A&p Midterm - Chapter 4 Review

Keratin is a tough protein found in the skin that acts as a barrier, preventing moisture from being absorbed like a sponge. It helps to keep the skin waterproof and prevents it from becoming saturated with water while swimming.

The epidermis is the outermost layer of the skin and does not have its own blood supply. It receives nutrients and oxygen from the underlying dermis through diffusion. This lack of blood vessels in the epidermis is important for its main function, which is to act as a protective barrier for the body against external factors such as pathogens, UV radiation, and dehydration.

A massive third-degree burn can cause severe damage to the skin, leading to the loss of fluids from the body. This loss of fluids can result in dehydration, which is a significant threat to life. Dehydration occurs when the body does not have enough water to carry out its normal functions. It can lead to complications such as electrolyte imbalances, organ failure, and even death if left untreated. Therefore, dehydration is a critical concern that needs to be addressed promptly in cases of massive third-degree burns.

The correct answer is "cutaneous." Cutaneous refers to the skin, which is the outermost layer of the body that acts as a protective barrier. It is made up of multiple layers of cells and contains various structures such as hair follicles, sweat glands, and sensory receptors. The term "cutaneous" is commonly used in medical and anatomical contexts to describe anything related to or located on the skin.

The papillary layer of the dermis is not the deepest layer of the skin. It is actually located immediately beneath the epidermis. The dermis has two layers, the papillary layer and the reticular layer, with the reticular layer being the deeper layer. The papillary layer is responsible for producing the pattern for fingerprints, contains nerve endings, and is highly vascular.

The secretions of the eccrine glands are primarily composed of water, sodium chloride, and small amounts of waste products, lactic acid, and vitamin C. Eccrine glands are the most numerous sweat glands in the human body and are responsible for regulating body temperature through the production of sweat. This sweat is mostly composed of water and electrolytes, such as sodium chloride, which help to maintain the body's balance. The presence of lactic acid and vitamin C in the secretion may have additional functions, such as providing antibacterial properties or supporting skin health.

Cold sores are caused by the herpes simplex virus. This viral infection manifests as small, painful blisters on the lips, mouth, or nose. The virus remains dormant in the body and can be triggered by factors such as stress, illness, or sun exposure. Cold sores are a result of the virus disrupting the normal balance of the body, causing localized inflammation and discomfort. The other options listed are not caused by viruses but by factors such as fungi, bacteria, or external irritants.

The correct answer is dehydration and infection. Severe burns can cause a loss of fluids from the body, leading to dehydration. This can be life-threatening as it can affect the functioning of vital organs. Additionally, burns can create an open wound, which increases the risk of infection. Infection can further complicate the healing process and pose a serious threat to the person's health. Therefore, both dehydration and infection are significant concerns in cases of severe burns.

Acne is a common skin condition characterized by inflammation and blockage of the sebaceous glands. These glands are responsible for producing sebum, an oily substance that helps lubricate the skin. When the sebaceous glands become clogged, it can lead to the development of acne. The inflammation associated with acne is a result of the body's immune response to the blocked glands, causing redness, swelling, and the formation of pimples. Therefore, the correct answer is "sebaceous glands."

Fingernails are a modification of the epidermis because they are made up of a tough protein called keratin, which is also found in the epidermis. The epidermis is the outermost layer of the skin and it protects the underlying tissues. Fingernails are formed by specialized cells in the epidermis called nail matrix cells, which produce keratin and push the nail forward as it grows. Therefore, the epidermis is responsible for the formation and growth of fingernails.

The synovial membrane is a connective tissue membrane that lines the cavities of joints, tendon sheaths, and bursae. It secretes synovial fluid, which lubricates the joints and reduces friction during movement. Unlike the other options listed, the synovial membrane is specifically associated with joints and is responsible for their smooth functioning.

The secretion of sebum, an oily substance that moisturizes the skin and hair, is stimulated by hormones, particularly male sex hormones. These hormones, such as testosterone, play a crucial role in regulating the production of sebum in the sebaceous glands. Increased levels of male sex hormones can lead to excessive sebum production, which can contribute to oily skin and acne.

Pain and touch receptors are found in the dermis. The dermis is the layer of skin located beneath the epidermis and is responsible for providing strength and elasticity to the skin. It contains various structures such as blood vessels, hair follicles, sweat glands, and nerve endings. Pain and touch receptors, also known as mechanoreceptors, are sensory receptors that detect and respond to mechanical stimuli such as pressure, vibration, and touch. These receptors are essential for our ability to sense and respond to external stimuli and are found within the dermis.

Melanocytes are cells responsible for producing the pigment melanin, which gives color to the skin, hair, and eyes. These cells are found in the stratum basale, the deepest layer of the epidermis. This layer is in direct contact with the underlying dermis and is responsible for the continuous production of new skin cells. Melanocytes transfer melanin to nearby skin cells to protect them from the harmful effects of UV radiation. Therefore, the stratum basale is the correct location for the presence of melanocytes.

The categories of epithelial tissue membranes are cutaneous, serous, and mucous. Cutaneous membranes refer to the skin, which is the outermost protective layer of the body. Serous membranes line the internal body cavities and cover the organs, producing a lubricating fluid that reduces friction. Mucous membranes are found in various parts of the body, such as the respiratory and digestive tracts, and they secrete mucus to protect and lubricate the surfaces.

The correct sequence of layers of the epidermis going from outermost to innermost layer is corneum, lucidum, granulosum, spinosum, germinativum. This sequence represents the different layers of cells in the epidermis, with the corneum being the outermost layer and the germinativum being the innermost layer where new skin cells are produced. The lucidum, granulosum, and spinosum layers are located between the corneum and germinativum, each with their own functions in the skin's barrier and cell production processes.

The correct answer for this question is "stratum germinative cells, basale, stratum germinative". The stratum germinative cells, also known as the basal cells, are located in the basal layer of the epidermis. These cells are actively mitotic, meaning they undergo cell division, and they replace the superficial cells that are constantly being rubbed off. Therefore, the stratum germinative cells play a crucial role in the regeneration and renewal of the epidermis.

The most external region refers to the outermost layer of a tissue or organ. In this case, the correct answer is stratified squamous epithelium. Stratified squamous epithelium is a type of tissue that consists of multiple layers of flat cells. It is found in areas that experience wear and tear, such as the skin or the lining of the mouth and esophagus. This type of epithelium provides protection against mechanical stress and helps to prevent damage from abrasion or friction.

The rule of nines is a method used by physicians to estimate the volume of fluid lost in a severely burned patient. This method involves dividing the body into regions, with each region representing a certain percentage of the total body surface area. By assessing the extent of burn in each region, the physician can estimate the overall volume of fluid lost and determine the appropriate treatment plan for the patient.