Skin, Hair & Nails - Level 2

Melanin is responsible for making the skin pigmentation darker. Melanin is a pigment produced by specialized cells called melanocytes. It is responsible for the color of our skin, hair, and eyes. The more melanin produced, the darker the skin becomes. Melanin is produced as a natural response to protect the skin from the harmful effects of the sun's ultraviolet (UV) radiation. It acts as a shield, absorbing and dissipating the UV radiation, thereby reducing the risk of sunburn and skin damage.

Melanocyte cells produce melanin. Melanin is a pigment that gives color to the hair, skin, and eyes. It is responsible for determining the color of our skin and hair. Melanin also helps protect the skin from the harmful effects of the sun's ultraviolet (UV) rays.

The papillary layer of the epidermis contains nerve endings and a blood and lymph network. This layer is located just below the outermost layer of the skin, called the stratum corneum. The nerve endings in the papillary layer are responsible for sensing touch, temperature, and pain, while the blood and lymph network helps in supplying nutrients and oxygen to the skin cells and removing waste products.

The skin is not directly involved in the function of movement. Movement is primarily controlled by the muscles and the skeletal system, while the skin serves functions such as sensation, protection, and vitamin production. The skin is responsible for detecting sensations such as touch, pressure, and temperature, providing a protective barrier against external factors, and producing vitamin D when exposed to sunlight. However, movement is not a direct function of the skin.

Terminal hairs are found on the scalp, under the arms, and in the pubic region. Terminal hairs are thick, long, and pigmented, and they are typically found in areas where hair growth is more prominent. These areas include the scalp, underarms, and the pubic region. Therefore, the correct answer is "All of the above."

Erythema refers to the reddening of the skin, which occurs due to the dilation of blood capillaries. This dilation is a result of increased blood flow to the affected area, often caused by inflammation or an immune response. Erythema can be a symptom of various conditions, such as sunburn, allergies, infections, or autoimmune diseases. It is characterized by a red or pink coloration of the skin, which may be accompanied by warmth, swelling, or pain.

Keratin is the tough protein found in the epidermis, nails, and skin. It provides strength, structure, and protection to these tissues. Melanin is responsible for skin and hair color, reticulin is a type of connective tissue protein, and collagen is a protein found in the skin, tendons, and bones. However, none of these proteins are specifically known for their toughness in the context of the epidermis, nails, and skin.

The subcutaneous layer of the skin, also known as the hypodermis, is the layer that contains adipose tissue. Adipose tissue is a type of connective tissue that stores fat and provides insulation and cushioning for the body. It is located beneath the dermis and is responsible for giving the skin its plumpness and smooth appearance.

The sebaceous gland is responsible for secreting sebum, which is an oily substance that helps lubricate and protect the skin and hair. Sebum helps to moisturize the skin and hair, keeping them from becoming dry and brittle. It also helps to protect the skin from bacteria and other harmful substances. Therefore, the correct answer is "Secrete sebum."

The epidermis is the outermost layer of the skin and does not have a direct blood supply. It is composed of multiple layers of cells and serves as a protective barrier for the body. The lack of blood vessels in the epidermis is one of the reasons why it is more susceptible to injury and slower to heal compared to the dermis and subcutaneous layers, which have a rich blood supply.

The epidermis is the most superficial layer of the skin. It is the outermost layer that provides protection to the underlying tissues and organs. It is made up of multiple layers of cells and is responsible for the production of new skin cells, which then migrate to the surface and replace the old ones. The epidermis also contains melanocytes, which produce melanin, the pigment responsible for skin color.

Ringworm is a fungal infection of the skin caused by various types of fungi known as dermatophytes. It is characterized by a red, circular rash that may be itchy or scaly. The infection is commonly found on the scalp, feet, or groin, but can occur on any part of the body. Impetigo is a bacterial skin infection, herpes simplex and herpes zoster are viral infections. Therefore, ringworm is the correct answer as it specifically refers to a fungal infection of the skin.

The erector pili muscle affects the hair. This muscle is responsible for causing the hair to stand up or "goosebumps" when it contracts. When the muscle contracts, it pulls on the hair follicle, causing the hair to become more upright. This response is often triggered by cold temperatures or emotional stimuli.

Fibroblast cells are responsible for producing elastin and collagen. Elastin provides elasticity to tissues, while collagen gives strength and structure. Fibroblasts are found in connective tissues throughout the body and play a crucial role in maintaining the extracellular matrix. They are known for their ability to synthesize and secrete various components of the extracellular matrix, including elastin and collagen. Therefore, fibroblast cells are the correct answer for this question.

The matrix is the area of the nail where living cells are produced. It is located at the base of the nail, beneath the cuticle. The matrix is responsible for the growth and development of the nail, producing new cells that push the older cells forward, resulting in nail growth. It is rich in blood vessels and nerves, which provide nutrients and sensation to the nail.

The reticular layer of the dermis contains collagen and elastin. Collagen provides strength and support to the skin, while elastin allows the skin to stretch and recoil. These two proteins are essential for maintaining the structure and elasticity of the skin. The papillary layer, on the other hand, is located above the reticular layer and is primarily responsible for nourishing the epidermis.

Mitosis, the process of cell division, occurs in the stratum germinativum layer of the epidermis. This layer is also known as the basal layer and is responsible for producing new skin cells. The cells in this layer continuously divide to replace the old cells that are shed from the surface of the skin. Therefore, the correct answer is stratum germinativum.

Desquamation refers to the shedding or sloughing off of dead skin cells from the surface of the skin. This process occurs in the horny layer of the epidermis, which is the outermost layer. The horny layer, also known as the stratum corneum, is composed of dead skin cells that have undergone a process of keratinization, becoming tough and resistant. As new cells are produced in the lower layers of the epidermis, they gradually move up towards the surface and replace the older, dead cells, resulting in desquamation.

The correct order of the layers of the epidermis from deepest to most superficial is Basal cell, prickle-cell, granular, clear, horny. This is because the basal cell layer is the deepest layer of the epidermis and is responsible for producing new skin cells. The prickle-cell layer is above the basal cell layer and is named for the spiky appearance of its cells. The granular layer is next, followed by the clear layer, and finally the horny layer, which is the outermost layer of the epidermis and consists of dead skin cells.

The dermal papilla provides a crucial source of nourishment for hair. It is located at the base of the hair follicle and is responsible for supplying nutrients and oxygen to the hair bulb, which is necessary for hair growth and maintenance. The dermal papilla contains blood vessels that deliver nutrients and hormones to the hair follicle, promoting healthy hair growth. Without the nourishment provided by the dermal papilla, the hair follicle would not be able to produce new hair cells and maintain the growth cycle.

Paronychia is a common nail disease that is characterized by inflammation and bacterial infection of the skin surrounding the nail. It can be caused by a variety of factors such as trauma to the nail, biting or picking at the nails, or exposure to chemicals or irritants. Symptoms of paronychia include redness, swelling, pain, and pus-filled blisters around the nail. Treatment typically involves keeping the affected area clean and dry, applying warm compresses, and in some cases, taking antibiotics.

The hair follicle is a small sac-like depression in the skin where hair growth begins. It is located beneath the surface of the skin and is responsible for producing and nourishing the hair shaft. The hair follicle contains the hair root, which is the living part of the hair, and the hair bulb, which is the base of the hair follicle where new hair cells are produced. Therefore, the hair follicle is the correct answer as it is the structure from which hair grows.

Keratinization is the process of converting living cells into tough, protective, and waterproof cells filled with keratin. The stratum granulosum is the layer of the epidermis where keratinization occurs. This layer is responsible for producing and depositing keratin, which helps to strengthen and protect the skin. The cells in the stratum granulosum contain granules that release lipids, which help to form a water barrier on the skin's surface.