Comparative Anatomy (Bones of the thoracic limb)

[@morenamorena2813]

This is so helpful thank you!

[@pinoyvetanatomist3742]

Thank you

[@shielajoytorres5033]

Doc, is there any difference between the distal phalanx of the forelimb and the hind limb in the horse? Is the navicular bone only present in the forelimb? Thanks po for answering. 😁

[@pinoyvetanatomist3742]

there is no much difference between the bones of the distal phalanx of the forelimb and hindlimb. there could be in size but they are anatomically the same. the navicular bone is present in both thoracic and pelvic limbs. Thanks.

[@shielajoytorres5033]

@@pinoyvetanatomist3742 thank you so much po for answering, doc.

[@patriciamingmiranda270]

Kindly explain where and what is the first metacarpal bone of equine? It is said that it is absent, then why is there a second, third, fourth and fifth metacarpal? I can't find the right answer for me.

[@pinoyvetanatomist3742]

in the original pattern of vertebrate digits, there are 5 digits. but during embyonic development, only the 3rd metacarpal bone develops in horses. this is called the cannon bone. the 2nd and 4th are vestigial and attached to 3rd as splint bones. the 1st and 5th are missing as they are programmed not to develop. this has something to do in their evolution.

[@patriciamingmiranda270]

@@pinoyvetanatomist3742 is there a case where 5 metacarpal bones are present? Assuming that all 5 digits are able to develop during the embryonic development.

[@patriciamingmiranda270]

Would this mean that it is safe to assume that nomology holds up across species?

[@pinoyvetanatomist3742]

@@patriciamingmiranda270 I am not familiar with nomology so I cannot give u an answer about that

[@patriciamingmiranda270]

@@pinoyvetanatomist3742 Thank you for the great explanation and discussion with you. God bless.