The potential must be strong enough to send a(n) potential to the cns.

It is true that the potential must be strong enough to send a potential to the CNS. The stronger the potential, the more it will excite the transmitter in relaying the message to another neuron, therefore, if this happens, the more will it be easier to pass the message.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.