PNB 3255 Questions and Answers 2024

homeostasis - dynamic steady state; small fluctuations around the set point negative feedback - response returns regulated variable toward set point (response removes stimulus), closed loop used for homestasis positive feedback - response to the effector reinforces the stimulus; promotes useful change Properties of water - polar-covalent bond creates sticky molecules, solvent to ionize compounds (electrolytes), high specific heat, lubrication & cushioning dehydration synthesis - molecules are put together while losing a water molecule hydrolysis - breaks a bond in a molecule using water 4 types of tissues - epithelial, connective, muscle & nerve epithelial tissue function - covers exposed surfaces, lines internal passageways, forms glands, provide physical barrier, exchange, secretion, absorption epithelial tissue characteristics - cellularity (junctions) polarity (apical & basal surfaces) attachment (basal lamina/basement membrane), avascularity (no blood!) regenerative (quick reproduction) simple epithelial cells - one layer of cells, best diffusion stratified epithelial cells - several layers of cells & for protection 3 types of epithelial cells - squamous (flat) cubodial, columnar Connective Tissue categories - CT Proper, Cartilage, Bone (dentin, blood & mesenchyme) CT Proper - built from fibroblasts, contains fibrocytes Scurvy - lack of V-C leads to defective collagen synthesis Loose CT Proper - areolar, adipose, reticular