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
Smallest cardiac veins contribute to normal physiologic shunting of blood. As a consequence of the input of these vessels, blood in the left heart is less oxygenated than the blood found at the pulmonary capillary beds, albeit to a very small degree. The "openings of smallest cardiac veins" are located in the endocardium. Here the smallest cardiac veins return blood into the heart chambers from the capillary bed in the muscular cardiac wall, enabling a form of collateral circulation unique to the heart. Not every endocardial opening connects to the thebesian veins as some connect to the vessels of Wearn, which are arteries.