1 + 2 = 7, Or, Don't Get Sick in Colorado
This email made my day:
Thanks for your email. It made my day. What an interesting question!
In all my years of teaching Histology, never have I been asked that
particular question...people often seem more concerned with
memorizing than wondering!
You are THINKING!!
There are several benefits of branching in cardiac muscle cells.
First, as you've pointed out, by having each cardiac muscle cell
(fiber) send out branches, it increases the capacity of each fiber to
pass electrical stimulatory currents to other fibers. In addition to
the nerves and Purkinje fibers, electrical communication via
intercalated disks is a key part of the remarkable system of
conductivity that spreads contraction through the heart.
Another benefit of branching is this: By having an "irregular" shape,
the complex squeezing action of the heart muscle is facilitated. As
you know, the heart squeezes like a fist to act as a pump, and the
squeezing motion is precise and repetitive. Skeletal muscle fibers
usually move in one plane, and can accomplish what they need to by
being unbranched and exerting their force in one direction.
I hope that helps.
Good luck with your studies!
All the best,
David T. Moran, Ph.D.
PO Box 1142
Niwot, CO 80544 USA
It took the sting out of getting laughed at by one of our fine higher-education institutes, which refused to even send me free information on their nursing program.
We had a substitute teacher yesterday because our regular instructor, a nurse, had to cover a 'critical shortage of nurses' at her hospital.
I wonder how that happens?