This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
All of the following statements about Diploic veins are true except 
Select and explain. 
A. Develop around 8th wks of gestation, B. These have no valves, C. Present in cranial bones, D. Have a thin wall lined by single layer of endothelium
A: Develop around 8th wks of gestation
Answer: A: Develop around 8th wks of gestation 
Explanation: Diploic veins form sinuses in cancellous tissue between laminae of cranial bones.The skull is unilamellar at bih without any dipole. The diploic veins sta to develop at around 2 years of age along it diploe.These veins are lined by endothelium suppoed by some elastic tissue and are valveless.Reference"Chaurasia&;s human anatomy vol 3 ,4th edition, page no.96