physiology and histology Flashcards
When do free radicals produce more free radicals?
while causing oxidation reactions
Free radicals are superoxidizers that not only cause an oxidation reaction but also produce new free radicals in the process.
What causes injured skin to restore itself to its normal thickness?
hyperproduction of cells
Through a hyperproduction of cells and blood clotting, injured skin can restore itself to its normal thickness.
What is the dermis?
support layer below the epidermis
The dermis, also called the derma, corium, cutis, or true skin, is the support layer of connective tissues above the hypodermis.
What are ceramides?
glycolipid materials
Ceramides are a group of waxy lipid molecules such as glycolipids that are important to barrier function and water-holding capacity such as glycolipids. Lipids are reduced if the skin is dry, damaged, or mature.
What is true of the stratum corneum?
It is the outermost layer of the skin.
The stratum corneum , also known as the horny layer, is the top, outermost layer of the epidermis.
What is the result of the contraction of the arrector pili muscle?
goose bumps
When we are cold, the arrector pili muscles attached to the hair follicles contract and cause goosebumps.
What are membranes of ridges and grooves that attach to the epidermis?
dermal papillae
The dermal papillae are membranes of ridges and grooves that attach to the epidermis.
Which of the following statements is true about the nail plate?
It contains no nerves.
The hard, or horny, nail plate contains no nerves or blood vessels.
What are sweat glands that are found all over the body with openings on the skin’s surface through pores and that are not attached to hair follicles?
eccrine
What is the formal name for the horny layer?
stratum corneum
The stratum corneum, also known as the horny layer, is the top, outermost layer of the epidermis.
What is the average internal temperature of the body in degrees Fahrenheit?
98.6
The body’s average internal thermostat is set at 98.6 degrees Fahrenheit.
What happens in the stratum granulosum?
Keratin is produced.
The production of keratin and intercellular lipids takes place in the stratum granulosum.
What is an esthetician’s primary focus?
all of the answers
An esthetician’s primary focus is on preserving, protecting, and nourishing the skin.
What are corneocytes?
hardened keratinocytes
Keratinocytes on the surface have hardened into corneocytes, the waterproof protective cells.
What are hair papillae?
cone-shaped elevations at the base of the follicle
Hair papillae are the small, cone-shaped elevations at the bottom of hair follicles.
What does scar tissue lack?
hair and sweat glands
Scar tissue lacks hair and sweat glands.
What protein fiber is found in the dermis and gives skin its flexibility and firmness?
elastin
Elastin is the fibrous protein that forms elastic tissue and gives skin its elasticity.
Which nerves react to heat, cold, pain, pressure and touch?
sensory
Sensory, or afferent nerve fibers send messages to the central nervous system and brain to react to heat, cold, pain, pressure, and touch.
What part of the skin provides a protective cushion and energy storage for the body?
subcutaneous layer
The subcutaneous layer is composed of loose connective tissue. This tissue creates a protective cushion that gives contour and smoothness to the body, and it is also a source of energy for the body.
What happens in the stratum germinativium?
Cells divide
The stratum germinativum, also known as the basal cell layer, is located above the dermis and is composed of a single layer of basal cells laying on a “basement membrane.” In this active layer, stem cells undergo continuous cell division (mitosis) to replenish the skin cells that are regularly shed from the surface.
How is B-keratin different from A-keratin?
It has lower moisture and fat than A-keratin.
B-keratin has lower moisture and fat content than soft A-keratin does, and is a particularly tough, elastic material.
What causes transepidermal water loss?
evaporation
Transepidermal water loss (TEWL) is water loss caused by evaporation on the skin’s surface.