Table of Contents
Microscopic characteristics include the pattern of the medulla, pigmentation of the cortex, and types of scales on the cuticle (Figure 3-12).
What are the 3 microscopic layers of hair and name the 3 types of hairs?
The hair shaft is comprised of three layers: the cuticle, cortex, and medulla. The cuticle is the hair’s outer most layer which has shingle or scale like cells that overlap. These cells work defensively to prevent damage to the hair’s inner structure and to control water content of hair fiber.
What are 3 properties of the hair’s cuticle?
So, to answer those earlier questions: Hair follicles are located deep beneath the scalp while a hair cuticle is the outermost layer of a hair strand. Since cuticles are the outermost layer of hair, their shine, moisture, and smoothness (or lack thereof) are what’s on display for the world to see.
What can you tell from the microscopic examination of hair?
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.
How do you describe hair under a microscope?
Under a microscope, human hair looks a lot like animal fur. More specifically, it appears as a keratin/ pigment filled tube that’s covered with lots of small external scales. These scales are what tells apart healthy hair from damaged hair.
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 are the 3 basic medulla types?
When the medulla is present in human hairs, its structure can be described as fragmentary or trace, discontinuous or broken, or continuous. Figure 95 is a diagram depicting the three basic medullary types.
What are the properties of hair?
The main physical proprieties of the hair depend mostly on its geometry; the physical and mechanical properties of hair involve characteristics to improve: elasticity, smoothness, volume, shine, and softness due to both the significant adherence of the cuticle scales and the movement control (malleability), as well as.
What are 2 facts about the hairs cortex?
The cortex of the hair shaft is located between the hair cuticle and medulla and is the thickest hair layer. It also contains most of the hair’s pigment, giving the hair its color. The pigment in the cortex is melanin, which is also found in skin.
What are chemical properties of hair?
The overall chemical composition of hair is 45 % carbon, 28 % oxygen, 15 % nitrogen, 7 % hydrogen and 5 % sulphur. The hair shaft is essentially composed of keratin. Hair keratin is hard, compact and strong. This fibrous protein is gradually formed inside cells from the germinal layer.
What kind of instrument is used to analyze hair samples?
Forensic analysts use an instrument called a comparison microscope to view a known hair sample and an unknown sample alongside one another to see if they share similar characteristics and could have come from the same source.
What type of evidence is hair?
Hair is considered class evidence and is useful in backing up other circumstantial evidence, such as by placing someone at the crime scene.
What conclusions can be drawn from microscopic hair analysis?
Three general conclusions can be reached as a result of microscopic hair analysis: exclusion, no conclusion, or association.
What is hair made of?
Hair is made of a tough protein called keratin. A hair follicle anchors each hair into the skin. The hair bulb forms the base of the hair follicle. In the hair bulb, living cells divide and grow to build the hair shaft.
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 type of microscope is used to examine hairs?
A stereo microscope is typically used for the initial examination of hair (mounted and unmounted) before moving on to the compound microscope.
What are the functions of the 3 parts of the hair shaft?
The hair shaft is formed of three layers: The medulla – the deepest layer of the hair shaft, only seen in large and thick hairs. The cortex – the middle layer of the hair shaft which provides the strength, colour and texture of a hair fibre. The cuticle – the outer layer of the hair shaft is thin and colourless.
What are the 4 parts of hair?
The hair follicle is made up of four parts: Hair Bulb. The hair bulb is located at the base of the hair follicle. Sebaceous Gland. The sebaceous gland produces an oily substance called sebum that moisturizes both the hair shaft and the skin. The Inner and Outer Root Sheath. Arrector Pili Muscle.
What are the three concentric regions of a hair from the outside to the inside?
What are the concentric regions of a hair shaft, from the outside in? The regions of a hair from outside in are the cuticle, cortex and medulla.
What are the 3 ways that a cuticle can vary?
They vary in color, size, and distribution in a single hair. In humans, pigment granules are commonly distributed toward the cuticle as shown in Figure 16, except in red-haired individuals as in Figure 17. Animal hairs have the pigment granules commonly distributed toward the medulla, as shown in Figure 18.
What are the 4 medulla patterns?
In the Present Study medulla has been classified into Absent, Fragmented, Discontinuous and Continuous types (Photo attached).
What is meant by 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 are the 5 major elements in hair?
The five elements of hair design are: line, form, space, texture, and color. The five important principles of hair design are: proportion, balance, rhythm, emphasis, and harmony.
Is hair a liquid?
The hair growth reflects the status of ion channels and pumping only possible because of the solid–liquid growth interface driven by the gradient in chemical potential nearly perpendicular to the skin surface. Thus, a hair root is a solid–liquid system for hair formation from serum protein.
