PHYSIOLOGIC MANIFESTATIONS OF STRESS

• Pupile dilate of increase visual perception when serious threats to the body arise.

• Sweat production (dhiaphoresis) increases to control elevated body heat due to increased metabolism.

• The heart rate increases, which leads to an increased pulse rate to transport nutrients and by product of metabolism more efficiently.

• Skin is pallid because of constrictions of peripheral blood vessels, an effect of norepinephrine.

• Blood pressure increase because of

1. Constriction of vessels in blood reservoirs, such as the skin, kidneys, and most large interior organs.
2. Increased secretion of rennin, an effect of norepinephrine.
3. Increased sodium and water retention due to release of mineralocorticoids, which resultsin increased blood volume.
4. Increased cardiac output.
5. The rate and depth of respirations increase because of dilation of the bronchioles, promoting hyperventilations.

• Urinary output decreases.

• The mouth may be dry.

• Peristalsis of the intestines decreases, resulting in possible constipations and flatus.

• For serious threats, mental alertness improves.

• Muscle tensions incrase to prepare for rapid motor activity or defense.

• Blood sugar increases becauseof release of glucocorticoids and gluconeogenesis.

• Lethargy, mental lassitude, inactivity (parasympathetic dominance) may ensue.

• There may be decreased physiologic functioning and loss of skeletal muscle tone (parasympathetic dominance)