The synthesis of Vitamin D in the skin begins with the conversion of a derivative of which steroid when exposed to UV radiation?
Explanation
This question assesses the understanding of the biochemical pathway for Vitamin D synthesis in the skin, specifically identifying the precursor molecule.
Other questions
In the adult human body, the skin accounts for approximately what percentage of the total body weight?
Which layer of the epidermis is found only on the palms of the hands and the soles of the feet?
What type of cell in the epidermis is responsible for producing the pigment melanin, which gives skin and hair its color?
The entire layer of the stratum corneum is replaced during a period of approximately how many weeks?
Which layer of the dermis is composed of loose, areolar connective tissue and projects into the stratum basale to form dermal papillae?
What is the name of the structure that is a keratinous filament growing out of the epidermis?
During which phase of hair growth do cells divide rapidly at the root of the hair, pushing the hair shaft up and out?
What is the average rate of hair growth per day during the anagen phase?
Which type of sweat gland is found all over the skin’s surface, especially on the palms, soles, and forehead, and produces a hypotonic sweat for thermoregulation?
The skin acts as a sensory organ. Which specialized receptor responds to light touch and is concentrated on the tips of the fingers?
Even when the body does not appear to be sweating, approximately how much sweat is secreted in a day as insensible perspiration?
What is the most common form of skin cancer in the United States, affecting the mitotically active stem cells in the stratum basale?
The ABCDE mnemonic helps in the diagnosis of early-stage melanoma. What does the 'B' in this mnemonic stand for?
A second-degree burn is characterized by damage to which layers of the skin?
What is the term for a raised or hypertrophic scar that results from an overproduction of collagen after a wound has healed?
According to the 'rule of nines' used for burn assessment, what percentage of the body surface area is assigned to the anterior trunk?
Which genetic disorder is characterized by the inability of melanocytes to produce melanin, leading to a lack of pigment in the skin, hair, and eyes?
What is the name of the crescent-shaped region at the base of the nail, formed by a thick layer of epithelium over the nail matrix?
The reticular layer of the dermis is composed of what type of connective tissue?
Which of the following functions is primarily attributed to the hypodermis?
What two proteins, which give the stratum granulosum its grainy appearance, make up the bulk of the keratinocyte mass in that layer?
How many layers of cells are typically found in the stratum corneum?
What is the primary purpose of the arrector pili muscle contracting in response to stimuli from the sympathetic nervous system?
A deficiency in vitamin D can lead to a painful condition in children where the bones are misshapen due to a lack of calcium, known as what?
What is the term for bedsores, which are caused by constant, long-term, unrelieved pressure on body parts, leading to tissue death?
The nail body is composed of densely packed dead cells filled with which protein?
What is the primary function of sebum, the substance secreted by sebaceous glands?
What condition results from an allergic reaction that manifests as dry, itchy patches of skin that resemble rashes?
What is the primary cell type found in the epidermis?
The deepest epidermal layer that attaches the epidermis to the basal lamina is known as the:
On average, how many hairs are lost and replaced per day?
Melanin is transferred from melanocytes to keratinocytes via which cellular vesicle?
Which skin condition is a result of over-productive sebaceous glands, leading to the formation of blackheads and inflammation?
What type of burn fully extends into the epidermis and dermis, destroying the tissue and affecting nerve endings?
Eumelanin and pheomelanin are two primary forms of melanin. What colors do they produce, respectively?
How long after initial sun exposure does it typically take for melanin synthesis to peak?
The stratum spinosum is composed of how many layers of keratinocytes?
What is the name of the clear, lipid-rich protein found in the stratum lucidum that provides a barrier to water?
During vigorous activity, sweat glands can be stimulated to produce how much sweat per hour?
Which sensory receptor in the skin is responsible for detecting vibration?
A scar differs from normal skin because it is a collagen-rich tissue formed after wound healing that lacks what?
What is the name for the part of a hair that is anchored in the follicle and lies below the surface of the skin?
The catagen phase of the hair growth cycle, which marks a transition from active growth, lasts for how long?
Which layer of the skin is avascular, meaning it does not have any blood vessels within it?
What is the name for the condition in which melanocytes in certain areas lose their ability to produce melanin, resulting in patches of lighter-colored skin?
In the ABCDE mnemonic for melanoma, what does the 'E' represent?
What is the term for the area of skin, rich in collagen, that is formed after the process of wound healing and differs from the original skin structure?
What is the main component of the secretions from apocrine sweat glands that makes the sweat thicker and subject to bacterial decomposition?
According to the American Academy of Dermatology, what percentage of people from ages 18 to 50 have a tattoo?