Chapter 5 Skin Flashcards
Describe the three parts of the skin
- Epidermis: keratinized stratified squamous epithelium
- Dermis: strong, flexible CT
- Hypodermis: subcutaneous layer that is mostly adipose tissue
What types of cells are found in the epidermis and what is the function of each? (4) Where are langerhans cells found?
- keratinocytes: produce fibrous protein keratin
- melanocytes: produce pigment melanin
- epidermal dedritic (langerhans) cell: macrophhages that activate immune system
- found on soles of feet*
- tactile (merkel) cells: light touch, mechanoreceptors
Melanocytes in detail:
Do people with darker or lighter skin have more melanin? What does melanin do? People who live where have more melanin? What happens when UV light is overconsumed?
notes
- darker skin = more melanin
- protects from sun UV rays
- people who live near the equator have more melanin
- overconsumption of UV rays destroys the nucleus, disable the tumor suppressor gene, and stimulate the P53 oncogene
What is stratum basale? What are they made of? How many days does it take for a cell to move from the basal layer to the surface? What do newly formed cells become a part of? What 2 cells are present?
- deepest epidermal layer firmly attached to the dermis (CT)
- single row of actively mitotic stem cells
- journey from basal layer to the surface takes 25-45 days
- newly formed cells become part of the superficial layers
- melanocytes and lagerhans cells present
What cells are found in the dermis (4)
-fibroblasts, macrophages, occasionally mast/white cells
What are the 2 types of layers that make up the dermis? What makes up each layer? (4, 1)
- Papillary: areolar CT and blood vessels
- contains capillaries, Meissner’s corpuscles, free nerve endings - Reticular layer: dense irregular CT
What structures are found in the dermis? Diagram
-epidermal ridge
-dermal papillae
-meissners corpuscle
-pacinian corpuscle
-apocrine glands
-eccrine glands
-sebaceous glands
-arrector pilli muscle
-hair folicle
-
What are arrector pili muscles and what is their function in skin?
- smooth muscles attached to hair follicles
- produces goose bumps in the cold
What are epidermal ridges and dermal papillae? what forms fingerprints?
Epidermal ridges
- papillae lie over large mounds called dermal ridges that makes epidermal ridges
- sweat pores open along crest to give us identifying sweat films called fingerprints
Dermal papillae
-peglike projections on the surface, formed by the papillary layer pushing up against the epidermis
What might it mean if the skin were red, pale, jaundiced (yellow), cyanotic?
red: polycythemia
yellow: problem with liver
pale: anemia
cyanotic: heart problems, cold
Know the functions of skin (6) (2, 3, 4, 1, 1, 1)
- body temperature regulation
- routine insensible perspiration
- cooldown of body through dilation of dermal vessels & increased sweat gland activity - protection: 3 types of barriers
- chemical: low pH secretions (acid mantle) & defensins retard bacterial activity
- physical/mechanical: keratin & glycolipids block water & water-soluble substances
- biological: Langerhans cell (dendritic), macrophages - metabolic functions
- synthesis of vD precursor from cholesterol, activated by sunlight
- cortisone –> hydrocortisone
- chemical conversion of carcinogen and hormones
- harmful chemical –> harmless or vice versa - cutaneous sensations
- temperatue, touch, pain - blood reservoir (dermis is vascular)
- 5% body’s blood vol - excretion
- wastes/salt in sweat
What is metastasis? (3)
Notes
What are the risk factors of cancer? (4) What is the treatment? Where are most skin cancer found? When do moles become melanomas?
- capability of the cancer to spread to other parts of the body
- localized means treatable
- usually skin cancers are benign and do not metastasize
- overexposure to UV radiation, irritation by infection, chemicals, trauma
- cut, burn (radiotherapy), and poison (chemotherapy)
- melanocytes found in epidermas called melanoma: highly metastatic
- moles beome melanoma when ABCD rule: Asymmetry, border irregular, color is black/brown/tan/red/blue, diameter larger than 6mm
Describe first, second, and third degree burns. (3, 4, 6 - what is the color of 3rd degree burns?)
Notes
What is the threat of burns? In how many hours is it a serious threat? How do you treat it?
- first degree burns
- epidermal damage only
- localized redness, edema, pain
- partial thickness burns - second degree burns
- epidermal and uper dermal damage
- blister appears
- partial thickness burns
- critical when have >25% - thrid degree burns
- entire thickness of skin damaged
- gray-white/red/black
- no initial edema or pain (nerve endings destoryed)
- skin grafting necessary
- critical when have >10%
- critical when have face, hands, feet
- dehydration (skin reservoir of blood) & electrolyte imbalance leading to renal shutdown and circulatory shock
- serious threat after 24 hours
- hydration & antibiotics
What is the Rule of Nines and when is it used? Be able to calculate burns percentage in various examples
- estimate volume of fluid loss from burns & the amount that should be given
- anterior/posterior legs total = 36%
- anterior/posterior arms total = 18%
- anterior posterior trunk = 36%
- anterior/posterior head and neck = 9%
- perineum = 1%
In order for a tattoo to be permanent, ink must be deposited into what layer of the skin?
dermis
