Question

The brain and spinal cord develop from ectoderm arranged in a tubular structure called the neural tube. The anterior part of the neural tube expands, and constrictions appear that create multiple regions. Arrange the parts of the embryonic brain chambers in a 5 week embryo from top to bottom.
A. Diencephalon
B. Myelencephalon
C. Metencephalon
D. Mesencephalon
E. Telencephalon
Choose the most appropriate answer from the options given below:

• A. A, B, C, D, E
• B. A, E, C, D, B
• C. E, A, D, C, B
• D. C, B, D, A, E

Hint:

Remember the alphabetical and hierarchical order. The forebrain divides into T and D. The midbrain (Mesencephalon) stays the same. The hindbrain divides into Met- and Mye-. Alphabetically, Met- comes before Mye-. This gives the sequence T, D, Mes, Met, Mye.

Answer 1

The Correct Option is C

Step 1: Concept Overview:
The central nervous system's development starts with the neural tube. Its front (rostral) end differentiates into the brain. Initially, three primary brain vesicles appear: prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain). By week 5, these divide into five secondary vesicles. The task is to order these five vesicles from anterior to posterior (top to bottom).

Step 2: Sequence Elaboration:
The three vesicles develop into five as follows:
- Prosencephalon (forebrain) divides into: 1. E. Telencephalon (most anterior): future cerebral hemispheres. 2. A. Diencephalon: future thalamus, hypothalamus, etc.- Mesencephalon (midbrain) remains: 3. D. Mesencephalon.- Rhombencephalon (hindbrain) divides into: 4. C. Metencephalon: future pons and cerebellum. 5. B. Myelencephalon (most posterior): future medulla oblongata.

Step 3: Solution:
The anterior-to-posterior sequence of the five secondary vesicles is: Telencephalon \(\rightarrow\) Diencephalon \(\rightarrow\) Mesencephalon \(\rightarrow\) Metencephalon \(\rightarrow\) Myelencephalon.
This corresponds to the sequence E, A, D, C, B. Therefore, option (C) is the correct answer.