The heart then pumps the oxygenated blood out to the body via the aorta (the great artery arising from the left ventricle of the heart). The bronchial arteries are blood vessels that branch off from the aorta to supply blood and nutrition for the lung itself and the bronchial tubes.
Some people experience weakness in a certain area of their bodies, such as the arms or legs. Others may experience full body weakness, which is often the result of a bacterial or viral infection such as influenza or hepatitis.
Myasthenia gravis causes weakness of the voluntary muscles. Voluntary muscles are those that are under your control. Autonomic muscles, such as the heart and the digestive tract, are usually not affected. The muscle weakness of myasthenia gravis worsens with activity and improves with rest. The muscle weakness can lead to a variety of symptoms, including: 1  Breathing difficulty because of weakness of the chest wall muscles.  Chewing or swallowing difficulty, causing frequent gagging, choking, or drooling.