Medulla Oblongata

The medulla oblongata is the part of the brain at the base of the brainstem, where the brain joins the spinal cord. It controls many autonomic (involuntary) actions and non-skeletal muscle.It contains the cardiovascular centre, which controls heart rate. Chemoreceptors detect changes in the carbon dioxide concentration and pH of the blood, and pressure receptors in the aorta and carotid arteries detect changes in blood pressure. The cardiovascular centre responds by sending impulses along sympathetic nerves to increase heart rate, or along the vagus nerve (parasympathetic) to decrease it, by acting on the sinoatrial node.It also contains the respiratory centre, which controls the rate and depth of breathing. This receives impulses from chemoreceptors and from stretch receptors in the lungs, and sends impulses to the intercostal muscles and diaphragm.The medulla oblongata also coordinates reflexes such as swallowing, coughing, sneezing and vomiting, and controls peristalsis in the gut.Damage to the medulla oblongata is often fatal, because breathing and heart rate can no longer be regulated.