Development of the Limbs Flashcards
When do digits start forming
8th week
When does 1 ossification occur
12th week
Cartilage, connective tissue and bone of limbs come from
Somatic mesoderm
Development of limbs proceeds in what direction
Proximodistally
Stylopod
Humerus and femur
Zeugopod
Radius/ulna and tibia/fibula
Autopod
Carpels, metacarpals, digits and tarsals, metatarsals
Week 5 developments
Hand and foot plates
Chondrification center appears
Week 6 developments
Digital ray of hands
Entire limb skeleton is cartilagenous
Week 7 developments
Digital rays of feet
Osteogenesis of long bones begins
Rotation of limbs
Week 8 developments
Separate digits are formed
Apoptosis
When do motor axons from spinal cord enter limbs
5th week
How do sensory axons find their way to limbs
They follow motor axons
Where do schwann cells come from
Neural crest cells
Primary axial artery becomes
Brachial artery in upper limb or deep artery of thigh