Course1, Test1, Human Development

Front 1

Intramembranous mesoderm breaks down to 3 levels:

Back 1

periaxial mesoderm,
medial mesoderm
intermediate mesoderm

Front 2

The periaxial mesoderm forms 3 separate types of cells in the 4th week.

Back 2

Dermatome - skin
myotomes - voluntary skeletal muscles
sclerotomes - vertebral column around the developing neural tube.

Front 3

During the 4th week of human development, the vertebral column is being created, the intervertebral discs are created by the combination of two cells:

Back 3

sclerotome cells (forms the annulus fibrosis)
notochord cells (forms the nucleus pulposus)

Front 4

What does the word metamerism mean?

Back 4

That the body develops in a way where it is for the most part has repeating segments.

Front 5

The deep muscles of the back develop from the ___________ during human development?

Back 5

epimere

Front 6

The lateral musculature of the back develop from the __________ during human development?

Back 6

hypomere.

Front 7

The cranial limb buds (arms) start to appear at approximately what day of development?

Back 7

25th day. By the end of the eight week of development all 4 limbs with distinct digits are present.

Front 8

The limbs are developed from two layer:

Back 8

ectoderm turns into the "apical ectodermal ridge"
mesoderm layer just inferior to that forms the mesenchymal core. The mesenchymal core determines the type of limb that will develop

Front 9

What were the historical consequences of mothers who took Thalidomide during pregnancy?

Back 9

Their babies were born with deformed (or no) limbs.

Front 10

Too much apical ectodermal ridge (part of the ectoderm in the developing limb) could cause what?

Back 10

Polydactyly.

Front 11

Describe the development muscles of the arm and how the innervations were developed:

Back 11

The muscles formed from mesoderm in the middle of the limb. The muscles posterior to the bone are called extensors, and anterior are called flexers. They are seperated by an intermuscular septum.

Branches of the Ventral Primary Rami of C5-T1 created the Brachial [nerve] Plexus in order to innervate the muscles on both sides of the septum. In the plexus, many of the nerves join together forming trunks of the plexus. There are main devisions: anterior and posterior.