Jump instructions in 8086 microprocessors are used to change the flow of instruction execution. There are two types of jump instructions: unconditional jump instructions which do not check any flags, and conditional jump instructions which check flags like carry or zero before jumping. Common jump instructions include unconditional JMP, and conditional JC, JE, JNE, JP, JNP. Loop instructions use the CX register as a counter, decrementing it each pass through the loop until CX reaches zero.