The human body is a fascinating biological machine. Within the human body are a series of organ systems. Each of these systems is vital to the proper functioning of a person. Many of these organ systems are dependent on each other - what effects one system can easily effect others. This article will take a look at some of the major organ systems in the human body. Of course, there is no way for this to be a comprehensive analysis - a detailed study of human anatomy and physiology takes years of work.
The Cardiovascular System
The human heart holds a special place in the psyche of mankind. It is one of the few organs that we can feel working. The cardiovascular system is responsible for pumping vitally needed blood (and the oxygen and nutrients contained therein) around the body. Connected to the heart is a complex web of arteries and veins. Together, the heart and these blood vessels make up the cardiovascular system.
The Respiratory System
The respiratory system is made up of the lungs and air passages that allow air to travel from your mouth to those lungs. The respiratory system has a close symbiosis with the cardiovascular system. Blood is pumped by the heart to the lungs, where oxygen from the air you breathe is transfered to the blood. If both of these systems are not working properly, you won't get the oxygen you need to your other organs.
The Gastrointestinal System
The GI system is a highly complex set of organs stretching from your mouth to your anus. In fact, organs of the GI system take up a good portion of your internal structure. Food taken in travels from your mouth, through the esophagus, to the stomach, to the small intestine, then to the large intestine, with the waste finally being expelled out your rear. On it's journey through your GI tract, the food is processed in about a million different ways - with the nutrients and water being extracted in literally dozens of different chemical reactions.
In addition to the above listed organs, the liver and pancreas both play a role in the GI system (although they also are involved in other organ systems as well)
The Integumentary System
This is a fancy name for the skin. It also includes hair and nails. Skin is the largest organ in the body, and it is quite active. Skin helps control your temperature, expels waste, and protects you from both microscopic bacteria and viruses as well as bigger things. Skin also contains the structures which are involved in touch, vibratory sensation, and the sensation of heat and cold. You couldn't live long without a functioning integumentary system.
The Musculoskeletal System
The musculoskeletal system comprises your bones and muscles. Bones provide structure and support, while muscles allow you to move. Not much more to say about this, most people are pretty familiar with bones and muscles.
These are the organs which allow people to reproduce. In men you have the penis and testicles, while in women you have the vagina, cervix, uterus, and ovaries. Again, these are organs most people are pretty familiar with, so there's little need to go in to detail on these.
The Nervous System
The nervous system is made of the brain and the nerves send signals from the brain around the body. The nervous system is sometimes divided in to the central nervous system, which is the brain and spinal chord, and the peripheral nervous system, which are the nerves outside the brain and spinal chord. Problems with any part of the nervous system can cause a variety of disorders.
The Endocrine System
The last human organ system I'll mention here is the endocrine system. This is the organ system which is responsible for making a very wide range of chemicals, all of which are important for the proper functioning of the human body. The endocrine system takes signals from the brain and also involves the adrenal glands and thyroid.
So there you have it, a very brief overview of some of the major organ systems of the human body. You'll note that some organs are not mentioned here (special senses like the eyes, for example). A complete review of every organ system in humans would start to become rather long and dull very quickly.