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Flashcards in Physiologic Response to Surgery Deck (65)
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1

Define Stress Response

Hormonal & metabolic changes that are triggered by "stress"

2

Physiological Changes that Occur During the Stress Response

Hormonal
Metabolic
Immunological
Hematological

3

Psychological Changes that Occur During the Stress Response

Fatigue
Malaise
Depression

4

Behavioral Change that Occurs During the Stress Response

Reluctance to move

5

Hormonal Response to Stress

Activation of HPA axis & sympathetic nervous system
Receive input from area of trauma or injury
Normal feedback mechanism fails: system doesn't get shut off

6

Sympathetic Nervous System Response to Stress

Adrenal medulla releases catecholamines
Increased norepinephrine from presynaptic nerve terminals
Leads to tachycardia & HTN

7

Renal Effects due to Activation of the Sympathetic Nervous System

Renin release causes conversion of angiotensin I to II
Aldosterone release leads to Na+ retention

8

Pancreatic Effects due to Activation of the Sympathetic Nervous System

Glucagon release
Decreased release of insulin
Some insulin resistance

9

Hepatic Effects due to Activation of the Sympathetic Nervous System

Glycogenolysis
Increased glucose & lactate concentration
Mobilization of FFA from lipid stores

10

Hormones Released by the Anterior Pituitary in a Stress Response

ACTH
GH
Prolactin

11

What releasing factors are released from the hypothalamus to trigger hormone release from the anterior pituitary?

CRH
GHRF

12

What is the posterior pituitary controlled by?

Hypothalamus: directly

13

Hormones Released from the Posterior Pituitary in a Stress Response

ADH

14

Changes in the Anterior Pituitary During a Stress Response

Increased ACTH
Increased GH
Increased prolactin

15

Increased ACTH Leads to

Increased release of cortisol & glucocorticoids from the adrenal medulla

16

Increased GH Leads to

Increased blood sugar
Antagonizes insulin
May have positive role in wound healing

17

Why is there increased prolactin in the stress response?

Decreased prolactin inhibiting factor

18

Increases in ADH Leads to

Further increase in ACTH

19

Function of Cortisol

Promotion of protein breakdown & gluconeogenesis
Inhibits glucose use & increases blood sugar
Promotes lipolysis further increasing blood glucose
Glucocorticoid anti-inflammatory effects
Mineralocorticoid effects causing fluid retention & potassium loss

20

Function of Insulin

Promotes uptake of glucose into muscle & adipose tissue
Coverts glucose into glycogen & triglycerides
Inhibits protein catabolism & lipolysis

21

Function of Increased Glucagon Release

Promotes hepatic glycogenolysis
Increases gluconeogenesis from amino acids in the liver
Has lypolytic activity

22

Effects of the Stress Response on Thyroid Hormones

Total & Free T3 decrease & return to normal after several days
TSH decrease for 2 hours & then return to normal

23

Carbohydrate Metabolism in a Stress Response

Glucose homeostasis mechanisms are ineffective
Lack of insulin to get sugar into the cells

24

Hyperglycemia Leads to

Wound infection
Impaired wound healing

25

Protein Metabolism in a Stress Response

Increased cortisol & cytokine concentration
Weight loss & muscle wasting
Can measure protein loos indirectly by nitrogen excretion in the urine

26

Increased Cortisol & Cytokine Concentration Leads to

Catabolism primarily from skeletal muscle
Albumin production reduced & alters extracellular volume

27

Lipid Metabolism in a Stress Response

Lipolysis & ketone production

28

Hormones Involved in Water & Electrolyte Metabolism in a Stress Response

ADH
Renin

29

ADH in a Stress Response

Promotes water retention
Concentrates urine

30

Renin in a Stress Response

Stimulates angiotensin II which stimulates aldosterone production
Na+ & water resorption
K+ loss