Positive and Negative Feedback Mechanisms.
By the end of the tutorial , the student should be able to :
• Appreciate the different levels of organization in the human body.
• The different body systems of a human body.
• Appreciate extracellular fluid and the internal environment
• Define homeostasis and its example
• Understand the origin and removal mechanisms of the ECF
• The pivotal role of two body systems in the maintenance of homeostasis
• Homeostasis control systems
• Feedback loops types with examples
• Example when positive feedback loop causes death
Levels of Organization
• System Level
• Organismic Level
Cells as the living units of the body Cells as the living units of the body
• Basic living unit of the body is the cell
• Each organ is an aggregate of many different cells held together by intercellular
• Red blood cells, numbering 25 trillion in each human being, transport oxygen from
the lungs to the tissues
• The entire body contains about 100 trillion cells.
• Groups of organs that perform related functions and interact to accomplish a common activity essential to survival of the whole body
• Do not act in isolation from one another
• Human body has 11 systems