Expert: Walter Hintz - 7/19/2006

Question
1.  Minerals are deposited: a) within bone marrow; b) within bone cells; c) between bone cells; d) all the above.

I am having a hard time trying to research this one.  I asked you this question a couple days back and you replied c) as your answer.  However, I think it could be all, well, I am wondering about a).  What is your reasoning for ruling out a) and b)?

2.  The close relationship between the endocrine and nervous systems is shwon in the: a) existence of numerous glands in the brain; b) short-lived impulses which trigger longer-lasting homonal affects; c) use of the term "neuroendocrine system"; d) all of the above.  

This one I emailed also and you replied b).  I asked you about the potential of it being c.  I found on the internet at a sight that states "The endocrine system and the nervous system are so closely associated that they are collectively called the neuroendocrine system."  Do you believe it could be all the above?  You said you ruled out c because endocrine secretions are stimulated by nerve impulses.  Both invovle homeostasis.  Nerve impulses bring about a fast response and hormones a longer response.  The terminology neuroendocrine system involves regulation by the pituitary gland.  You said you thought it could be an answer, but it does not necessarily imply a "close" relationship.  Do you think it could be all the above?  

3.  A nerve impulse may be described as: a) an electrical message; b) an electromagnetic message; c) a chemical message; d) a chemical change occurring in the brain.

Thanks for your help.  The first two are the ones that I am researching and digging into.  Appreciate your expertise.

~Teresa

Answer
Hi Teresa
1. I chose c for this reason: Deposits of minerals (mostly calcium) could not be made intercellular. Mineral buildup in a clee would disrupt the cell. Remember that bone is mostly non living material.  Living cells occur in the marrow which is part of the circulatory system and in the periostenum which is a layer on the bone surface.  The bone itself is fibrous protein and hydroxyapetite.

2. I would not chose all the above because of the term "numerous glands in the brain" whatever that means.  If the question refers to the pituitary the question is poorly worded as this gland is not really in the brain.  Perhaps I am splitting hairs.  Now as to c: I guess I am being picky but the use of a term does not really show anything. b tells us what is happening.  Do you get my point here?

3.This is another somewhat anbiguous question.  We can rule out (a) because the impulse is not an electron flow. (Can you imagine nerve impulses traveling at the speed of light)
On the other hand the impulse involves a depolarization of ions across a membrane taht involve EM forces so (b) is good.  Now we have a problem since the result of the impulse involves neurotransmitters (chemicals)  I think (b) is the best answer