Integumentary System Flashcards
What is the purpose of the integumentary system?
This protects the body from invasion of chemicals, UV, microorganisms and physical damage. It helps regulate the body temp (sweat), sensory organs (pain receptors), involved in the endogenous synthesis of vitamin D, moisturises the skins surface to prevent dehydration.
What are the components of the integumentary system?
Skin, hair, nails, sweat glands and hair grease glands. Mammary glands for breastfeeding.
What are the components of the skin?
Three layers, epidermis, dermis, and subcutaneous. There accessory structures within the epidermis and dermis layer such as hair, nails and exocrine glands.
What is the epidermis layer of the skin?
Outermost layer. Composed of 4-5 layers of stratified, squamous, keratinised epithelial cells. They’re protected by the fibrous insoluble intracellular keratin which is a water repelling glycolipid. It is relatively thin and can be sloughed off. It contains a few melanocytes, releasing melanin giving skin its tanned colour. It is also made from Langerhans cells as part of the immune response as they act as macrophages (phagocytes).
What is the dermis layer of the skin?
Middle layer of skin, relatively thick. Composed of the fibrous connective tissue collagen, supporting the epidermis. It has lymph and blood vessels, muscle and nerve fibres, hair follicles and sweat glands. It has elastic fibres that make the skin return to its shape. sweat from sweat glands help the thermoregulation of the skin by evaporating off its surface and removing the heat. It contains a lot of melanocytes, protecting the body from UV rays.
What is the subcutaneous layer of the skin?
The innermost and thickest layer. Consisting of fibroblasts, connective tissue, larger nerves, blood vessels, macrophages. Its purpose is to attach the skin to the muscles and bones. It contains adipocytes which act as an energy store and insulation.
What is hair made from?
It is a keratinous filament (dead keratinised cells) growing out through the epidermis layer from a hair follicle in the dermis layer.
How is hair composed in the skin?
Within the hair bulb, the basal cells divide and produce more keratin. the hair cells migrate up the hair shaft, overtime the cells die and become the outer dead hair.
The hair papilla provides oxygen and nutrients to enable cell division and cell growth.
What is the function of hair?
Protection from the sun (head), trapping dust particles (eyelashes), prevent sweat from going in the eyes (eyebrows). Allow sensory input from air movement. Helps thermoregulate as its connected to the arrector pili muscle that contracts in response to sympathetic nervous signals, making the hair stand up to trap air as insulation.
What are sudoriferous glands?
Sweat glands, eccrine and apocrine. They are slender tubes embedded in the dermis. Sweat is released upon exocytosis and it contains water, salts, antibodies, traces of urea. The sudoriferous gland is surrounded by myoepithelial cells which contract to push the sweat up the gland and out the sweat pore.
What are the two types of sudoriferous glands and their functions?
Eccrine - open directly onto skins surface and produce hypotonic sweat. Found all over the body, mainly in hands and feet. Involved in thermoregulation.
Apocrine - open onto hair follicles, lie deeper in the dermis, found in armpits, external ear canal and areola. It has organic compounds that release thicker sweat and is susceptible to bacterial decomposition, It is produced under nervous and hormonal control.
What is the function of sebaceous glands?
To produce sebum. This is an oily waxy substance that lubricates the skin and hair. It helps the skin stay flexible and hydrated, keeping the dry dead keratinised cells soft, prevents the cracking of the skin. It helps to also waterproof the skins surface.
How are sebaceous glands composed?
Attached to a hair follicle, and are inversely proportional to the hair follicles diameter. present on our whole body except hands and feet.
How are nails composed?
Nail beds in the specialised epidermis on finger and toe tips, rich in blood vessels. The nail body forms at the nail root, it is composed of densely packed keratinocytes. The lateral nail fold overlaps the mail on either side which helps anchor the nail to the body. The lunula (white bit) is a thick layer of epithelium over the nail matrix. the hyponychium is the area beneath the free area of the nail.
What is the function of nails?
Protects the parts of the body that experience maximal mechanical distress. It aids picking up small objects. It is also used as an indicator of many nutrient deficiencies including iron, calcium, B, A, C, D vits.
