Section 1-1 Health and Homeostasis

1
Section 1-1 Health and Homeostasis

• Homeostasis is a state of relative constancy.
• Homeostasis comes from two Greek words, homeo,
  which means the same, and stasis, which means
  standing.
• Homeostatic mechanisms exist at all levels of
  biological organization, from cells to organisms
  to ecosystems.
• These homeostatic mechanisms are vital to
  survival and reproduction.

2
Section 1-1

• Human health depends on maintaining healthy
  physical, psychological, and social environments.
  
• The health of the environment and the health of
  organisms, including human beings, are
  interdependent.
• adverse changes in the environment can affect on
  human health.
• The health of organisms also requires social and
  psychological conditions conducive to mental
  health.

3
Section 1-1

• Health is dependent on properly functioning
  homeostatic mechanisms.
• When these mechanisms break down, illnesses often
  result.
• Stress results in disease by disrupting
  homeostatic mechanisms.
• not all diseases result from homeostatic
  imbalance
• Genetics
• Viruses
• Bacteria

4
Section 1-2 Evolution and the Characteristics of
Life

• All life-forms alive today exist because of
  evolution.
• The process of evolution results in improvements
  in existing species.
• It may also lead to the formation of new species.
• Evolution is responsible for the great diversity
  of life-forms.

5
Section 1-4 Critical Thinking

• Critical thinking rules allow us to carefully
  analyze problems, issues, and information for
  errors of reasoning.
• Careful analysis helps us distinguish knowledge
  from beliefs or judgments.

6
Seven Rules for Critical Thinking
Section 1-4

• 1. Gather complete information
• 2. Understand and define all terms
• 3. Question the methods by which data and
  information were derived
• 4. Question the conclusions
• 5. Uncover assumptions and biases
• 6. Question the source of the information
• 7. Understand your own biases and values

7
Figure1-8
Section 1-3

• The scientific method generally starts with
  observations that lead to hypotheses and
  experiments to test them.
• Hypothesis a tentative explanation of the
  phenomenon
• Experiment a procedure designed to test some
  idea