The common carotid artery gives off no branches in the neck. At the level of the hyoid bone or of the level of C4, the common carotid artery bifurcates into the external carotid artery and the internal carotid artery. The three major structures contained in the fascial carotid sheath are the carotid artery, internal jugular vein and vagus nerve. In the upper part the carotid sheath also contains the Glossopharyngeal nerve, the Accessory nerve and the hypoglossal nerve which pierce the fascia of the carotid sheath. Ongoing events • Abramoff-Reed gambling scandal • Al Jazeera bombing memo • Avian influenza (H5N1) outbreak • Black sites scandal • Conservative leadership race (UK) • Fuel prices • Irans nuclear program • Jilin chemical plant explosions • Kashmir earthquake • Malawi food crisis • Malaysian prisoner abuse scandal • New Delhi bombings investigation • Niger food crisis • North Indian cyclone... The carotid artery is a major artery of the head and neck that supplies blood to the head and neck. ... Section of an artery An arterial road is a class of highway. ... The hyoid bone (Os Hyoideum; Lingual Bone) is a bone in the human neck, not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue. ... In human anatomy, the carotid artery is a major artery of the head and neck. ... Jugular vein - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... The vagus nerve is tenth of twelve paired cranial nerves and is the only nerve that starts in the brainstem (somewhere in the medulla oblongata) and extends all the way down past the head, right down to the abdomen. ...

The role of the cardiovascular system is to deliver oxygen and to remove wastes ( e.g. carbon dioxide). It consists of the hear, blood vessels and lymphatics. The heart is made up of specialised muscles called the myocytes. it is similar to the skeletal muscles but with many important differences represent the adaptation of the heart to its function as a pump. like skeletal muscles, the heart conduct action potentials which trigger the contractory mechanism of the muscles. However, action potentials are in different durations: 0.3 second, compared with 0.001 seconds in skeletal muscles. in contrast to skeletal muscles, action potentials in all cardiac myocytes are generated continuously and can poass from one muscle cell to another via electricak couplins between myoctes. therefore , excitation arising anywhere in the hear will spread throughout the heart. The Sino-atrial node, which is situated in the right atrium, "fired" actin potential at a highest speed, so it turns out that our heart rate will be determined by the action potential arising from the AV node. The heart is divided into left and right side. Each sides contain two chamber: the atrium and the ventricles. Size of venticles are larger than that of the artium. Deoxygenated blood collected from the venous system will return to the heart via the superior and inferior vena cava and enters the right atrium. Which then passes via the tricuspid vlave lying between the right atrium and ventricle and pass into the right ventricles. With contraction of the R ventricles, the blood will then be squeeze into the pulmonary artery via the pulmonary valves and enter into the pulpmonary system for gaseous exchage. The oxygenated blood will then re-enter the heart via the pulmonary vein and enters the left atrium. With contraction of the atrium, the blood passess via the bicuspid vlave or the mitral valve and enters the left ventricle. With contraction of the left ventricle, the heart will be pump to the circulation around the body via the aorta.