Sinus

Look up sinus or Sinus in Wiktionary, the free dictionary.

Sinus may refer to:

Anatomy

• Sinus (anatomy), a sac or cavity in any organ or tissue
  • Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including:
    • Maxillary sinus, is the largest of the paranasal sinuses, under the eyes, in the maxillary bones
    • Frontal sinus, superior to the eyes, in the frontal bone, which forms the hard part of the forehead
    • Ethmoid sinus, formed from several discrete air cells within the ethmoid bone between the eyes and under the nose
    • Sphenoidal sinus, in the sphenoid bone at the center of the skull base under the pituitary gland
  • Anal sinuses, the furrows which separate the columns in the rectum
  • Dural venous sinuses, venous channels found between layers of dura mater in the brain
  • Sinus (botany), a space or indentation, usually on a leaf

Other uses

• Sine, a trigonometric math function (Latin sinus)

See also

• Sinus Medii, a small lunar mare
• Sinus Successus, a lunar feature
• Hemocoel, a space filled with hemolymph in organisms with open circulatory systems
• Sines, a municipality in Alentejo, Portugal (Latin Sinus)
• Sinusitis, a common ailment resulting in the inflammation of the paranasal sinuses