Question_ Proximal vs Distal

[Hina Budhwani]

Hi Elizabeth,

 

When I attended your review on autonomics for head/neck, I thought I got it. But after doing the clicker session in class yesterday, I feel shaky. I feel that I got the nerves pathway and what each nerve carries well, but still having difficulty with understanding proximal/distal. Here is an example from yesterday..

 

Person receives a blow to head on his right orbit. Amongst other complains was dryness over the corneal surface and anesthesia over lateral side of his right upper lid. Which nerve is injured?

a- lesser petrosal

b-greater petrosal

c- proximal portion of lacrimal

d- distal portion of lacrimal

e-zygomatic branch of maxillary

 

Ok, so I understand that since we are talking about sensation here along with the dryness, it has to involve the lacrimal nerve after the joining of communicating branch. However, I am having difficulty understanding proximal/distal to what? to lacrimal gland or joining of communicating branch? The answer is d, but I dont understand it. Could you please explain?

 

My understanding is that proximal to something is prior to joining of nerves and distal is after joining.. is this right? Id appreciate your help.

 

Thanks

Hina

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[Elizabeth Hogan]

You are correct with your thinking. With the way the answers are worded the point of reference was where the lacrimal nerve branches from V1. Therefore, the proximal portion of the nerve is referring to the portion close to its branching point and distal is referring to the nerve close to where it innervates the eye.  It is a little tricky but if they just give you the nerve name and then speak about proximal and distal they are using its branching point as the reference point.

Elizabeth

Sent from my iPad

[Hina Budhwani]

Thanks a lot, Elizabeth! This makes sense.

-----askan...@googlegroups.com wrote: -----

To: "askan...@googlegroups.com" <askan...@googlegroups.com>
From: Elizabeth Hogan <13ru...@gmail.com>
Sent by: askan...@googlegroups.com
Date: 12/01/2011 01:46PM
Subject: Re: [Anatomy DES] Question_ Proximal vs Distal