animal test Human Animal Examination of hair ✓Hair tip ✓Hair root ✓Color to naked eye & under microscope 3 ✓Length ✓Breadth if human, is it the ✓Texture hair of a certain ✓Dyed or undyed person? ✓Blood group & DNA  Hair Tip A- Brush- like (Crushed) ; Axillary, pubic or blunt instrument (Shuma) B- Cleanly cut; Recent hairdressing or sharp instrument (Knife, Axe) C- Rounded end; between cut and tapering , 1-2 weeks after hair cut D- Tapering end 3 weeks after hair cut, eye brows or eye lashes  Hair Root A. Healthy root with sheath ruptured Pulled by force  Hair Root B- Degenerated and fallen by itself Shrunken root devoid of sheath 4 from what part of the body did the hair come? ✓Attached debris; semen , vaginal epithelium, nasal secretions, feces. 5 MLI of hair examination 1. Criminal cases 2.Burn and Scald. ✓ Scalp injuries 3. Firearm injures. ✓ Identification of assailant ▪ Hand of victim 4. Poisoning. ▪ Rape 5. Disputed paternity. ▪ Crime scene