UNIT 4

Question 1

General Adaptation Syndrome (3 Stages)

Answer 1

• Proposed by self in 1946
• GAS responses may be rapid or delayed: nervous response are rapid and endocrine responses may be rapid or delayed

3 Stages:

• Alarm Phase: short-term homeostatic adjustments
• Resistance Phase: long-term homeostatic adjustments
• Exhaustion Phase: failure of homeostatic mechanisms owing to inability to sustain adjustments in resistance phase

Question 2

GAS (4F responses)

Answer 2

GAS results in enhanced body function. consistent with the demands of the 4F responses
(feeding, flight, fight and fuck):
-elevated BP
-Bronchodilation and increased ventilation
-Increased blood glucose
-CNS arousal: enhanched cognitive function (mental alterness), enhanced short-term memory and endorphin secretion (elevated pain tolerance)

Question 3

Describe GAS and Homeostasis

Answer 3

• In healthy individual, stress response restores homeostasis
• Maladaptive behaviours develop in cases where: stressor is prolonged or severe and individuals ability to response is impaired
• Result may be distressed

Question 4

List some disease of different systems that are associated with stress (Table 12-1)

Answer 4

-

Question 5

Desribe Stress and Disease

Answer 5

Stress response may actually cause disease:

• SNS –> vasoconstriction
• Prolonged vasoconstriction –> Ischemia (ex: necrotizing perio dx)

Stress response may be participating factor in disease flare-ups (ex: cold sore flare ups)

Question 6

Describe stress response as an etiologic factor in dx.

Answer 6

-Hypertension:
SNS stimulation –> vasoconstriction –> hypertension
-Coronary artery disease: stress elevates serum cholesterol
-Diabetes mellitus: elevated glucocorticoids –> elevated glucose

Question 7

Stress and Heart Disease Interrelated

Answer 7

Stress -->
Hypertension -->
Increased heart effort --> 
Increased heart O2 requirement --> 
Inability to response to O2 demand (coronary artery disease --> 
Angina

Question 8

Stress as a Exacerbating Factor in Disease

Answer 8

-Exacerbation of pre existing heart disease:
SNS stimulation –> vasoconstriction –> hypertension –> heart forced to work harder
-Multiple sclerosis (mechanisms unclear)
-Rheumatoid arthritis (mechanism unclear)

Question 9

Prolonged Stress Complications (Acute Kidney Failture)

Answer 9

Vasoconstriction can cause renal tubule necrosis and impaired globular filtration which may result in ACUTE KIDNEY FAILURE

Question 10

Prolonged Stress Complication (Gastric Stress Ulcers)

Answer 10

Stress of severe trauma

• SNS stimulation results in vasoconstriction which results in gastric mucosa regeneration impaired and mucosal mucus secretion impaired
• Glucocorticoids results in delayed tissue regeneration

-Both these incidents can result in GASTRIC STRESS ULCERS

Question 11

Prolonged Stress May Cause (3 things “IMD”)

Answer 11

Infection: glucocorticoids inhibit inflammation and immune responses. Opportunistic infections may be present

Malignancies: glucocorticoids effects on immune surveillance and immune responses

Delayed Tissue Repair:

• Glucocorticoids causes tissue break down (tissue catabolism)
• Glucocorticoids causes increased risk of infection
• SNS releases adrenalin which causes vasoconstriction (O2 and nutrient supply to damaged tissue decreases)