Integumentary System Flashcards
epidermis
- what is it made of?
- what does it not have?
most superficial layer of the skin
- epithelial cells
- blood vessels
stratum basale
the deepest portion of the epidermis, made up of a single layer of cells that continually undergo division
most epidermal cells are ____
keratinized
keratin
waxy protein that helps to waterproof the skin
dermis
- made of what?
- what 2 specific things does it contain?
lies directly beneath the epidermis
- mostly of connective tissues, but also blood vessels, sensory receptors, hair follicles, sebaceous glands, sweat glands
- elastin and collagen fibers
subcutaneous layer
- AKA?
- what is important to note about it?
- what is it made of?
hypodermis
- it is not actually a layer of the skin
- connective tissue that binds to underlying muscles
what are the 4 types of cells found in the epidermis?
keratinocytes, melanocytes, langerhans cells, merkel cells
what are the 4 types of cells found in the dermis?
fibroblasts, adipocytes, macrophages, mast cells
keratinocytes
- found in epidermis/dermis?
most common cell in epidermis, arise from stem cells in the stratum basale, flatten and die as they move toward the surface of the skin, produce keratin: a protein that hardens the cell and makes the skin water resistant
- epidermis
melanocytes
- found in epidermis/ dermis?
produce melanin: pigment that gives the skin its color and protects against UV radiation
- epidermis
langerhans cells
- found in epidermis/ dermis?
antigen-presenting cells of the immune system (phagocytes), more common in stratum spinosum than other layers of epidermis
- epidermis
merkel cells
- found in epidermis/ dermis?
cutaneous receptors, detect light touch, located in stratum basale
- epidermis
fibroblasts
- found in epidermis/ dermis?
secrete collagen, elastin, glycosaminoglycans, and other components of the extracellular matrix
- dermis
adipocytes
- found in epidermis/ dermis?
fat cells
- dermis
macrophages
- found in epidermis/ dermis?
phagocytic cells that engulf potential pathogens
- dermis
mast cells
- found in epidermis/ dermis?
antigen presenting cells that play a role in the inflammatory response (release histamine)
- dermis
what type of homeostasis is the skin involved in?
temperature
how is the temperature of the body controlled?
a negative feedback system consisting of a receptor, control center, and effector
receptors
sensory cells located in the dermis of the skin
control center
is the hypothalamus, located in the brain
effectors
include sweat glands, blood vessels, muscles (shivering)
vasodilation
happens to the blood vessels near the surface of the skin and releases heat into the environment to lower body temperature
what are the 2 exocrine glands found in the skin?
sebaceous glands and sweat glands
exocrine glands
secrete substances into ducts
sebaceous glands
holocrine glands that secrete sebum. connected to hair follicles and secrete sebum through the hair pore
sebum
oily mixture of lipids and proteins. inhibits water loss from the skin and protects against bacterial and fungal infections
sweat glands are either 1 of 2 types of glands?
eccrine or apocrine glands
eccrine glands
not connected to hair follicles, activated by elevated body temperatures. can be found on forehead, neck and back. secrete salty solution of electrolytes and water. are activated as part of the body’s thermoregulation
apocrine glands
secrete an oily solution containing fatty acids, triglycerides, and proteins. located in the armpits, groin, palms, and soles of feet. secrete oily sweat under stress or anxiety. bacteria feed on it and produce body odor
