Integumentary System- (Chapter 5) Integument = “covering” ~16% of body mass: ~2 meter2. Composed of: 1. Cutaneous membrane: A. Epidermis - superficial epithelium B. Dermis - underlying CT w/ blood supply 2. Accessory structures A. Hair B. Nails C. Exocrine glands Functions: 1. Protect underlying tissues from infection, exposure and dehydration. 2. Excrete salts, water, and organic waste. 3. Maintain normal body temp (conserve and radiate heat). 4. Synthesize Vitamin D3 for calcium metabolism. 5. Store nutrients (fat). 6. Sensory detection: touch, pressure, pain, and temp. Epidermis (on handout). The corrugated border between dermis and epidermis helps bond epidermis to dermis (increased surface area for attachment). In thick skin epidermal ridges show on the surface as fingerprints: function to enhance gripping. Epidermis water resistant but not water proof: Insensible perspiration = water loss through. epidermis: ~500ml (1 pint) / day (more if damaged, e.g. burn). Callus = thickening of epidermis, due to repeat friction. Blister = separation of epidermal layers or epidermis from dermis, space fills with interstitial fluid.. Skin Color Pigment based: epidermal pigments and blood pigments contribute to the color. 1. Epidermal Pigmentation: A. Carotene: yellow-orange, from diet -converted into Vitamin A, -localized to epithelium, -functions in normal maintenance of epithelia and photoreceptors, -excess accumulates in stratum corneum. B. Melanin: brown, from melanocytes: -for UV protection. Melanocytes: in stratum basale: -synthesize melanin from tyrosine (amino acid), -packaged in melanosomes, -transferred to cytoplasm of keratinocytes ,-cluster around top side of nucleus, -eventually digested by lysosomes. Everyone has ~1000 melanocytes /mm2: -pale people: small melanosomes, present only in stratum basale and spinosum, -dark people: larger, greater number of melanosomes, retained up through stratum granulosum. Freckle = overproduction of melanin from single melanocyte UV exposure:-some needed for Vitamin D3 production, -excess = damage (DNA mutation), -fibroblasts ! altered CT structure, wrinkles, -epidermal cells, melanocytes ! cancers: squamous cell carcinoma melanoma 2. Dermal Circulation: hemoglobin pigment -oxygenated blood = red color, hemoglobin in RBCs, through skin looks pink *vasodilation ! skin looks more red *vasoconstriction ! skin looks more pale, -Cyanosis = low oxygen, blood deep purple, skin appears blue/purple results from low temp, heart failure, asthma. Abnormal skin color: -Jaundice: liver fails to excrete bile, accumulates in skin, yellow. -Addison’s Disease: pituitary secretes excess adrenocorticotropic hormone, stimulates melanocytes, excess melanin, bronzing. -Albinism: genetic mutation in melanin biosynthesis pathway, lack pigmentation in skin, hair and eyes. -Vitiligo: autoimmune disease ! destruction of melanocytes. Vitamin D3 Production:Cells of stratum spinosum and basale. UV energy + cholesterol = Vitamin D3. Vitamin D3 used by kidney to synthesize the hormone calcitriol. Calcitriol necessary to signal small intestine to absorb calcium. No VitD ! no calcitriol ! no calcium absorption ! weak bones. Dermis (on handout) Collagen fibers from reticular layer blend into papillary and subcutaneous layers to attach integument to body: -wrinkles = dermis stretched beyond its elastic capacity, collagen fibers damaged. -stretch marks = collagen & elastic fibers torn. -collagen & elastin fibers arranged in parallel bundles aligned to resist the expected direction of force = lines of cleavage. -cuts parallel to lines of cleavage will heal faster and with less scar than those perpendicular. Dermis highly vascularized: must “feed” itself and epidermis above. Contusion = bruise, trauma that ruptures blood vessels but does not break skin, blood pools in dermis and must be removed by phagocytes (slow process). Sensory perception in integument: Skin highly innervated for sensory perception, mostly in dermis: 1.
Our experiment is designed to determine if white candles burn at a faster or slower rate than colored candles. . Simultaneously, we also included a candle made of beeswax. This beeswax candle was included to see if a natural beeswax candle would burn faster or slower quicker than the synthetic paraffin wax candle. We will use candles of the same size and shape and manufactured by the same company. They will be lighted at the same time and the temperature of the room will not change.…
What is Science p. 4 – Science aims to explain and understand
Science as a collective institution aims to produce more and more accurate natural explanations of how the natural world works, what its components are, and how the world got to be the way it is now.
7. What is Science p. 5 – Science works with testable ideas
Only testable ideas are within the purview of science.…
Kuhn adds, science is invention and not a smooth continuous progression suggested by Popper but rather a “gestalt switch” (Narasimhan, 1997, p.4) in paradigms described as ‘revolutionary’. Kuhn does however describe a ‘normal’ phase agreeing with Popper (Narasimhan, 1997, M. Reiss 2010).…
Astronomers also determined the circumference of the Earth with the gnomon.10
Calculations were done with counting-rods and then later used the abacus.11
Ho Peng Yoke, Modern Scholarship of the history of Chinese Astronomy (Australia,
1977), p. 1
Chris Mihos, http://burro.astr.cwru.edu/stu/advanced/pre20th_ancients_others.html, p.1
(under construction) Computer
SBU Bike Storage Lockers
Rappaccini cares more about science than mankind. One reason being is that he experimented on Beatrice and Giovanni. In the poem, Beatrice says “the effect of my father’s fatal love of science, which estranged me from all society of my kind.”(P.289, Para. 5) This quote exposes that Beatrice never got to meet other people because she became poisonous from the plant that her father created.…
Contrast and Comparison of Nursing Grand Theorists
The purpose of this paper is to compare and contrast nursing theorists from the four categories which are identified by Meleis as: Needs, Interaction, Outcome and Caring. (Meleis, 2012, Chapter 9) I have chosen Faye Abdellah, Imogene King, Myra Levine and Jean Watson as the grand theorists that I would like to explore for this study in contrast and comparison. This decision was made, in part, due to the…
“There is not a single rule, however plausible, and however firmly grounded in epistemology, that is not violated at some time or other” (Feyerabend, 2003, p. 81). The inability of the research to support these two hypotheses does not indicate failure, but the possibility of progress in the science (Feyerabend, 2003). More research, possibly encountering a different perspective could clarify the direction the hypotheses should take.…
According to Blakeley et al (2009, p.24) social science concentrates on differences between social groups such as age, race, gender etc. rather than those between individuals.
Social lives include differences among people as well as similarities, and the things people value, as well as the resources they have, are also unequally distributed. Differences can refer to variations between individuals- these may be physical, behavioural, or related to attitudes and preferences.…