CBSE Class 10 Answered

All reflex actions are involuntary in nature but all involutary actions are not reflexes. For example - The beating of heart and peristalsis are involuntary actions, but not reflex action.

Reflex actions ar very quick but all involutary actions may not be quick. 

Reflex actions are usually at the level of spinal cord whereas the involuntary actions generallly involve brain too

Reflex actions are done to meet emergencies where as an involuntary action is not done for emergencies, but to fulfill a critical life process as circulation of blood, movement of food in food pipe, etc.

A reflex action may be conditioned as in the case of salivation response by a dog on just hearing the bell in Pavlov's expt. but an involuntary action would not be generally influenced by external conditioning.