Ignorance and 5 hindrances

The five hindrances or obstacles of common buddhism are: 1. worry/restlessness/regret /distraction 2. hate (ill-will) 3. sensual desire 4. skeptical doubt (ignorance?) 5. lazy/lethargy Ignorance is not listed. Do all 5 together imply ignorance? It says: > These are the five obstacles and hindrances, corruptions of the heart > that weaken wisdom. Another theory might be that ignorance (confusion) is the same as doubt. If one doesn’t know any better, the opportunity to gain *access* to concentration (right meditation) are more slim. If one misunderstands that is also ignorance. If one is skeptical that might be ignorance. Perhaps the five hindrances are primarily a technical manual, a means to access concentration or develop tranquility/equanimity/energy (seven factors); in which case ignorance has an indirect role. Why (How) is or isn’t ignorance one of the five hindrances?