Unit B Section B3 Introduction Interacting Systems of Cells
Completion requirements
Section 3: ο»ΏInteracting systems of cells are needed for healthy human functions.
Unit B: Section 3 β Introduction
Figure B.S.3.1 β The coccyx is also known as the tailbone.
Figure B.S.3.2 β Tiny vestigial organs cause bumps on your skin and tiny hairs to stand up.
Figure B.S.3.3 β Wisdom teeth are located at the back of an adult humanβs mouth.
The human body has a few organs that donβt seem to have a useful purpose. These body parts were once useful in human ancestor species, but are no longer necessary in the modern human body. These structures are called vestigial organs.
One example of a vestigial organ is the coccyx. The coccyx is the pointed bone at the end of the human spine. It is also known as the tailbone, because a tail was attached at this location in human ancestor species. The coccyx is not a necessary structure to the human body. It has been incorporated into the human body, as some muscles attach to this bone.
Another example of a vestigial structure is wisdom teeth. Wisdom teeth are located in the very back of an adult humanβs mouth. Wisdom teeth donβt emerge until a person is in their late teens or early twenties, and unfortunately, there is not always enough room in the jaw for them. Our human ancestors ate tough raw plants, and used the extra wisdom teeth to grind their food. Modern humans have smaller jaws with room for less teeth, which is a good fit for our modern diet requiring less grinding of very hard foods.
Today, vestigial wisdom teeth are a common health problem. Sometimes wisdom teeth come in sideways or stay below the gumline. Wisdom teeth often get infected by bacteria because they are difficult to keep clean. As a result, many people get their wisdom teeth pulled out.
Words to Think About:
Check out the word cloud below. It pictures the important words that you are going to learn in this section. Watch for these words, and combinations of these words, as you read. When you see them highlighted, you can click on them to learn more about
what the word means. You can also visit the course glossary and read definitions for all of these words.
Lessons in This Section
Lesson B9: Human Systems: Digestion
Key Question β How does the human body ingest and absorb nutrients?
Lesson B10: Human Systems: Respiration
Key Question β How do gases move in and out of the human body?
Lesson B11: Human Systems: CirculationKey Question β How do nutrients travel to all parts of the human body?
Lesson B12: Human Systems: Excretion
Key Question β How do wastes exit the human body?
Lesson B13: Human Systems: Regulation and Communication
Key Question β How does the human body react to stimuli?
Reading and Materials for This Section
Science in Action 8
Reading: Pages 126 β 153
Materials Lists for Unit:
Figure B.S.3.4 β The appendix is a small organ connected to the large intestine.
Figure B.S.3.5 β Surgeons remove the appendix if it becomes infected.
Figure B.S.3.6 β Appendicitis symptoms include nausea, fever and pain in the lower right abdomen.
The Appendix
The appendix is a small pouch that is attached to the large intestine. The appendix is located on the lower right side of the abdomen. For many years, most scientists thought that the appendix was a vestigial organ and that it served no purpose in the modern human body.
Recent research by scientists indicates that the appendix may have a useful purpose after all. Helpful digestive bacteria have been found in the appendix. Scientists think that if the body has a digestive problem, the good bacteria in the appendix can repopulate the large intestine and help it return to health.
The appendix can get infected by harmful bacteria, causing severe pain in the lower right abdomen. This condition is called appendicitis. A person with severe abdominal pain should immediately go to a hospital emergency room. If someone has appendicitis, their appendix needs to be surgically removed before it bursts open. If an appendix bursts, the infection can escape from the intestines and spread into the rest of the body, which can be life-threatening.
The appendix is a small pouch that is attached to the large intestine. The appendix is located on the lower right side of the abdomen. For many years, most scientists thought that the appendix was a vestigial organ and that it served no purpose in the modern human body.
Recent research by scientists indicates that the appendix may have a useful purpose after all. Helpful digestive bacteria have been found in the appendix. Scientists think that if the body has a digestive problem, the good bacteria in the appendix can repopulate the large intestine and help it return to health.
The appendix can get infected by harmful bacteria, causing severe pain in the lower right abdomen. This condition is called appendicitis. A person with severe abdominal pain should immediately go to a hospital emergency room. If someone has appendicitis, their appendix needs to be surgically removed before it bursts open. If an appendix bursts, the infection can escape from the intestines and spread into the rest of the body, which can be life-threatening.
Watch More
Your Appendix: Vestigial or Vital?
ο»ΏNew research shows that the appendix serves a useful purpose in humans. Watch these videos to find out more.
ο»ΏNew research shows that the appendix serves a useful purpose in humans. Watch these videos to find out more.