Category: B

Five pairs of arched structures that form the lateral and ventral walls of the pharynx of the embryo. The first is the mandibular arch; the second is the hyoid arch; the third, fourth, and fifth arches are transitory. They are partially separated from each other externally by the branchial clefts and internally by the pharyngeal…

Inability to use the muscles of the face or mouth (e.g., to whistle a tune or suck liquids through a straw).  

Basilar process of the occipital bone.  

Antitoxic serum obtained from horses immunized against the venom of the black widow spider (Latrodectus mactans) and used specifically to treat bites of the black widow spider. The serum is available from Merck Co., Inc., West Point, PA 19486.  

An antibody that prevents an antigen from binding with a cellular receptor.  

An antibiotic that inhibits the growth of microorganisms.  

An antibiotic that kills microorganisms.  

The angle formed by the meeting of the axes of the orbits.  

An acute infectious disease caused by Bartonella quintana or B. henselae. It is characterized by skin lesions that may vary from small papules to pyogenic granulomas or pedunculated masses. These occur anywhere on the skin and may involve mucous membranes. If the lesions ulcerate, they can extend to and destroy underlying bone. In addition, the…

A small saccular congenital aneurysm of a cerebral vessel. It communicates with the vessel by a small opening. Rupture of this type of aneurysm may cause subarachnoid hemorrhage, a devastating form of stroke. Encounter an anomalous swelling that develops at the point where arteries supplying the brain intersect. These swellings, known as berry aneurysms, typically…