NBDE Part I key terms

Air-filled cavity within the body of the maxilla that opens into the nasal cavity; its thin floor lies close to the roots of maxillary posterior teeth, so sinusitis or root infection can mimic dental pain.

Network of veins in the infratemporal fossa draining the maxilla, mandible, and nasal cavity; it connects with the cavernous sinus through emissary veins, providing a route for spreading dental infection.

Oval opening in the greater wing of the sphenoid bone that transmits the mandibular division of the trigeminal nerve along with the accessory meningeal artery.

Branch of the facial nerve that carries taste from the anterior two-thirds of the tongue and parasympathetic fibers to the submandibular and sublingual glands; it joins the lingual nerve in the infratemporal fossa.

Synovial joint between the mandibular condyle, the mandibular fossa, and the articular tubercle, separated by a fibrocartilaginous disc that permits both rotation and translation.

Small pyramidal space behind the maxilla containing the maxillary nerve, pterygopalatine ganglion, and branches supplying the nose, palate, and pharynx; it communicates with several cranial fossae and the oral cavity.

Connective tissue sleeve containing the common carotid artery, internal jugular vein, and vagus nerve; it runs through the neck and its contents serve as landmarks for local anesthesia and surgical dissection.

Perforated part of the ethmoid bone that forms the roof of the nasal cavity and transmits olfactory nerve filaments from the nasal mucosa to the olfactory bulb.

Fifth cranial nerve, the main sensory nerve of the face and motor nerve of the muscles of mastication; it divides into ophthalmic, maxillary, and mandibular branches.

Cytoplasmic pathway that converts one glucose molecule into two pyruvate molecules, generating ATP and NADH without requiring oxygen; it is the first stage of carbohydrate catabolism.

Mitochondrial cycle that oxidizes acetyl-CoA to carbon dioxide while producing NADH, FADH2, and GTP; it links carbohydrate, fat, and protein metabolism to the electron transport chain.

Process in the inner mitochondrial membrane in which electron transport drives proton pumping, and the resulting proton gradient powers ATP synthase to make most cellular ATP.

Synthesis of glucose from noncarbohydrate precursors such as lactate, glycerol, and amino acids, occurring mainly in liver and kidney and using several enzymes that reverse glycolysis.

Reversible enzyme inhibition in which a molecule resembling the substrate binds the active site and competes with the substrate; raising substrate concentration can overcome it.

Substrate concentration at which an enzyme works at half its maximum velocity; a low Km indicates high enzyme affinity for substrate, and competitive inhibitors raise the apparent Km.

Voltage difference across a resting cell membrane, usually negative inside, set mainly by potassium permeability and maintained by the sodium-potassium pump and selective ion channels.

Rapid, all-or-none change in membrane voltage caused by sequential sodium influx and potassium efflux; it propagates along axons and triggers neurotransmitter release at nerve terminals.

Principle that increasing ventricular filling (preload) stretches cardiac muscle and increases the force of contraction, so the heart ejects more blood within physiologic limits.

Volume of plasma filtered by the kidney glomeruli per unit time; it depends on filtration pressure, surface area, and permeability, and is estimated clinically from creatinine clearance.

Shift of the hemoglobin oxygen dissociation curve to the right when carbon dioxide or hydrogen ion concentration rises, which reduces oxygen affinity and enhances oxygen delivery to active tissues.

Organized community of microorganisms attached to a surface and embedded in a self-produced matrix; dental plaque is a biofilm, and its structure increases resistance to antibiotics and immune defenses.

Lipopolysaccharide component of the outer membrane of gram-negative bacteria; it triggers fever and inflammation through innate immune receptors and can cause septic shock.

Soluble toxin secreted by bacteria, often highly potent and specific for particular host cells; many exotoxins are proteins that can be inactivated to form toxoids used in vaccines.

Coating of a microbe with antibodies or complement fragments so phagocytes can bind it more efficiently and engulf it; it bridges innate and adaptive immunity.

Organized collection of activated macrophages, often with multinucleated giant cells and a rim of lymphocytes, formed to contain persistent pathogens or foreign material.

Reversible change in which one mature cell type is replaced by another mature type, often an adaptation to chronic irritation; in the airway, columnar epithelium may become squamous.

Disordered growth in which cells show altered size, shape, and organization; it is not cancer but may be a precursor lesion, especially in stratified squamous epithelium.

Microorganism that usually does not cause disease in healthy hosts but produces infection when immunity is weakened, normal flora is disturbed, or a foreign device is present.

Ability of a pathogen to change surface antigens over time, allowing it to evade antibodies from a previous infection; examples include influenza virus and trypanosomes.

Group of genes encoding cell-surface proteins that present peptide antigens to T lymphocytes; MHC molecules are central to immune recognition and transplant rejection.

Accessory cusp or ridge on the lingual surface of the mesiolingual cusp of a maxillary first molar, most common in permanent maxillary molars.

Ridge on the occlusal surface of maxillary molars running from the mesiolingual cusp to the distobuccal cusp; it is a hallmark of maxillary molar anatomy.

Raised enamel ridge on the mesial or distal border of an occlusal table or lingual surface; it helps retain food and contacts the adjacent tooth's marginal ridge.

V-shaped space between adjacent teeth, buccal, lingual, occlusal, or cervical to the contact area; it allows food to escape and supports gingival health.

Anteroposterior curvature of the occlusal plane seen from the side, formed by the alignment of incisal edges and cusp tips; excessive curve may require orthodontic leveling.

Mediolateral curvature of the occlusal plane caused by the inward tilt of mandibular posterior teeth and outward tilt of maxillary posterior teeth.

Maxillomandibular relationship in which the condyles are in their most anterior, superior position against the articular eminences, independent of tooth contact.

Occlusion of the teeth when the mandible is in centric relation or in maximum intercuspation; it is the habitual biting position and a reference for occlusal treatment.

Horizontal distance between the incisal edge of the maxillary incisor and the labial surface of the mandibular incisor, measured parallel to the occlusal plane.

Greatest bulging point of a tooth surface in a given view; it affects food deflection, gingival stimulation, and the shape of embrasures and contact areas.