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Diffusion and the Molecules of Life. Levels of Hierarchy and Organization in Living Systems and Multi-cellular organisms. Molecules of Life. Anatomy and Physiology in the Hierarchy of Life. Molecules Cells Tissues Organs/Structures Organ Systems Organisms
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Diffusion and the Molecules of Life Levels of Hierarchy and Organization in Living Systems and Multi-cellular organisms
Anatomy and Physiology in the Hierarchy of Life Molecules Cells Tissues Organs/Structures Organ Systems Organisms Environment
Levels of Organization • Chemical Level (Organic Chemistry and Biochemistry • Cellular Level (Intro. Or Cell Biology): organelles, genes, mitosis, meiosis • Tissue Level (Histology): groups of cells with common function—classes of tissues, epithelia (covering), connective tissues (support, protection) • Organ Level (Anatomy): how tissues combine to form structures in body—lungs, bones, blood vessels, etc. • Organ System level (Physiology) How organs and structures work together to accomplish specific functions: e.g., circulatory system, nervous system, skeletal system, etc. • Organism: Entire body working together (Ecology or physiology in environment)
The importance of Diffusion • Diffusion versus Osmosis (diffusion across a membrane) • Diffusion fast and effective across microscopic distance • Virtually all living processes involve diffusion and/or osmosis • Cell membranes control diffusion and allow for life chemical reactions to take place • Diffusion lets tissues do job and permits organ systems to function • Examples: • Oxygen in circulatory system • Food in digestive system • Calcium in muscular function • Nerve impulses Cell membranes and Diffusion
Body Systems and Diffusion • Understand path through body of: • Food/Nutrients (glucose) • Oxygen • Carbon Dioxide • Nitrogen
Homeostasis “…the ability to maintain relatively constant internal conditions even though the outside world changes continuously…” • Within cells • Within body
Feedback Mechanisms • Negative Feedback Examples • home heating system • Glucose regulation in blood • Positive Feedback Examples • Fire-Starting • Blood clotting
Web Links • Cellular basis of physiology • Diffusion/Osmosis animation
Next Time: Overview of Body Systems