Human Body Systems An Introduction

Remember, the human body is organized in several levels, from the simplest to the most complex. . . Cells – the basic unit of life Tissues – clusters of similar cells performing a similar function. Contains all one type of cell Organs – made of tissues that perform one specific function. Contains different types of cells Organ Systems – groups of organs that perform a specific purpose in the human body ***The purpose of the 11 organ systems is for the human body to maintain homeostasis.

Digestive System Purpose: to break down food particles into smaller micromolecules that can be absorbed into the bloodstream and used by the cells of the body.

Excretory System Purpose: to rid the body of wastes, including excess water and salts

Respiratory System Purpose: to provide the body with a fresh supply of oxygen for cellular respiration and remove the waste product carbon dioxide

Circulatory System Purpose: to deliver oxygen, food, and other molecules to the various cells. Removes waste products, like CO2, from cells. Circulates materials around the body

Nervous System Purpose: to coordinate the body’s response to changes in its internal and external environment

Sensory Nerves allow us to feel; hot, cold, pressure, pain Sensory Nerves allow us to feel; hot, cold, pressure, pain. Motor Nerves allow us to move muscles

Endocrine System Purpose: to control growth, development, metabolism and reproduction through the production and secretion of hormones

Skeletal System Purpose: to provide structure and support to the human body Bones are where new blood cells are made (in the bone marrow)

Muscular System Purpose: works with the skeletal and nervous system to produce movement, also helps to circulate blood through the human body

Immune (& Lymphatic) System Purpose: to destroy and remove infectious diseases ( bacteria and viruses) from the human body

Integumentary System  Purpose: to act as a barrier to protect the body from the outside world. It also keeps the body from dehydrating, protects against disease and helps regulate body temperature. The main organs of this system consists of the skin, hair, nails & glands

Reproductive System The Reproductive System: Allows organisms to reproduce and pass their characteristics on to offspring