noun (plural coni /-nʌɪ/)Anatomy
1 (in full conus arteriosus /ɑːˌtɪərɪˈəʊsəs/) The upper front part of the right ventricle of the heart.
- Since the aorta and the pulmonary artery develop from a common conus arteriosus, irregular and imperfect development of the septum between them may also produce variations.
- The heart appears to be the most primitive of all adult vertebrates, with the auricle, ventricle and conus arteriosus arranged in straight line, rather than being doubled over one another.
- A conus artery arising from the aorta was found in 50% of 651 subjects.
2 (in full conus medullaris /ˌmɛdəˈlɑːrɪs/) The conical lower extremity of the spinal cord.
- The spinal cord tapers caudally to become the conus medullaris.
- An MRI (not shown) showed the conus medullaris to be at L1 - L2, and the sacrum to be dysplastic.
- A spinal ultrasound from the second day of life (not provided) showed the spinal cord conus to be normally positioned at L1.
late 19th century: from Latin, literally 'cone'.
Entry from US English dictionary