Bio 168 Exam Questions and Answers 100% Pass

Bio 168 Exam Questions and Answers 100% Pass integumentary system - Skin, hair, glands and nails Protection - Mechanical trauma, pathogens, and environment Sensation - sensory receptors that detect changes in the internal and external environment, allowing the body to maintain homeostasis when needed Thermoregulation - Maintenance of a stable internal body temperature through negative feedback loops Excretion - Small amounts of waste products are eliminated from the body via sweat Vitamin D synthesis - Found in the cells of the deep epidermis, and begins the transformation into vitamin D when exposed to UV radiation 2 100% Pass Guarantee Katelyn Whitman, All Rights Vitamin D - required for the small intestine to absorb calcium ions from food, which is important in nerve function, muscle contraction, and building and maintaining bone tissue Kerantinocytes - 95% of cells in the epidermis are keratinocytes. manufacture keratin (fibrous protein that makes a tissue tougher) linked by desmosomes arranged in layers, or strata, in the epidermis layers of the epidermis - stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale stratum basale - single layer of stem cells closest to the blood supply in the dermis. most metabolically active keratinocytes 3 100% Pass Guarantee Katelyn Whitman, All Rights stratum spinosum - thickest stratum of the epidermis also close to the blood supply, also metabolically active helps produce vitamin D Stratum granulosum - releases a lipid-based substance via exocytosis that coasts the cells, and create the hydrophobic propereties of the skin also isolates the cells from water and nutrients and kills them stratum corneum - several layers of dead, flattened keratinocytes Dendritic (Lanerhans) cells - phagocytes of t