Chapter 11 Properties Of The Hair And Scalp

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 keratin, which is a protein that provides structure and support to the hair. Additionally, the cortex also contains pigment cells that determine the hair's color.

The correct answer is sebaceous. The oil glands in the skin that are connected to the hair follicles are called sebaceous glands. These glands produce sebum, an oily substance that helps to moisturize and protect the skin and hair.

Hair follicles are not found on the soles of the feet because the skin on the soles is thick and does not have hair follicles. Hair follicles are responsible for producing and growing hair, but the skin on the soles of the feet is adapted for bearing weight and walking, so it does not have hair follicles.

The medulla is the innermost layer of the hair. It is a soft, spongy, and flexible layer that runs through the center of the hair shaft. The medulla is not always present in every hair strand, and its presence or absence can vary depending on the individual and the type of hair. It plays a role in the overall strength and elasticity of the hair.

To help minimize tangles in extremely curly hair when washing, using a detangling rinse is the best option. Detangling rinses are specifically formulated to soften and smooth the hair, making it easier to comb through and reducing the risk of tangles. Drying shampoos may strip the hair of its natural oils, leading to further tangling, while strong scalp manipulations can cause breakage and damage to the hair. Using soap instead of shampoo may not provide the necessary conditioning properties to prevent tangles.

Hair texture is classified as coarse, medium, or fine based on the diameter of the individual hair strands. Coarse hair has a larger diameter and feels thicker and more robust, while fine hair has a smaller diameter and feels thinner and more delicate. Medium hair falls in between coarse and fine hair in terms of thickness. This classification helps in determining the appropriate hair care products and styling techniques for different hair types.

Trichology is the correct answer because it specifically refers to the scientific study of hair, its diseases, and care. Dermatology is the study of skin, biology is the study of living organisms in general, and cosmetology is the study of beauty treatments and cosmetics. Therefore, trichology is the most appropriate term for the study of hair.

Sebum is the oily substance secreted from the sebaceous glands. These glands are found in the skin and their main function is to produce sebum, which helps to lubricate and waterproof the skin and hair. Sebum also helps to protect the skin from drying out and provides a natural barrier against bacteria and other pathogens. Sweat, lymph, and catagen are not substances secreted from the sebaceous glands, making sebum the correct answer.

Human hair is primarily made up of a protein called keratin, which contains the elements carbon, oxygen, hydrogen, nitrogen, and sulfur. Therefore, the correct answer is nitrogen and sulfur.

Hair porosity refers to the ability of the hair to absorb and retain moisture. It is determined by the condition of the hair cuticle, which can be either tightly closed, normal, or raised. Hair with low porosity has a tightly closed cuticle, making it difficult for moisture to penetrate. Hair with high porosity has a raised cuticle, allowing moisture to easily enter and escape. Understanding hair porosity helps in choosing the right hair care products and treatments to maintain optimal moisture balance and prevent damage.

Canities is the correct technical term used to describe gray hair. It refers to the natural graying of hair due to the loss of pigment melanin. This term is commonly used in medical and scientific contexts to describe the phenomenon of hair turning gray or white with age. Tinea refers to a fungal infection of the skin, alopecia refers to hair loss, and albino describes a person or animal with a congenital absence of pigment, resulting in white hair, skin, and eyes.

Shaving, clipping, and cutting the hair on the head do not affect the rate or pattern of hair growth. The idea that hair grows back faster, darker, or coarser after being cut is a common misconception. Hair growth is determined by factors such as genetics, hormones, and overall health, not by external factors like cutting or shaving. Therefore, these actions have no effect on hair growth.

Asians tend to have extremely straight hair. This is a common characteristic among many Asians, as their hair typically lacks natural curl or wave. This straight hair texture is often attributed to genetic factors and is a distinguishing feature of Asian hair types.

Scabies is a highly contagious skin disease caused by a mite that burrows under the skin. The mite, known as Sarcoptes scabiei, causes intense itching and a rash that is typically worse at night. It is transmitted through close personal contact or by sharing contaminated items such as clothing or bedding. Scabies can affect people of all ages and is commonly found in crowded living conditions such as nursing homes or prisons. Treatment usually involves topical medications to kill the mites and relieve symptoms.

A hydrogen bond is a physical bond easily broken by water or heat. Hydrogen bonds occur when a hydrogen atom is attracted to an electronegative atom, such as oxygen or nitrogen. These bonds are relatively weak and can be disrupted by the presence of water or by an increase in temperature.

Peptide bonds are the correct answer because they are the chemical bonds that link amino acids together in a protein chain. These bonds form through a condensation reaction, where the carboxyl group of one amino acid reacts with the amino group of another, resulting in the formation of a peptide bond and the release of a water molecule. Peptide bonds are crucial for the structure and function of proteins, as they determine the specific sequence and shape of the protein chain.

Dandruff can easily be mistaken for dry scalp because both conditions result in flakes of dead skin on the scalp. However, there are some differences between the two. Dandruff is usually accompanied by itching and can be caused by an overgrowth of a yeast-like fungus on the scalp. On the other hand, dry scalp is caused by a lack of moisture and oil on the scalp, leading to dryness and flaking. While both conditions may appear similar, the underlying causes and treatments differ.

Tinea is a fungal infection of the skin, commonly known as ringworm. It is characterized by itching, redness, and a circular rash. Numbness and blisters are not typical symptoms of tinea. Sudden hair loss may occur if the infection affects the scalp, but it is not a defining characteristic. Therefore, the correct answer is itching, as it is a common symptom experienced by individuals with tinea.

Fine hair is more fragile than coarse or medium hair. This means that it is more prone to breakage and damage. Fine hair strands are thinner and have less density, making them more delicate and easier to break. They require gentle handling and special care to prevent damage from styling, heat, and chemical treatments.

Vellus hair is a type of hair that is very fine and short, commonly found on the body of children and women. It is often referred to as "peach fuzz" and does not have a medulla, which is the innermost layer of the hair shaft. The absence of a medulla in vellus hair is due to its thin and delicate nature. This distinguishes vellus hair from other types of hair, such as oily, pigmented, and dark hair, which typically have a medulla.

The correct answer for the medical term for dandruff is "pityriasis." Pityriasis is a common skin condition characterized by the excessive shedding of dead skin cells from the scalp, resulting in white or gray flakes. It is often accompanied by itching and can be caused by various factors such as dry skin, fungal infections, or certain skin conditions. Canities refers to the graying of hair, alopecia is the medical term for hair loss, and simplex refers to a condition that is uncomplicated or not involving other factors.

Normalizing shampoo is specifically designed to treat oily scalp and hair. It helps to balance the scalp's natural oil production and remove excess oil and buildup. By using a normalizing shampoo, it can effectively cleanse the scalp and hair, leaving them feeling clean and refreshed.

The correct answer is pediculosis capitis. Pediculosis capitis refers to the infestation of hair and scalp with head lice. Hyperttichosis is a condition characterized by excessive hair growth. Trichoptilosis is the splitting or fraying of hair ends. Fragilitas cranium is not a recognized term related to head lice infestation.

Hair density refers to the number of individual hair strands on a given area of the scalp. It is measured by counting the number of hairs in a specific square inch or centimeter of the scalp. This measurement helps determine how thick or thin a person's hair is.

Dandruff is caused by a fungus. Fungal infections on the scalp can lead to the shedding of dead skin cells, which appear as dandruff. This fungus, known as Malassezia, is naturally present on the scalp but can multiply excessively, leading to dandruff. It feeds on the natural oils produced by the scalp, causing irritation and flaking. Antifungal treatments, such as medicated shampoos, are often used to control dandruff by reducing the overgrowth of this fungus.

A cowlick is a tuft of hair that stands straight up, often in a different direction from the rest of the hair. This occurs due to the natural growth pattern of the hair follicles, causing the hair in that area to resist lying flat. Cowlicks are commonly found on the crown of the head and can be difficult to style or control.

Coarse hair is stronger than fine hair because it has a larger diameter and more protein content. The larger diameter of coarse hair provides more structural support, making it less prone to breakage. Additionally, coarse hair typically has a higher density of cuticle layers, which adds to its strength. Fine hair, on the other hand, has a smaller diameter and fewer cuticle layers, making it more fragile and susceptible to damage. Therefore, coarse hair is stronger than fine hair.

The catagen phase signals the end of the growth phase. During this phase, the hair follicle stops producing new cells and the hair stops growing. It is a transitional phase between the active growth phase (anagen) and the resting phase (telogen).

A scalp massage does not affect hair growth. While a scalp massage can improve blood circulation and promote relaxation, it does not directly impact the growth of hair follicles. Hair growth is primarily determined by factors such as genetics, hormones, and overall health. Therefore, a scalp massage may feel good and have other benefits, but it does not have a direct effect on hair growth.

Finasteride is an oral prescription medication specifically designed for men. It is used to treat male pattern baldness, a condition that affects men and causes hair loss. The medication works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), which is the hormone responsible for hair loss in men. Since women do not typically experience male pattern baldness, finasteride is not recommended for them. Therefore, the correct answer is "men only".

The hair cuticle is the outermost layer of hair. It acts as a protective covering for the inner layers of the hair shaft. It consists of overlapping scales that help to protect the hair from damage and keep it hydrated. The cuticle also plays a role in determining the texture and appearance of the hair.

Women generally have faster hair growth compared to men. This is due to hormonal differences between the sexes. 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, women's hair follicles may be more active and have a shorter resting phase, leading to faster growth. Therefore, the correct answer is "faster".

Bald men are commonly perceived as less successful. This perception may stem from societal stereotypes and biases that associate baldness with aging and a decline in physical attractiveness. These stereotypes can lead to assumptions that bald men are less successful in their careers or personal lives, despite there being no actual correlation between baldness and success. It is important to recognize and challenge these stereotypes to prevent unfair judgments based on appearance.

Pheomelanin is the type of melanin that provides natural colors ranging from red and ginger to yellow and blond tones. Eumelanin is responsible for darker hair colors, while polymelanin and biomelanin are not involved in determining hair color.

During the anagen phase, new hair is produced. This is the active growth phase of the hair follicle, where cells divide rapidly and hair grows at a rate of about half an inch per month. This phase can last for several years, and it is during this phase that the hair shaft is formed and pushed up through the scalp.

Wet hair with normal elasticity will stretch up to 50 percent of its original length. This means that when wet, the hair can be stretched to half of its original length without breaking or losing its shape. This is an important characteristic of healthy hair, as it indicates that it can withstand some tension and manipulation without being damaged.

The arrector pili is a tiny, involuntary muscle located at the base of the hair follicle. This muscle is responsible for causing the hair to stand up straight, resulting in the phenomenon commonly known as "goosebumps." When the arrector pili muscle contracts, it pulls on the hair follicle, causing the hair to become more erect. This response is often triggered by cold temperatures or strong emotions, such as fear or excitement.

Hair is made up of a protein called keratin, which accounts for its strength and structure. Therefore, it can be concluded that hair is approximately 90 percent protein.

A whorl is a term used to describe hair that forms in a circular pattern on the crown of the head. It is characterized by a specific direction of hair growth that creates a circular or spiral shape. This term is commonly used in the field of hairstyling and hair analysis to identify and classify different hair patterns. The other options, crown hair, cowlick, and ringed hair, do not accurately describe this specific circular pattern of hair growth on the crown of the head.

The medulla is composed of round cells.

Vellus hair is also known as lanugo hair. Lanugo hair refers to the fine, soft, and unpigmented hair that covers the body of a fetus or newborn baby. It is usually shed and replaced by terminal hair, which is thicker and more pigmented, as the baby grows. This type of hair is different from other types mentioned in the question, such as lanthionine hair, malassezia hair, and monilethrix hair, which are not related to vellus hair.

Cross-sections of hair can be almost any shape because hair can vary in texture and thickness from person to person. The shape of the cross-section is determined by the shape of the hair follicle, which can be round, oval, or flattened. This variation in shape is what gives individuals their unique hair types, such as straight, wavy, or curly. Therefore, it is incorrect to say that cross-sections of hair are always round, oval, or flattened, as they can be almost any shape.

Congenital canities refers to the premature graying of hair that occurs at or before birth. This condition is rare and occurs due to a lack of pigment-producing cells in the hair follicles. Unlike regular graying of hair that happens with age, congenital canities is present from birth or develops during infancy. The premature graying is usually uniform and affects all the hair on the body.

Malassezia is the correct answer because it is a naturally occurring fungus that can cause dandruff when it overgrows on the scalp. This fungus is commonly found on the skin of humans, but when it multiplies excessively, it can lead to the flaking and itching associated with dandruff. Controlling the growth of Malassezia is important in managing dandruff symptoms.

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Hypertrichosis is the correct answer because it refers to a condition of abnormal hair growth on areas of the body. This condition causes excessive hair growth beyond what is considered normal for a person's age, sex, and ethnic background. Hypertrichosis can occur in specific areas or can be generalized, affecting the entire body. It can be caused by various factors, including genetics, hormonal imbalances, medications, and certain medical conditions.

Salt bonds account for about one-third of the hair's overall strength. These bonds are formed between the positive and negative charges of amino acids in the hair protein structure. They contribute to the hair's strength and stability, but they are not as strong as other types of bonds like disulfide bonds. Therefore, one-third is the correct answer as it indicates the approximate proportion of the hair's overall strength that can be attributed to salt bonds.

The anagen phase refers to the active growth phase of hair follicles. During this phase, the hair cells divide rapidly, resulting in the growth of new hair. The anagen phase can vary in duration depending on various factors, such as genetics and overall health. While it typically lasts for a few years, it can range from three to five years in most individuals.

The term for the spiral shape of a coiled protein is helix. A helix is a three-dimensional structure formed by a chain of amino acids that twist around a central axis. This structure is stabilized by hydrogen bonds between the amino acids. The helix shape is an important characteristic of proteins and plays a crucial role in their function and stability.

Chemicals need to have an alkaline pH in order to penetrate a healthy cuticle hair layer. The cuticle is the outermost layer of the hair and is made up of overlapping scales. These scales lay flat when the hair has a neutral pH, but when the pH becomes alkaline, the scales lift, allowing chemicals to enter the hair shaft. This is why alkaline solutions, such as hair relaxers or color treatments, are used to penetrate and alter the structure of the hair.