The Incredible Human Body

Hello folks and welcome to the tour of a lifetime! We are going to be seeing many incredible sights today so buckle up and enjoy the ride. We begin our journey in the femoral artery of this extremely fit female subject, Miss Waters. (Be sure to thank her when the ride has come to an end.) Okay, here go. The femoral artery is very large in size and is located in the inner part of the thigh. A femoral artery can often be palpitated and used as a catheter access artery. It is an extremely amazing thing, the femoral artery. It is an access point for catheters that can travel all the way to the heart and brain! Next we travel through the common iliac and upwards into the abdominal aorta. As we continue to travel upwards we see our subject’s ovaries.

Ovaries are the female reproductive organ made up of two oval shaped glands that produce eggs and hormones. Next we see the bladder. The bladder is an elastic organ that stores urine before it is discharged from the body. As we continue on we come to the small and large intestines. Did you know that an average small intestine of an adult is 6-7 meters long? That is crazy! Now do you all see the bean shaped organs we are approaching? Those are called kidneys. Now you know where kidney beans get their name from. Traveling along we see the stomach, pancreas and liver, all very important organs. While the liver filters toxins in the body and aids in digestion, the pancreas works to provide our body with the insulin that manages the levels of sugars in the blood. Folks, we have just received an alert that a bacterium is starting to invade the left lower lobe of Miss Waters right lung. We must hurry along our journey.

10 minutes later…. Now that we have reached the inferior vena cava we will continue on to the superior vena cava. Whoa! Hold on people, the blood is pushing us quickly and into the right ventricle. The right ventricle has one more opening in the pulmonary valve. In order to push blood into the pulmonary trunk to reach the lungs, the right ventricle must contract. There is a semilunar valve that opens at the pulmonary trunk during ventricular systole. The pulmonary trunk is divided into two different arteries, left and right. The right pulmonary artery then divides into many branches per lobe of the lung. As we travel down the branches we finally arrive at the right lower lobe. Hold on folks, it’s about to get real crazy in here.

The pulmonary artery we have traveled through has now split off into many branches that have formed a capillary bed on the alveoli. Alveoli have always made me think of raviolis. Darn, now I’m hungry. Why don’t we stop for Chinese after our trip? Okay so where was I? Oh yes, these capillaries join together to form the pulmonary artery. Now let’s take a trip to the alveolus. Exchanges of gas at the alveoli as well as oxygen, is then carried into the pulmonary vein. In case you were wondering, the alveoli are a balloon like structures at the airways. They are covered by a thin membrane formed by pulmonary epithelium, capillary epithelium and fused basement membranes. The inside of the alveolus is covered in a film of surfactant. All of these structures exchange gases across the alveolus. Because the lungs tissues are often exposed to pathogens by way of blood or respiratory, it has special defense mechanism to fight off the bacterium. If you look up, you can them swooping in and come to the rescue! Go get them boys! These amazing little super heroes can be either specific or non-specific.

“The body’s defense mechanisms protect us from disease causing microorganisms that invade our bodies, from foreign tissue cells that may have been transplanted into our own bodies, and from our own cells when they have turned malignant or cancerous.” (HS130 e-textbook, Thib, Chapter 13.) The body’s frontline army is called the immune system. Pretty much it is exactly how it sounds; the immune system makes our body immune to diseases. Or it tries the best it can anyway. The immune system defends against invaders both inside and outside of the body. Specific immunity is our body’s reaction to a specific threat. Non Specific immunity is our body’s reaction to anything that it does not recognize as a normal body substance. Inside us are special cells and substances to produce immunity. Some of these include; Antibodies: normal body substances that recognize abnormal or unwanted substances. Antigens: abnormal or unwanted substances.

Phagocytes: is a type of white blood cell that digests and destroys unwanted substances. Lymphocytes: type of white blood cell that produces anti-bodies. B lymphocytes: type of cell that causes production of anti-bodies that circulate in plasma. T lymphocytes: type of cell that destroys invading cells.

All of these guys join together and create an army of immunity inside our bodies. As you can see, the battle is almost over and the good guys have once again prevailed! Now that we have seen the battle of the lungs, we must continue on our journey. Besides, I am really hungry. Now we are entering the right bronchus. Continuing north we come to the trachea also known as the windpipe. Now we have come to the larynx. In order to continue on, we must wait until the epiglottis opens up and lets us through. The epiglottis is a piece of cartilage that acts like a lid over the larynx. It prevents food from entering the airway during swallowing. During inhalation, the epiglottis lifts up to let the air pass over the larynx. On three we are going to make a run for it. One, two, three, go! Whew that was awesome. Now we are in the pharynx of Miss Waters. Our journey has almost come to an end. I think we should tickle her pharynx and go out in style, what do you think? If we do, she will sneeze and out we will fly! Okay let’s go! (Miss Waters sneezes,) “AHHHCHOOO!” What an amazing ride, I hope you learned something new and had a great time. Now let’s go eat!