In which system do red blood cells carry oxygen from the lungs to the cells and then carry carbon dioxide back to the lungs to be exhaled?

Post the question

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.

C. gemstones they are the only non metallic mineral from the list.