A secondary headache is a symptom of a disease that can activate the pain-sensitive nerves of the head. Any number of conditions â varying greatly in severity â may cause secondary headaches. Possible causes of secondary headaches include: Acute sinusitis. Arterial tears (carotid or vertebral dissections)
The fallopian tube is a crucial structure involved in successful reproduction and, like with all structures in the human body, sometimes problems occur that hinder the structure's ability to function properly.
[1] Morphogenesis of complex plant cell shapes-the mechanical role of crystalline cellulose in growing pollen tubes. Aouar L, Chebli Y, Geitmann A. 2010. Sexual Plant Reproduction 23: 15â27. [2] How to shape a cylinder: pollen tube as a model system for the generation of complex cellular geometry.