L3+4 Shock etc

Question 1

What is shock?

Answer 1

Inadequate oxygen delivery and/or consumption at a cellular level.

Question 2

What is metabolism?

Answer 2

The set of chemical processes that maintain life; includes anabolic (building) and catabolic (breaking down) processes.

Question 3

What is perfusion?

Answer 3

The passage of fluid through the circulatory system or lymphatic system to an organ or tissue.

Question 4

What is ventilation?

Answer 4

The mechanics of air moving in and out of the lungs.

Question 5

What is oxygenation?

Answer 5

The process of oxygen diffusing passively from alveoli to pulmonary capillaries.

Question 6

What is dead space?

Answer 6

The volume of air that is inhaled but does not take part in gas exchange.

Question 7

What is preload?

Answer 7

The stretch of ventricles before contraction; blood volume in ventricles prior to contraction.

Question 8

What is afterload?

Answer 8

The pressure heart must work against to eject blood.

Question 9

What is third spacing?

Answer 9

Shift of fluid from vascular to interstitial space.

Question 10

What is acidosis?

Answer 10

Condition of excess acid in body fluids.

Question 11

What is the Trauma Triad of Death?

Answer 11

Metabolic acidosis, hypothermia, and coagulopathy that reinforce each other in a lethal cycle.

Question 12

What is oliguria?

Answer 12

Decreased urine output.

Question 13

What is the formula for cardiac output?

Answer 13

CO = SV × HR (Stroke Volume × Heart Rate)

Question 14

What is the formula for blood pressure?

Answer 14

BP = CO × PVR (Cardiac Output × Peripheral Vascular Resistance)

Question 15

How do you calculate approximate blood volume?

Answer 15

70ml/kg body weight.

Question 16

What is hypovolaemic shock?

Answer 16

Shock due to decreased blood volume (from haemorrhage, dehydration, burns, etc.).

Question 17

What is cardiogenic shock?

Answer 17

Shock due to heart pump failure, causing decreased stroke volume and cardiac output.

Question 18

What is obstructive shock?

Answer 18

Shock due to mechanical obstruction of blood flow through central circulation.

Question 19

What is distributive shock?

Answer 19

Shock due to loss of blood vessel tone (vasodilation) or inappropriate redistribution of blood volume.

Question 20

Name three types of distributive shock.

Answer 20

Septic shock, anaphylactic shock, and neurogenic shock.

Question 21

What is aerobic metabolism?

Answer 21

Breaking down substrates into ATP with oxygen; occurs in mitochondria.

Question 22

What is anaerobic metabolism?

Answer 22

Breaking down carbohydrates into ATP without oxygen; occurs in cytoplasm.

Question 23

How much ATP is produced per glucose molecule in aerobic metabolism?

Answer 23

~36 ATP.

Question 24

How much ATP is produced per glucose molecule in anaerobic metabolism?

Answer 24

2 ATP.

Question 25

What is the end product of anaerobic metabolism?

Answer 25

Lactic acid.

Question 26

What are the consequences of lactic acidosis in shock?

Answer 26

Reduced cardiac contractility, vascular hyporesponsiveness to vasopressors, impaired enzyme function, reduced oxygen-carrying capacity.

Question 27

How does the body detect low blood pressure?

Answer 27

Via baroreceptors (in carotid arteries and aortic arch) and chemoreceptors (monitoring O₂, CO₂, and H⁺).

Question 28

What is the 'fight or flight' response?

Answer 28

The sympathetic nervous system's response to stress, including increased heart rate, vasoconstriction, and redirection of blood flow.

Question 29

What are adrenergic receptors?

Answer 29

Cell membrane receptors that respond to catecholamines (epinephrine and norepinephrine).

Question 30

What effect do alpha receptors have?

Answer 30

Cause vasoconstriction of small arterioles and arteries, increasing peripheral vascular resistance.

Question 31

What is the inotropic effect?

Answer 31

Increased force of heart contraction.

Question 32

What is the chronotropic effect?

Answer 32

Increased heart rate.

Question 33

What is the dromotropic effect?

Answer 33

Accelerated electrical conduction through the heart.

Question 34

What hormones are released during sympathetic activation?

Answer 34

Epinephrine (adrenaline) and norepinephrine (noradrenaline).

Question 35

What is the effect of beta-1 receptors?

Answer 35

Increase heart rate and force of contraction.

Question 36

What is the effect of beta-2 receptors?

Answer 36

Cause bronchodilation and vasodilation in skeletal muscle.

Question 37

What are the metabolic effects of alpha receptor activation?

Answer 37

Glycogenolysis and gluconeogenesis, increasing blood glucose.

Question 38

What does RAAS stand for?

Answer 38

Renin-Angiotensin-Aldosterone System.

Question 39

What triggers renin release?

Answer 39

Decreased renal blood flow, decreased filtrate in nephron, and decreased blood pressure.

Question 40

Where is renin produced?

Answer 40

In the juxtaglomerular cells of the kidneys.

Question 41

What does renin convert?

Answer 41

Converts angiotensinogen to angiotensin I.

Question 42

Where is angiotensinogen produced?

Answer 42

In the liver.

Question 43

What is ACE?

Answer 43

Angiotensin-Converting Enzyme, which converts angiotensin I to angiotensin II.

Question 44

Where is ACE primarily found?

Answer 44

In the vascular endothelium of lungs.

Question 45

What are the four major effects of angiotensin II?

Answer 45

1) Direct vasoconstriction of arterioles, 2) Stimulation of aldosterone release, 3) Enhancement of ADH release and action, 4) Stimulation of thirst center.

Question 46

What is the function of aldosterone?

Answer 46

Increases sodium and water reabsorption in kidneys, increasing blood volume.

Question 47

Where is aldosterone produced?

Answer 47

In the adrenal cortex.

Question 48

What does ADH stand for?

Answer 48

Antidiuretic Hormone (also called vasopressin).

Question 49

What are the two primary stimuli for ADH release?

Answer 49

Increased plasma osmolality and decreased blood pressure.

Question 50

Where is ADH synthesized?

Answer 50

In the supraoptic and paraventricular nuclei of the hypothalamus.

Question 51

Where is ADH released from?

Answer 51

The posterior pituitary gland.

Question 52

What receptors does ADH bind to in the kidneys?

Answer 52

V₂ receptors.

Question 53

What is the primary action of ADH in the kidneys?

Answer 53

Increases water permeability of collecting ducts, enhancing water reabsorption.

Question 54

What happens to water following ADH action?

Answer 54

More water is reabsorbed from urine back into circulation, increasing blood volume.

Question 55

What vascular effect does ADH have at higher concentrations?

Answer 55

Causes vasoconstriction by binding to V₁ receptors on vascular smooth muscle.

Question 56

What are the three stages of shock?

Answer 56

Early/Compensatory Phase, Progressive Phase, and Irreversible Phase.

Question 57

What are typical signs of compensatory shock?

Answer 57

Anxiety, tachycardia, cool/pale skin, decreased urine output, increased thirst, rapid respirations.

Question 58

What occurs in the progressive stage of shock?

Answer 58

Lethargy, metabolic acidosis, enzyme leakage, vascular hyporesponsiveness, increased capillary permeability, activation of clotting cascade.

Question 59

What defines irreversible shock?

Answer 59

Circulatory and respiratory failure as compensatory mechanisms fail, leading to death.

Question 60

What percentage of blood loss typically causes hypovolaemic shock?

Answer 60

15-20% acute loss.

Question 61

What happens with 10% blood loss?

Answer 61

No effect on cardiac output or arterial pressure.

Question 62

What happens with 10-25% blood loss?

Answer 62

Cardiac output falls but arterial pressure is maintained via increased PVR.

Question 63

What happens with 30-40% blood loss?

Answer 63

Cardiac output and arterial pressure decrease to zero.

Question 64

How much blood loss occurs with a fractured femur?

Answer 64

1000-2000ml.

Question 65

How much blood loss occurs with a fractured pelvis?

Answer 65

1000ml+.

Question 66

What is the immediate response to hypotension (seconds)?

Answer 66

Sympathetic nervous system activation.

Question 67

What is the short-term response to hypotension (minutes)?

Answer 67

ADH vascular effects.

Question 68

What is the intermediate response to hypotension (minutes to hours)?

Answer 68

RAAS vasoconstriction and ADH renal effects.

Question 69

What is the long-term response to hypotension (hours to days)?

Answer 69

Aldosterone, ADH, and thirst mechanisms.

Question 70

How do RAAS and ADH systems interact?

Answer 70

Synergistically - angiotensin II stimulates ADH release, and both hormones increase water retention and can increase peripheral vascular resistance.