The main regulation center responsible for respiration is medulla oblongata and pons virolli which lie in brain.

The regulatory centers for respiration are located in the medulla oblongata and pons. The medulla oblongata is the main control center for respiration, while the pons plays a supportive role.

1. Medulla Oblongata:
The medulla oblongata is located at the base of the brainstem and is responsible for regulating essential bodily functions, including respiration. It contains two important respiratory centers: the dorsal respiratory group (DRG) and the ventral respiratory group (VRG).

- Dorsal Respiratory Group (DRG): The DRG is primarily responsible for initiating inspiration. It receives input from various sensory receptors that detect changes in carbon dioxide (CO2) and oxygen (O2) levels in the blood. When the CO2 levels increase or the O2 levels decrease, the DRG sends signals to the diaphragm and intercostal muscles to contract, initiating the process of inspiration.

- Ventral Respiratory Group (VRG): The VRG is involved in both inspiration and expiration. It consists of inspiratory neurons that work alongside the DRG to control the muscles involved in breathing. Additionally, the VRG contains expiratory neurons that become active during forced expiration or when there is a need to increase the rate of breathing.

2. Pons:
The pons is located above the medulla oblongata and serves as a bridge between the medulla and other parts of the brain. It contains the pneumotaxic center and the apneustic center, which help regulate the duration and depth of each breath.

- Pneumotaxic Center: The pneumotaxic center is responsible for fine-tuning the respiratory rate and controlling the transition between inspiration and expiration. It sends inhibitory signals to the DRG, limiting the duration of inspiration and promoting a smooth transition to expiration.

- Apneustic Center: The apneustic center is located in the lower pons and sends excitatory signals to the DRG. It enhances the intensity and duration of inspiration, leading to a prolonged inspiratory phase.

Both the medulla oblongata and pons work together to ensure the regulation of respiration. While the medulla oblongata primarily controls the basic rhythm of breathing, the pons modifies and fine-tunes this rhythm to match the body's metabolic needs.