Credit: Eric McCandless/Getty Images Photo: Season 7: These Arms of Mine
On the last episode of Grey's Anatomy, Callie wanted the million-dollar grant to go toward xenograft research. Xenografts are tissues and organs transplanted from one species to another. For example, organs from pigs and baboons have been transplanted into human bodies.

Meredith wowed Derek with her prowess during the emergency craniotomy. A craniotomy is a procedure in which a window is opened in the skull. This type of operation is used to correct brain traumas like aneurysms and hemorrhages.

Cristina stepped up for Roy, a patient with fungal pneumonia — an infection of the lungs caused by fungi, the spores of which usually enter the body through inhalation. It's treated through anti-fungal medications and sometimes through debridement —the clearing away of affected tissue. That said, fatality rate is as high as 90% in patients with an immunodeficiency.

Sources: cedars-sinai.org, northwestern.edu

RELATED FEATURES:
Who’s On and Who's Off in Season 7, Episode 5?
Get to Know the Music From Grey's Anatomy Season 7, Episode 5