Chapter 6 Lecture 14

Question 1

The cardiogenic plate arises from:

A. Embryonic endoderm

B. Somatic mesoderm

C. Splanchnic mesoderm

D. Intermediate mesoderm

E. Neural crest

Answer 1

C. Splanchnic mesoderm

Question 2

An inductive stimulus from which structure stimulates the transformation of the epithelial sclerotome into secondary mesenchyme?

A. Neural crest

B. Somite

C. Ecto dermal placodes

D. Embryonic endoderm

E. Notochord

Answer 2

E. Notochord

Question 3

Which of these structures in the embryo is unsegmented?

A. Somitomeres

B. Neuromeres

C. Notochord

D. Somites

Answer 3

C. Notochord

Question 4

The intermediate mesoderm is the precursor of the:

A. Urogenital system

B. Heart

C. Somites

E. Vertebral bodies

Answer 4

A. Urogenital system

Question 5

What forces are involved in the folding of the neural plate to form the neural tube?

Answer 5

A change in cell shape at the median hinge point and pressures of the lateral ectoderm acting to push up the lateral walls of the neural plate.

Question 6

What role do Neuromeres play in the formation of the central nervous system?

Answer 6

Provide the fundamental organization of parts of the brain in which they are present. Certain homeobox genes are expressed in a definite sequence along the neuromeres.

Question 7

From what structures do the cells that form skeletal muscles arise?

Answer 7

The somites. Axial muscles form from cells derived from the medial halves of the somites, and limb muscles arise from cellular precursors located in the lateral halves of the somites.

Question 8

Where do the first blood cells of the embryo form?

Answer 8

In blood islands that arise from mesoderm of the wall of the yolk sac.

Question 9

The sclerotome arises from cells that were located in the

A. Notochord

B. Paraxial mesoderm

C.Intermediate mesoderm

D. Lateral plate mesoderm

E. None of the above

Answer 9

B. Paraxial mesoderm