4: Integumentary Flashcards
What are the two layers of the skin?
Epidermis and dermis
Is the hypodermis part of the integument?
No
What are the 5 functions of the integument?
Protection
Prevent dehydration
Sensation
Temperature regulation
Vitamin D synthesis
Where is the epidermis of the thick skin found?
Palms and bottom of feet
What are the layers of the epidermis from superficial to deep?
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
What layer of the epidermis consist of 10-40 layers of cells?
Stratum corneum
What layers of the epidermis consist of 2-4 layers of cells?
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
What layer of the epidermis is not found in the whole integument? Where is it found?
Stratum lucidum
Found in the thick skin
What kind of vasculature does the epidermis have?
None, it’s avascular
What epidermal layer contains dead keratinocytes?
Stratum corneum
What epidermal layer attaches to the basement membrane via collagen fibers?
Stratum basale
What feature of the Stratum basale increases the surface area between the epidermis and the papillary layer of the dermis? What does this do?
Epidermal ridges
Increases strength of connection between the two
What feature of the Papillary layer increases the surface area between the epidermis and the papillary layer of the dermis? What does this do?
Dermal papillae
Resist mechanical stress
What is the Stratum basale primarily made of? (Two names)
Keratinocytes called basal stem cells
What is the role of basal stem cells?
All of the keratinocytes in the epidermis are produced from this single layer of cells, which are constantly dividing to produce new cells. As new cells are formed, the existing cells are pushed superficially away from the stratum basale.
What is the location and function of a Merkel cell?
Stratum basale
functions as a sensory receptor for touch
What is the location and function of a melanocyte?
Stratum basale
Produces melanin by apocrine secretion
What determines skin color?
ACTIVITY of melanocytes, not amount of melanocytes. All people have the same number
What structure joins the cells of the Stratum spinosum?
Desmosomes
What layer contains epidermal dendritic cells?
Stratum spinosum
What are epidermal dendritic cells for? In what layer?
function as macrophages by engulfing bacteria, foreign particles, and damaged cells in the Stratum spinosum
In what layer do keratinocytes begin to produce keratin?
Stratum spinosum
What layer of the epidermis produces a water-repellant glycolipid?
Stratum spinosum
What gives the Stratum granulosum its grainy appearance?
The large production of keratin and keratohyalin
What makes up the bulk of the cell mass in the Stratum granulosum?
Keratin and karetohylain
In what epidermal layer do cell organelles begin to die and disintegrate?
Stratum granulosum
What is the Stratum lucidum composed of?
Dead, flattened, compacted keratinocytes
What binds the cells of the Stratum lucidum?
eleidin, a clear protein rich in lipids, derived from keratohyalin
How long does it take for the Stratum corneum to replace itself?
About 4 weeks
Where does the stratum corneum get its name?
The increased keratinization of the cells is also called cornification
What causes a nevus?
Overgrowth of melanocytes
What causes freckles?
Excessive melanocyte activity
What are the two layers of the dermis?
Papillary layer
Reticular layer
What is the papillary layer of the dermis composed of?
Areolar connective tissue
What is the reticular layer of the dermis composed of?
Dense irregular connective tissue
What causes wrinkles?
Loss of collagen and elastic fibers, decreased thickness of dermis
What is the structure of the hypodermis?
Areolar and adipose tissue
What are the 5 terms of the nail we need to know?
Free edge, lunula, cuticle, nail root, nail body
What is the lunula?
Little white half-moon at the base of the nail, but still under the nail
What gives the reticular layer its name?
The net-like (reticulated) framework of elastin fibers
What are the three layers of hair?
Medulla, cortex, cuticle
What layer of hair is living cells?
Medulla
What part of the hair follicle extends into the dermis?
The hair bulb
What part of the hair is in the hair follicle below the skin?
The hair root
How fast does hair grow?
2mm/week
What is the growth cycle of hair?
Anagen phase
Catagen phase
Telogen phase
What happens in the anagen phase? How long does it last?
Hair actively grows, lasts 2-7 years
What happens in the catagen phase? How long does it last?
Transition phase where the follicle shrinks, lasts 2-3 weeks
What happens during the telogen phase? How long does it lasts?
Follicle is inactive, hair stops growing and is shed. Lasts 2-4 months
What is the name of an oil gland? What’s the name for the “oil?”
Sebaceous gland produces sebum
What is the name of a sweat gland?
Sudoriferous gland
What are the two types of sudoriferous glands? What’s the difference and where are they located?
Eccrine glands produce watery sweat and are all over the body
Apocrine glands produce viscous sweat & are found in the axillary, nipple, anal, and genital areas
What gland attached to the hair shaft is responsible for acne?
Sebaceous gland
What are the 3 types of hair and where are they found?
Lanugo hair (fetal)
Vellus hair (fine hair on most of body)
Terminal hair (head, armpit, pubic region, male facial hair)
What layers of the skin does a first-degree burn affect?
Epidermis
What layers of the skin does a second-degree burn affect?
Epidermis and part of the dermis
What layers of the skin does a third-degree burn affect?
Entire epidermis and dermis
What epidermal layer does basal cell carcinoma originate in? Is it dangerous?
Stratum basale. Most common, least dangerous
What epidermal layer does malignant melanoma originate in? Is it dangerous?
Stratum basale. Most deadly type. Arises from melanocytes
