How does Michael Crichton use imagery in Prey?

Imagery:

"I have a ringing in my ears, which is a bad sign. And I feel a vibrating in my chest and abdomen. The baby is spitting up, not really vomiting. I am feeling dizzy. I hope I don't lose consciousness. The kids need me, especially the little one. They're frightened. I don't blame them. I am too."

"And one thing you could count on was that any big, hot broth of bacteria was likely to get contaminated by a virus, and if that virus couldn't infect the bacteria, it would mutate to a form that could. You could count on that the way you could count on finding ants in your sugar bowl if you left it on the counter too long."