Neck uterus. Thus the adjective "cervical" may refer either to the neck (as in "cervical vertebrae" or "cervical lymph nodes") or to the uterine cervix (as in "cervical cap" or "cervical cancer"). The neck contains vessels that link structures in the head to the body. In humans these structures include part of the esophagus, larynx, trachea, thyroid and parathyroid glands, lymph nodes, and the first part of the spinal cord. Major blood vessels present include the carotid arteries and the jugular veins. Cervical lymph nodes surround the blood vessels. The thyroid gland and parathyroid gland are endocrine glands involved in the
Heart the aorta. Two small openings above the aortic valve carry blood to the heart itself, the left main coronary artery and the right coronary artery. The heart wall is made up of three layers: the inner endocardium, middle myocardium and outer epicardium. These are surrounded by a double-membraned sac called the pericardium. The innermost layer of the heart is called the endocardium. It is made up of a lining of simple squamous epithelium, and covers heart chambers and valves. It is continuous with the endothelium of the veins and arteries of the heart, and is joined to the myocardium with