What's this?

What’s this? #3 Assume the cow is a sphere…

What was up with that beef ball? Was it those pesky physicists again, trying to validate their theoretical model?

It’s actually a globosus amorphous (not “amorphous blobosus”, as I used to so confidently tell people…) — where a fertilised egg doesn’t develop properly in the womb. Instead, it tends to form a ball of fat wrapped up in skin, and feeds parasitically on the umbilical cord of its twin (you might also know someone like this).

Umbilicus (I bet it would have been an outie bellybutton)

Umbilicus (I bet it would have been an outie bellybutton)

Also known as an ‘acardiac acephalic twin’ (acardiac = without heart, acephalic = without brain) or ‘acardiac amorphous twin’, these form as a result of abnormal development of one of a pair of twins (or septuplets!). They most commonly occur in cattle, but also occur in several other species such as goats, sheep and horses.

The normal twin is usually called the ‘pump twin’ because it provides the oxygenated blood to the abnormal twin which has no heart of its own.  Blood comes from the mother, via the placenta to the normal twin.  It then leaves the normal twin and, instead of going back to the mother, travels through the acardiac twin.  BUT the blood actually flows the wrong way around the acardiac twin as a result of this hijacked perfusion.  The blood flows to the intestinal arteries first, and because the blood has already flowed through the mother and normal twin first, it is super low in oxygen.  This is why, if anything develops at all, it is usually only the hind limbs and some organs — the parts that got any oxygen.

Our little guy only managed an eye socket and a piece of cartilage, which is why it was so shapeless and easily mistaken for a guinea pig or plush pathogen.

Sock it to me!

Sock it to me!

Piece of cartilage

Piece of cartilage

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3 thoughts on “What’s this? #3 Assume the cow is a sphere…

  1. Pingback: I’m sticking with you. | Veterinary Forensic Pathology

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