Cells at Work: Realisations

Neisseria meningitidis

U-1146 and AE 3803 walked together through a blood vessel along an optic nerve, both happy, her cheeks still featuring an adorable pink. After their kiss the two had lingered a little at the retina, simply taking in the beautiful sight before them, enjoying each other's company. But they still had their duties and so had somewhat reluctantly left the capillary again some time ago. By now 3803 had finished her delivery, her oxygen box now replaced for one with carbon dioxide.

Despite her having to return it to the lungs, she had decided to take a deliberate detour, joining 1146 on his patrol for a bit longer. Something he was very delighted by. They had little time together as it was and he was grateful for every moment more.

He watched her look around, as they walked ever closer to the brain, even though there wasn't much to see, until they came closer to the optic chiasm.

Optic Chiasm

Also the known as the Chiasma opticum is the part in the brain where the optic nerves from both eyes, responsible for transmitting the sensory information for vision, cross. It is located at the bottom of the brain just below (inferior) the hypothalamus.

The ceiling and walls of the blood vessel became see-through, showing them the massive cable bundle that was the right optic nerve below them to their left, as the buildings flanking their path were replaced by balustrades. They had stepped onto a bridge, granting them a good view on a net of blood vessels all around them. Just like their own, those vessels led from and to the brain ahead, which was yet hidden behind the buildings of the bone at the other side.

"Wow; amazing." He heard 3803 exclaim. "How high up are we?"

"I'm not sure, but we should be a few floors above the next blood vessel." 1146 replied looking to the arteries and venules surrounding the optic nerve.

"Have you ever wondered what the outside looks like?" She asked after a while, gazing to the nerve itself.

"Hm?"

She turned to him, her amber eyes glowing with excitement. "I mean we know that our world, this body, is in shape like ours, but what about the world it inhabits?"

"I don't know." He confessed, though it was a rather fascinating thought, even if he'd never really entertained it before. "Some have tried to find out, usually by looking from the blood vessels in places such as sclera and iris, but anything larger than a mosquito turns into a blurry mass. Other times the outside light is simply too bright to make anything out."

3803 seemed somewhat disappointed by his response. "So no one knows?"

He shrugged. "Not necessarily. The information gathered by the eyes is processed in the brain by the neurons. It is possible that some of them know."

"I suppose there isn't a way to ask them." She noted, but there was a flicker of hope in her eyes again.

"The blood-brain barrier makes it difficult." 1146 explained. "If you ever have a delivery to the brain, you'll be giving the oxygen and nutrients to an astrocyte. They along with the pericytes and endothelial cells separate the brain from the rest of us, protecting and providing for it, making sure the neurons can function undisturbed, even when conditions in the circulatory system should change."

Despite this information however 3803 smiled. "Well, it won't hurt to ask."

1146 chuckled, adoring her positive attitude. "I suppose."

They continued to cross the bridge and the neutrophil couldn't help but notice that the pair of them attracted a bit of attention and so did she. "There have been quite a few cells staring at us."