The brain stem is made up of

Options

A. Midbrain, pons, cerebellum
B. Midbrain, pons, medulla oblongata
C. Diencephalon, medulla oblongata, cerebellum
D. Cerebellum, cerebrum, medulla oblongata

Answer

### Step-by-Step Solution:

1. **Understanding the Brain Stem**: The brain stem is a crucial part of the brain that connects the cerebrum to the spinal cord. It plays a vital role in regulating many involuntary functions of the body.

2. **Identifying the Components of the Brain Stem**: The brain stem is composed of three main parts:
- **Midbrain**: This is the uppermost part of the brain stem. It is responsible for functions such as vision, hearing, and motor control.
- **Pons**: This is the largest part of the brain stem, located above the medulla and below the midbrain. The pons serves as a bridge connecting the cerebrum and cerebellum.
- **Medulla Oblongata**: This is the lower part of the brain stem. It controls involuntary functions such as breathing, heart rate, and blood pressure.

3. **Evaluating the Options**:
- **Option 1**: Midbrain - Incorrect, as it only mentions one part.
- **Option 2**: Midbrain, Pons, and Medulla Oblongata - Correct, as it includes all three components.
- **Option 3**: Diencephalon, Medulla Oblongata, and Cerebellum - Incorrect, as it includes diencephalon which is not part of the brain stem.
- **Option 4**: Cerebrum and Medulla Oblongata - Incorrect, as it does not include the midbrain or pons.

4. **Conclusion**: The correct answer is that the brain stem is made up of the midbrain, pons, and medulla oblongata.