Injury associated systemic inflammatory response

Question 1

Which immunological responses occur after injury?

Answer 1

SIRS - systemic inflammatory response syndrome and CARS - compensatory anti inflammatory response syndrome.
Both responses purpose is to return to homeostasis. Excessive inflammatory response or reduced can lead to multiple organ failure, balance between both must be achieved to reach homeostasis.

Question 2

Which cells are produced after trauma or cell stress?

Answer 2

Alarmins or DAMPs (damage associated molecular patterns) along with PAMPs (pathogen associated molecular patterns) interact with specific receptors both on cell surface and intracellular.

Question 3

Which cells are produced after trauma or cell stress?

Answer 3

Alarmins or DAMPs (damage associated molecular patterns) along with PAMPs (pathogen associated molecular patterns) interact with specific receptors both on cell surface and intracellular.

Question 4

Best characterized DAMP is…

Answer 4

HMGB1 (High mobility group protein B1)

Question 5

Can mitochondrial DNA act as a DAMP?

Answer 5

Yes, release of mtDNA triggers inflammatory response and activates macrophage inflammasome.
mtDNA is present 1000x higher in trauma patients.

Question 6

Which receptors mediate innate response to both microbial infection and sterile inflammation?

Answer 6

PRR (pattern recognition receptors)

Question 7

Name PRR (pattern recognition receptor) classes:

Answer 7

TLR (toll like receptor)
NLR (nucleotide like receptor)
CLR(c type lectin receptor)
RLR fuck it

Question 8

Which neuroendocrine pathways respond to injury?

Answer 8

HPA axis (hypothalamic pituitary adrenal) which releases glucocorticoid hormones
Sympathetic nervous system which releases epinephrine, norepinephrine and catecholamines.

Question 9

Which hormones pituitary gland produced?

Answer 9

Anterior lobe produces hGH, ACTH, TSH, LH, FSH, PRL

Posterior lobe stores vasopressin and oxytocin produced from hypothalamus.

Question 10

Which hormones pituitary gland produced?

Answer 10

Anterior lobe produces hGH, ACTH, TSH, LH, FSH, PRL

Posterior lobe stores vasopressin and oxytocin produced from hypothalamus.

Question 11

Describe adrenocorticotropin (ACTH) function.

Answer 11

Produced in response to biological stress.

Main functions are increased production and release of cortisol by the adrenal gland.

Question 12

Describe cortisol function.

Answer 12

Cortisol increase gluconeogenesis, decreases immune response, aids metabolism of fat, protein and carbohydrates, also decreases bone formation.

Question 13

Describe TSH function.

Answer 13

Stimulates thyroid gland to produce T4 and T3, which are responsible for regulation of metabolism.

Question 14

Describe luteinizing hormone.

Answer 14

LH stimulates endocrine cells in gonads to produce androgens.

Question 15

Describe FSH function.

Answer 15

In females stimulate growth and recruitment of immature ovarian follicles.
In males stimulate primary spermatocytes to undergo 1st division of meiosis to form secondary spermatocytes.

Question 16

Describe prolactin function.

Answer 16

Stimulates mammary glands to produce milk.

Question 17

Describe HPA axis once an injury occurs.

Answer 17

Once trauma occurs, hypothalamus will release corticotropin releasing hormone which will stimulate production and secretion of adrenocorticotropin hormone in the ant lobe of pituitary gland. ACTH will act on adrenal glands, stimulating secretion of glucocorticoid hormones, mainly cortisol.

Question 18

Describe HPA axis once an injury occurs.

Answer 18

Once trauma occurs, hypothalamus will release corticotropin releasing hormone which will stimulate production and secretion of adrenocorticotropin hormone in the ant lobe of pituitary gland. ACTH will act on adrenal glands, stimulating secretion of glucocorticoid hormones, mainly cortisol.

Question 19

Describe the layers of adrenal cortex.

Answer 19

Outermost layer is zona glomerulosa, produces mineralocorticoid, aldosterone.
Middle layer is zona fasciculata, produces glucocorticoids, cortisol.
Innermost layer is zona reticularis, produces androgens.

Question 20

Describe adrenal medulla.

Answer 20

Surrounded by adrenal cortex, secretes catecholamines such as epinephrine, norepinephrine and dopamine in response to stimulation by sympathetic preganglionic neurons.

Question 21

Describe sympathetic nervous system response to injury.

Answer 21

Injury occurs which activates SNS, releasing ACh in adrenal medulla, stimulating secretion and production of epinephrine and norepinephrine into the blood. These hormones will activate fight or flight response, increasing heart rate, blood pressure, heart contractility, metabolism, glycogenolysis, gluconeogensis., vasoconstriction, etc.

Question 22

Function of aldosterone.

Answer 22

Regulates mineral balance, blood pressure and homeostasis by sodium reabsorption and potassium excretion.

Question 23

During stress what happens to insulin?

Answer 23

Hyperglycemia and insulin resistance are hallmarks of injury and critical illness.

Question 24

Aldosterone role in injury?

Answer 24

Interferes with insulin signaling pathways, making us more insulin resistant.

Question 25

Insulin is…

Answer 25

Hormone produced in pancreas, which mediates an overall host anabolic state through hepatic glycogenolysis and glycolic, peripheral glucose uptake, lipogenesis and protein synthesis.

Question 26

What are heat shock proteins?

Answer 26

Group of intracellular proteins that are expressed during times or stress such as a burn injury, inflammation, oxidative stress and infection.
They help monitor and maintain proper protein folding.

Question 27

Describe autophagy

Answer 27

Conserved degradation of cell through lysosome dependant regulated mechanism.
Under conditions of hypoxia and low cellular energy, this also occurs to provide additional nutrients for energy production.

Question 28

What are cytokines?

Answer 28

Class of protein signaling compounds essential for innate and adaptive immune responses.
examples: TNF-alpha, interleukins, etc.

Question 29

Describe eicosanoids.

Answer 29

Signaling molecules derived from oxidation of arachidonic acid.
Composed of 3 families:
Prostaglandin PG
Thromboxane TX
Leukotrienes LT

Question 30

Eicosanoid pathway

Answer 30

Eicosanoids are not stored, they are generated in response to stimuli.
Arachidonic acid is released from phospholids by enzyme called phospholipase A2. Enzyme cyclooxygenase can then produce PGs or TXs or lipoxygenase can produce LT or HETE.