Digestive System Image: Don Bliss/National Cancer Institute

The human body is made up of several organ systems that work together as one unit. Some of these systems include the:

• circulatory system
  
• digestive system
  
• nervous system
  
• reproductive system

It is important to keep in mind that these systems don't just exist as individual units. The final product of these cooperating systems is one unit called the body. To learn about ten major organ systems of the body, see Organ Systems.

More Body Systems:

Organ Systems Quiz
Do you know which organ system contains the largest organ in the body? Test your knowledge of human organ systems.

Nervous System
This system is responsible for sending, receiving, and interpreting information from all parts of the body.

Limbic System
Limbic system structures are involved in many of our emotions and motivations, particularly those that are related to survival.

Snow leopard Credit: U.S. Fish and Wildlife Service

Monash University researchers have discovered a way to help the endangered snow leopard by producing induced pluripotent stem (iPS) cells from ear tissue cells of adult snow leopards. Induced pluripotent stem cells are genetically altered adult stem cells that can develop into a variety of different types of cells. The researchers hope to be able to coax the iPS cells into forming gametes for the future reproduction of these animals through cloning or other methods.

According to study researcher Rajneesh Verma, "By generating these stem cells, we've taken the first step in creating reproductive cells from adult tissues of an endangered animal. In the future, we aim to harness the potential of the iPS cells and create off-spring. This would help save species from extinction." This study marks the first time iPS cells have been generated from a member of the feline family. If the researchers are successful in creating reproductive cells, the cells could be used to conserve snow leopard tissue through cryopreservation.

Learn more about this study:

• Saving the Snow Leopard With Stem Cells Science Daily

Learn more about stem cells and cloning:

• Stem Cells
  
• All About Cloning
  
• Cloning Clinic
  

Image: Graur Razvan Ionut FreeDigitalPhotos.net

Can lack of sleep cause you to gain weight? Research from Uppsala University indicates that those who don't get about eight hours of sleep a night have higher activation levels in the area of the brain that controls appetite. Through the use of magnetic imaging, researchers were able to view brain images of study participants as they viewed images of food. Those participants who suffered from a lack of sleep experienced increased levels of hunger and brain activity.

According to researcher Christian Benedict, "After a night of total sleep loss, these males showed a high level of activation in an area of the brain that is involved in a desire to eat. Bearing in mind that insufficient sleep is a growing problem in modern society, our results may explain why poor sleep habits can affect people's risk to gain weight in the long run." This study indicates that lack of sleep can alter our perception of food and play a role in long term weight gain.

Learn more about this study:

• Lack of Sleep Makes Your Brain Hungry (Science Daily)

Brain Cell: Oligodendrocyte Credit: Jurjen Broeke / Public Domain Image

Researchers have had a breakthrough in umbilical cord stem cell studies. Different cell types have been created for the first time from umbilical cord stem cells. In the study, umbilical cord stem cells were induced into developing into cells called oligodendrocytes. These cells are a type of glial cell which help to insulate nerve cells in the central nervous system. This discovery may help in the development of new treatments for spinal cord injuries and diseases of the nervous system.

According to lead researcher James Hickman, "This is the first time this has been done with non-embryonic stem cells. We're very excited about where this could lead because it overcomes many of the obstacles present with embryonic stem cells." A major advantage to using umbilical cord stem cells is that unlike embryonic stem cells, they have not been shown to induce immune reactions. Also, umbilical cord stem cell use does not pose ethical issues related to the source of the cells as does embryonic stem cell use.

Learn more about this study:

• A First: Brain Support Cells from Umbilical Cord Stem Cells Science Daily