“Skin as a Barrier and Sensory Organ”
- What is the primary function of the skin as a barrier? a) Temperature regulation
b) Protection against pathogens
c) Sensory reception
d) Vitamin D productionAnswer: b) Protection against pathogens
Explanation: The skin acts as a physical barrier to prevent pathogens, such as bacteria and viruses, from entering the body. - Which layer of the skin is responsible for the sensation of touch? a) Epidermis
b) Dermis
c) Hypodermis
d) Subcutaneous layerAnswer: b) Dermis
Explanation: The dermis contains sensory receptors (like Meissner’s corpuscles) that allow the skin to detect touch, pressure, and vibration. - Which of the following is a component of the skin’s barrier function? a) Keratin
b) Melanin
c) Collagen
d) All of the aboveAnswer: d) All of the above
Explanation: Keratin forms a protective barrier, melanin protects against UV radiation, and collagen provides structural integrity to the skin. - What is the role of melanocytes in the skin? a) To detect temperature changes
b) To produce melanin
c) To detect pain
d) To form hair folliclesAnswer: b) To produce melanin
Explanation: Melanocytes in the epidermis produce melanin, which gives the skin its color and protects it from UV radiation. - Which part of the skin is responsible for thermoregulation? a) Epidermis
b) Dermis
c) Hypodermis
d) Sweat glandsAnswer: d) Sweat glands
Explanation: Sweat glands play a crucial role in thermoregulation by releasing sweat, which cools the body when it evaporates. - Which structure in the skin helps with pain sensation? a) Meissner’s corpuscles
b) Merkel cells
c) Nociceptors
d) Ruffini endingsAnswer: c) Nociceptors
Explanation: Nociceptors are specialized sensory receptors in the skin that detect painful stimuli. - What is the outermost layer of the skin? a) Epidermis
b) Dermis
c) Hypodermis
d) Stratum corneumAnswer: a) Epidermis
Explanation: The epidermis is the outermost layer of the skin, providing a protective barrier against environmental damage. - Which layer of the skin contains the sweat glands and hair follicles? a) Epidermis
b) Dermis
c) Hypodermis
d) Stratum basaleAnswer: b) Dermis
Explanation: The dermis contains sweat glands, hair follicles, blood vessels, and sensory receptors. - Which of the following functions is performed by the skin’s barrier? a) Sensing light
b) Absorbing nutrients
c) Preventing dehydration
d) Producing blood cellsAnswer: c) Preventing dehydration
Explanation: The skin acts as a barrier to prevent water loss from the body, helping to maintain hydration. - Which type of skin cell is responsible for the skin’s protective barrier against UV light? a) Keratinocytes
b) Melanocytes
c) Langerhans cells
d) Merkel cellsAnswer: b) Melanocytes
Explanation: Melanocytes produce melanin, which absorbs and scatters UV radiation, protecting deeper layers of the skin from UV damage. - What is the primary function of the subcutaneous layer of the skin? a) Protection from pathogens
b) Temperature regulation
c) Sensory reception
d) Waterproofing the skinAnswer: b) Temperature regulation
Explanation: The subcutaneous layer, or hypodermis, contains fat cells that act as insulation to help regulate body temperature. - Which sensory receptor is involved in detecting light touch? a) Ruffini corpuscles
b) Meissner’s corpuscles
c) Pacinian corpuscles
d) NociceptorsAnswer: b) Meissner’s corpuscles
Explanation: Meissner’s corpuscles are specialized sensory receptors in the skin that detect light touch and vibration. - Which of the following contributes to the skin’s waterproof nature? a) Collagen fibers
b) Keratin
c) Melanin
d) ElastinAnswer: b) Keratin
Explanation: Keratin, a tough protein produced by keratinocytes, helps form the skin’s waterproof barrier, preventing water loss. - What type of cells are responsible for detecting pressure in the skin? a) Merkel cells
b) Meissner’s corpuscles
c) Pacinian corpuscles
d) Langerhans cellsAnswer: c) Pacinian corpuscles
Explanation: Pacinian corpuscles are deep pressure receptors located in the dermis and subcutaneous tissue, detecting vibrations and pressure. - What is the primary purpose of sweat production? a) Detoxification
b) Thermoregulation
c) Sensory perception
d) Immune defenseAnswer: b) Thermoregulation
Explanation: Sweat production helps regulate body temperature by releasing heat through evaporation. - Which of the following contributes to skin’s immunity? a) Keratinocytes
b) Langerhans cells
c) Sweat glands
d) Sebaceous glandsAnswer: b) Langerhans cells
Explanation: Langerhans cells are part of the immune system and help detect and fight infections in the skin. - What is the role of sebaceous glands in the skin? a) Produce sweat
b) Produce oil for lubrication
c) Detect touch
d) Detect temperature changesAnswer: b) Produce oil for lubrication
Explanation: Sebaceous glands produce sebum, an oily substance that lubricates the skin and helps maintain its waterproof barrier. - Which layer of the skin is most responsible for protecting the body from UV radiation? a) Epidermis
b) Dermis
c) Hypodermis
d) Subcutaneous tissueAnswer: a) Epidermis
Explanation: The epidermis, particularly the layer of keratinocytes, provides protection from UV radiation, especially through the action of melanin. - What is the function of the stratum corneum in the skin? a) Sensing touch
b) Forming a barrier to prevent water loss
c) Producing melanin
d) Producing collagenAnswer: b) Forming a barrier to prevent water loss
Explanation: The stratum corneum is the outermost layer of the epidermis, composed of dead keratinocytes that form a barrier preventing water loss. - Which of the following factors can impair the skin’s barrier function? a) Excessive hydration
b) Exposure to UV light
c) Increased melanin production
d) Excessive sweatingAnswer: b) Exposure to UV light
Explanation: UV light exposure can damage the skin, weaken its barrier function, and increase the risk of skin cancer. - What is the role of the skin in maintaining the body’s homeostasis? a) Regulating blood pressure
b) Regulating temperature
c) Producing hormones
d) All of the aboveAnswer: b) Regulating temperature
Explanation: The skin plays a crucial role in homeostasis by helping regulate body temperature through sweat production and blood flow adjustments. - Which of the following is true about the dermis? a) It contains sweat glands and hair follicles
b) It is the outermost skin layer
c) It consists mostly of fat
d) It is avascularAnswer: a) It contains sweat glands and hair follicles
Explanation: The dermis is located beneath the epidermis and contains hair follicles, sweat glands, blood vessels, and sensory receptors. - What do Merkel cells in the skin detect? a) Light touch and texture
b) Deep pressure
c) Temperature changes
d) PainAnswer: a) Light touch and texture
Explanation: Merkel cells are specialized mechanoreceptors in the epidermis that detect light touch and texture. - How does the skin contribute to the immune system? a) By producing antibodies
b) By acting as a physical barrier
c) By regulating blood flow
d) By secreting hormonesAnswer: b) By acting as a physical barrier
Explanation: The skin acts as the first line of defense against pathogens, preventing their entry into the body. - What role do the sebaceous glands play in skin health? a) They produce sweat for cooling
b) They produce sebum to keep skin hydrated
c) They detect temperature changes
d) They produce melaninAnswer: b) They produce sebum to keep skin hydrated
Explanation: Sebaceous glands secrete sebum, which helps lubricate and protect the skin. - Which type of sensory receptor is responsible for detecting vibration in the skin? a) Meissner’s corpuscles
b) Pacinian corpuscles
c) Ruffini corpuscles
d) Merkel cellsAnswer: b) Pacinian corpuscles
Explanation: Pacinian corpuscles are specialized for detecting vibrations and deep pressure. - What is the primary function of the hypodermis? a) Protection from UV radiation
b) Sensing touch and pressure
c) Insulation and energy storage
d) Producing sebumAnswer: c) Insulation and energy storage
Explanation: The hypodermis (subcutaneous layer) acts as insulation to help regulate body temperature and stores energy in the form of fat. - What is the role of collagen fibers in the skin? a) To detect pain
b) To provide structural support and elasticity
c) To produce sweat
d) To prevent UV damageAnswer: b) To provide structural support and elasticity
Explanation: Collagen fibers in the dermis provide structural integrity, support, and elasticity to the skin. - How does the skin prevent excessive water loss? a) By producing sweat
b) By forming a lipid barrier
c) By detecting temperature changes
d) By producing collagenAnswer: b) By forming a lipid barrier
Explanation: The skin forms a lipid barrier in the epidermis that prevents excessive water loss from the body. - Which skin structure is responsible for the growth of hair? a) Sweat glands
b) Hair follicles
c) Meissner’s corpuscles
d) Merkel cellsAnswer: b) Hair follicles
Explanation: Hair follicles, located in the dermis, are responsible for the growth of hair by producing hair cells.
