Table of Contents
what is meant by the “morphology” of hair? Structural characteristics. how many hairs fall out during an average day? 100.
What is the morphology of hair?
Scalp hair morphology–alternatively described as hair texture, form, shape or type–refers to the structural appearance of the hair shaft protruding from the follicle.
What does the morphology of hair tell forensic scientists?
A forensic scientist who studied the morphology (shape, form, and structure) of a hair specimen could testify as to the gross physical characteristics of the hair (color, degree of curl, etc.), its internal and external structural characteristics, the likely somatic region from which the hair originated (scalp, beard, Aug 16, 2009.
What two categories are a hair’s morphology?
THE STRUCTURE OF HAIR A hair consists of two parts: a follicle and a shaft (Figure 3-2). The follicle is a club-shaped structure in the skin.
What is the morphology of hair and explain the value of hair evidence in a criminal case?
The value of hair evidence is related to the variability of hair characteristics between individuals in the population, which can be visualized through the use of comparison microscopy. If the hair originated from an animal, it is possible to further identify it to a particular type of animal.
What 3 characteristics make hair a useful forensic tool?
What characteristics make a hair a useful forensic tool? The color, the unique patterns, and textures and the opportunity to get DNA all help forensics analysis identify suspects.
Could polar bear hair be confused with human hair if so how could it definitely be differentiated from human?
The polar bear hair has an M.I. of 30. Usually animal hair has an M.I. greater than 33, so this could be construed as human; it can be differentiated by the cuticle. The medulla is found on the interior of the hair; it may be continuous, fragmented, or absent.
Can the morphology of a hair sample can tie the hair to a single person?
The morphology of a hair sample can tie the hair to a single person. DNA is not always available in a hair sample. The properties of hair do not change as we age. At most crime scenes, investigators will only be able to recover partial fingerprints.
What are the 3 components of hair?
Each hair shaft is made up of two or three layers: the cuticle, the cortex, and sometimes the medulla.
What is the medulla in the hair?
The medulla, only present in thicker hair types, is the innermost layer of your hair. It consists of a soft, thin core of transparent cells and air spaces.
What is microscopic hair analysis?
air microscopy, or microscopic hair analysis, is the practice of comparing hairs under a microscope to determine whether they came from the same person. 1 Examiners look at hair color, chemical treatment, pigment aggregation, shaft form, and other observable characteristics. Hair analysis is a form of pattern matching.
What do microscopic hair exams determine?
A microscopic hair examination can also determine if a hair was forcibly removed, artificially treated or diseased. A comparison microscope can be used to compare a questioned hair to a known hair sample in order to determine if the hairs are similar and if they could have come from a common source.
Why is hair considered as circumstantial evidence?
After reading this chapter, you will understand that: Hair is class evidence. Hair can be used to back up circumstantial evidence. Hair absorbs and adsorbs substances both from within the body and from the external environment.
What is the main protein in hair?
Hair is a filamentous biomaterial consisting mainly of proteins in particular keratin.
What is wool hair?
1. a. The dense, soft, often curly hair forming the coat of sheep and certain other mammals, such as the goat and alpaca, consisting of cylindrical strands of keratin covered by minute overlapping scales and much valued as a textile fiber. b. Fabric or yarn made of this hair.
What are hair holes called?
Hair follicles are small, pocket-like holes in our skin. As the name suggests, they grow hair. The average human has about 100,000 hair follicles on the scalp alone, according to the American Academy of Dermatology.
What is hair and fiber analysis?
Hair – Analysts can tell investigators if individual hairs are human or animal, and in the case of human hair, where on the body the sample originated. Hair samples are primarily collected using tweezers. Fiber – Fibers are threadlike elements from fabric or other materials such as carpet.
Why is the study of hair valuable in forensic chemistry?
Hair is a valuable tool for forensic scientists. It is more resistant to decay than most other body tissues and fluids, thus remaining intact far longer than other evidence. This durability makes hair one of the most frequently found pieces of evidence at crime scenes.
What are the source of hair evidence?
RAPE – The nature of this crime can result in the cross transfer of fibers and hairs between clothing of victim and suspect and such articles as blankets or automobile seat covers. If a victim goes to the hospital for an exam, the hair combings may be good sources of hair and fiber evidence.
How do you Analyse hair?
Hair analysis is done by collecting a hair sample and sending it to a laboratory. If a DNA test is done on the hair, then the hair collected needs to have the root attached. Hair samples are taken from a specific part of the body, such as from the back of the scalp by the neck or from the pubic area.
What fibers can be considered hair?
What fibers can also be considered hair? Fibers that are also hair include wool, mohair, cashmere, and, more rarely, llama, alpaca, and camel.
How do you examine hair evidence?
The hair can be analyzed by determining the chemical makeup of the hair or extracting DNA from the hair follicle. Hair can also be analyzed through the use of a microscope or by simply comparing two or more hairs against one another.
What makes human hair different from an animal hair?
Human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft, whereas animal hairs may exhibit radical color changes in a short distance, called banding. The distribution and density of pigment in animal hairs can also be identifiable features.
Why is animal hair different from human hair?
Pigment concentration: Human hair has even distribution of pigment throughout cortex, while animal hair is more concentrated toward the center/medulla area. Cuticle patterns: Human hair is imbricate pattern, while animals can have a range including coronal and spinous.
How do scientists know if hair has been dyed?
Scientists develop modern analytical techniques as a tool for advancing forensic investigations. In a recent study, scientists have combined two modern techniques, called surface-enhanced Raman spectroscopy and X-ray fluorescence, to distinguish between different colors in individual hair strands.
