Brain Bee Challenge: Round V

Cortisol, adrenaline (epinephrine), and endorphins are hormones that are released in response to stress. Cortisol is released by the adrenal glands and helps the body respond to stress by increasing blood sugar levels and suppressing the immune system. Adrenaline, also known as epinephrine, is released by the adrenal glands and prepares the body for a "fight or flight" response by increasing heart rate and blood pressure. Endorphins are natural painkillers that are released by the brain in response to stress and help to alleviate pain and improve mood.

Parkinson's disease is caused by the loss of dopamine in the basal ganglia, a region of the brain that is involved in movement control. Dopamine is a neurotransmitter that helps to transmit signals between nerve cells in the brain, and its depletion leads to the characteristic motor symptoms of Parkinson's disease, such as tremors, stiffness, and difficulty with coordination. This explanation aligns with the fact that Parkinson's disease is associated with the loss of dopamine in the basal ganglia, making it the correct answer.

A circadian rhythm refers to the 24-hour cycle of behavior or physiological change that is regulated by an internal biological clock. This rhythm influences various processes in our body such as sleep-wake cycles, hormone production, body temperature, and metabolism. It helps to regulate our sleep patterns, alertness levels, and overall bodily functions.

Apoptosis is the correct answer because it refers to programmed cell death induced by specialized biochemical pathways. Unlike necrosis, which is a form of cell death caused by external factors such as injury or infection, apoptosis is a tightly regulated process that occurs as part of normal development or in response to certain signals. Mitochondrial starvation is not a recognized term or process related to programmed cell death.

Lithium is commonly used as a mood stabilizer to treat bipolar disorder, also known as manic-depressive illness. This disorder is characterized by extreme shifts in mood, energy levels, and activity levels. Lithium helps to regulate these mood swings and reduce the severity of manic episodes. It is not used to treat schizophrenia or dissociative identity disorder, which are separate neurological disorders with different symptoms and treatment approaches.

Neuritic plaques in Alzheimer's disease are composed of beta amyloid. Beta amyloid is a protein fragment that accumulates and forms plaques in the brain, disrupting communication between neurons and leading to the characteristic cognitive decline seen in Alzheimer's disease. Dopamine and tau are not directly associated with the formation of neuritic plaques in Alzheimer's disease.

C fibers are the unmyelinated peripheral sensory fibers that mediate information about tissue damage. These fibers are slow-conducting and transmit pain signals, temperature changes, and itch sensations. They are found in various tissues throughout the body and are responsible for the perception of pain and discomfort. Unlike myelinated fibers, C fibers do not have a protective myelin sheath, which contributes to their slower conduction speed.

Fragile X mental retardation is the most common cause of inherited mental retardation in males. Fragile X syndrome is a genetic disorder that affects the X chromosome and causes intellectual disability, learning disabilities, and behavioral problems. It is caused by a mutation in the FMR1 gene, which leads to a lack or reduced production of a protein necessary for normal brain development. This condition predominantly affects males, although females can also be carriers.

Myasthenia gravis is a disease that affects the muscle acetylcholine receptors, leading to muscle weakness. It is an autoimmune disorder where the body's own immune system mistakenly attacks the acetylcholine receptors, preventing proper communication between nerves and muscles. This results in muscle fatigue and weakness, particularly in muscles that control eye and eyelid movement, facial expression, chewing, swallowing, and breathing. The correct answer is Myasthenia gravis.

Chlorpromazine is the correct answer because it was one of the first antipsychotic drugs developed in the 1950s. It was widely used to treat symptoms of schizophrenia during that time. Fluoxetine and Lexapro, on the other hand, are selective serotonin reuptake inhibitors (SSRIs) commonly used to treat depression and anxiety disorders, but they are not antipsychotic drugs.