The Bionic Woman actress explained that she enjoyed working with Kevin McKidd on new BBC Scotland drama One Night In Emergency because he had also spent time in the States.
"It's funny but I met Kevin when we were both in America," she said. "I was doing Bionic Woman and he was doing Journeyman. We're in the US, playing leading characters in big productions. We're in huge trailers and it's always really sunny.
"Next minute, we're in Glasgow, he's driving me to rehearsals, and it's pouring with rain. We're filming in a deserted hospital in the middle of the night and I'm on my way to visit a morgue. It's different, to say the least."
Ryan added that everything is "bigger" in America, saying: "There is an element of razzle-dazzle to it all, I guess, but the sheer scale of it is incredible. But it's so nice to have someone like Kevin who has been through the American experience, someone you can talk to about it and go, 'Wow - that was crazy'."
Ryan also said that she had felt uncomfortable when she was invited to "gifting suites", in which celebrities are offered new products to try for free.
"It's a bit strange standing there thinking, 'I don't know if I should take this stuff because I don't need it'," she said. "But everyone is saying, 'Take it, take it'. I settled on a pair of Ray-Bans and felt that was enough."