1,362
edits
Changes
Somite Development - Anatomy & Physiology (view source)
Revision as of 07:21, 31 August 2008
, 07:21, 31 August 2008→Somite Maturation
:'''Scelerotome''' - develops into axial skeleton, ribs and vertebrae.
:'''Scelerotome''' - develops into axial skeleton, ribs and vertebrae.
:'''Dermomyotome''' - develops into ''myotome'' and ''dermotome''.
:'''Dermomyotome''' - develops into ''myotome'' and ''dermotome''.
::'''Myotome''' - develops into skeletal muscle of the limbs and body.
::'''Myotome''' - develops into [[Muscles - Anatomy & Physiology#Skeletal Muscle|skeletal muscle]] of the limbs and body.
::'''Dermotome''' - develops into the dermis.
::'''Dermotome''' - develops into the [[Skin - Anatomy & Physiology#Dermis|dermis]].
*Somites develop in an identical manner, although those at the posterior develop after those at the anterior.
*Somites develop in an identical manner, although those at the posterior develop after those at the anterior.
*Somitic derivatives form according to the somite's position along the anterior - posterior axis.
*Somitic derivatives form according to the somite's position along the anterior - posterior axis.
**Formation of sclerotome, myotome and dermotome is not intrinsic, but governed by '''environmental signals'''.
**Formation of sclerotome, myotome and dermotome is not intrinsic, but governed by '''environmental signals'''.
**However, positional information is '''predetermined and intrinsic''' to the somite. Positional information is important to form the appropriate type of vertebrae, muscle and skin along the anterior - posterior axis.
**However, positional information is '''predetermined and intrinsic''' to the somite. Positional information is important to form the appropriate type of vertebrae, [[Muscles - Anatomy & Physiology|muscle]] and [[Skin - Anatomy & Physiology|skin]]long the anterior - posterior axis.
**Positional information is governed by HOX gene expression. Each somite expresses a unique number of HOX genes.
**Positional information is governed by HOX gene expression. Each somite expresses a unique number of HOX genes.
*The chick has 12 somites.
*The chick has 12 somites.