Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Skin
Chapter 5 - A & P Lecture
| Question | Answer |
|---|---|
| what is the epidermis? | superficial layer of stratified squamous epithelial tissue that protects and reduces water loss |
| what is the dermis? | deep layer of connective tissue that aids in structural strength |
| what is the subcutaneous tissue? | loose connective tissue that connects skin to underlying structures (not part of skin) |
| does the epidermis have blood vessels? | no it's avascular and nourished by diffusion from capillaries of the papillary layer of the dermis |
| what is the epidermis composed of? | epithelial cells arranged into layer or strata |
| how are the epidermis and dermis separated? | basement membrane |
| list the 4 epidermal cells? | keratinocytes, melanocytes, langerhans cells, merkel |
| what are keratinocytes? | most abundant cell in the epidermis that produces keratin for strength |
| what are melanocytes? | produces melanin that is transferred to keratinocytes and contributes to skin color |
| are melanocyttes dependent? | no, same number in all people |
| what are langerhans cells? | part of the immune system |
| what are merkel cells? | will detect light touch and superficial pressure |
| how does keratinization affect epidermal cells? | as cells move upward they fill with keratin, die, and serve as a layer that resist abrasion (permeability layer) |
| list the epidermal strata from bottom to top? | stratum basale, spinosum, granulosum, lucidum, corneum |
| what are the characteristics of the stratum basale? | deepest portion of epidermis and single layer of cuboidal/columnar cells |
| does the stratum basale have high or low mitotic activity? | high mitotic activity, keratinocyte stem cells undergo mitosis about every 19 days |
| what holds keratinocytes together? | desmosomes |
| how many day does it take to move the stratum basale to the surface and be sloughed off? | 40 to 56 days |
| what are the characteristics of stratum spinosum? | 8 to 10 layers of many-sided cells that flatten as they are pushed upward |
| what does the stratum spinosum contain? | new desmosomes, lipid-filled lamellar bodies, and additional keratin fibers |
| what are the charcteristics of stratum granulosum? | 2 to 5 layers of flattened, diamond-shaped cells |
| what does the stratum granulosum contain? | grules of keratohyalin in the cytoplasm |
| what do lamellar bodies do in the stratum granulosum? | move to the plasma membrane and release their lipid contents into the extracellular space |
| what takes place in the superficial layers of the stratum granulosum? | nucleus and other organelles degenerate and cells dies (keratin fibers & keratohyalin granules do not degenerate) |
| what are characteristics of stratum lucidum? | thin, clear zone of dead keratinocytes with indistinct boundaries |
| where is stratum lucidum found? | palms & soles |
| what are characteristics of stratum corneum? | most superficial, consists of 25 or more layer fo dead overlapping squamous cells joined by desmosomes called cornified cells |
| how many layers of epithelial strata does thick skin have? | all 5 |
| where is thick skin found? | areas subject to pressure/friction ex: palms, fingertips, soles |
| how many layer of epithelial strata does think skin have? | 4(no stratum lucidum) |
| what are some characteristics of thin skin? | more flexible, covers rest of body, hair grows |
| what is a callus? | an increase in number of layers in stratum corneum |
| what is a corn | a callus on a bony prominence |
| what 3 factors is skin color determined by? | pigments, blood cirulating, thickness of stratum corneum |
| what is melanin? | group of chemicals derived from amino acid tyrosine that is colored brown to black (may be yellowish or reddish) and protects against UV light |
| what cause albinism? | deficiency or absence of pigment determined by genes, hormones, exposure to light |
| what is carotene? | yellow pigment form vegetables in the stratum corneum, adipose cells of dermis, and subcutaneous tissue |
| describe the melanin transfer to keratinocytes? | 1) melanocytes produce melanin 2) melanin is packed in melanosomes 3) melanosomes move into cell processes of melanocytes 4) keratinocytes phagocytize tops of melanocyte cell processes 5) keratinocytes acquire melanosomes |
| what a racial variations in skin color due to? | types/# of melanin, size/#/distribution of melanosomes, hormones (estrongen/MSH) during pregnancy |
| what is cyanosis? | blue color caused by decrease in blood oxygen content |
| what is erythema? | red color cause by increased blood flow |
| does thickness impact color? | yes, the thickness of stratum corneum impacts color |
| what is the most common type of cancer? | skin cancer which is the result from damage from UV radiation that damages the DNA in epidermas |
| how does melanin affect likelihood of developing skin cancer? | fair skin people are at greater risk than dark skinned people |
| what are the 3 types of skin cancer? | basal cell carcinoma, squamous cell carcinoma, melanoma |
| what are the characteristics of basal cell carcinoma? | most common, cells of stratuma, varried appearance, cured by removal/destruction |
| what are the characteristics of squamous cell carcinoma? | cells of stratum spinosum, varied appearance, may bleed, cured by removal/destruction |
| what is the most deadly type of skin cancer? | melanoma |
| what is the ABCDE rule? | A(asymmetry), B(border), C(color not uniform), D(diameter greater than 6mm), E(evolving or changing) |
| characteristics of the dermis? | gives structural strength, connective tissue with fibers (collagen, elastic, reticular), fibroblasts, macrophages, and adipocytes |
| what does the dermis contain? | nerves, blood vessels, hair follicles, smooth muscles, glands, lymphatic vessels |
| what are the sensory functions of the dermis? | pain, itch, tickle, temp., touch, pressure, two point discrimination |
| what are the 2 layers of the dermis? | papillary & reticular |
| what is the paillary layer? | superficial , areolar with lots of elastic fibers, dermal papillae, capillary bed, free nerve ending sensing pain |
| what is the reticular layer? | deep, dense irregular of collagen & elastic fibers |
| what does the reticular layer contain? | some adipose tissue, hair follicles, nerves, oil glands, ducts of sweat glands, heat sensor |
| what are clevage (tension) lines? | elastic and collagen fibers oriented in some directions more than others |
| why are clevage lines important in surgery? | if incision parallel to lines there is faster healing and less scar tissue |
| what are stretch marks? | where skin is overstretched |
Created by:
academicweapon.com