Assertion: portal vein | /r/HasProperty | destitute of valve
Facets:
value: in the adult
type: LOCATION
Source sentences:
text: In the adult the portal vein and its tributaries are destitute of valves; in the fetus and for a short time after birth valves can be demonstrated in the tributaries of the portal vein; as a rule they soon atrophy and disappear, but in some subjects they persist in a degenerate form.