Chullin 121: What is Alal? What is Marteka?

We know that bones, tendons, horns and hooves can supplement the meat of an animal so that it will become the required size to become ritually defiled with tum'at ochlin, food ritual defilement.  Also mentioned is a substance not defined.  It is known as alal.  The Gemara attempts to define alal.

• Rabbi Yochanan says that it is marteka
• Reish Lakish sat that it is meat residue still attached to the hide after the meat has been cut off with a knife
• The meaning of marteka is unclear and the rabbis debate possible definitions
• Rashi says that marteka is the tendon of the neck and spin, a hard ligament
• Rabbeinu Tam points out that when marteka is mention in Massechet Zevachim (35a), Rashi offers the same explanation but the reference is to fowl which do not have this type of tendon
• Rabbeinu Tam says that marteka is dead or whithered flesh
• This opinion is supported in the Aruch, where the term reads as 'mardeka' and in Middle Persion mardeka means 'dead'
• Tosafot say in the name of Rashi that marteka is one of the tendons or hard veins of the throat
• They explain that it is called alal because 'tendons' we might conclude that the harder tendons would not be included as they are less edible than other tendons.