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

A 35-year-old male presents with knee pain and swelling after twisting his knee while playing soccer. He reports a sensation of the knee “locking” and “giving way.” Physical examination reveals joint line tenderness and a positive McMurray test.  What is the most likely diagnosis? 

Which of the following substances is released by activated platelets to recruit more platelets to the site of injury? 

A 45-year-old male with a history of osteoporosis is found to have low bone density on a DEXA scan. Laboratory tests show normal calcium and phosphate levels.  What is the most likely explanation for his low bone density? 

What is the significance of increased sporadic DNA mutations in older adults? 

A 30-year-old male athlete experiences increased bone density in his lower limbs after a period of intense training.  Which cells are primarily responsible for this adaptive response? 

What is the first step in the degeneration process of herniated disc disease? 

A 40-year-old male is diagnosed with Li-Fraumeni syndrome, a hereditary cancer syndrome associated with mutations in the TP53 gene.  What is the primary function of the TP53 gene in normal cells? 

A 7-year-old girl presents with headaches, vomiting, and difficulty walking. MRI reveals a mass in the posterior fossa.  What is the most likely diagnosis?