A sheep has so much fat around it's heart to protect the valves in  the heart. There is also a lot of fat there to maintain the body  temperature of the heart.
Definition and Causes. Upper respiratory tract infection (URI) is a nonspecific term used to describe acute infections involving the nose, paranasal sinuses, pharynx, larynx, trachea, and bronchi.The prototype is the illness known as the common cold, which is discussed here, in addition to pharyngitis, sinusitis, and tracheobronchitis.efinition and Causes. Upper respiratory tract infection (URI) is a nonspecific term used to describe acute infections involving the nose, paranasal sinuses, pharynx, larynx, trachea, and bronchi.
What is a lower respiratory infection? Lower respiratory (tract) infection or LTRI is a generic term for an acute infection of the trachea (windpipe), airways and lungs, which make up the lower respiratory system. LTRIs include bronchitis, croup and pneumonia.