A 50-year-old male presents with numbness and tingling in his ring and little fingers. He reports that his symptoms are worse when he leans on his elbow or bends his arm for extended periods. Physical examination reveals a positive Tinel’s sign at the elbow.  What is the most likely diagnosis? 

A patient who recovered from a previous infection has a rapid and robust immune response upon re-exposure to the same pathogen. Which cells are responsible for this enhanced response in humoral immunity? 

A 50-year-old male with a history of hepatitis B infection is diagnosed with liver cancer.   How can hepatitis B virus contribute to cancer development? 

A patient is infected with a bacterial pathogen. Which cells present antigens to CD4 T cells to initiate an adaptive immune response? 

A 55-year-old female with breast cancer is found to have cells that have undergone epithelial–mesenchymal transition (EMT).  What is the primary consequence of EMT in cancer progression? 

Where do B cells develop and mature? 

A newborn presents with asymmetry in gluteal folds during a well-baby exam. The Ortolani maneuver elicits a palpable “clunk.” Which of the following is the most likely diagnosis? 

A 45-year-old male presents with lower back pain radiating down his left leg. He reports numbness and weakness in his left foot. MRI reveals a herniated disc at the L4-L5 level.  What is the most likely cause of his symptoms? 

A 40-year-old female with a fractured ankle has been in a cast for 8 weeks. She now experiences muscle weakness and stiffness in her lower leg.  What is the most likely cause of her symptoms? 

A 50-year-old female with a family history of breast cancer is found to have a mutation in the BRCA1 gene, a tumor suppressor gene.  What is the most likely consequence of this mutation?