skin Flashcards
What is the primary protective function of the skin?
The skin protects deeper tissues of the body by acting as a barrier against bacteria and preventing injury to underlying organs. It also prevents fluid loss from tissues (dehydration).
How does the skin contribute to sensation?
The skin is an important organ for general sensation, allowing us to feel touch, pressure, pain, and temperature.
What is the role of sebum secretion by the skin?
Sebum lubricates the hairs and keeps the skin soft and flexible. It also has bactericidal properties, providing additional protection.
How is vitamin D formed in the skin?
The skin contains ergosterol, which is converted into vitamin D by the action of direct sunlight.
What excretory function does the skin perform?
The sweat glands in the skin help in excretion by removing water, certain inorganic salts, and small amounts of other waste products from the body.
How does the skin regulate body temperature?
The skin helps regulate body temperature through the production of sweat and the dilation or constriction of blood vessels in the dermis.
What are the two main layers of the skin?
The skin is divided into two layers: the superficial layer called the epidermis and the deeper layer known as the dermis.
What is the composition of the epidermis?
The epidermis consists of stratified epithelium and is non-vascular. It varies in thickness in different parts of the body and is particularly thick and horny on the palms of the hands and soles of the feet.
What is the dermis composed of?
The dermis is composed of connective tissue containing elastic fibers. It is a tough, flexible layer with structures such as blood vessels, lymphatic vessels, sensory nerve endings, hair follicles, sebaceous glands, and sweat glands.
What are the two main layers of the epidermis?
The epidermis is divided into the germinative zone (inner layer) and the horny zone (outer layer).
What structures are found in the dermis?
The dermis contains blood vessels, lymphatic vessels, sensory nerve endings, hair follicles, hairs, arrectores pilorum muscles, sebaceous glands, and sweat glands
Where are hair follicles and hairs located?
Hair follicles and hairs are present on almost the entire surface of the body, except for the palms of the hands and the soles of the feet. The hair root lies in the dermis, and the shaft projects above the skin.
What are sweat glands and where are they found?
Sweat glands are coiled tubular glands found in the dermis in most areas of the body, particularly many in the palms of the hands and soles of the feet. Each gland has a coiled portion called the body and a duct that opens onto the skin’s surface at a pore.
What are the components of a nail?
Nails are flattened horny structures located on the distal ends of the fingers and toes. The proximal part is called the root, embedded in the cuticle, while the exposed portion is the body of the nail, and the distal portion is the free edge.
