Chapter 11-properties Of The Hair & Scalp-milady

The medulla is the innermost layer of hair. It is a soft, spongy, and flexible region located at the center of the hair shaft. The medulla is not always present in all hair types, and its presence or absence can vary among individuals.

A detangling rinse is the most suitable option for minimizing tangles in extremely curly hair when washing. Curly hair tends to get easily tangled, and using a detangling rinse helps to smooth out the hair strands and make them easier to comb through. A detangling rinse typically contains ingredients that help to soften and moisturize the hair, making it more manageable and reducing the risk of tangles. This option is more effective than a drying shampoo, strong scalp manipulations, or using soap instead of shampoo, as these alternatives may not provide the necessary conditioning and detangling properties.

The oil glands in the skin that are connected to the hair follicles are called sebaceous glands. These glands secrete sebum, an oily substance that helps lubricate and protect the skin and hair. Sebaceous glands are found all over the body, except for the palms of the hands and the soles of the feet. They play an important role in maintaining the health and hydration of the skin and hair.

The correct answer is cortex. The cortex is the middle layer of the hair shaft, located between the outer cuticle and the inner medulla. It is responsible for giving the hair its strength, elasticity, and color. The cortex contains a protein called keratin, which forms the structural framework of the hair. It also contains pigment cells that determine the hair color.

Asians tend to have extremely straight hair because of their genetic makeup. The shape of the hair follicles and the amount of a protein called keratin in the hair shaft contribute to this characteristic. The straightness of Asian hair is often attributed to the round shape of the hair follicles, which allows the hair to grow straight out of the scalp. Additionally, the low levels of a specific type of keratin protein called trichohyalin in Asian hair also contribute to its straight texture.

Scabies is a highly contagious skin disease caused by a parasite called a mite that burrows under the skin. It is characterized by intense itching and the formation of small, red bumps or blisters. Scabies is typically spread through close skin-to-skin contact and can affect people of all ages. Treatment usually involves the use of topical creams or lotions to kill the mites and relieve symptoms.

The soles of the feet do not have hair follicles. Hair follicles are found on various parts of the body, including the forehead, back of the hands, and back of the neck. However, the soles of the feet are an exception to this, as they are covered with thick skin that does not contain hair follicles.

Hair texture refers to the thickness or diameter of individual hair strands. Coarse hair has a larger diameter and feels thicker, while fine hair has a smaller diameter and feels thinner. Medium hair falls in between. This classification helps in understanding and categorizing different hair types, which can inform styling and product choices.

Fine hair is more fragile than coarse or medium hair. This means that it is more prone to breakage and damage compared to other types of hair. Fine hair is thinner and has a smaller diameter, making it weaker and more delicate. It requires extra care and gentle handling to prevent further damage.

Hair porosity refers to the hair's ability to absorb and retain moisture. It is determined by the hair's cuticle structure, which can be either tightly closed (low porosity), partially open (medium porosity), or fully open (high porosity). Hair porosity affects how easily hair can absorb and retain moisture, as well as how prone it is to damage from heat and chemical treatments. It is an important factor to consider when choosing hair care products and styling techniques.

Canities is the correct technical term used to describe gray hair. This term refers to the natural graying of hair due to the loss of pigment. It is a result of the reduction in melanin production, which gives hair its color. Canities is a common occurrence as people age, and it can be influenced by factors such as genetics and lifestyle. Tinea refers to a fungal infection of the skin, alopecia refers to hair loss, and albino refers to a person or animal with a congenital absence of pigment.

Pityriasis is the correct medical term for dandruff. Pityriasis refers to a common scalp condition characterized by the excessive shedding of dead skin cells from the scalp, leading to the appearance of white flakes. It is often accompanied by itchiness and can be caused by various factors such as dry skin, fungal infections, or dermatitis. While "canitites," "alopecia," and "simplex" are all medical terms related to hair loss or other skin conditions, they do not specifically refer to dandruff.

Sebum is an oily substance that is secreted from the sebaceous glands. These glands are located in the skin and their primary function is to produce sebum, which helps to moisturize and protect the skin and hair. Sebum also plays a role in waterproofing the skin and preventing it from drying out. It is different from sweat, lymph, and catagen, which are not oily substances secreted from the sebaceous glands.

Trichology is the scientific study of hair, its diseases, and care. It focuses specifically on understanding the structure, function, and growth of hair, as well as diagnosing and treating hair and scalp conditions. Dermatology is the branch of medicine that deals with the skin, including hair and scalp, but it encompasses a wider scope of skin-related issues. Biology is the study of living organisms in general, and cosmetology is the study and application of beauty treatments, including hair care, but it does not focus solely on the scientific study of hair.

Shaving, clipping, and cutting the hair on the head has no effect on hair growth. The rate of hair growth is determined by factors such as genetics, hormones, and overall health. These hair grooming practices may give the illusion of thicker or darker hair due to the blunt ends, but they do not actually change the rate or texture of hair growth.

Peptide bonds are the correct answer because they are the chemical bonds that hold together amino acid molecules in a protein chain. These bonds form between the carboxyl group of one amino acid and the amino group of another amino acid, resulting in the formation of a peptide bond. Peptide bonds are essential for the structure and function of proteins, as they create the backbone of the protein chain and determine its overall shape and stability. Convex bonds, helium bonds, and protein bonds are not accurate terms to describe the bonds between amino acids.

Hair density refers to the number of individual hair strands present on a specific area of the scalp. It is measured by counting the number of hair strands in a given square inch of the scalp. This measurement helps determine the thickness or thinness of the hair and can be classified as low, medium, or high density.

Normalizing shampoo is specifically designed to control and balance excess oil production on the scalp. It helps to remove excess oil, dirt, and impurities from the hair and scalp, leaving it clean and refreshed. Using a normalizing shampoo regularly can help regulate the oil production on the scalp, reducing the greasiness and improving the overall health of the hair and scalp.

Vellus hair is a type of hair that is short, thin, and often colorless. It is commonly found on areas of the body that are not covered by terminal hair, such as the face, back, and arms. Unlike terminal hair, vellus hair does not have a medulla, which is the innermost layer of the hair shaft. This is because vellus hair is much finer and less developed compared to terminal hair, which is thicker and longer. Therefore, vellus hair almost never has a medulla.

Human hair is primarily composed of keratin, a protein made up of amino acids. Nitrogen is a key component of amino acids, which are the building blocks of proteins. Sulfur is also present in hair, as it forms disulfide bonds that contribute to the strength and structure of the hair strand. Therefore, the correct answer is nitrogen & sulfur.

A hydrogen bond is a physical bond easily broken by water or heat because hydrogen bonds are relatively weak compared to other types of chemical bonds. They occur when a hydrogen atom is attracted to a highly electronegative atom, such as oxygen or nitrogen. These bonds are important for many biological processes, such as the folding of proteins and the structure of DNA. Water and heat can disrupt the hydrogen bonds by providing energy to overcome the attractive forces between the hydrogen and electronegative atoms, causing the bond to break.

Tinea is a fungal infection of the skin, also known as ringworm. It is characterized by itching, which is the most common symptom of this condition. Numbness and blisters are not typically associated with tinea. Sudden hair loss can occur if tinea affects the scalp, but it is not a defining characteristic of the infection. Therefore, the correct answer is itching.

Pheomelanin is the type of melanin that provides natural colors ranging from red and ginger to yellow and blond tones. It is responsible for producing lighter hair and skin colors, as well as freckles. Eumelanin, on the other hand, is responsible for darker hair and skin colors. Polymelanin and biomelanin are not types of melanin and do not play a role in determining hair and skin color.

Pediculosis capitis is the correct answer because it refers to the infestation of the hair and scalp with head lice. Hypertrichosis refers to excessive hair growth, trihoptilosis is the splitting of hair ends, and fraglitas crinium is the condition of easily broken hair.

A cowlick is a tuft of hair that stands straight up. It is a common term used to describe a section of hair that grows in a different direction from the rest, creating a noticeable and often stubborn tuft. This can occur due to genetics or the natural growth pattern of the hair follicles.

Coarse hair is stronger than fine hair because it has a larger diameter and is more resistant to breakage. The larger diameter allows for more protein and moisture to be retained in the hair shaft, making it less prone to damage. Fine hair, on the other hand, has a smaller diameter and is more delicate, making it more susceptible to breakage. Therefore, coarse hair is generally considered to be stronger than fine hair.

During the anagen phase, new hair is produced. This is the active growth phase of the hair follicle, where cells in the root of the hair divide rapidly, leading to the production of new hair cells. The hair shaft grows longer during this phase, and it can last for several years. After the anagen phase, the hair follicle enters the catagen phase, followed by the telogen phase, where the hair stops growing and eventually falls out. Therefore, anagen is the correct answer as it specifically refers to the phase of new hair production.

The catagen phase signals the end of the growth phase. This phase is a transitional phase between the anagen (growth) phase and the telogen (resting) phase of the hair growth cycle. During the catagen phase, the hair follicle shrinks and detaches from the dermal papilla, which results in the cessation of hair growth. It is a short phase that lasts for about 2-3 weeks before entering the telogen phase. Cysteine and cystine are amino acids that are not related to the hair growth cycle.

Dandruff can easily be mistaken for dry scalp because both conditions can cause flaking and itching of the scalp. However, there are some differences between the two. Dandruff is caused by an overgrowth of yeast on the scalp, while dry scalp is caused by a lack of moisture. Dandruff flakes are usually larger and oilier, while dry scalp flakes are smaller and drier. Additionally, dandruff is often accompanied by redness and irritation, while dry scalp may just have flaking without any other symptoms. Therefore, it is important to differentiate between the two in order to provide appropriate treatment.

Women's scalp hair generally grows faster than men's hair. This can be attributed to hormonal differences between men and women. Women tend to have higher levels of estrogen, which promotes hair growth, while men have higher levels of testosterone, which can slow down hair growth. Additionally, genetic factors and individual variations can also play a role in the rate of hair growth.

The hair cuticle is the outermost layer of the hair. It is a protective layer that covers the hair shaft and consists of overlapping cells that resemble scales. The cuticle plays a crucial role in protecting the inner layers of the hair from damage, such as heat, chemicals, and environmental factors. It also helps to retain moisture and maintain the overall health and appearance of the hair.

Bald men are commonly perceived as less successful because society often associates a full head of hair with youth and vitality. This stereotype can lead to the assumption that baldness is a sign of aging or potential health issues, which may be seen as barriers to success. Additionally, cultural ideals of attractiveness often prioritize a full head of hair, so those who are bald may be perceived as less physically attractive. However, it is important to note that these perceptions are subjective and can vary from person to person.

The arrector pili is the tiny, involuntary muscle in the base of the hair follicle. When this muscle contracts, it causes the hair to stand up, creating "goosebumps" on the skin. This muscle is responsible for controlling the position of the hair and is particularly active during times of fear or cold temperatures.

A whorl refers to hair that grows in a circular pattern on the crown of the head. It is characterized by a distinct circular or spiral shape, where the hair grows in a circular direction from a central point. This term is commonly used in hairstyling and hair analysis to describe a specific pattern of hair growth. The other options, such as crown hair, cowlick, and ringed hair, do not accurately describe this specific circular pattern of hair growth on the crown of the head.

The average growth of healthy scalp hair is commonly accepted to be about 1/2 inch per month. This means that, on average, a person's hair will grow half an inch in length every month.

Scalp massages do not affect hair growth. While scalp massages can promote relaxation and improve blood circulation in the scalp, there is no scientific evidence to suggest that they directly stimulate hair growth. Hair growth is primarily influenced by factors such as genetics, hormones, and overall health. Therefore, although scalp massages may have other benefits, they do not have a direct impact on hair growth.

Finasteride is a medication specifically designed to treat hair loss in men. It works by inhibiting the production of dihydrotestosterone (DHT), a hormone that contributes to hair loss in men. Since women do not typically experience the same pattern of hair loss caused by DHT, finasteride is not recommended for them. Therefore, the correct answer is "men only."

Dandruff is caused by a fungus. Fungal infections on the scalp can lead to the shedding of dead skin cells, which appear as white flakes known as dandruff. This fungus, called Malassezia, is naturally present on the scalp of most individuals, but in some cases, it can overgrow and cause dandruff. Anti-dandruff shampoos and treatments often contain antifungal agents to target and control the growth of this fungus, providing relief from dandruff symptoms.

A carbuncle is a type of skin infection that is characterized by a cluster of boils. It is larger in size compared to a furuncle, which is a single boil. Carbuncles can range in size from a few centimeters to several inches in diameter. They are often red, swollen, and painful.

Wet hair with normal elasticity will stretch up to 50% of its original length. When hair is wet, it becomes more flexible and can stretch without breaking. Normal elasticity means that the hair has a healthy level of moisture and protein, allowing it to stretch and return to its original length without any damage. A stretch of 50% indicates that the hair can stretch to half of its original length before reaching its maximum elasticity.

Hypertrichosis is a condition characterized by abnormal hair growth on certain areas of the body. It can manifest as excessive hair growth on the face, arms, back, or other parts of the body. This condition can be either congenital (present at birth) or acquired later in life. Hypertrichosis can be caused by various factors such as genetics, hormonal imbalances, medications, or underlying medical conditions. Treatment options for hypertrichosis include hair removal methods like shaving, waxing, or laser therapy, as well as addressing any underlying causes if possible.

Hair is primarily composed of a protein called keratin, which makes up about 90% of its structure. Keratin is a fibrous protein that provides strength and elasticity to the hair shaft. It forms a protective layer around the hair, preventing damage and breakage. Therefore, it can be concluded that hair is approximately 90% protein.

Malassezia is the correct answer because it is a naturally occurring fungus that can cause dandruff when it grows excessively on the scalp. This fungus feeds on the oils produced by the hair follicles and causes irritation, leading to the characteristic symptoms of dandruff such as flaking and itching. Controlling the growth of Malassezia is important in managing dandruff.

Vellus hair is commonly known as "languo hair".

Alopecia totalis refers to the complete loss of scalp hair. This condition is characterized by the absence of hair on the entire scalp, leading to a completely bald head. It is a more severe form of alopecia areata, which is a condition that causes patchy hair loss. Androgenetic alopecia, on the other hand, is a common form of hair loss that is caused by genetic and hormonal factors. Alopecia universalis is a rare condition that results in the loss of all hair on the body, including the scalp, eyebrows, and eyelashes.

Salt bonds account for about one-third of the hair's overall strength. This means that these bonds contribute significantly to the hair's ability to maintain its structure and resist breakage. While other factors such as disulfide bonds also play a role in hair strength, salt bonds make up a significant portion of it. Understanding the importance of salt bonds can help in the care and treatment of hair to maintain its strength and prevent damage.

Trichorrhexis nodosa is the correct technical term for knotted hair. This condition is characterized by weak points in the hair shaft that cause it to break easily, leading to the formation of knots or nodules. These knots can be felt as rough or brittle areas in the hair. Monilethrix refers to a different condition where the hair shaft has a beaded appearance. Trichoptilosis is the term for split ends, and hypertrichosis refers to excessive hair growth.

The anagen phase refers to the active growth phase of hair follicles. During this phase, the hair grows continuously for a certain period of time before entering a resting phase. The anagen phase can last from a few years, during which the hair can grow quite long, before it eventually transitions into the catagen phase. Therefore, the correct answer is "years".

A coiled protein is known as a helix. This refers to the spiral shape that the protein takes on. The helix structure is formed by a repeating pattern of amino acids, which are the building blocks of proteins. This structure allows the protein to be compact and stable.

Congenital canities refers to the condition of having gray or white hair from birth or early childhood. This means that the manifestation of congenital canities occurs at or before birth, as stated in the answer. It is not a condition that develops during adolescence, middle age, or in the later years of life. Therefore, the correct answer is that congenital canities manifests at or before birth.