Ch. 2: Homeostasis, Allostasis, and Adaptive Response to Stressors, pp. 12-23

Ch. 2: Homeostasis, Allostasis, and Adaptive Response to Stressors, pp. 12-23

Indicators that an individual is experiencing high stress include all the following except

a. tachycardia.

b. diaphoresis.

c. increased peripheral resistance.

d. pupil constriction.

ANS: D

Pupils dilate during stress from the effects of catecholamines. Tachycardia, diaphoresis, and

increased peripheral resistance are indicators of stress and also occur because of

catecholamine release

Which is not normally secreted in response to stress?

a. Norepinephrine

b. Cortisol

c. Epinephrine

d. Insulin

ANS: D

Insulin secretion is impaired during stress to promote energy from increased blood glucose.

Norepinephrine is secreted during stress as a mediator of stress and adaptation. Cortisol is

secreted during stress as a mediator of stress and adaptation and stimulates gluconeogenesis

in the liver to supply the body with glucose. Epinephrine is secreted during stress as a

mediator of stress and adaptation and increases glycogenolysis and the release of glucose

from the liver.

Selye's three phases of the stress response include all the following except

a. allostasis.

b. resistance.

c. alarm.

d. exhaustion.

ANS: A

Allostasis is defined as the ability to successfully adapt to challenges. Allostasis may/may

not occur in response to stress. Alarm, resistance, and exhaustion are the three phases of the

stress response as described by Selye in the general adaptation syndrome.

Many of the responses to stress are attributed to activation of the sympathetic nervous

system and are mediated by

a. norepinephrine.

b. cortisol.

c. glucagon.

d. ACTH.

ANS: A

Norepinephrine is secreted in response to activation of the sympathetic nervous system

during stress by the adrenal medulla. Cortisol is secreted by the adrenal cortex. Glucagon is

secreted by the pancreas. ACTH is secreted by the pituitary gland.

The effects of excessive cortisol production include

a. immune suppression.

b. hypoglycemia.

c. anorexia.

d. inflammatory reactions.

ANS: A

Cortisol suppresses immune function and inflammation and stimulates appetite. Cortisol

leads to hyperglycemia by stimulating gluconeogenesis in the liver.

All the following stress-induced hormones increase blood glucose except

a. aldosterone.

b. cortisol.

c. norepinephrine.

d. epinephrine.

ANS: A

Aldosterone results in water and sodium retention and potassium loss in the urine. It does

not affect blood glucose. Cortisol is a glucocorticoid secreted by the adrenal cortex. Cortisol

stimulates gluconeogenesis in the liver, thus increasing blood glucose. Norepinephrine

inhibits insulin secretion, thus increasing blood sugar. Epinephrine increases glucose release

from the liver and inhibits insulin secretion, thus increasing blood glucose.

Allostasis is best defined as

a. steady-state.

b. a state of equilibrium, of balance within the organism.

c. the process by which the body heals following disease.

d. the overall process of adaptive change necessary to maintain survival and

well-being.

ANS: D

Allostasis refers to the overall process of adaptive change necessary to maintain survival

and well-being.

The primary adaptive purpose of the substances produced in the alarm stage is

a. energy and repair.

b. invoke resting state.

c. produce exhaustion.

d. set a new baseline steady-state.

ANS: A

These resources are used for energy and as building blocks, especially the amino acids, for

the later growth and repair of the organism. The substances do not produce a resting state.

The substances can produce exhaustion if they continue, but that is not the adaptive purpose

of these. Although a new baseline steady-state may result from the stress response that is not

the adaptive purpose of the substances produced during the alarm stage.

Persistence of the alarm stage will ultimately result in

a. stress reduction.

b. permanent damage and death.

c. movement into the resistance stage.

d. exhaustion of the sympathetic nervous system.

ANS: B

If the alarm stage were to persist, the body would soon suffer undue wear and tear and

become subject to permanent damage and even death. Actions taken by the individual

during the resistance stage lead to stress reduction. The resistance stage may or may not

occur following the alarm stage, based on resource availability. The sympathetic nervous

system will continue to function, resulting in continued release of stress hormones.

The effect of stress on the immune system

a. is unknown.

b. has been demonstrated to be non-existent in studies.

c. most often involves enhancement of the immune system.

d. may involve enhancement or impairment the immune system.

ANS: D

Many studies demonstrate that long-term stress impairs the immune system, but many

researchers identify that short-term stress may enhance the immune system.

Aldosterone may increase during stress, leading to (Select all that apply.)

a. decreased urinary output.

b. increased blood potassium.

c. increased sodium retention.

d. increased blood volume.

e. decreased blood pressure.

ANS: A, C, D

Aldosterone increases water and sodium reabsorption and potassium excretion by the renal

distal tubules and collecting ducts, thus leading to decreased urinary output, sodium

retention in the body, and increased extracellular fluid volume. Because it leads to

potassium excretion, aldosterone leads to decreased blood potassium.

Chronic activation of stress hormones can lead to (Select all that apply.)

a. cardiovascular disease.

b. depression.

c. impaired cognitive function.

d. autoimmune disease.

e. overactive immune function.

ANS: A, B, C, D

Excessive cortisol levels promote hypertension, atherosclerosis, and the development of

cardiovascular disease. Chronic overactive stress hormones may result in atrophy and death

of brain cells. Elevated levels of stress hormones are found in individuals with depressive

disorders. Chronic stress leads to immune function impairment, rather than overactive

immune function, and has been implicated in autoimmune disorders.

Events which occur during the alarm stage of the stress response include secretion of (Select

all that apply.)

a. catecholamines.

b. ACTH.

c. glucocorticoids.

d. immune cytokines.

e. TSH.

ANS: A, B, C, D

During the alarm stage, catecholamines (epinephrine, norepinephrine), ACTH,

glucocorticoids, and immune cytokines are secreted. TSH is not secreted during the stress

response.