Day 10 Observations
Date: Thu, 25 Apr 1996 09:37:02 -0500
Subject: Commentary on Day 10 chick MRI
John T. has annotated four frames for the daily news. Here are some comments.
Day 10 chick - MRI
The chick is moving even more today than yesterday. Although we can see some structures in the egg clearly (such as the yolk, shell membrane and albumen), the amniotic sac is generally "stirred up" by the chick's motion. Frame 57 is an extreme example.
Furthermore, if we take repeated images at the same place in the egg, we see different parts of the chick as time passes (use patience and "reacquire" many times). Frames 29 and 65 illustrate this point.
One interesting frame is #22, at the bottom of the yolk (top view) showing some of the blood vessels that bring nutrients to the chick. There are many blood vessels in the egg, connecting the chick to the yolk and to the membranes along the inside of the shell which are used to breathe (remember, the shell is porous). These blood vessels appear bright if they pass through the slice (Frame 65, the aorta, and another vessel at the bottom edge of the air sac at G5), and darker if they lie entirely within the slice (Frame 22).
C.D.Gregory: April 25, 1996