Changes

==Gastrulation at the Tail Bud==

==Gastrulation at the Tail Bud==

*Cells at the posterior of the primitive streak are allocated to form the tail bud. When the primitive streak elongates, these cells don't follow, but migrate posteriorly and form a condensed ball of cells called the tail bud.

Cells at the posterior of the primitive streak are allocated to form the tail bud. When the primitive streak elongates, these cells don't follow, but migrate posteriorly and form a condensed ball of cells called the tail bud. The tail bud exists to form cells of the hindlimb. Tail notochord and somites form through regression of the tail bud. No endoderm exists in the tail bud. Production of the tail bud is called '''secondary gastrulation''', production of the primitive streak, node and notochord is called '''primary gastrulation'''. Without the tail bud, the notochord would run out of cells before the hindlimb could be made. In animals that have tails, cells at an additional site undergo gastrulation.

*The tail bud exists to form cells of the hindlimb.

*Tail notochord and somites form through regression of the tail bud.

**'''No endoderm exists in the tail bud.'''

*Production of the tail bud is called '''secondary gastrulation''', production of the primitive streak, node and notochord is called '''primary gastrulation'''.

*Without the tail bud, the notochord would run out of cells before the hindlimb could be made.

*In animals that have tails, cells at an additional site undergo gastrulation.

[[Category:Developmental Biology]][[Category:To Do - A&P]]

[[Category:Developmental Biology]][[Category:To Do - AimeeHicks]]