Diffusion and the Molecules of Life

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Diffusion and the Molecules of Life

• Levels of Hierarchy and Organization in Living
  Systems and Multi-cellular organisms

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Molecules of Life
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Anatomy and Physiology in the Hierarchy of Life

• Molecules
• Cells
• Tissues
• Organs/Structures
• Organ Systems
• Organisms
• Environment

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Levels of Organization within Human Body
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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 functionclasses of tissues, epithelia
  (covering), connective tissues (support,
  protection)
• Organ Level (Anatomy) how tissues combine to
  form structures in bodylungs, 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)

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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
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Body Systems and Diffusion

• Understand path through body of
• Food/Nutrients (glucose)
• Oxygen
• Carbon Dioxide
• Nitrogen

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Homeostasis
the ability to maintain relatively constant
internal conditions even though the outside world
changes continuously

• Within cells
• Within body

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Feedback Mechanisms

• Negative Feedback Examples
• home heating system
• Glucose regulation in blood
• Positive Feedback Examples
• Fire-Starting
• Blood clotting

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Web Links

• Cellular basis of physiology
• Diffusion/Osmosis animation

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Next Time

• Overview of Body Systems