Body Organization

Science, Grade 6


Table Of Contents: Body Organization

1. Levels of Organization - Organ Systems
The human body is a collection of interacting organ systems. Some of those systems are the cardiovascular system, the digestive system and the nervous system. These organ systems work together to sustain life in the human body.
2. Levels of Organization - Organs.
Within organ systems, each organ has a different function or set of functions. For example, as food travels through the digestive system, the organs of the digestive tract break down the food into nutrients the body can use and waste products the body doesn’t need. The pancreas helps us process sugar by producing insulin while the liver processes fats and produces cholesterol, among other substances.
3. Levels of Organization - Tissues
Each organ is made up of tissues that support the organ function. There are four types of organ tissues: epithelium, connective, muscle and nerve tissue.
4. Levels of Organization - Cells
Tissues are collections of cells of different types that interact to support the function of the tissues, organs and overall organ system.
5. Homeostasis Principle
Our organ systems work constantly to keep every aspect of the system stable and functioning well. The organ systems are challenged by changes from inside and outside the body and must help the body adjust to those changes and keep the organs functioning effectively. This ongoing effort by the body to maintain a stable internal environment in the face of change is known as the principle of homeostasis.
6. Homeostasis Example - Temperature Regulation
Human body temperature is regulated very tightly to keep it to 98.6 degrees Fahrenheit by an internal thermostat found at the base of the brain. If your body gets too cold, you shiver to generate heat and regain your normal body temperature. If your body gets too warm, the blood vessels dilate and you also sweat to regain normal temperature. These methods of adjusting to body temperature help your body systems maintain homeostasis despite changing external conditions.