ch. 11.3 Stress and health

Question 1

What function does cortisol play in the initial response to stress?

Answer 1

Cortisol increases blood levels of glucose and there- fore makes more energy available.

Question 2

How does McEwen’s definition of stress differ from Selye’s?

Answer 2

Selye’s definition treated favorable and unfavorable changes as equally stressful.

McEwen’s definition focuses on events that an individual considers threatening.

Question 3

Describe the HPA axis

Answer 3

HPA axis, consisting of the hypothalamus, pituitary gland, and adrenal cortex. Activation of the human hypothalamus induces the anterior pituitary gland to secrete adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal cortex to secrete cortisol, which enhances metabolic activity, elevates blood levels of sugar, and increases alertness

Question 4

What kind of cell releases cytokines?

Answer 4

Leukocytes (white blood cells) release cytokines.

Question 5

What changes do prostaglandins stimulate?

Answer 5

Prostaglandins stimulate the hypothalamus to produce fever, decrease hunger, decrease sex drive, and increase sleepiness.

Question 6

How do the effects of stress mimic the effects of illness?

Answer 6

Stress increases release of cytokines, which commu- nicate with the hypothalamus via prostaglandins. The hypothalamus reacts with the same responses it uses to combat illness, such as inactivity and loss of appetite.

Question 7

How does prolonged stress damage the hippocampus?

Answer 7

Stress increases the release of cortisol, which enhances metabolic activity throughout the body. When neurons in the hippocampus have high metabolic activity, they become more vulnerable to damage by
toxins or overstimulation