Hair is considered one of the components of the integumentary system, along with the skin, nails, glands and nerves. Mammalian hair has many functions including protection from environmental factors and the ability to disperse sweat gland products such as pheromones. Almost every part of the human body is covered by hair except for the palms, hands and bottoms of the feet. On average, every person has about five million hairs; each of these hairs is born from a follicle or tiny tube-like structure that grows into the dermis layer of the skin. Oftentimes this follicle even reaches the subcutaneous layer, which is made of fat and connective tissue. (UXL Complete Health Research, 2001)
At the base of each hair follicle there are capillaries and
…show more content…
The hair of the scalp is longer and more flexible, while the hair of the eyebrows tends to be short and stiff. Oval shaped hair shafts produce wavy hair, flat hair shafts create curly hair and hair shafts that are perfectly round create straight hair. There are also different types of melanin, a natural compound responsible for the production of color in the eyes, skin and hair. There is yellow, brown and black melanin, each produced by melanocytes located at the follicle base. With age, melanin production decreases, causing greying of hair. (Applegate & Saunders, 2001, pp …show more content…
This cycle tends to last anywhere from five to seven years and is shorter for hair on the eyebrows, armpits and pubic area. Inside the bulb of each hair is a component called the dermal papilla which controls the hair growth while the matrix of the hair, which contains a large amount of epidermal cells that rapidly divide, is responsible for the length of the hair. Next is the catagen phase which is characterized as a transition period between the anagen and telogen phases. At this time the hair bulbs are pushed out in order to become keratinized and the hair appears short and thick. This phase tends to only last between two and three weeks. During the telogen phase, no new cell division occurs, which means that the length of the hair remains the same. This pause allows the dermal papilla to fill up the matrix with new cells in preparation for the anagen phase to begin again. This phase can last between three and nine months. After this phase, the anagen phase begins again. The telogen phase is periodically followed by shedding, or exogen. This leads to the last phase, the exogen phase. This phase is characterized by the shedding of hair. Each day about one hundred hairs are shed from the average individual’s scalp. The shaft of the hair is shed and the follicle remains. Despite the fat that the exogen phase usually follows the telogen phase, there are exceptions when it does not, resulting in hair follicles needing to go
Jablonsky and Chaplin states in their article that when it comes to us not having as much hair, we have looked a...
Just because a hair is found at the scene doesn’t mean that it belongs to the perpetrator. It is important to take Locard’s Principle into account, “The microscopic debris that cover our bodies are the mute witnesses... of all our movements and all our encounters.” (Robertson, 7.2) When you come into contact with something or someone, there is always a transfer, even if it isn’t noticeable. There are different types of transferring, primary and secondary. Primary transfer is when something transfers from you to another source. When someone comes into contact with that source, there is a chance that your hair or fiber transfers onto the other person. This is secondary transfer. Because humans shed hair frequently, it is easy for hair to go through secondary transfer and end up somewhere that the individual had never been. Hair can remain on a source for a couple hours without being transferred and it does not break down very easily, so this can remain in place for a long time. (Robertson,
The integumentary system is composed of the skin and the structures related to the skin, which include the hair, the finger nails, the sensory receptors and the glands (Shier, Butler, & Lewis, 2009). This system has an important function since it provides protection to the body, helps to maintain body temperature, and contains sensory receptors (p.117). The skin has essential function such as regulating homeostasis and body temperature, also delaying the loss of water from deeper tissues, storing sensory receptor, synthesizing biomechanical, and discharging waste from the body (p.117). The skin has two layers: the epidermis (outer layer) and the dermis (inner layer) (p.117). There is also a subcutaneous layer or hypodermis (p.117). According to Shier, Butler, and Lewis 2009 “as its name indicates, this layer is beneath the skin and not a true layer of the skin” (p.117). This layer has the blood vessels that supply the skin (p.117).
The integumentary system is an organ system that is often overlooked when compared to other major organ systems. The importance of the integumentary system and its role in thermoregulation and its first line protection for the body is of utmost importance. The integumentary system includes the following organs: skin, hair, nails, and exocrine glands. Skin is a very large organ, and is the most important organ of the integumentary system. The surface area of skin is about 20 square feet, and weighs about 10 pounds. The importance of skin is to protect the body from UV light, chemical, disease and physical trauma that can occur to the body. The skin helps regulate body temperature. It does this through storage of adipose tissue and through secretions of sweat. It also allows for sensing touch, Different temperatures that the body comes into contact with are sensed and these messages are sent to the brain so that a reaction can occur in order to protect the body. A very important part of the integumentary system is that it is responsible for making vitamin D. Vitamin D is key in the function of calcium absorption.
It is made mostly of connective tissue (areolar and dense irregular). Connective tissue provides support to the epidermis because it consists of numerous collagen and elastin fibers. The dermis serves as a first line of protection so that pathogens (bacteria and/or microbes) that have made it through the epidermis cannot move any farther. The dermis produces a gel-like substance within the areolar connective tissue that slows down the movement of microbes. The dermis also supplies blood and nutrients to the epidermis (via blood vessels) and supports sensory reception (nerve fibers). Accessory structures found in the dermis include a portion of the hair follicle, secretory glands (sebaceous and sweat glands), touch receptors (nerve fibers) and blood vessels. There dermis has two layers: the papillary layer and reticular layer. The papillary layer is the outer top portion of the dermis that is below (deep to) the epidermis. It has a sub layer called dermal papillae. Dermal papillae has ridge-like projections that interlock with ridges in the lower portion of the epidermis (epidermal ridges). These ridge-like projections have sensory receptors and capillaries. The sensory receptors are called tactile corpuscles that detect light, delicate touch and capillaries supply blood and nutrients to the epidermis above. The reticular layer is the deeper portion of the dermis and consists mostly of dense irregular connective tissue (ground substance and randomly arranged collagen fibers). The lamellated corpusle is a large, leaflet like sensory receptor located in the reticular layer. This receptor detects pressure, rough touch and
In conclusion, the question of how hair texture among an ethnicity is determined has yet to be answered. However, new developments such as the evidence that all humans have the same single origin in Africa and mutations in the P2RY5 gene can determine the hair texture of a human, have shown that researchers are quite close in determining the hair texture of an ethnicity. These developments have the possibility of leading to new hair removal and hair growth treatments. The future looks bright for hair research and hopefully in the next 20-50 years the question is answered.
The most common type of hair loss is androgenetic alopecia. Androgenetic alopecia is male or female pattern baldness and will affect 40% of men by the age of 35, and by the age of 50 about 50% of men will have significantly thinning hair. In women pattern hair loss is most likely to occur after menopause. It is called pattern hair loss because in men the hair is lost in a well-defined pattern, beginning above both temples. Over time, the hairline recedes to form a characteristic “M” shape. Hair also thins at the crown, often progressing to partial or complete baldness. The pattern of hair loss in women is...
Human pigmentation is influenced by hemoglobins within blood vessels in the skin, carotene and melanins. Melanin, the basis of pigmentation, can be found in the forms of eumelanin and phaeomelanin. Eumelanin is the brown-black pigment located in the skin, hair, and eyes. Phaeomelanin is a yellow to reddish-brown pigment found in small quantities within the skin, eyes, and red hair. Because of these two pigments, to a greater or lesser degree, we have the variation in human pigmentation that is seen today.
Expert gynecologist James Clark stated, “Next to the bone marrow, hair is the fastest growing tissue in the human body.” Many people believe that an individual can speed up the hair growth process by buying products for their hair or giving it a trim every once in a while. Researchers have stated that hair will not grow faster and that genetics play a huge role in this. An individual cannot simply force their hair to grow faster. The hair must go through the three certain growth phases to grow which will be discussed later. Shampoos and other chemicals to make an individuals hair grow faster is just wasting the individuals money. Many hair specialists explain that instead of trying to quickly grow out hair unnaturally, an individual should eat healthy with a balanced diet to grow healthy hair. Since hair is already a dead cell, it will not absorb vitamins or other nutrients that an individual wants to achieve (Hoffenstein 42). The healthier the hair, the more likely it will grow longer. There are many myths about how a person could speed up their hair growth such as trimming the hair or buying special hair treatments; however, many researchers, trichologists, and individuals believe that hair grows at a certain speed based on an individuals stress, hygiene, and genetics.
Method When conducting this research study about The Natural Hair Movement, it focuses on the opinions on how individuals and society feel about ethic hair. Societies perception on hair promote an opinion on why ethic hair is considered unattractive in the 20th century. This study utilizes an ideological criticism method to look at how ethic hair is treated unfairly in society. To do so it employs social comparison theory as a lens to closely focus on societies opinions about the appearance of ethic hair, compared to individual’s personal opinions. Qualitative Findings
When approaching the topic of hair chemistry, one may think about the question, where does hair come from? Saclike holes called follicles are located all over the human body. At the bottom of these follicles are a cluster of papilla responsible for the growth of hair. As the papilla, otherwise known as hair bulbs reproduce to make new hair cells, the old ones are pushed up towards the surface of the skin causing the hair to grow longer. This may seem like a simple concept to grasp. However, the process of hair growth is a little more in depth.
Keratin is part of the family of fibrous structural proteins and is the key component in creating the outer layer of skin (cartilage), hair, nails, and teeth for humans. This essential protein is created from the combination of 18 different amino acids, one especially notable one being cysteine, which is rich in sulfur. This important protein plays an important role in the cohesion of hair, this is produced by keratinocytes and within the cornified layer of the epidermis, there are large amounts of keratinocytes in keratin filaments.
People with ocular albinism may have slight lightening of hair and skin colors as well, compared to other family members. At present, researchers have found 10 different types of oculocutaneous albinism, and five types of ocular albinism. Newer laboratory research studying DNA has shown that there are numerous types of changes in the genes of those with albinism, including within families. The most common types of oculocutaneous albinism are called "ty-negative" and "ty-positive". Persons with type-negative albinism have no melanin pigmentation, and more difficulty with vision.
Melanesia consists of several islands that rest within a sub region of Oceania. Melanesia islands include: Fiji, Papua New Guinea, New Caledonia, Solomon Islands and Vanuatu. One theory stated that salt-water whitening, sun exposure, excess fish consumption, American or European heritage were responsible for the light hair color. However, a study conducted by Sean Myles
The most common type is oculocutaneous albinism also known as OCA. There are four types of OCA that affect the hair skin and eyes. The first type is OCA type 1, the people who have this type have a complete absence, so melanin so their skin is very pale, white hair, and light eyes. The color may increase as time goes on.