Cervical pa of esophagus all are true except?

Poosystemic (Poo caval) anastomosis is seen in lower pa (abdominal pa) of esophagus.Cervical esophagus begins at lower border of cricoid cailage (at C6 veebral level) as a downward continuation of pharynx.Muscularis externa of cervical esophagus contains only skeletal muscle (striated muscle) fibers.Foreign body obstruction is common in this pa of esophagus.