Introduction
Every living organism has certain essential needs, including energy production, constant water and
salt content, and reproduction. The way each organism meets these needs can vary. Complex organisms
like humans have developed a number of systems to ensure genetic diversity, maintain homeostasis,
digest food, and eliminate wastes, among other essential bodily functions. Without these systems,
humans would never have advanced past the stage of unicellular organisms.
Organ Systems
We are going to learn about eleven organ systems that
contribute to the survival of the living cells of the vertebrate body:
- Integumentary
- Muscular
- Skeletal
- Nervous
- Endocrine
- Circulatory
- Lymphatic
- Respiratory
- Urinary
- Reproductive
Each organ system contributes to the survival of all of
the living cells of the body by integrating its function(s) into the whole.
A tissue is a group of cells and intercellular substances that interact in one or more tasks. There
are four types:
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
An organ is a group of tissues organized to perform a task or tasks. For example, the heart is an
organ that pumps blood through the body. The heart consists of muscle tissue, nervous tissue,
connective tissue, and epithelial tissue.
Organ systems consist of organs that interact
physically, chemically, or both to perform a common task. The circulatory system, for example,
includes the heart, the arteries, and other vessels that transport blood through the body.
Organ systems maintain stable internal conditions. They acquire nutrients and raw materials, and
dispose of wastes. They protect the body against injury and attack, and allow reproduction and
nourishment of young.
This animation (Audio - Important) provides an introduction to
organ systems.
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