Chapter 5 - Integumentary System Flashcards
The integumentary system consists of what?
skin and derivatives such as hair, glands, sensory structures, nails
What is the largest organ in the body by surface area and weight?
the skin
How big is our skin?
approximately 2 square meters and 4.5 to 6.5 kg
What are the functions of the skin?
thermoregulation
protection
cutaneous sensations
excretion and absorption
synthesis of vitamin D
immunity
How does thermoregulation occur?
negative feedback to maintain temperature using vasodilation/constriction of dermal blood vessels, and more or less sweat.
What are the 2 major parts of skin?
epidermis
dermis
What kind of tissue makes up the epidermis?
avascular, keritinized, stratified, squamous epithelial tissue.
The epidermis is 90% what type of cell?
keratinocytes
The epidermis is 8% what type of cell?
melanocytes
What are the 4 types of cells that make up the epidermis?
keratinocytes
melanocytes
Langerhans cells
Merkel cells
What are the layers of the epidermis?
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
In what layer to cells begin to undergo apoptosis?
stratum granulosum
Which layer is only found in the skin of the palms of the hands and soles of the feet?
stratum lucidum
What are the two types of skin?
thin skin
thick skin
What type of skin has hair and sebaceous glands?
thin skin
What type of skin is found on the soles of the feet and palms of the hands?
Thick skin
Does thin skin have a stratum lucidum?
No
Which type of skin has more sensory receptors?
Thick skin
How long does keratinization take?
approximately 4 weeks
What is psoriasis?
An autoimmune skin condition in which keratinization is accelerated to 7 to 10 days.
What happens to keratin formed too quickly?
it is abnormal, and forms silvery, flaky scales on knees, elbows and the scalp.
What is the dermis composed of?
connective tissue
blood vessels
nerves
sensory structures
glands
hair follicles
How many regions are in the dermis?
2 regions
What are the regions of the dermis called?
papillary region
reticular region
Which of the 2 dermis regions is superficial?
papillary region
The papillary region is approximately how much of the thickness of the dermis?
1/5
What type of CT makes up the papillary region?
areolar CT
What type of CT makes up the reticular region?
dense, irregular CT
In which region of the dermis are free nerve ending that are sensitive to pain, itch, tickle, heat and cold?
papillary region
The reticular region has what depth of the dermis?
4/5
Hair follicles, nerves, sebaceous glands and sweat glands are in which region of the dermis?
reticular region
What is fibrosis?
the formation of scar tissue
What type of scar is slightly raised above the original wound?
hypertrophic scars
What type of scar extends well beyond the boundaries of the original wound?
keloid scars
What are three things that pigment the skin?
melanin
carotene
hemoglobin
What is albinism?
a recessive disorder where people can’t synthesize tyrosinase and have no pigment in their hair, skin or eyes.
What is vitiligo?
an autoimmune disorder where melanocytes are missing from patches of skin which turns white.
Which pigment is a yellowish orange?
Carotene
How does hemoglobin pigment skin?
Caucasians have translucent epidermis so skin may look red, pink, or blue
What are epidermal ridges?
fingerprints
What forms fingerprints?
the epidermis conforming to the underlying dermal papillae
What kind of sensations does skin have receptors to detect?
touch
vibration
pressure
temperature
tickling
itch
pain
Rickets and osteomalacia are disorders of what?
Vitamin D deficiency
What do lamellated corpuscles do?
detect pressure
