Ch. 12 Integumentary System Flashcards
sebaceous glands
secrete sebum (oil) that lubricates the skin and discourages the growth of bacteria on the skin
sweat glands
help regulate body temp and water content by secreting sweat, a small amount of metabolic waste is also secreted
what does hair help with?
helps control the loss of body heat
what do nails do?
protects the dorsal surface of the last bone of each toe and finger
epidermis
the outermost layer of skin
epithelial tissues
for a protective covering for all of the internal and external surfaces of the body
squamous epithelial tissue
forms the upper layer of the epidermis, consists of flat, scaly cells that are continuously shed
keratin
fibrous, water-repellent protein. Soft keratin is a primary component of the epidermis, hard keratin is found in the hair and nails.
melanocytes
cells in the basal layer that produce and contain a dark brown to black pigment called melanin
dermis
thick layer of living tissue directly below the epidermis, it contains connective tissue, blood and lymph vessels, and nerve fibers
sensory nerve endings
sensory receptors stimuli such as touch, temp, pain, and pressure
collagen
means glue, a tough, yet flexible, fibrous protein material found in the skin and in the bones, cartilage, tendons, and ligaments
mast cells
found in connective tissue of the dermis, respond to injury, infection, or allergy by producing and releasing substances, including heparin and histamine
heparin
released in response to an injury, anticoagulant
histamine
released in response to allergens, causes the signs of an allergic response, including itching and increased mucus secretion
subcutaneous layer
located just below the skin, connects the skin to the surface muscles
hidrosis
the production and excretion of sweat
arrector pili
tiny muscle fibers attached to the hair follicles that case the hair to stand erect
unguis
finger nail or toenail
lunula
pale half-moon shaped region at every nail root, active area of the nail where new keratin cells form
comedo
noninfected lesion formed by the buildup of sebum and keratin in a hair follicle
anhidrosis
abnormal condition of lacking sweat in response to hear
diaphoresis
profuse sweating
hyperhidrosis
a condition of sweating in one area or over the whole body