1) Because if you spell sinus backwards, it becomes sinus which in latern means inter galctual head smetis.
2) According to my knowledge, the 'sinus' was originally called the 'inf-inf' based on its anatomical root, however as medicine evolved, it led to many misdiagnosed cases of speech impairments and hours of unnecessary therapy for sick patients who would visit the town doctor or shaoman and seek treatment for their inf-inf infection. Once this complication was recognized, it was renamed to avoid future confusion using the name of the discovering doctor, Mr. Sinus Smetis.
A sinus infection, or sinusitis.
Sinus headaches can be saused by a sinus congestion and inflammation, called sinusitis. Sinusitis is caused by either a respiratory infection or allergies.
When the heart is functioning properly the sinus node controls the firing of action potential that contract the heart. When the sinus node dominates the heart will contract in a synchronized and effective rhythm This is called sinus rhythm.
It's called the subcapsular sinus
There are people who say sinus doctor when they see a doctor treating a sinus patient, but I wouldn't say a sinus doctor, because a doctor who treat sinus patients also treat general ear, nose, and throat problems.Allergy doctors called as an allergist or an immunologist; these doctors can treat a sinus patient too.
normal sinus rhythm (NSR)