Integumentary system quiz Flashcards
what are the 5 functions of the integumentary system?
1 protective covering 2 body temp regulation 3 sensory receptors 4 vitamin D synthesis 5 waste excretion
what is the most superficial layer of skin?
epidermis
what are the 2 kinds of epidermis?
thick- palms, soles of feet
thin- everything else
what is the epidermis composed of?
stratified squamous epithelium tissue
what are the 4 types of cells in the epidermis?
1 keratinocytes
2 melanocytes
3 dendritic cells
4 merkel cells
what type of cell is the predominant type of epidermis that makes keratin
keratinocytes
what is keratin?
1 structural protein which toughens and waterproofs the surface of epidermis
2 resist abrasion
which cell manufactures melanin?
melanocytes- epidermis
what are dendritic (langerhans) cells?
1 immune cells
2 long dendritic processes that connect to epidermis
3 make a mesh in the epidermis trapping foreign things coming into the epidermis, migrate to dermis and into lymphatic system
what are merkel cells?
1 tactile mechanoreceptors
2 only receptor in the epidermis
which layer of skin is the deepest and actively mitotic?
stratum basale
how many layers does thin skin have? which layer is missing from thin skin?
4 layers, stratum lucidum
what are the 5 layers of thick skin?
1 stratum basale 2 stratum spinosum 3 stratum granulosum 4 stratum lucidum 5 stratum corneum
which layer begins synthesis of keratin and makes the cells look spiky?
stratum spinosum- slightly mitotic
what is the stratum germinativum?
stratum basale + stratum spinosum
what happens in the stratum germinativum?
it is the primary site of cholecalciferol manfacturing
which layer is made up of flattened cells filling up with keratin?
stratum granulosum
which layer is made up of 20-30 layers flattened, keratinized dead cells?
stratum corneum
what is dermis composed of and what does it house?
composed of connective tissue and houses muscle fibers, blood vessels, hair follicles, exocrine glands and sensory nerve fibers
which layer is known as “true skin”?
dermis
what are the 2 layers of dermis?
papillary layer- upper 2/3
reticular layer- lower 1/3
where is the papillary layer?
loose connective tissue directly underlying the epidermis
what do you call the pulling of elastic fibers in the papillary layer?
dermal ridges- fingerprints and toe prints
what do the dermal ridges do?
help grip with more friction
where is the reticular layer?
it is dense regular connective tissue underlying the papillary layer
what are the characteristics of the reticular layer?
it is quite distensible and resilient which allows the skin to return to position when pulled up- elasticity
when the reticular layer is overstretched what happens?
it tears producing stretch marks (striae distensae)
where is the subcutaneous layer?
it is the superficial fascia or hypodermis and is not officially part of the skin
what is the subcutaneous layer made of?
adipose tissue and loose connective tissue interlaced with blood vessels
what is the role of the adipose tissue?
1 conserve internal body heat or impede entrance of external heat
2 bind skin to underlying structures
what causes pink skin coloration?
blood flow in dermis and subcutaneous layers
what are the 2 causes of yellow skin coloration?
1 carotene- temporary
2 thick stratum corneum with increased keratin- permanent
what is carotene?
yellowish pigment acquired through diet- temporary
where do you most commonly see a thicker stratum corneum related to skin tone?
primarily found among people of asian descent
what are the causes of brown skin coloration/
due to melanin, produced by melanocytes found in the stratum basale; imparts a light to dark brown coloration depending on concentration
human skin color differences are primarily due to differences in what?
melanin and its distribution; most people have same number of melanocytes
what are freckles?
small isolated patches of highly concentrated melanin secretion
