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 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 68-year-old woman is brought to her primary care physician by her son due to concerns about her behavior over the past 9 months. He reports that there were times she would leave the stove on after she finished cooking, causing her husband to always check the stove after meals. Even though he would tell the patient he will be visiting her in a few weeks, she completely forgets when he arrives. He has also noticed she is mildly irritable at things that usually would not bother her. Past medical history is unremarkable, and her only medication is a multivitamin. She is a retired secretary and currently lives with her husband. Her vital signs are unremarkable. Montreal Cognitive Assessment (MoCA) testing is significant for impairments in visuospatial function and memory (0/5 items on delayed recall, even with cues). The rest of the neurological exam is unremarkable. TSH and vitamin B12 tests are normal. Which of the following is most likely to be found on histology?

The two major anatomical divisions of the nervous system are the

During transmission across a typical chemical synapse,

Natural selection tends to correlate the structures of a nervous system with an animal's interaction with the environment. A good example are sessile or slow-moving mollusks such as clams, which