Chapter 5 Flashcards
What are the three accessory structures of the integumentary system?
Hair and follicles, exocrine glands, nails
What do sensory receptors in the dermis pick up?
Touch, pressure, temperature, pain
What does the subcutaneous layer do?
Separates skin from underlying organs
What do exocrine glands do?
Excrete salts, water, and organic waste
What two main things does the integumentary system produce?
Melanin and keratin
Is the epidermis vascular or avascular?
Avascular, relies on diffusion
What cells dominate the epidermis?
Keratinocytes
What are the two types of skin? What is the difference between them?
Thin skin and thick skin, thick skin has an extra layer (squamous lucidum)
What are the layers of the epidermis from deep to superficial?
Stratum basale, spinosum, granulosum, (lucidum), corneum
What cells do the stratum basale have?
Basal cells that produce keratinocytes
What is the point of epidermal ridges?
To interlock with dermal papillae for stability
What are merkel cells?
Tactile cells
Where are melanocytes found?
Stratum basale
Is the stratum granulosum alive?
No
What causes granules?
Keratohyalin
What is the stratum corneum made of?
Dead cells
About how long does it take from cells to move from deep to superficial?
About 7 to 10 days
How long do cells stay in the corneum before being shed?
About 2 weeks
What are the two layers of the dermis?
Papillary and reticular
What is the papillary layer composed of?
Areolar tissue
What does the papillary layer contain?
Capillaries, lymphatic vessels, sensory neurons
What is the reticular layer composed of?
Dense irregular connective tissue
What are tension lines?
Patterns produced by the parallel bundles of collagen and elastic fibers
Why are tension lines important in the medical field?
Cuts parallel to them tend to heal better than cuts perpendicular
What is the hypodermis composed of?
Adipose tissue
What are the two pigments in the skin?
Melanin and carotene
What are melanosomes destroyed by?
Lysosomes
What causes difference in skin color?
In lighter skin, melanosomes are transferred to keratinocytes in the two deepest layers of the skin, and are destroyed by lysosomes. In darker skin, melanosomes are transferred to keratinocytes in the two superficial layers of skin, making pigment visible.
What happens with melanin in albinism?
Distribution of melanocytes are normal, but the body is unable to produce melanin.
What does melanin do?
Protects skin from UV rays
What is the point of the arrector pili muscle?
Goosebumps
What allows sensory reception in hair?
Root plexus of sensory nerves
What anchors hair to the skin?
Hair root
What are the three layers of hair from inside to out?
Medulla, cortex, cuticle
What do sebacous glands produce?
Oily lipid secretion called sebum for hair follicles
What does sebum do?
Inhibit bacterial growth, lubrication and protection of hair shaft, conditions surrounding skin
What do aprocrine sweat glands do?
Secrete thick, potentially odorous sweat into hair follicles
What do eccrine sweat glands do?
Secrete sweat directly onto skin surface, more numerous than apocrine sweat glands
What is the puropse of sweat?
Cooling skin surface to lower body temperature, flush microorganisms off the skin surface, antibiotic properties
