1. Chapter 1 Major Themes of Anatomy & Physiology
Structure and Function
Homeostasis

2. Anatomy - The Study of Form
Anatomy involves:
Simplest observation – examination of surface structures
Deeper understanding requires cadaver dissection (which is cutting & separation of tissues to study their relationships)
Comparative anatomy - the study of more than one species to analyze evolutionary trends – we obtain many insights into human anatomy by studying other species.
Physical examination
Palpation (feeling structures with the fingertips), auscultation (listening to natural sounds made by the body), percussion (tapping on the body and listening for echoes)
Gross anatomy - what is visible with naked eye
Histology - examination of cells with microscope

3. Physiology - The Study of Function
Study of bodily functions by use of methods of experimental science
Comparative physiology involves the study of different species
Basis for the development of new drugs and medical procedures

4. What is Life? Properties that distinguish from nonliving things:
organization & cellular composition
biochemical composition (DNA, proteins, etc)
metabolism is transformation of molecules into others
responsiveness is ability to sense & react to stimuli
homeostasis is to maintain stable internal environment
development is change over time (growth or differentiation)
reproduction is producing copies of themselves
What is death?
Clinical death is no brain waves for 24 hours

5. Structure - A Hierarchy of Complexity
Subatomic particles compose atoms
Atoms compose molecules
Molecules compose organelles
Organelles compose cells
Cells compose tissues
Tissues compose organs
Organs compose organ systems
Organ systems compose the organism

6. Homeostasis
Hippocrates noted that body normally returns to a state of equilibrium by itself
needs to detect the change & oppose it
Walter Cannon ( ) coined the term homeostasis indicating stable internal environment
Internal environment described as dynamic equilibrium
fluctuates within a range around a certain set point
Forrest Definition (1996):
A state of internal constancy
But how do we maintain homeostasis?....

7. Negative Feedback and Stability
Negative Feedback is the mechanism of Homeostasis
Negative Feedback’s keeps a variable close to its set point
Body senses a change & activates mechanisms to reverse it

8. Negative Feedback, Set Point
Room temperature does not stay at set point of 68 degrees -- it only averages 68 degrees

9. Human Thermoregulation
Temperature sensing nerve cells in base of brain control shivering, sweating & vasomotor activity
vasodilation & vasoconstriction
Evaporation of water & heat radiation occur

10. Structures Needed for Feedback Loop
Receptor = structure that senses change (sensor)
stretch receptors in heart & large blood vessels send information of an elevated BP to integrator
Integrator = control center (integration center)
cardiac center in brainstem that signals heart to slow
Effector = structures that carry out commands of the control center (Effector Organ)
heart slows and BP decreases

11. Positive Feedback Loops
Self-amplifying cycle in which a physiological change leads to an even greater change in the same direction
Normal way of producing changes during birth, blood clotting, protein digestion & generation of nerve signals

12. Fever If temperature rises above 108 degrees
metabolic rate increases causing body to produce heat faster still
Temperature increases & cycle repeats again
Fatal at 113 degrees

13. Review of Major Themes
Unifying principles behind all aspects of human anatomy and physiology
cell theory: all structure & function result from the activity of cells
homeostasis: maintaining stable conditions within the body
hierarchy of structure: levels of complexity
unity of form and function: physiology can not be separated from anatomy (Shape Dictates Function)