Unit 1.1 Homeostasis/A&P

• Form


  Reflects function
• The body is complex with a structural organization level hierarchy
• Although bodies have the same basic organization, there is anatomical variation
• There is physiological variation too, which is much more extensive and can be based on anatomical differences
• Interdependence


  Relationship between structure and function
• Homeostasis


  Maintenance of relatively stable internal conditions despite changing outer environment
• Homeostasis


  1. Stimulus

  2. Receptor

  3. Integration

  4. Effector

  5. Correction
• Negative feedback


  Counteracts stimulus
• Positive feedback


  Amplifies stimulus
• Positive feedback mechanisms


  • Childbirth
  • Blood clotting
• The nervous and endocrine systems play an important role in the integration and communication necessary for maintaining homeostasis
• Gradient


  High to low
• Energy flows down gradient
• Ions


  Charged particles with unequal numbers of protons and electrons
• Electrolytes


  Substances that conduct an electrical charge in solution
• Covalent bond


  Strong bond
• Ionic bond


  Weak bond
• Hydrogen bond


  Weak attraction
• Water


  Universal solvent
• Hydrophilic


  Substances that dissolve in water
• Hydrophobic


  Substances that do not dissolve in water
• Mixture


  Combination of substances
• Energy


  Capacity to do work
• Chemical reaction


  Formation or breaking of chemical bonds
• Metabolism


  All chemical reactions in the body
• Organic compounds in the body


  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
• Polymer


  Molecule made from monomers
• Carbohydrates


  Energy source
• Lipids


  Hydrophobic, variety of functions
• Proteins


  Amino acids folded into complex structures
• ATP


  Cell's energy
• DNA


  Instructions for protein synthesis
• RNA


  Carries out protein synthesis
• Cell


  Cell membrane, cytoplasm with organelles, nucleus
• There is diversity in cells, with different shapes, sizes, and functions
• Extracellular fluid


  Watery environment outside cell
• Plasma membrane


  Barrier that separates internal and external environments
• Functions of the plasma membrane


  • Mechanical barrier
  • Selective permeability
  • Electrochemical gradient
  • Communication
  • Cell signaling
• Diffusion


  Passive membrane transport down concentration gradient
• Osmosis


  Diffusion of water through a semipermeable membrane