MCAT Social and Behavioral Sciences : Physiology and Stress
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Example Questions
Example Question #1 : Stress
Which chemical is responsible for the initiation of the stress response?
Dopamine
Antidiuretic hormone
Glucose
Cortisol
Epinephrine
Epinephrine
Epinephrine raises blood pressure and increases glucose production from stored glycogen in response to stress. When glucose is exhausted, the adrenal gland increases its output of cortisol to stimulate glucose synthesis. Dopamine works in the brain to influence bodily movements. Antidiuretic hormone decreases urine output.
Example Question #2 : Stress
People who experience chronic stress exhibit a decrease in which of the following physiological responses?
Blood pressure
Pain
Immune response
Conversion of glucose to glycogen
Fatigue
Immune response
Prolonged stress results in the failure of the immune system when there is not enough energy for it to function. Physical illness takes over. When the body first reacts to stress, catecholamines raise the blood pressure and increase glucose production from stored glycogen. When stress persists, glucose is exhausted and the body looks to alternative fuels to provide energy. The effects of catecholamines, which initiate the stress response, eventually cause headache and back and neck pain.
Example Question #3 : Stress And Emotion
Excerpt from "The Chicago Employment Agency and the Immigrant Worker," Grace Abbott, American Journal of Sociology 1908 14:3, 289-305
In the late nineteenth and early twentieth centuries, immigrants poured into the United States without knowledge of English or American customs. They were also usually unaware of the local cost of living or typical wage. These immigrants turned to employment agencies that would help them find work, for a fee. The extreme dependence of immigrants on the employment agencies coupled with their general ignorance of the American system brought about an ethical dilemma for the employment agent in which it became very easy to take advantage of people seeking a job. This resulted in an extreme prejudice directed at immigrants by the American employment system. A study was conducted in the early 1900s gauged the degree of corruption among employment agents and the results of this study have been provided (see Tables 1, 2, and 3)
Table 1
Table 2
Table 3
Unemployment and underemployment can be major causes for stress. Which of the following physiological responses would be expected for someone in a stressful situation?
I. Increase in cortisol levels
II. Decrease in cortisol levels
III. Increase in thyroid stimulating hormone (TSH)
IV. Decrease in TSH
I and III
I and IV
I only
II and III
I and IV
Cortisol is released in response to stress hormones such as ACTH. These stress hormones also suppress the release of thyroid stimulating hormone, which decreases thyroid activity. So during a stressful situation, ACTH levels increase, which leads to an increase in cortisol levels and a decrease in TSH
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