Physiology Intro

• Physiology


  The study of the normal functioning of a living organism and its component parts, including all its chemical and physical processes
• Physiology


  Closely related to anatomy
• Cell


  The smallest unit of structure capable of carrying out all life processes
• Levels of organization in the human body

  • Atoms
  • Molecules
  • Cells
  • Tissues
  • Organs
  • Organ systems
  • Organisms
• Function


  Explains the "why"
• Mechanism


  Describes the "how"
• Red blood cell example of function versus mechanism

  • Function - "Because cells need oxygen and red blood cells bring it to them"
  • Mechanism - "Oxygen binds to hemoglobin molecules contained in the red blood cells"
• Structure and function are closely related
• Molecular interactions often depend on the structure of molecules
• A molecule's function depends on its structure and shape
• Compartmentation


  Allows a cell, tissue, or organ to specialize and isolate functions
• Living organisms need energy for growth, reproduction, movement, etc.
• Cell-to-cell communication


  Local and long-distance communication between and among cells controls many body functions
• Information flow


  Coordinates body function, e.g. the transfer of information stored in DNA used to build proteins
• Homeostasis


  The ability of the body to maintain a relatively constant internal condition, a characteristic of all living organisms
• Pathophysiology


  The study of failure to compensate and maintain homeostasis
• Homeostasis is not the same as equilibrium
• An external or internal change can result in a loss of homeostasis
• Dynamic steady state


  The continuous monitoring and response to maintain homeostasis
• The composition of the extracellular fluid (ECF) and the intracellular fluid (ICF) is relatively stable (steady state), but the materials are constantly moving between them (dynamic)
• Parts of experimental design

  • Hypotheses
  • Independent and dependent variables
  • Experimental control
  • Data collection and replication
• The Scientific Method


  1. Make an observation

  2. Form a question

  3. Propose a hypothesis

  4. Make a prediction

  5. Conduct the experiment

  6. Gather data/results

  7. Accept or reject hypothesis
• Crossover study


  Each individual acts as a subject and a control
• Other study designs


  • Blind studies
  • Double-blind studies
  • Double-blind crossover studies
• Placebo effect


  When a control subject experiences alleviation of symptoms
• Nocebo effect


  When a control receiving a placebo experiences side effects of the experimental treatment
• Line graph


  • The x-axis frequently represents time
  • The points represent averaged observations
  • The points may be connected by lines
  • The slope of the line between two points shows the rate at which the variable changed
• Scatter plot


  • Each point represents one member of a test population
  • The individual points of a scatter plot are never connected by lines
  • A best fit line may be estimated to show a trend in the data
  • The line may be calculated by a mathematical equation
• Histogram


  • Quantifies the distribution of one variable over a range of values
• Bar graph


  • Each bar shows a distinct variable
  • The bars are lined up side by side along one axis so that they can be easily compared with one another
  • Scientific bar graphs traditionally have the bars running vertically
• Standard features of a graph

  • Units and labels on the axes
  • A key
  • A figure legend
• Graphs are used to organize and present data in a clear way
• Circulatory System


  • Includes Heart, blood vessels, blood
  • Representative Functions: Transport of materials between all cells of the body
• Digestive System


  • Includes Stomach, intestine, liver, pancreas
  • Representative Functions: Conversion of food into particles that can be transported into the body; elimination of some wastes
• Endocrine System


  • Includes Thyroid gland, adrenal gland
  • Representative Functions: Coordination of body function through synthesis and release of regulatory molecules
• Immune System


  • Includes Thymus, spleen, lymph nodes
  • Representative Functions: Defense against foreign invaders
• Integumentary System


  • Includes Skin
  • Representative Functions: Protection from external environment
• Musculoskeletal System


  • Includes Skeletal muscles, bone
  • Representative Functions: Support and movement
• Nervous System


  • Includes Brain, spinal cord
  • Representative Functions: Coordination of body function through electrical signals and release of regulatory molecules
• Reproductive System


  • Includes Ovaries and uterus, testes
  • Representative Functions: Perpetuation of the species