Instructions

Part 1:

Suppose that vampires actually exist and that the condition is caused by a prion disease that eliminates the ability to manufacture red blood cells (RBC) by changing their body’s DNA throughout the bone marrow. They need to drink blood in order to replenish their RBC count. RBC are normally produced in the bone marrow and destroyed in the spleen once they have existed for about 4 months. Sketch a diagram of the two regulatory pathways, including feedback loops, described here (i.e. sketch one diagram for normal humans and sketch another for the modified vampire pathway): The number of red blood cells (RBC count) in the body is the variable being regulated. Over time, the number of RBC decreases due to the action of the spleen. However, if exposed to sunlight, which triggers activation of Vitamin D, which in vampires dramatically raises the Ca++ concentration in plasma, triggering apoptosis (cell death) of RBC so sunlight is a stimulus that will decrease RBC. The kidneys have nerve endings that detect blood O2 levels as a measure of RBC count and release the hormone erythropoietin (EPO) to stimulate release of RBC from the bone marrow. However, in vampires the bone marrow cannot make more cells. They have evolved a mechanism where the release of EPO triggers a diversion of blood flow away from the spleen to slow the rate of RBC destruction. Also, detection of low RBC count triggers the vampire brain to release the hormone vampyrine which causes the sensation of hunger. If the vampire feeds, levels of RBC go up since they are not digested but transported into the blood vessels. (6 points)

Part 2:
Read the paper “Prediabetes Phenotype Influences Improvements in Glucose Homeostasis with Resistance Training” by JD Eikenberg et. al (2016) from PLOS One posted as a .pdf file in the “Introduction to Physiology” Canvas folder (or found here https://doi.org/10.1371/journal.pone.0148009 ) (Links to an external site.)and answer the questions about it. There are 8 questions worth 1-3 points each.

Write your answers in complete sentences. I am expecting your answers to be from one to five sentences, depending on the question. (I am not looking for a lot of writing, just to see if you read and understood the paper and to see what your opinion is about some of the issues raised in it.) I will award points based on the correctness and completeness of answers, or if it is your opinion that it makes sense and that you explained your position clearly.