05/10/2023 Notes Flashcards
What does the Integumentary system consist of?
Skin (cutaneous layer) and its derivatives (hair, nails, skin glands)
Skin is the _____ organ of the body
Largest
How much of the total body weight does skin comprise?
7-8% of the total body weight
What tissues form skin?
Epithelial, Connective, Nervous, and Vascular tissues
What is dermatology?
The study and treatment of the integumentary system
What is a pachyderm?
A large mammal with thick skin (rhinos, hippos, elephants)
What are the six functions of the integumentary system?
Protection, prevention of water loss, temperature regulation, metabolic regulation, sensory reception, and excretion by means of secretion
The skin is _____ permeable
Selectively
Skin protects against what?
Microbes, bumps, scrapes, and harmful UV radiation
Epidermal Dendritic Cells fight against what?
Infections and skin cancer
Skin is water-_____?
Resistant
What are washerwoman’s hands?
Water enters the skin through osmosis and gives it a bulging, wrinkly appearance as the epidermis swells
How can water escape the body?
Perspiration (sweating), airways, underlying tissues
How can a severe burn cause dehydration?
Damage to the skin allows abnormally large amounts of water to escape the body
What supplies nutrients to the dermis and epidermis?
Dermal blood vessels
What does vasoconstriction do?
Constrict dermal blood vessels to conserve body heat and inactivates epidermal sweat glands
What does vasodilation do?
Dilate dermal blood vessels to dissipate body heat and activates epidermal sweat glands to engage perspiration
How does the body receive vitamin D?
Synthesized by epidermal cells when exposed to UV light OR through dietary supplements
Why is vitamin D essential to the body?
Essential for absorbing calcium and phosphorus from small intestines for synthesis of healthy bones
What is Rickets?
A disease caused by vitamin D deficiency that results in softened and weakened bones; often seen in children
What can excessive exposure to UV light cause?
Suppressed immunity, premature aging of skin, skin damage, and an increased risk of skin cancer
What do the numerous nerve endings in the skin allow us to feel?
Heat, cold, touch, pressure, texture, and vibration
What does perspiration eliminate?
Waste products like water, salts, and urea
What layers compose the epidermis?
Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, and Stratum Basale
Does the entire epidermis contain all 5 layers?
No
What parts of the epidermis contain 5 layers?
Palms, soles, and lips
Why do the palms, soles, and lips contain 5 layers instead of 4?
They are exposed to extra friction
What is the true protective layer of the skin?
Stratum Corneum
How many layers composed the Stratum Corneum?
20-30 layers of flattened, dead cells that contain large amounts of keratin
The dry Stratum Corneum and inhibitory skin secretions prevent what
The growth of dangerous microorganisms
What is cornification?
Process brought on by keratinization and the hardening, flattening process that takes place as cells migrate to the surface
What is the extra layer found only in the palms, soles, and lips?
Stratum Lucidum
In what layer does keratinocytes begin to die?
Stratum Granulosum
Why is the Stratum Basale and Stratum Spinosum called the Stratum Germinativum?
These two deepest layers still have mitotic activity ongoing
What cells are found in the Stratum Lucidum?
Epidermal Dendritic Cells
How long does it take for cells from the Stratum Basale to travel to the outermost layer and fall off?
Approximately 6-8 weeks
What cells are found in the Stratum Basale?
Keratinocytes, Melanocytes, and Tactile (merkell) Cells
What do keratinocytes do?
Produce keratin; they are also the most abundant cell found in the epidermis
What produces pigments that darken the skin tone and protects DNA of cells from harmful UV radiation?
Melanocytes
Tactile (merkell) cells are sensitive to what?
Touch
What are the four major cells found in the epidermis?
Keratinocytes, melanocytes, tactile (merkell) cells, and epidermal dendritic cells
What does keratin do to the skin?
Toughen it and make it resistant to water
What causes dandruff?
Yeast from the genera Pityrosporsum or Malassezia
How are calluses formed?
Friction stimulates addition mitotic activity in the stratum basale and creates thicker skin in the stimulated area
What layer of the epidermis does tattoo ink reach?
Stratum Basale
