[Learning Objectives Assessed: 3a, 3c, 3e, 4a, 4b, 4c, 4d, 4e, 4f, 5e, 6a, 6c, 6f, 7b]
Fantastic Voyage is a science fiction movie in which a group of scientists in a submarine are miniaturized and injected into a patient s bloodstream. Their mission is to travel to the patient s brain and remove a blood clot that has caused the patient to become comatose.
During their journey to the brain, the shrunken scientists encounter many of the structures discussed in this lesson and have some dangerous encounters with them. They have to move quickly to avoid being attacked by the patient’s immune system, which recognizes them as foreign objects.
For this discussion forum, imagine yourself as one of these scientists and respond to the following questions from the viewpoint of traveling through a patient’s bloodstream in a miniaturized submarine.
What type of blood cell would pose the greatest threat? Support your choice. Imagine that your miniaturized submarine is attacked by a defensive blood cell. Write a short description about the specific type of blood cell (include its appearance) and the attack.
Besides the defensive blood cells, what other threats would you face from the patient’s immune system? Describe a few structures that would attempt to destroy you and the way they would attempt to do this.
All posts must be two paragraphs or more (a paragraph is described as containing at least three sentences). Read other students posts and respond to at least one other student.
Use any personal experience, if appropriate, to help support your post. If differences of opinion occur, discuss the issues and provide examples to support your opinions.
Orignal post – $6
Replies – 2 x $2 = $4.00
Expert Solution Preview
Introduction:
As a medical professor responsible for creating assignments and evaluating the performance of aspiring medical students, it is important to design thought-provoking assignments that assess their knowledge and application of medical concepts. The following are my answers to the content discussed in the assignment.
1. What type of blood cell would pose the greatest threat? Support your choice. Imagine that your miniaturized submarine is attacked by a defensive blood cell. Write a short description about the specific type of blood cell (include its appearance) and the attack.
The white blood cell called a neutrophil would pose the greatest threat to the miniaturized submarine. Neutrophils are highly mobile, aggressively attack foreign substances that enter the bloodstream, and are present in larger numbers than any other type of white blood cell. They detect invading microorganisms, bacteria, and fungi through rapid chemotaxis and phagocytosis processes. Once they detect these substances, they move towards them by releasing a network of substances called extracellular traps to immobilize the pathogen, degrade it and rupture the cell membrane.
If a miniaturized submarine would be attacked by a neutrophil, the first observable characteristic would be its shape. Neutrophils are spherical or polymorphic in shape and are about twice the size of red blood cells. As they arrive to attack the submarine, they release all their stored granules – neutrophil elastase, myeloperoxidase, and reactive oxygen species – to kill the invading body. Neutrophil elastase causes tissue damage, while myeloperoxidase catalyzes the oxidation of substrates leading to the production of reactive oxygen species. The reactive oxygen species overwhelm the oxidative defenses of the invading body and ultimately result in its destruction.
2. Besides the defensive blood cells, what other threats would you face from the patient’s immune system? Describe a few structures that would attempt to destroy you and the way they would attempt to do this.
Apart from the attacking defensive blood cells, a miniaturized submarine would face additional threats from the immune system. Some of these threats can be attributed to the complement system, antibodies, and cytokines. The complement system is made up of approximately 30 proteins that work together in a cascade to form effector molecules that help in the removal of invading pathogens. The antibodies serve as a tool to identify invading bodies as foreign, and cytokines are chemical messengers that regulate the immune response.
The structures that would attempt to destroy the miniaturized submarine are macrophages, natural killer cells, and cytotoxic T cells. Macrophages are phagocytic cells that engulf and digest invaders, while natural killer cells eliminate foreign substances in the bloodstream by binding to an invading body and releasing cytotoxic substances like perforin and granzymes. Cytotoxic T cells identify antigen-presenting cells that have introduced foreign particles and kill them through their cytotoxic action. They also secrete cytokines that amplify the immune response and recruit macrophages and neutrophils, which in turn, attack the submarine.
