Basic Sciences and Anatomy Flashcards

The circle of Willis is formed by which set of arteries?

Answer: Internal carotid, anterior cerebral, posterior cerebral, anterior and posterior communicating arteries

The circle of Willis is an anastomotic ring formed by the internal carotid arteries, anterior and posterior cerebral arteries, and the anterior and posterior communicating arteries.

Which phase of the cardiac cycle corresponds to ventricular filling?

Answer: Diastole

Diastole is the phase when ventricular muscle relaxes and the ventricles fill with blood from the atria.

In the context of dental sedation, which muscle is the primary muscle of mastication responsible for elevating the mandible?

Answer: Masseter

The masseter is the primary elevator of the mandible and one of the most powerful muscles of mastication.

Which electrolyte imbalance is most likely to cause cardiac arrhythmias during anesthesia?

Answer: Hypokalemia

Hypokalemia (low serum potassium) destabilizes myocardial cell membranes and can precipitate life-threatening arrhythmias including ventricular fibrillation.

The trachea bifurcates into the right and left main bronchi at the level of which anatomical landmark?

Answer: Angle of Louis (sternal angle) at T4-T5

The trachea bifurcates at the carina, located at the level of the sternal angle (angle of Louis), which corresponds to the T4-T5 vertebral level.

Which of the following correctly describes the blood-brain barrier?

Answer: It consists of tight junctions between capillary endothelial cells, limiting passage of polar molecules

The blood-brain barrier is formed by tight junctions between cerebral capillary endothelial cells, restricting passage of polar, ionized, or large molecules.

The phrenic nerve, which innervates the diaphragm, originates from which cervical nerve roots?

Answer: C3-C5

The phrenic nerve arises from cervical nerve roots C3, C4, and C5, which is summarized by the mnemonic 'C3, 4, 5 keeps the diaphragm alive.'