Wk5 Limb

Question 1

limb bud

Answer 1

A thickened portion of the lateral plate somatic mesoderm which will form the tissues of the limb (excepting the muscles)

Question 2

apical ectodermal ridge

Answer 2

An anterior-posterior ridge of ectoderm running along the distal edge of the limb bud. Signals outgrowth to the limb bud mesenchyme

Question 3

zone of polarizing activity

Answer 3

A region of the posterior margin of the limb bud mesenchyme which signals to promote posterior specification

Question 4

premuscle masses

Answer 4

In the limb bud, dorsal and ventral masses of cells which will form the muscles, derived from the somites

Question 5

mesenchymal condensations

Answer 5

In the limb bud, regions of higher density of mesenchymal cells which pre-figure the limb cartilages (and bones)

Question 6

polydactyly

Answer 6

More than a normal number of digits

Question 7

syndactyly

Answer 7

Fused digits

Question 8

brachydactyly

Answer 8

Short digits

Question 9

ectrodactyly

Answer 9

Split hand split foot

Question 10

amelia

Answer 10

A lack of limbs

Question 11

phocomelia

Answer 11

An absence of intermediate segments of limb