Mr. M, a 30-year old male, has been noticing some changes in his
body. Normally a lean, fit, six-foot individual with a medium bone
frame and fine features; he has noticed that his jaw is getting
thicker and his forehead and brow ridges are more pronounced. He
has had to have his wedding ring enlarged because his knuckles are
larger, and he has to buy wider shoes because his normal shoes feel
too tight. He let these symptoms slide until he realized that he
was developing bigger breasts, he was having intimacy problems
(because he was impotent), and he was getting severe headaches.
Following a visit to the doctor and numerous tests; (including
blood tests, MRI and CAT scans) he is given the news – he has a
brain tumor! The doctor explains that two types of cells in his
adenohypophysis are growing out of control. The increased pressure
caused by the expanding cell mass is producing his headaches and
the excessive hormones that these cells are secreting are producing
the changes in his appearance. (14 points) Given the changes in his
features, hands and feet: What condition is he suffering from? (1)
Which hormone would be responsible for this condition? (1) How is
the release of this hormone normally regulated? Describe the
signaling mechanism associated with this hormone’s release and
indicate what stimuli would increase or decrease its release.
(Hint: a well-labeled diagram can be used to answer this question)
(3) What signaling mechanism does the hormone use on its target
tissues (be specific)? (1) What overall effect does this hormone
have on its target tissues? Define all terms used.(2) How does this
hormone affect energy sources and metabolism? Describe all terms
used. (3) Given his other symptoms: What other hormone would be
affected by the tumor? Justify your answer by indicating how it
affects its target tissues. (2) If you were provided with a blood
sample that had high levels of this hormone but you were not given
any of the patient information, under what conditions would an
elevated level of this hormone be considered normal? Justify your
answer. (1)