But what is it about a smile that makes it feel sincere or fake? The answer lies in a blend of facial anatomy and emotional authenticity.

Fueled by social media, more boys and men are turning to supplements like amino acids, creatine monohydrate, pre-workout ...

In romance novels and online advice columns, enlarged pupils are commonly enlisted as imagery to indicate sexual arousal and ...

This content was created by our physicians and experts. The biceps brachii muscle is a large muscle that sits in the front of the arm between the shoulder and the elbow joints. It has two attachments ...

The Achilles tendon is a thick tendon located in the back of the leg, just above the heel. It connects the gastrocnemius and soleus muscles in the calf to an insertion point at the calcaneus (heel ...

Edited* by Marc R. Montminy, The Salk Institute for Biological Studies, La Jolla, CA, and approved May 5, 2010 (received for review January 20, 2010) ...