Unit 1: The organisation of the human body                    1   2   3   4   5

5. Organs and organ systems

An organ is a structure made of several associated tissues which carry out a determinate function.

Organs formed organ systems, which form all together the human body. The Anatomy is the science which studies the structure and morphology of organs and organ systems, and the Physiology studies their function.

a) Organ systems related to nutrition function:

Digestive system. It is formed by the digestive tube and digestive glands.

It process and transforms food to obtain nutrients which cells are able to assimilate.

Respiratory system. It is compounded by respiratory passages and lungs.

It obtains oxygen from air and expels carbon dioxide from the metabolic activity.

Circulatory system. It is formed by the heart and blood vessels. Its function is distribution of nutrients and oxygen through the body and to collect the waste substances and carbon dioxide from cells.

Excretory system. It is formed by kidneys and urinary passages and other organs like sweat glands. Its function is to expel the waste substances out of the body.

b) Organ systems related to interaction function:

Locomotor system. It is formed by:

- Muscle system. It is formed by skeletal muscles.

  Its function is the movement (locomotion, mimic and postural maintenance)

- Skeletal system. It is formed by bones.

  Its functions are locomotion (joint to muscle system) and protection

  of some organs.

Nervous system. Formed by encephalon, spinal cord and nerves.

It is responsible of nervous coordination.

Endocrine system. Its organs are endocrine glands which produce hormones.

c) Organ system related to reproduction function:

Reproductive system. It can be female and male reproductive system, but both have gonads (organs which produce gametes) and reproductive passages.

5.1. Is the skin an organ or a tissue? Why?

5.2. Indicate what system is responsible for:

a. Blood distribution.

b. Expelling carbon dioxide

c. Obtaining nutrients

d. Taking oxygen from the air

e. Reproduction

f.  Movement of body

5.3. Listen and indicate what organ system is described: