The hawk's nictitating membranes swept across its eyes to protect them during the dive.

The doctor examined the patient's tympanic membrane for signs of infection.

Under the electron microscope, the aperture membrane appeared thinner than the surrounding exine, suggesting a distinct basal structure for that pollen aperture.

During the dissection, the medical students carefully examined the serous membranes covering the organs to understand their protective functions.

During the experiment, researchers noticed plasma membranes changed their permeability in response to the new drug.

The plasma membrane controls the movement of ions and molecules into and out of the cell.

During the lecture, the professor showed diagrams of virginal membranes to explain variations in anatomy.

During the exam, the doctor observed that the patient's mucous membranes were unusually pale, indicating possible anemia.

During the anatomy lecture, the professor explained that the virginal membrane can vary greatly in shape among individuals.

When she was admitted to the hospital, the obstetrician confirmed a rupture of membranes and prepared for delivery.