| C4 | fourth cervical nerve; fourth cervical vertebra; fourth component of complement |
|---|---|
| A2 P2 | aortic second sound; pulmonary second sound |
| BS | Bachelor of Science; Bachelor of Surgery; Bacillus subtilis; Bartter syndrome; base strap; bedside; ... |
| bs | bedside; bowel sound; breath sound |
| C4a | activated fourth component of complement |