Publish and Perish, part 30: Fainting and Worse

[Context: read the previous part or start at the beginning. TW: bad amateur fiction!]

In general, Gerald didn’t build many pre-planned jokes into his lectures, but he did permit himself an occasional riff. Today’s physiology lecture, on the regulation of blood pressure, was the setting for one such riff.

“…So we all agree that maintaining blood flow to the brain is, like, extremely important, right?” he said.

He could see lots of nodding.

“Good. And, to review, why is it so challenging for the heart to deliver blood to the brain when you’re standing upright?”

A few hands went up.

“Yes, Minh?”

“I believe the way you put it was ‘gravity is cruel’,” said Minh.

“Yes, that does sound like something I would say. And what in the blazes did I mean by that?”

A couple of additional hands joined the others.

“Hank?”

“To get from the heart to the head, blood has to flow upward, against gravity,” said Hank.

“Yes, good. And so, given this issue, would you say that the brain is vulnerable to disruptions in blood supply? More vulnerable than other organs that are lower in the body, such as the lungs? Hands up for yes.”

Lots of hands went up.

“OK. All right. We have one more thing to make sense of here, and that is the phenomenon of fainting.” Gerald took a breath. “There are many factors that influence the likelihood of fainting, but a lot of them boil down to the idea that fainting is a response to low blood pressure, or the threat of low blood pressure. But why? Why on earth would you respond to a low BP by dropping to the ground? Turn to your neighbor and discuss for one minute.”

Gerald surveilled the students. Some were talking, but many appeared dazed, which was typical for this topic.

“Here’s a hint,” he interrupted. “Picture me giving this lecture and then fainting.” He swayed melodramatically at the podium, then made a controlled fall, clutching the podium all the way down.

“Now,” he called out loudly from the floor, “some of you can no longer see me, but picture me splayed out horizontally. Where is my heart now in relation to my brain? Take one more minute on this.”

Gerald got to his feet, waited the additional minute, and called on Sven.

“We thought maybe if you’re unconscious the brain doesn’t have much to think about and doesn’t need much blood?” Sven offered.

Gerald quickly processed this not-bad-but-not-right answer.

“That’s not a horrible idea,” he allowed, “but let’s stay focused on the issue of gravity. Does anyone have an answer that relates more directly to gravity?”

A hand in the back inched upward.

“Sherrill?”

“Your heart no longer needs to fight gravity to get blood to your brain?” Sherill suggested tentatively.

“Right! Once you’re lying down, it is much easier for the heart to pump blood to the brain, because the brain is no longer elevated way above the heart. What a great trick, right?” Gerald smiled and paused. “Well, aside from the fact that you might get eaten by a tiger or something.”

The students made a variety of involuntary sounds, as if they collectively couldn’t tell whether Gerald was joking or serious or somewhere in between.

“And so,” Gerald continued, his voice rising, “we come to one of those facts of human evolution that I would not have predicted. As we humans spent more and more time standing upright and walking around on our hindlimbs, it turned out that, over thousands of generations, people who were genetically predisposed to faint survived to reproduce better than people who were not!” He smiled and wrapped up: “Just think about that! Collapsing to the ground at inopportune moments is not just funny — it’s a survival strategy favored by evolution! Whenever I think about that, it kind of blows my mind.”

Gerald stopped and noted the still-varying states of wonder and/or amusement on students’ faces.

The moment was cut short by the entrance of Anastasia Bubble, the biology department secretary, through the lecture-hall door.

She looked uneasy as she walked to Gerald and whispered to him.

“Dr. Cutler, I’m so sorry to interrupt. We just found out that . . . Dr. Stevens passed away this morning.” She held her face taut as if trying not to cry.

Gerald returned her stiff gaze. Herb Stevens was gone? Hadn’t he seen him just yesterday?

“Since he teaches the next class in this room — or, uh, used to,” Anastasia Bubble continued awkwardly, “. . . could you maybe address his class when they arrive at 10? Just briefly?” She looked and sounded apologetic. “Please?”

[Update: the story continues with part 31.]