Chapter 5 Guide: The Integumentary System
Acne is usually an infectious inflammation of the
sebaceous glands, resulting in pimples (pustules)
Describe the events of keratinization that occurs in the epidermis.
the process in which the outermost cells of the epidermis are replaced by dead cells containing keratin.• As cells divide in the stratum basale, they are pushed from the base layers to the surface stratum corneum
Identify the cell found in the epidermis, their function, and their relative positions in the layers of the epidermis: Tactile (Merkel) cells
Tactile (Merkel) cells• Sensory receptors that sense light touch• Abundant in highly sensitive skin areas (e.g., fingertips)• Interacts with nerve ending
Compare the cellular origin and metastatic potential of the three major types of skin cancers. Understand the diagnostic criteria used for evaluating melanoma (ABCD/ABCDE).
Basal cell carcinoma (BCC) originates in the basal cells, which are found in the lowest layer of the epidermis. BCC is the most common type of skin cancer, and it rarely spreads beyond the site of origin. It typically appears as a pearly or waxy bump or a flat, flesh-colored or brown scar-like lesion. Squamous cell carcinoma (SCC) arises from the squamous cells, which are found in the upper layer of the epidermis. SCC is less common than BCC, but it has a higher potential to spread to other parts of the body if left untreated. SCC often appears as a red, scaly patch or bump that may bleed easily. Melanoma arises from the melanocytes, which are cells that produce the pigment melanin. Melanoma is less common than BCC and SCC, but it is the most deadly type of skin cancer because it can spread quickly to other parts of the body. Melanoma can appear as a dark, irregularly shaped mole or lesion, and it may exhibit the ABCD/ABCDE criteria for diagnosis: Asymmetry: one half of the mole or lesion is different from the other half. Border irregularity: the edges of the mole or lesion are uneven or scalloped. Color: the mole or lesion has different colors or shades, or it is not uniform in color. Diameter: the mole or lesion is larger than 6 mm (about the size of a pencil eraser). Evolving: the mole or lesion is changing in size, shape, or color, or it is becoming symptomatic (such as itching or bleeding).
Identify the cell found in the epidermis, their function, and their relative positions in the layers of the epidermis: Dendritic(Langerhans) cells
Dendritic(Langerhans) cells• Star-shaped macrophages that patrol deep epidermis• Are key activators of the immune system
Compare the structure, secretions, functions, and locations of eccrine, apocrine, and sebaceous glands.
Eccrine glands: Eccrine glands are the most numerous sweat glands in the body and are found in almost all areas of the skin. They consist of a coiled secretory portion located in the dermis and a duct that extends to the surface of the skin. Eccrine glands secrete a clear, odorless fluid that helps regulate body temperature through evaporative cooling. Eccrine glands are active from birth and are not influenced by hormones. Apocrine glands: Apocrine glands are larger and less numerous than eccrine glands and are found primarily in the axillary and genital regions. They consist of a coiled secretory portion located in the dermis and a duct that opens into the hair follicle. Apocrine glands secrete a thicker, milkier fluid that is high in proteins and lipids and is often colonized by bacteria, leading to body odor. Apocrine glands become active at puberty and are regulated by androgens. Sebaceous glands: Sebaceous glands are found throughout the skin, except for the palms and soles. They consist of a holocrine gland that secretes sebum, an oily substance that lubricates and waterproofs the skin and hair. Sebaceous glands become more active at puberty, under the influence of androgens.
Describe the two major layers of the integument (skin)
Epidermis: superficial region• Consists of avascular epithelial tissue• Dermis: underlies epidermis• Mostly fibrous connective tissue,vascular
Explain the reasons why extensive 2nd degree or 3rd degree burns can be life-threatening.
Extensive second-degree or third-degree burns can be life-threatening for several reasons. One reason is that they can cause dehydration and electrolyte imbalances, as the burned skin is unable to retain fluids and salts. Additionally, burns can cause infection, especially if the protective barrier of the skin is compromised. Finally, burns can lead to respiratory problems, as inhalation of hot gases or smoke can damage the lungs
Explain the classification of burns based on the specific tissue layers affected.
First-degree burns: affect only the outer layer of skin, called the epidermis. They are characterized by redness, pain, and mild swelling. Examples include sunburns or minor burns from hot liquids. Second-degree burns: affect the outer layer of skin (epidermis) and the layer beneath it (dermis). They are characterized by blisters, severe pain, and swelling. These burns can be superficial or deep, depending on the extent of damage to the dermis. Third-degree burns: affect all layers of skin, including the subcutaneous tissue beneath it. They are characterized by a charred or white appearance, and they may be accompanied by numbness due to nerve damage. Third-degree burns require immediate medical attention.
List the accessory structures associated with the dermis.
Hair follicles: These are found in the reticular layer and are responsible for producing hair. Sebaceous glands(Oil glands): These are also found in the reticular layer and are responsible for producing sebum, an oily substance that helps to lubricate the skin and hair. Sweat glands: These are located in the reticular layer and produce sweat, which helps regulate body temperature. Blood vessels: The dermis contains an extensive network of blood vessels that provide oxygen and nutrients to the skin. Nerves: The skin contains numerous nerve endings that are responsible for sensation and perception of touch, pressure, pain, and temperature. Lymphatic vessels
Describe the basic structure and function of hair and location
Hair is a structure that grows from hair follicles located in the dermis, but it is derived from the epidermis. Each hair follicle is composed of multiple layers of cells, including the hair bulb, the hair matrix, and the inner and outer root sheaths.Hair pigments are made by melanocytes in hairfollicles• Combinations of different melanins(yellow, rust, brown)create hair colors• Gray/white hair results when melanin production decreases The function of hair is to protect the skin from environmental factors, such as UV radiation, and to provide insulation for the body. Hair also has sensory functions, as hair follicles contain nerve endings that are sensitive to touch and can detect changes in the environment.
Explain the Rule of Nines in calculating the severity of burns.
Head and neck: 9% Arms: 9% each Chest: 18% Abdomen: 18% Back: 18% Legs: 18% each Genital area: 1% The Rule of Nines can be used to estimate the TBSA affected by a burn. For example, if a patient has burns on both legs and the chest, this would account for 18% + 18% + 18% = 54% TBSA. Burns are considered critical if:• >25% of body has second-degreeburns• >10% of body has third-degree burns• Face, hands, or feet bear third-degree burns
briefly describe the subcutaneous layer.
Hypodermis (superficial fascia)• Subcutaneous layer deep to skin• Not part of skin but shares some functions• Mostly adipose tissue that absorbs shock and insulates• Anchors skin to underlying structures - mostly muscles
Explain how changes in skin color may be used as clinical signs.
Jaundice: A yellowing of the skin and whites of the eyes, caused by a buildup of bilirubin in the blood, often seen in liver disease. Cyanosis: A bluish discoloration of the skin and mucous membranes caused by decreased oxygenation of the blood, often seen in respiratory or circulatory disorders. Erythema: A redness of the skin caused by increased blood flow, often seen in inflammation, infection, or allergic reactions. Pallor: A paleness of the skin caused by decreased blood flow, often seen in anemia or shock. Ecchymoses/hematomas: Bruises, black-and-bluemarks• Result of clotted blood beneath skin• As clot is broken down, color changes
Identify the cell found in the epidermis, their function, and their relative positions in the layers of the epidermis: Keratinocytes
Keratinocytes• Major cells of epidermis• Produce fibrous keratin• More rigid thancollagen• Major component of skins protectiveproperties• Tightly connected bydesmosomes• Millions slough off every day
Describe the pigments that contribute to skin color
Melanin is the most important pigment in determining skin color. It is produced by melanocytes located in the basal layer of the epidermis and gives skin its brown or black color. The amount and distribution of melanin in the skin are determined by genetics, sun exposure, and hormonal factors. Freckles and pigmented moles are local accumulations of melanin Carotene is a yellow-orange pigment found in certain fruits and vegetables. It can be stored in the skin, particularly in areas such as the palms and soles, and contributes to skin color. Hemoglobin is a red pigment found in red blood cells. It contributes to skin color by giving a pinkish hue to the skin, particularly in areas such as the lips and cheeks.
Identify the cell found in the epidermis, their function, and their relative positions in the layers of the epidermis: Melanocytes
Melanocytes• Spider-shaped cells located in the deepest epidermis• Produce pigment melanin• Packaged into melanosomes• Transferred to keratinocytes• Protect nucleus from UV damage
Explain the role of puberty in gland activation
One of the most significant changes that occur during puberty is the activation of the gonads, which are the primary reproductive glands responsible for producing sex hormones such as testosterone and estrogen. puberty plays a crucial role in the activation of glands throughout the body, which in turn produce and regulate hormones that are vital for growth, development,
Describe the functions of the integumentary system, including the roles in protection (physical, chemical, biological barrier function), sensation, vitamin D synthesis, thermoregulation, excretion, and how it acts as a blood reservoir.
Protection: The skin acts as a physical, chemical, and biological barrier to protect the body from external harm. The skin's physical barrier helps prevent damage to internal organs and tissues from environmental hazards such as heat, cold, and trauma. The skin's chemical barrier helps prevent penetration by harmful substances such as acids, alkalis, and other toxins. The skin's biological barrier is provided by specialized cells that help fight off invading microbes such as bacteria and fungi. Sensation: The skin contains numerous sensory receptors that respond to touch, pressure, temperature, and pain. These receptors help us perceive our environment and respond to stimuli. Vitamin D synthesis: The skin contains specialized cells that can produce vitamin D when exposed to sunlight. Vitamin D is important for calcium absorption and bone health. Thermoregulation: The skin plays an important role in regulating body temperature. When we get too hot, sweat glands in the skin produce sweat, which cools the body through evaporative cooling. When we get too cold, blood vessels in the skin constrict, reducing blood flow and conserving heat. Excretion: The skin can eliminate certain waste products, such as water, urea, and lactic acid, through sweat glands. Blood reservoir: The skin can act as a temporary blood reservoir, storing up to 10% of the body's blood volume in the skin's blood vessels. This can help maintain blood pressure and provide a reserve of blood in case of injury or other emergencies.
Identify and describe the specific layers of the dermis, including the tissue types found in each dermal layer.
The papillary layer is the uppermost layer of the dermis and is composed of loose connective tissue. It contains papillae that project into the epidermis and contain capillaries, lymphatic vessels, and sensory receptors. The papillary layer also contains collagen and elastin fibers that provide support and elasticity to the skin. The reticular layer is the deeper and thicker layer of the dermis, composed of dense irregular connective tissue. It contains blood vessels, nerves, sweat glands, hair follicles, and sebaceous glands. This layer is responsible for providing the skin with strength, elasticity, and resilience. Also contains Cutaneous plexus which contains network of blood vessels between the reticular layer and the hypodermis
Describe the specific layers of the epidermis.
The stratum basale is the deepest layer of the epidermis and contains basal cells, which are responsible for producing new cells to replace those shed from the skin's surface. This layer also contains melanocytes, which produce the pigment melanin that gives skin its color. The stratum spinosum is composed of several layers of cells, including keratinocytes that produce keratin, a protein that helps protect the skin. This layer also contains Langerhans cells, which play a role in the immune response. The stratum granulosum is a thin layer of cells that produce the protein keratin and the lipid-rich substance that forms the skin's barrier. The stratum corneum is the outermost layer of the epidermis and is composed of flattened, dead cells that have been filled with keratin. This layer provides a barrier against water loss and protects the skin from environmental factors. Overall, the epidermis is composed of primarily keratinocytes, with melanocytes and Langerhans cells also present. The cells in the epidermis are organized in a layered fashion to allow for efficient production and shedding of cells as the skin is exposed to wear and tear from the environment.
What are treatments for burns
Treatment includes:• Debridement (removal) of burned skin• Antibiotics• Temporary covering• Skin grafts
Name the specific layers of the epidermis.
the stratum basale (basal layer), stratum spinosum (prickle cell layer), stratum granulosum (granular layer), and stratum corneum (horny layer)