Integumentary System Flashcards
what can too much melanin prevent the production of?
Vitamin D
what is the hypodermis made of?
loose, areolar connective, tissue and fat
what shape are cells in granulosum?
flat
what surrounds the hair’s medulla?
cortex
what are merocrine glands?
same as eccrine
what layer of the dermis contains a mesh of collagen and elastin fibers?
papillary layer
how much of our body’s vitamin D requirement comes from UV exposure to the skin?
80%
What part of skin provides strength, absorbs friction and is only found on palms of hands and soles of feet?
stratum lucidum
what is nail body made of?
densely packed, dead keratinocytes
what are the accessory structures of the integumentary system?
1) hair
2) nails
3) glands
what does chemotherapy kill in the hair?
matrix
what sweat gland excretes dermicidin?
eccrine
What extends from epidermis and encloses hair root; more keratinous in upper region?
external root sheath
true or false: hair that is external to the skin is dead
true
what kind of tissue is epidermis made of?
closely packed, epithelial cells
True or false: stratum, corneum cells are constantly shed and replaced
True
Gland usually associated with hair follicle
apocrine
where are sebaceous glands found?
All over the body
what is the cortex made of?
compressed keratinized cells
What connects skin and fascia; insulates and stores energy as fat; and cushions
hypodermis
what layer of skin is also known as the “core“?
dermis
what are functions if nails?
1) protect tips of fingers and toes (areas that experience max mechanical stress)
2) support in picking up small objects
what type of cells are in stratum basale?
cuboidal epithelial
what is hair follicle made of?
3 concentric layers of cells
how thick is stratum spinosum?
varies in thickness; creates an even upper surface.
where are apocrine sweat glands usually found?
deep dermis of underarms and pubic region
type of tissue in dermis
dense, irregular connective tissue
Type of glands that are:
1) coiled
2) all over skin surface
3) abundant in palms, soles and forehead
Eccrine glands
what is the top layer of the dermis?
papillary layer
where do accessory structures start in embryos?
in the epidermis
what is the Integumentary System?
skin and support structures
what do the internal & external root sheaths provide?
1) thickness 2) strength
what % of folate can be reduced in 60 minutes if exposed to UV?
30-50%
what kind of tissue is the papillary dermis made of?
loose, areolar connective tissue
what does melanin do?
1) protects cell dna from UV 2) prevents breakdown of folic acid
what are the functions of the skin?
1) protect against environment 2) prevent water loss 3) prevent abrasion 4) deter microbes 5) provide sensation 6) temperature regulation
2 types of sweat glands
1) eccrine 2) apocrine
what does Meissner corpuscle sense?
1) light touch 2) low frequency vibration
thick, clear connective tissue covering hair root and connecting it to dermis
glassy membrane
what is the layer of miotically active basal cells in the hair bulb called?
hair matrix
what surrounds hair papilla to give hair color?
melanin
what is stratum corneum made of?
dead keratinized cells
thickness of epidermis
thin = 50-150 microns;
thick = 400-1400 microns
how many layers does stratum corneum have?
15-20
what do melanocytes do?
make pigment
what do sebaceous glands secrete?
sebum or oil
what do immune cells in the skin do?
engulf bacteria or pathogens
what are sudoriferous glands?
sweat glands
what can too much melanin prevent the production of?
vitamin D
antibiotic peptide secreted by sweat gland
Dermcidin
what is the surface area of skin?
1.5-2.0 square meters
where do you find a lot of Merkel cells?
hands and feet
what does the hair papilla contain?
capillaries and nerve endings
layers of epidermis
1) stratum basale 2) stratum spinosum 3) stratum granulosum 4) stratum lucidum (palms/soles only) 5) stratum corneum
what layer of skin contains fibroblasts?
dermis
what tissue in hypodermis or subcutaneous layer
loose connective tissue and fat
what color is stratum lucidum?
clear
what is prime function of eccrine glands?
thermoregulation
To secrete through a duct w/o affecting the cells of the gland
what is exocytosis
what layer prevents water loss? how?
granulosum; by a lipid film that covers each cell
which layer of the dermis contains exocrine and sebaceous glands
reticular
what layer of skin provides cells to the nail root matrix?
stratum basale
what are keratinocytes?
stem cells that product keratin
what chemical in the skin is converted to vitamin D3 when exposed to UV?
7-dehydrocholesterol
what structure does the hair bulb surround?
hair papilla
what are the two types of melanin?
1) Eumelanin (black/brown) 2) pheomelanin (red)
what type of cells are in the internal root sheath?
basal cells that surround the root
what are two sensory receptors?
1) Meissner corpuscle
2) pacinian corpuscle
how did pheomelanin occur?
Gene mutation
what structures are found in the dermis?
1) blood 2) lymph 3) hair 4) nerves 5) mast cells 6) macrophages 7) sweat and oil glands
what kind of skin cells are in the hair bulb?
basal cells
what are functions of hair?
1) protection from UV/dust 2) provide sensory input 3) thermoregulation 4) communication to outside world
what type of tissue is the reticular dermis made of
dense, irregular connective tissue with collagen and elastin
what layer covers the hair cortex?
cuticle
what does Pacinian corpuscle sense?
1) high frequency vibration 2) pressure
what does basal layer attach to?
basement membrane/dermis
what sense are Merkel cells involved in?
Touch
what is nail body made of?
densely packed dead keratinocytes
what are apocrine glands controlled by?
nerves and hormones
what is purpose of sebum?
1) lubricate stratum corneum 2) prevent water loss in low humidity 3) has antibacterial properties
what does apocrine sweat contain?
1) water 2) salts 3) organic compounds that thicken sweat and cause odor
what glands play a part in pheromones?
apocrine
what is a melanosome?
A cellular vesicle that distributes melanin into keratinocytes and throughout skin
what layers of skin contain keratinocytes?
basal and spinosum
what type of melanin was the original?
eumelanin
when is keratinization of hair complete?
when cells push through the skin surface
typically, how much of body weight is skin?
16%
what is hair cuticle made of
very hard, keratinized cells
what is the hair’s medulla?
innermost section of hair shaft; “marrow”
how many layers are in granulosum?
3-5
what layer of the dermis contains a mesh of collagen and elastin fibers?
papillary layer
what shape are cells in granulosum?
flat
what layer of the dermis contains the hair shaft?
papillary
what type of sweat does eccrine glands produce?
hypotonic (more water than solutes)
what is stratum lucidum made of?
densely packed keratin
where does hair growth start?
basal cells of the bulb
what typically stimulates sebaceous gland activity?
hormones after puberty
what is the innermost layer of the hair follicle?
internal root sheath
what does “cyte” mean?
Cell
what do supra nuclear caps made by melanin do?
protect the nucleus from UV to prevent dna mutation
what are the layers of the dermis?
1) papillary 2) reticular
what are the immune cells in the stratum Spinosum?
epidermal dendritic cells aka: langerhans cells
what is the largest organ of the body?
Skin
are apocrine glands larger or smaller than eccrine glands?
Larger
what is the eponychium
cuticle
what part of the hair determines texture (straight/curly)?
Cortex
what is nail root?
where nail body forms
how many layers in the dermis
Two
Where does mitosis occur?
1) stratum basale 2) stratum spinosum
name layers of skin
1) epidermis 2) dermis hypodermis or subcutaneous is not really skin but supports
what do mast cells do?
create histamine
what is the hyponychium
free edge of nail
