Physiology 1, Fall 2008, LPC

Chapter 1- Introduction

Physiology = study of the living function of living objects. 

Levels of Organization – atoms -> molecules -> cells -> tissues -> organs -> organ systems -> organisms -> population of one species -> ecosystem of different species -> biosphere

10 physiological organ systems – immune, integumentary, musculoskeletal, respiratory, digestive, urinary, reproductive, circulatory, nervous, endocrine

All organ systems interrelated

Key Concepts or Themes in Physiology

1. Homeostasis – keeps body within tolerable limits

Body influenced from exterior and interior.
Tight range of conditions in intracellular & extracellular fluids.
Body uses energy

Control Systems – nervous & endocrine systems
Input signal -> controller -> output signal

2. Biological  energy use

Source = food + O2
Metabolism -> ATP + building blocks -> energy and/or synthesis

3. Structure/function relationships

Compartmentation of the body and of cells
Mechanical properties of cells, tissues, and organs
Molecular interactions

4. Communication

Chemical or electrical signals, ie, endocrine or nervous systems.
DNA communicates heredity and structure of organisms and its proteins

Mass flow – movement of substances with and between compartments of the body – gradient or active transport

Scientific Experiments
1. Hypothesis – a testable idea. Investigator observes an event, makes a logical guess, then tests the hypothesis by designing and doing an experiment.

2. Experiment

Independent variable
Dependent variable
Control           

Collect data
Interpret data

Replication
Sample size

3. Experiments on humans

Variability in population
Psychological effects – use placebos, blind study
Ethical consideration. Do no harm.

4. Types of human studies

Longitudinal studies – long period of time
Prospective study – forward looking
Cross-sectional study – variety of subjects to identify group with condition
Retrospective studies – use existing data
Meta-analysis – surveys literature

Scientific Literature

Books
Journals – scientific articles, peer reviewed, sometimes review articles
www  Examples -  www.scholar.google.com, www.ncbi.nlm.gov/PubMed, www.accessexcellence.org
Citations – see formats in text
Plagiarism