3. How the Body is Organized 1. Cellular Level - Individual cells are the basic building blocks of life 2. Tissue level - Tissue is formed when groups of cells act together 3. Organ Level - An organ is a system of tissues working together 4. System Level - Many organs acting together form a system, such as the DIGESTIVE SYSTEM
13. Swallowing and the Epiglottis Air enters via pharynx The epiglottis is a flap of tissue that has a very important job It covers the trachea when swallowing to prevent food to lungs It covers the esophagus when we breath, so air goes to lungs
20. Small Intestine in Cross Section SA is increased by fingerlike projections called VILLI These do the actual absorbing of fats, proteins and carbohydrates
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