OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What is the primary function of the medulla?

1. It controls voluntary muscle movements

2. It manages unconscious activities like breathing and heart rate

3. It regulates sleep cycles

4. It is responsible for taste sensation

The correct answer is: It manages unconscious activities like breathing and heart rate

The primary function of the medulla is to manage unconscious activities like breathing and heart rate. The medulla oblongata, located in the brainstem, plays a crucial role in autonomic functions that are essential for survival. It contains vital centers that control not only respiration but also cardiovascular responses, ensuring that breathing rate and heart rate adjust to meet the body's needs. This area of the brain operates without conscious thought, which is why it is involved in processes that the body regulates automatically. Additionally, damage to the medulla can result in critical health issues, emphasizing its importance in maintaining life-sustaining functions. In contrast, the other functions outlined in the other choices do not pertain specifically to the medulla. Voluntary muscle movements are primarily controlled by the motor cortex and related brain regions. Sleep cycles involve complex interactions between several brain areas, including the hypothalamus and the pineal gland, rather than the medulla. Lastly, taste sensation is processed primarily by the gustatory cortex, not the medulla. These distinctions clarify why managing unconscious activities is the correct answer regarding the medulla's primary role.