BSC 181 1st EditionExam # 1 Study Guide Lectures: 11 - 17Lecture 11 (February 6)1. What are the regions of the skin?Epidermis: (on the dermis, as close to the outside of the body you can get) (Epi: means upon)Dermis: underlies epidermis, mostly fibrous connective tissueHypodermis fascia: (underneath the epidermis and the dermis), subcutaneous layer deep to skin, not part of skin but shares some functions, mostly adipose, absorbs shock & insulates, anchors skin to underlying structures 2. What are the cells found in the epidermis?Keratinocytes: produce fibrous protein keratin, most cells of epidermis, desmosome connectionsMelanocytes: (melano: dark brown/black), 10–25% of cells in deepest epidermis, produce pigment called melanin (dark brown/black), packaged into melanosomes (somes: means body), protects nucleus from UV damageDendritic (langerhans) cells: macrophages (white blood cells), key activators of immune systemTactile (merkel) cells: sensory touch receptors3. What are the layers of the epidermis?Stratum basale: (deep/at the base), deepest epidermal layer, also called (germinating layer-where mitosis takes place), firmly attached to dermis, single row of stem cellsStratum spinosum: (“spiky”), several Layers thick, have the spike looking cells, cells contain web-like system of filaments attached to desomosmes, abundant melanosomes (pigment cells) and dendritic cells (immune cells)Stratum granulosum: (“grainy”), thin, (cells flatten, nuclei and organelles disintegrate, keratinization begins (help increase the protective layer on the surface of the skin), cells above this layer dieStratum lucidum: (only in thick skin/in soles of feet), it’s a clear layer, thin, translucent band superficial to the stratum granulosum, a few rows of flat, dead keratinocytes (keratin producing cells)Stratum corneum: (superficial/hard or tough), 20–30 rows of cells that are dead, flat, anucleate, keratinized, membranous sacs. Protect deeper cells from environment and water loss, protect from abrasion and penetration, barrier against biological, chemical, and physical assaultsLecture 12 (February 9)4. What are the layers of the dermis?Papillary Layer: areolar connective tissue with collagen and elastic fibers and blood vessels, loose tissue, phagocytes (a macrophage) can patrol for microorganisms that do not belongDermal Papillae: contains touch and pain receptors, superficial peglike projections (provides an adhesion so the epidermis and the dermis do not slip and slide across each other)Reticular Layer: it is dense fibrous connective tissue, elastic fibers provide stretch-recoil properties, collagen fibers bind water and provide strength and resiliency 5. What contributes to skin color?Melanin: only pigment made in skin (more equals darker skin)Carotene: (orangish yellow), most obvious in palms and soles Hemoglobin: (pinkish look to skin because of blood)6. What are the types of sweat glands?Eccrine Sweat Glands: Most numerous, Abundant on palms, soles, and forehead. Ducts connect to pores (These exit as a pore onto the skin, not all sweat glands do that) Function in thermoregulation, Regulated by sympathetic nervous system, Evaporation of Eccrine sweat glands helps to cool the bodyApocrine Sweat Glands: Ducts empty into hair follicles and they do not empty it on the skin surface the other ones, Confined to axillary and anogenital areas, these get kick started during puberty, they create body odor, Larger than eccrine sweat glandsCeruminous glands: lining of external ear canal; secrete cerumen (earwax-a modified apocrine gland)Mammary glands: (a modified apocrine gland), secretes milkSebaceous (Oil) Glands: this secretes sebum which is oily and it makes hair soft. Also not stimulated until puberty, most are found in hair follicles and secrete into hair follicles Lecture 13 (February 11)7. What are the types of hair?Vellus hair: pale, fine body of children and adult femalesTerminal hair: coarse, long hair of eyebrows, scalp, starts at puberty as well, appear in axillary and pubic regions of, both sexes, but face and neck of males as well8. What are the regions of a nail?Lunule: the white half-moon shape that is close to the skinFree edge of the nail: is the white part of the nailLateral Nail Fold: are the side edges of the nail that fold into the skinBody of the Nail: is just that, it is most of the nail that is not the free edge, the lateral fold, or the lunule9. Function of the skin?Protection, Body temperature regulation (blood vessels will dilate or constrict in order to regulate temperature), Cutaneous sensation, Metabolic functions, Blood reservoir, ExcretionLecture 14 (February 11)10. Be familiar with the skin cancersBasal Cell Carcinoma: Least malignant; most common, good prognosis, Stratum basale cells proliferate and slowly invade dermis and hypodermis, Cured by surgical excision (cutting out thetumor) in 99% of casesSquamous Cell Carcinoma: Second most common type, Involves keratinocytes of stratum spinosum, Usually scaly reddened papule on scalp, ears, lower lip, and hands, Does metastasize (more likely too), Good prognosis if treated by radiation therapy or removed surgically, Also has a good prognosis Melanoma: Cancer of melanocytes, Most dangerous, Highly metastatic and resistant to chemotherapy, Treated by wide surgical excision accompanied by immunotherapy*ABCD Rule: Asymmetry, Border irregularity, Color, Diameter11. Be familiar with the different types of burnsFirst Degree: Epidermal damage only, Localized redness, edema (swelling), and pain. An example is sunburnSecond Degree: Epidermal and upper dermal damage, this is where blisters appearThird Degree: Entire thickness of skin involved, Skin gray-white, cherry red, or blackened, Not painful (nerve endings destroyed) or swollen, Skin grafting (replacing of the skin/mesh) usually necessaryLecture 14 (February 13)12. How are bones classified?They are divided into two groups: axial (the bones in association with the trunk of the body) andappendicular (which are the bones associated with the attachments of the trunk) They are also classified by shape:Long bones: these are longer than they are wideShort bones: these are cubed shapedFlat bones: these are thin and they can be slightly curvedIrregular bones: these are oddly shaped bones, an example is the vertebrae13. Know the terms for the bone markingsTuberosity: rounded projection Crest: narrow, prominent ridge of bone Trochanter: large, blunt, irregular