Each cerebral hemisphere is divided into four lobes; the frontal, parietal, temporal, and the occipital. The Frontal Lobe is the most anterior lobe of the brain.Its posterior boundary is the fissure of Rolando, or central sulcus, which separates it from the parietal lobe.Inferiorly, it is divided from the temporal lobe by the fissure of Sylvius which is also called the lateral fissure.he Frontal Lobe is the most anterior lobe of the brain. Its posterior boundary is the fissure of Rolando, or central sulcus, which separates it from the parietal lobe. Inferiorly, it is divided from the temporal lobe by the fissure of Sylvius which is also called the lateral fissure.
Main article: Thoracic diaphragm. The diaphragm is the major muscle responsible for breathing. It is a thin, dome-shaped muscle that separates the abdominal cavity from the thoracic cavity. During inhalation, the diaphragm contracts, so that its centre moves caudally (downward) and its edges move rostrally (upward).
The main function of the bronchi and bronchioles is to carry air from the trachea into the lungs. Smooth muscle tissue in their walls helps to regulate airflow into the lungs. When greater volumes of air are required by the body, such as during exercise, the smooth muscle relaxes to dilate the bronchi and bronchioles.here are 3 major parts of the respiratory system: the airway, the lungs, and the muscles of respiration. The airway, which includes the nose, mouth, pharynx, larynx, trachea, bronchi, and bronchioles, carries air between the lungs and the bodyâs exterior. The lungs...