A 25-year-old student studies for a test in medical physiology. The visual contrast of the subject matter is enhanced due to lateral inhibition of the visual input by which cell type in the retina?

A 25-year-old student studies for a test in medical physiology. The visual contrast of the subject matter is enhanced due to lateral inhibition of the visual input by which cell type in the retina?

Which of the following is a positive Babinski's sign?

A 30-year-old female presents with muscle weakness in the lower extremities and palpitations. Her symptoms have been progressively worse over the course of a 2 weeks. She reports to be in great health, but had a period of abdominal pain and diarrhea approximately 5 weeks ago. Her temperature is 98.9 deg F (37.2 deg C), blood pressure 117/82 mmHg, pulse is 102/min, and respirations are 16/min. On physical exam, there is 4-/5 muscle strength throughout the lower extremities. Bilateral patellar reflexes are 1+ and ankle reflexes are absent. Lumbar puncture was performed, and results are pending. Part 2: What is the most appropriate initial treatment?

A 45-year-old male presents with recurrent severe left-sided head pain. The pain develops rapidly and feels as if someone is 'stabbing' his eye. He reports his left eye gets red and watery and that his left eyelid 'droops' during each episode. His headaches last approximately 30 minutes, and have been occurring a few times a day for the past 5 weeks; some of the attacks occur out of sleep and he feels like he can predict what time they will occur each day. He has tried over the counter acetaminophen, which provides no relief. He reports no visual abnormalities. Medical history is significant for a benign lung nodule. He has been smoking cigarettes for the past 25 years. During an attack, the patient appears restless and agitated. Which of the following is most likely the diagnosis?

A 34-year-old woman presents with neck pain. She is accompanied by her husband, who says she appears to have right-turning, tremor-like movement of the neck. The patient describes the pain as muscle spasm-like, and states that her symptoms improve with rest and sleep. She has recently begun taking Citalopram due to being diagnosed with major depressive disorder. She denies any alcohol or illicit drug use. On physical examination, there is right head turning with left lateral head tilt. Jerky head tremor is noted, with spasm and hypertrophy of the left sternocleidomastoid muscle. Which of the following is most likely the diagnosis?