Human Biology Ch.1.1 The human body is complex

How is the human body like a city?
-The skeletal system, like the framework of a building, provides support.
-The digestive system works with the respiratory system to provide energy and materials.

The five levels of organization in our body are:
Cells, tissues, organs, organ systems, and the organism. The individual cell captures and releases energy, uses materials, and grows.

* The cells are specialized for complex organisms.
Specialized cells perform specific jobs.
Cells must be organized in a tissue and human body contains several types of tissues.

Four main groups of tissues are classified into their function: Epithelial tissue, nerve tissue, muscle tissue, and connective tissue.

•Epithelial tissue: Covers all of the inner and outer surfaces of body.
•Nerve tissue: Carry electrical impulses between brain and the various parts of body in response to changing conditions. (messaging system)
•Muscle tissue: functions in movement. (muscle cells contract, or shorten, and then relax)
•Connective tissue: functions to hold parts of the body together. Provides support, protection, strength, padding, and insulation. (ex. Tendons & ligaments hold bones and muscles together.)

A structure that is made up of two or more types of tissue that work together to carry out a function in the body. Organ system is a group of organs that together perform a function that helps the body meet its needs for energy and materials.

The body’s systems interact with one another. The body’s many levels of organization, from cells to organ systems, work constantly to maintain the balance needed for the survival of the organism. The ability of your body to maintain internal conditions is called homeostasis.