Latissimus Dorsi...part 4 (a Muscle In Flight!)
It would amaze you that such remarkable nature and surgical use of this muscle was first described nearly a century and half ago! Whao! The brilliance of surgeons!
I disagree though, with accepted notions of its origins and insertion. I should be more comfortable with a transposition of these notions...for in this muscle, its blood and nerve supply derives from its pedicle...near the upper humerus!
It should make more sense that a muscle...or indeed any organ...hitherto rudimentary in its embryological stage...would carry its neurovascular bundle along as it gains size. A notable example is the tests!
The blood vessels and nerves to a muscle should elongate to match up with the muscle as it grows!
So, the hilus or epicentre of its blood and nerve supply should provide an accurate indication of the origin of a skeletal muscle!
"In my rendition on the latissimus dorsi muscle, I have for sakes of clarity of illustration, drawn two allusions:
First, between this wonderful muscle and the local hand fan.
Secondly, between the muscle and (boneless immobile all-muscle subcutanous) wings"...so states an earlier part of this series....
Many surgical and anatomical authorities have described Latissimus dorsi as "a lady between two majors"...with regard to its point of insertion (on the lesser tubercule of the humerus) in between those of pectoralis major anteriorly, and teres major posteriorly.... Better to say the inter-tubercular sulcus...or ridge.
Considering the close semblance that the trapezii (singular: trapezius) bear to a kite when viewed together as they lie superficially to the Latissimi however, my observation leads me to describe both Latissimi dorsi as "wings beneath a kite"! For the trapezii "taken together" really look like a kite!
While this allusion is with regard to the origins and general splay or layout of this muscle in situ, the former allusion relates to the insertion of the muscle.
One, a lady...and the other, wings...
So much ado about this "lady with wings" then! ....
As "she flies her lovely kite while bearing the company of two gallant majors"!
I am so besotted by this muscle that it compels a poem from my pen:
A MUSCLE IN FLIGHT!
A fan though it seems
But rather a lady of valour!
Poised between gallant majors In numbers of two
She bears a kite in flight
Beneath wings so supple and strange!
Mere muscle bereft of props of bone
Or whorls of tendons!
This Latissimus dorsi
A muscle of sorts!
A kite and wings
Up in the air they soar!
Here and there it turns!
This joy to surgeons!
A cut, a tease
A twist and a patch!
A pad to the head
And a lift for the bust!
This latissimus dorsi
A muscle in flight!
Dr Tosin Akindele is a medical practitioner and public affairs analyst.
POST SCRIPT
While older anatomists like R.J. Last dwelt so much on origins and insertion of muscles, newer ones like Keith Moore would rather talk about "attachments". It is cumbersome enough to memorize an unending succession of portmarks and blotches on bone specimens, it is too unwieldy if such muscular markings are variated into "reds" and "blues"!
And it really serves little purpose. Doesn't it?