the integumentary system 1 Flashcards
what does the integumentary system include
the body covering including the skin, nails and hair
what are the 2 main parts of the integumentary system
epidermis and dermis
what is the epidermis
surface epithelial layer of the skin
what is the dermis
the deeper connective tissue layer of the skin
what is not part of the skin
deep dermis
what 2 basic tissues does the skin consist of
epithelial and connective
what are the 2 fundamental layers of skin
outer epidermis and inner dermis
what is the epidermis made of
keratinized stratified squamous epithelial
what 4 cell types is the epidermis made of
keratinocytes
melanocytes
Langerhans cells
merkel cells
how much of the epidermis is keratinocytes
90%
how many layers are made up by keratinocytes
4-5
what do keratinocytes do
produce keratin
protect skin
waterproof
name the sublayers of the epidermis
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
how long does the renewal of the epidermis take
3-4 weeks
what is the role of the stratum basale
stem cells of the epidermis
describe the structure of the stratum basale
single layer of low columnar or cuboidal cells at the base of the epidermis
describe the structure of the stratum spinosum
several layers of polyhedral cells joined by many desmosomes
describe the structure of stratum granulosum
few layers of flattened cells with cytoplasmic granules
nuclei begins to degenerate
describe structure of stratum lucidum
several layers of flattened skin
nuclei hardly visable
when can the stratum lucidum not be identified
in thin skin
describe the structure of stratum corneum
several layers of flattened keratinised (dead) cells, embedded in a dense matrix of proteins.
what parts of the body contain thick skin
palms of hands and soles of feet
what do melanocytes do
produce melanin
transfer pigment to keratinocytes
what amount of the epithelial cells are melanocytes
8%
what do Langerhans cells do
immune response
where are langerhans cells found
stratus spinosum
describe how langerhans cells preform their function
cells that engulf foreign materials that invade the epidermis
where are merkel cell complexes found
stratum basale
how many factors contribute to skin color
3
how many factors contribute to skin color
3
what factors contribute to skin color
amount of melanin in the epidermis
amount of carotene
amount of oxygen bound to haemoglobin
what is albinism
an inherited recessive disorder
little or no melanin
what is melasma
dark brown symmetric areas on the face and neck
what is vitiligo
smooth white patches in skin due to loss of melanocytes
what are birthmarks
abnormal blood vessels or malformed pigment cells
how % of skin cancer is basal cell carcinoma
around 75%
describe features of basal cell carcinoma
grows very slowly, highly treatable and starts in the basal cell layer of the epidermis
what % of skin cancer is squamous cell carcinoma
around 20%
describe features of squamous cell carcinoma
middle aggression, but can be treated
what % of skin cancer is melanoma
roughly 5%
what % of skin cancer deaths are due to melanoma
73%
describe features of melanoma
usually in a mole and spreads quickly
what is jaundice
an abnormal yellow skin tone that usually signifies a liver disorder
what are the accessory structures
hair
skin glands
nails
what is hair made of
fused keratinized cells
what items make up hair
shaft and root
name the epidermal glands
sebaceous glands
sudoriferous/ sweat gland
ceruminous glands
what do sebaceous glands do
secrete oily sebum
what do ceruminous glands do
produce earwax
what are nails made of
packed hard dead keratinized cells
what are the functions of the integumentary system
temperature regulation
protection
sensory reception
excretion and absorption
vit D synthesis
where is aging of the integumentary
mainly dermis
what contributes to the aging of the integumentary
loss of collagen fibres, loss of electacity, loss of immune responses, thinning of skin
what is acne stimulated by
androgens
what induces skin cancer
ultraviolet rays of the sun
where is skin cancer most commom
fair skinned and the elderly
describe most skin tumours
benign and do not metastasize (spread to other sites)
what 2 key factors can contribute to skin cancer
environment and genes
name the 3 types of the skin cancer
basal cell carcinoma
squamous cell carcinoma
malignant melanoma
describe basal cell carcinoma
most commom
least dangerous
arrises from the cells of the stratum basale and eventually invades the dermis
how does basal cell carcinoma appear
a small shiny bump that develops a central depression and a beaded pearly edge
where does basal cell carcinoma normally occur
on the face
how is basal cell carcinoma treated
surgically removed and radiation therapy
where does squamous cell carcioma arise from
keratinocytes of the stratus spinosum
where does squamous cell carcioma normally appear
scalp, ears, lower lip or back of hand
what does squamous cell carcinoma look like
raised reddened scaly appearance
how many cancer cases are malignant melanoma
5%
where does malignant melanoma arise from
melanocytes of a preexisting mole
what is a first degree burn
involves only the epidermis
what is a second degree burn
involves the epidermis and part of the dermis but leaves some of the dermis intact
what is a third degree burn
the epidermis, dermis and often some deeper tissues are completely destroyed
