In physics, a photon is a bundle of electromagnetic energy. It is the basic unit that makes up all light. The photon is sometimes referred to as a quantum of electromagnetic energy. Photons are not thought to be made up of smaller particles. They are a basic unit of nature called an elementary particle. Properties of a Photon. Photons have some basic properties that help define what they are and how they behave.
Rad 270 Paranasal Sinuses. The maxillary sinus is aerated at birth. The other sinuses begin to aerate at 6 y/o. Aeration is completed by age 18. Chronic sinusitis T1 weighted normal sinus w&w/o gadolinium Polyps Multidetector CT scans of paranasal sinus in a patient with deviation of nasal septum. Brem M H et al.
Maxillary sinuses: These are the largest of the sinuses and are located behind the cheekbones near the maxillae, or upper jaws. Sphenoid sinuses: The sphenoid sinuses are located in the sphenoid bone near the optic nerve and the pituitary gland on the side of the skull. Ethmoid sinuses: The ethmoid sinuses are not single sacs. They are a collection of six to 12 small air cells that open independently into the nasal cavity.