Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PBL SEM 2 > PBL 2 - ASTHMA > Flashcards

PBL 2 - ASTHMA Flashcards

1
Q

what is asthma?

A

a disease characterised by widespread narrowing of the peripheral airways in the lung, varying in severity over short periods of time either spontaneously or in response to treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is asthma associated with?

A

variable airway obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the background tendancy of asthma?

A
  • genetic factors
  • environmental influences in early life (eg. maternal smoking, intrauterine nutrition, avoidance of dietary and environmental allergens in 1st few years of life)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are some specific triggers of asthma?

A
  • excreta of house dust mites
  • pollens
  • exercise or emotion
  • cold air
  • resp tract infections
  • fungal spores
  • animal fur, dander, saliva
  • occupational factors
  • drugs (eg. aspirin)
  • environmental pollutants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

name some structural changes due to asthma in the airways

A
  • smooth muscle hypertrophy and hyperplasia due to exercise of coughing
  • absence of ciliated epithelium — lack of cilia unable to move mucus — serious consequences in fight against infection
  • mucus plug — block small peripheral airways
  • basal membrane thickens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are basal cells?

A

lung stem cells — replace damaged cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the function of ciliated epithelial cells?

A

move mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the effect of cold air or dehydration on cilia?

A

cilia are bathed in a watery fluid — if this is diminished, there is an increase chance of an asthma attack as the antigen can get closer to the nerve terminals

  • makes the lining hyperosmolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the effect of a hyperosmolar lining on mast cells?

A

causes them to release histamine and prostaglandins, thus causing inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens when an allergen binds to a IgE antibody on a mast cell?

A
  1. very fast release of early (preformed) mediators including eosinophil chemotactic factor
  2. release of later mediators (synthesised de novo) — takes more time

this is why there is a fast response, get better get worse again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens when an allergen binds to an eosinophil bearing IgE antibody?

A

release of major basic protein — epithelial desquamation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the early mediators released by the mast cell?

A

histamine and chemotactic factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the effect of histamine release?

A

contraction of airways smooth muscle, increased vascular permeability, increased bronchial secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the effect of chemotactic factors release?

A

infiltration of airway wall by neutrophils and eosinophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the later mediators released?

A
  • leukotrienes C4, D4, E4 and prostaglandin D2
  • major basic protein from eosinophils
  • B-cell activating factor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the effect of leukotrienes released?

A

contraction of airways smooth muscle, increased vascular permeability, increased bronchial secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the effect of major basic protein secretions?

A

epithelial desquamation = loss of ciliated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

B-cell activating factor release?

A

mast cell participates in this. a much later mediator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is pulmonary fibrosis associated with in terms of FEV 1 + FVC?

A

reduced FVC but normal FEV1/FVC ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how do we diagnose asthma?

A
  • a history of recurrent episodes of symptoms, ideally corroborate by variable peak flows when symptomatic and asymptomatic
  • symptoms of wheeze, cough, breathlessness and chest tightness that VARY OVER TIME
  • personal/family history of other atopic conditions
  • recorded observation of wheeze heard by a healthcare professional
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is FEV1?

A
  • Forced Expiratory Volume 1

- how much air you can exhale in one second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is FVC?

A

= Forced Vital Capacity

- total amount of air you can exhale forcefully in one breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does a reduced FEV1/FVC ratio indicate?

A

obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how can spirometry and salbutamol be used together to diagnose asthma?

A
  • administer 4 puffs of salbutamol (bronchodilator, beta 2 agonist)
  • redo the spirometry 15 mins later
  • looking for a significant improvement in asthmatic patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how can you diagnose asthma with a peak flow meter?

A
  • patients take this home, take the best of 3 and record the results in a diary
  • results from patients with asthma will show a particular pattern (higher value in afternoon than in morning)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how can FeNO be used to diagnose asthma?

A
  • measure exhaled nitric oxide
  • inflammatory marker in the airways that can be elevated in patients with asthma
  • particularly useful in patients with allergic type asthma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is bronchoprovocation testing?

A
  • get patients to inhale a chemical that is an irritant of the airways and cause a drop in FEV1
  • give them progressively increasing concentrations of this to breathe in through a nebuliser
  • keep repeating the FEV1 and plot the % fall
  • if we can make it fall 20% then this is a positive test
  • suggests the airways are irritable and that giving this irritant causes the airways to become twitchy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

diagnose asthma with an allergy test?

A

skin prick test or measure specific IgE to allergens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is precision medicine?

A

targeted treatments to the needs of individual patients, on genetic, bio marker, phenotypic or psychosocial characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is asthma characterised by?

A

chronic airway inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

how do we know that asthma is a heritable trait?

A

concordance is higher in monozygotic than dizygotic twins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what chromosomes are asthma genes identified in?

A

GWAS-16 chromosomes

33
Q

when is asthma most common in males and females?

A

more common in boys before puberty, and women after puberty

34
Q

what is the major mite allergen and where is it mostly found?

A

Der p 1 — mite fecal particles

35
Q

what is the associated between maternal and paternal smoking and symptoms of asthma?

A
  • children who’s mother smoke are more likely to be wheezy
  • risk is highest if mother smoked in 1st year of life
  • the more the mother smokes, the stronger the effect
  • early exposure and number of cigarettes both matter
36
Q

what are the links between other factors and asthma?

A
  • breastfeeding — no evidence
  • nutrition — fast food increases risk, fruit is protective
  • obesity — increases risk
  • sedentary lifestyle — increases risk
37
Q

what does the exposure to antigen cause CD4 T cells to do?

A

differentiate into Th2 cells

38
Q

what do Th2 cells secrete?

A

Il-4 and Il-5

39
Q

what are the effects of Il-4 and Il-5?

A
  • Il-4 — causes B cells to become plasma cells and begin secreting IgE
  • Il-5 — acts on eosinophils and mast cells, making them reactive to the new antigen. other factors also released that are chemotactic agents for eosinophils
40
Q

what does the IgE bind to and what then happens?

A
  • mast cells in the mucosa — initial exposure doesn’t cause a reaction
  • IgE sits on the mast cell surface waiting to come into contact with the antigen again
41
Q

what happens upon re-exposure to the antigen?

A

mast cells will be activated and will degranulate — release inflammatory mediators

42
Q

why is there an increased response to any antigens in asthmatics?

A

there are increased numbers of mast cells in both the airway secretion and the epithelial lining of the lungs

43
Q

what do the mast cells release usually within the first few minutes of the initial exposure to the antigen?

A

histamine and prostaglandin (as well as leukotrienes, particularly LTC4)

44
Q

what is the late stage reaction caused by?

A

the accumulation of eosinophils (and some neutrophils) at the site

45
Q

late stage reaction vs initial phase reaction

A
  • late stage is a more sustained inflammation

- the initial phase is more bronchoconstriction without as much underlying inflammation

46
Q

what are good at treating the initial phase reaction?

A

bronchodilators (beta-adrenergics)

47
Q

what are good at preventing the inflammation that causes the late phase reaction?

A

steroids (and other anti-inflammatories)

48
Q

what types of cells are present in the bronchial epithelium?

A

pseudostratified columnar epithelial cells

49
Q

what cells are present in the lamina propria?

A

macrophages and mast cells (mast cells secrete histamine)

50
Q

what surrounds the lamina propria?

A

smooth muscle cells

51
Q

name key differences between a normal and asthmatic bronchiole wall

A

in asthma:

  • more goblet cells — more mucus production
  • increase in eosinophils in mucus and tissue
  • thickened basement membrane
  • increase in mast cells in lamina propria (more histamine release)
  • increase in other cells in lamina propria such as neutrophils and Th cells
  • smooth muscle hypertrophy
52
Q

what are the 3 characteristics of asthma?

A
  1. air flow obstruction
  2. bronchohyper-responsiveness (due to histamine release)
  3. inflammation (due to increase in neutrophils and other immune cells in the area)
53
Q

where are Th1 cells normally found?

A

lungs

54
Q

what is important about Th2 cells in asthma?

A

not normally found in the lungs, however ins asthma they are unregulated — creates an imbalance between Th1 and Th2 cells in the lungs

55
Q

Th1 vs Th2 cell function

A
  1. Th1 — promote inflammation by increasing cell mediated immunity
  2. Th2 — promote inflammation by increasing humoral immunity (antibody production)
    [stimulate plasma cells through Il-13 + Il-4 to promote IgE production by plasma cells which then goes to bind to mast cells]
    [stimulate eosinophil production through Il-5]
56
Q

why can asthma be worse at night?

A
  • increased exposure to allergens
  • airways tend to narrow during sleep — increased airflow resistance
  • cold room at night — dehydrates watery fluid that surrounds cilia — allergens can get closer to the nerve terminal — increases chance of an asthma attack
  • adrenaline levels are lowest at night — adrenaline helps to keep the muscle in the walls of the bronchi relaxed so that the airways remain wide
57
Q

what is adherance?

A

extent to which a person’s behaviours are aligned with treatment management plans agreed with a medical professional

58
Q

what affects adherance?

A
  • lack of knowledge about disease
  • lack of motivation and self-efficacy
  • physical and social opportunities
  • psychological and physical capability
59
Q

what pulse oximetry levels in relation to asthma?

A
  • 97% + = mild asthma
  • 92-97% = moderate asthma
  • < 92% = severe asthma
60
Q

normal values of blood gases

A
  • Hb = 13.3 - 17.7 gl/dl
  • pH = 7.37 - 7.45
  • PCO2 = 4.7-6.4 kPa
  • PO2 = over 10.7 kPa
61
Q

what is the respiratory rate and what are normal values? in asthma?

A

= number of breaths per minute

  • should be between 12 and 20 at rest
  • may be above 30 in asthma
62
Q

dry cough in asthma?

A
  • doesn’t produce expel mucus or phlegm
  • a response to an irritant that forces the bronchial tubes to spasm/constrict due to swelling and constriction of the airways
63
Q

what gene can make you susceptible to asthma?

A

PHF11 — increases IgE production

64
Q

what is the molecule which, secreted by IgE activated eosinophils in asthmatic patients, stimulates epithelial desquamation?

A

major basic protein

65
Q

what is the most common side effect of using a beta 2 agonist inhaler?

A

tremors

66
Q

what is the Henderson Hasselbalch equation used to calculate?

A

blood pH and estimated [HCO3-]

67
Q

the dorsal resp group is inhibited by signals from which other centre?

A

pneumotaxic

68
Q

what stimuli do the central chemoreceptors in the ventral side of the medulla respond to?

A

an increased PCO2

69
Q

what is trans pulmonary pressure a measurement of?

A

strength of elastic forces in the lungs

70
Q

if a 2 week trial of corticosteroids is given to a patient with suspected asthma, how much improvement in FEV1 should be seen after the trial to confirm the presence for reversible elements?

A

> 15%

71
Q

in a blood test, the cellular levels of which cell are measured to aid in the diagnosis of asthma?

A

eosinophils

72
Q

what is the definition of a psychosomatic illness?

A

a disorder in which the physical symptoms are caused or exacerbated by psychological factors, such as migraine headache, lower back pain, or irritable bowel syndrome

73
Q

approx how many people die from asthma each year?

A

250,000

74
Q

in extrinsic asthma, allergens bind to which immunoglobulin to cause a reaction?

A

IgE

75
Q

what does beclomethasone inhibit?

A

leukocyte infiltration

76
Q

major basic protein is an inflammatory mediator released in the lungs by which cells?

A

eosinophil

77
Q

what class of drug is ipratropium?

A

muscarinic receptor antagonist

78
Q

in meta-analysis, the probability of an event occurring in the treatment group compared to the probability in the control is known as what?

A

risk ratio

PBL SEM 2 (44 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions