Unit 7 - Respiratory Disorders Flashcards
(193 cards)
1
Q
What are the 4 functions of respiration?
A
- Ventilation
- Perfusion
- Diffusion
- Circulation
2
Q
What are the 3 things that can cause respiratory failure?
A
- Hypoventilation
- Impaired diffusion
- Pleural disorders
3
Q
What are the three things that can cause hypoventilation (that would result in respiratory failure)?
A
- Depression of respiratory centre
- Disease of respiratory muscles or nerves
- Thoracic cage disorders
4
Q
How can thoracic cage disorder cause hypoventilation?
A
- SCOLIOSIS - a curve in the backbone will impair the movement of the ribs –> impairs breathing, there will be uneven expansion
- KYPHOSIS (humpback) - issue with the expansion of the ribs = less expansion of the chest = compromises ventilation
5
Q
What 4 things can result in impaired diffusion (that would cause respiratory failure)?
A
- Pneumonia
- Interstitial lung disease
- ARDS (acute respiratory distress syndrome)
- Pulmonary edema
6
Q
What are characteristics of pneumonia?
A
- fluid accumulation in the lungs
- expansion will be compromised
- less surface area for diffusion
- respiratory membrane will be thicker = harder to breathe
7
Q
What are the characteristics of interstitial lung disease?
A
- Alveoli now have thick membranes
- harder to breathe b/c diffusion distance would be increased and diffusion would be compromised
8
Q
What are the characteristics of pulmonary edema?
A
- mitral valve stenosis (left ventricular failure)
- fluid in the lungs = less diffusion
9
Q
What are the two pleura of the lungs?
A
- Parietal pleura
2. Visceral pleura
10
Q
What does the pleural cavity contain?
A
Contains a thing layer of serous fluid
11
Q
What is the functional significance of the serous fluid in the pleural cavity?
A
Allows for chest expansion of the lungs
12
Q
What are the three kinds of pleural space disorders?
A
- Pneumothorax
- Pleural effusions
- Fibrothorax
13
Q
What happens if air enters the pleural space?
A
Atmospheric air pressure is greater than alveoli pressure
= compress the alveoli (atelectasis)
14
Q
What are the 4 different kinds of pleural effusions?
A
- Hydrothorax
- Empyema
- Chylothorax
- Hemothorax
15
Q
What kind of fluid is in the pleural space in a hydrothorax?
A
Serious fluid
16
Q
What kind of fluid is in the pleural space in an empyema?
A
Pus
17
Q
What kind of fluid is in the pleural space in a chylothorax?
A
Lymph
18
Q
What kind of fluid is in the pleural space in a hemothorax?
A
Blood
19
Q
What is building around the lungs when a fibrothorax happens?
A
Connective tissue
20
Q
What happens during a pneumothorax?
A
Air enters the pleural cavity
21
Q
Why is a pneumothorax bad?
A
Air takes up space
- restricts lung expansion
- alveoli can collapse b/c the atmospheric pressure is higher than alveolar pressure
22
Q
What are the two kinds of pneumothoraxes?
A
- Spontaneous
- air filled blister on the lung ruptures - Traumatic
- air enters through chest injuries
23
Q
What is an OPEN traumatic pneumothorax?
A
Air enters pleural cavity through the wound on inhalation and leaves on exhalation
24
Q
What is a TENSION traumatic pheumothorax?
A
Air enters pleural cavity through the wound on inhalation but CANNOT leave on exhalation
25
Why can the alveoli collapse if there is a breach of the pleural cavity (pneumothorax)?
Atmospheric pressure is higher than alveolar pressure
| - presses the alveoli shut
26
True or false:
| If an open pneumothorax is small, it will heal be itself
True
27
True or false:
| If an open pneumothorax is large, it will only heal if fixed by surgeons
True
28
What will a patient experience (S/S) with a tension pneumothorax?
Pain and tension!
29
How can a tension pneumothorax result in death?
Inferior vena cava can collapse
| - if there is a LOT of pressure in the RIGHT lung, it can collapse the vein
30
What are three features of a pneumothorax?
1. Tracheal shift
2. Cardiac compression
3. Lung deflation
31
True or False:
| Trachea will shift towards the injury in a pneumothorax
FALSE!
- trachea will shift AWAY from the injury
- atmospheric air will push against the lungs, heart, and trachea
32
What will the lung look like if x-rayed when the patient has a pneumothorax?
When the lung is collapsed, there is a lot of tissue and the lung looks WHITE (it has become more dense)
33
What are the two manifestations of respiratory failure?
1. Hypoxemia
| 2. Hypercapnia
34
What are the characteristics of hypoxemia?
- PO2 < 60 mmHg
- cyanosis results
- leads to impaired function of vital centers
- activation of sympathetic system
35
What happens to the patient (S/S) the sympathetic nervous system responds to low oxygen?
1. Agitated, combative behaviour, euphoria, impaired judgement
2. Convulsion, delirium
3. Stupor, coma
36
Why do patients develop hypotension and bradycardia when in a hypoxemic state?
As oxygen levels decrease, the neurons on the sympathetic nervous system start to fail, the compensation mechanisms fail (loss or compensation or decompensation)
37
What are the characteristics of hypercapnia?
- PCO2 > 50 mmHg
| - respiratory acidosis develops
38
What are the S/S of hypercapnia/respiratory acidosis?
- increased RR
- decreased nerve firing
- carbon dioxide narcosis (tremors, confusion, convulsion, coma)
- decreased muscle contraction
- vasodilation (headache, warm flushed skin)
39
What are 4 obstructive airway disorders?
1. Bronchial asthma
2. COPD (chronic bronchitis and emphysema)
3. Bronchiectasis
4. Cystic fibrosis
40
Why is asthma not classified as COPD?
It is episodic, not chronic
41
Why does respiratory obstruction happen more easily in children than adults?
Airways are MUCH smaller, therefore, an obstruction will happen much more easily
42
What are the two respiratory obstruction that occur in children that increase airway resistance?
1. Extrathoracic airway obstructions
| 2. Intrathoracic airway obstructions
43
What happens in an extrathoracic airway obstruction?
- Prolonged INSPIRATION
- INSPIRATORY STRIDOR
- Patient has difficulty expanding rib cage outward during inspiration
44
Where does extrathoracic airway obstructions occur?
UPPER airways
45
Where does intrathoracic airway obstuctions occur?
LOWER airways
46
What happens in an intrathoracic airway obstruction?
- prolonged EXPIRATION
- WHEEZING
- patient has difficulty pulling ribs inward during expiration
47
When does stridor occur?
Occurs in the extrathoracic airways during INSPIRATION
- When an object is obstructing the upper conducting tube
- Air is forced through a very small space
48
Which airways EXPAND during inspiration (2)?
1. Alveoli (intrathoracic airway)
| 2. Bronchi (intrathoracic airway)
49
What airways constrict during inspiration?
EXTRAthoracic airways
50
When does wheezing occur?
Occurs in the intrathoracic airways during EXPIRATION
- Pressure in the lungs is going up
- Bronchi construct during expiration
51
What are 2 upper airway obstructive disorders in children?
1. Croup
| 2. Epiglottitis
52
What is a lower airway obstructive disorder in children?
Acute bronchiolitis
53
What kind of pitch is associated with stridor?
High pitched sound on inspiration
54
What is croup caused by?
Influenza virus - characterized by inspirational stridor
| - Cough sounds brassy
55
When is croup most prevalent in children? Why?
3 months to 3 years of age
| - B/c their airways are very narrow
56
What is the recommendation for a child that is experiencing croup?
Take a walk in the cold air, in the winter months
| - Maybe cold air reduces inflammation in the airways(?)
57
What are the classifications of asthma (2)?
1. Extrinsic
| 2. Intrinsic
58
What is extrinsic asthma?
Allergic reaction
59
What is intrinsic asthma?
Attacks precipitated by non-allergic factors
60
What are some examples of factors that trigger intrinsic asthma (6)?
- Exercise
- Psychologic stress
- Chemical irritants
- Air pollution
- Bronchial infection
- Aspirin
61
What facilitates the change in the diameter of the airway?
Smooth muscle!
62
What happens to airway resistance when the smooth muscles of the airways contract?
Increases
63
What happens to airway conductance when the smooth muscles of the airways relax?
Increases
64
What is the most common form of asthma in children?
Extrinsic asthma
65
Describe the process of extrinsic (atopic) asthma.
1. Allergen present
2. Mast cells release inflammatory mediators
3. WBCs enter region and release more inflammatory mediators
4. Histamine causes dilation of vessels (red and swollen)
66
How long does it take for inflammatory mediators from mast cells to cause an acute response in atopic (extrinsic) asthma?
10 – 20 minutes
67
When will the late phase response of airway inflammation occur in atopic (extrinsic) asthma?
4 – 8 hours
68
What does extrinsic (atopic) asthma involve?
- Type 1 hypersensitivity
| - Have abundant IgE
69
What airways are affected in asthma?
Intrathoracic airways (not the alveoli)
70
What kind of cells interacts with IgE during an extrinsic asthma attack?
BASOPHIL (mast cells)
71
Describe the steps involved when IgE interacts with basophils (mast cells)
1. IgE on basophil membrane acts as receptors for the allergen
2. Granules in the basophils contain histamine
3. When allergen interacts with the IgE on the basophil cell membrane – Degranulation occurs -> histamine is released
4. Histamine mediates inflammation in the airway wall
5. Mucus secretion and multiplication of muscle cells
72
What are the effects after histamine is released (4)?
- Glands are bigger and more numerous (result of inflammation)
- Basement membrane is thickened
- Smooth muscle hyperplasia (at expense of lumen)
- More glands produce more mucus (further obstructing airway)
73
How can we treat broncho asthma (4)?
1. Bronchodilators
2. Corticosteriods
3. Humidifying air
4. Anti-histamine
74
What do bronchodilators do (2)?
- Open lumen
| - Relaxes smooth muscles of airway
75
What do corticosteroids do?
- Reduce inflammation
- Reduce mucus production
- Reduce growth of smooth muscle
- Increases airway conductance
76
Give an example of a bronchodilator
Ventolin
77
Give an example of a corticosteroid
Flowvent
78
What are the manifestations of asthma (3)?
1. Bronchial smooth muscle constriction
2. Mucosal edema
3. Hypersecretion of mucus
79
What are some causes of intrinsic (nonatopic) asthma (4)?
1. Hypersensitivity to bacteria or viruses infecting respiratory system
2. Exercise, hyperventilation, cold air
3. Inhaled irritants triggering inflammation or vagal reflex
4. Aspirin and other NSAIDs causing abnormal arachidonic acid metabolism
80
Why does intrinsic (nonatopic) asthma occur frequently when a person is exercising (4)?
- There is a lot of water loss (breathing out heavily)
- Na+ remains
- Concentration of ECF increases
- In vulnerable people, the smooth muscle will depolarize more readily
= Bronchospasm
81
What is Ventolin similar to?
Epinephrine and nonepinephrine
| - Sympathetic system is triggered = bronchodilation
82
What do the parasympathetic neurotransmitters cause in the bronchi?
Bronchoconstriction!
- Vagus nerve stimulated
- Released AcH
- Causes bronchoconstriction (only in thoracic cavity)
83
How can aspirin result in intrinsic (nonatopic) asthma?
ASA decreases inflammation – but if someone has an abnormal reaction to it, it can cause bronchoconstriction
84
What are the 2 chronic obstructive pulmonary disorders (COPD)?
1. Emphysema
| 2. Chronic obstructive bronchitis
85
What is emphysema?
COPD – enlargement of air spaces and destruction of lung tissue
- Decreased delivery of gases down into the lower airways
- Decreased exhalation of CO2 OUT of the system
86
What is Chronic Obstructive Bronchitis?
COPD – obstruction of the small airways
- Decreased delivery of gases down into the lower airways
- Decreased exhalation of CO2 OUT of the system
87
Why do alveoli enlarge in emphysema (4)?
- Alveoli lose connective tissue fibers (collagen and elastin)
- Adjacent alveoli become fused (to form 1 BIG alveoli)
- Poor gas exchange
- Smaller surface area for gas exchange
88
What is the pathophysiology behind emphysema?
An imbalance of trypsin and antitrypsin activity in alveoli
(When there is inflammation, trypsin is released from neutrophils. Trypsin breaks down elastin and leads to emphysema)
- Trypsin breaks down proteins of the foreign material in the lungs
89
Why does the body produce antitrypsin?
Antagonizes trypsin so that it does NOT digest the wall of the alveoli
Some people cannot produce ENOUGH antitrypsin
- Would lead to destruction of the alveoli
90
What kind of cell inside the alveoli secretes trypsin?
Neutrophils
91
Why is it more likely that if you’re a smoker that you’ll have emphysema?
Smoking reduces the ability of the cells to produce mucus (simple squamous), so more things get into the lungs. More neutrophils are needed to get rid of these foreign particles. More neutrophils releasing trypsin means that there isn’t enough antitrypsin being secreted = destruction of alveolar wall
92
What are the risk factors of emphysema?
1. Aging
2. Smoking
3. Inhalation of polluted air
4. Genetic mutation of defective antitrypsin
93
Why is it very unlikely that a child will have emphysema?
They haven’t lived long enough for the destruction of the walls of the alveoli
94
What is radial traction?
Return of alveoli to normal size upon exhalation
95
What happens to radial traction if there is a breakdown in elastin?
Radial traction decreases
96
What happens to the concentration of CO2 in alveoli if there is a breakdown of elastin (3)?
- There would be a retention of stale air in the alveoli
- Increase in CO2 in alveoli --> higher CO2 in the blood
- Excessive stimulation of CENTRAL chemoreceptors
97
What happens to the muscles of ventilation if there is an increased concentration of CO2 in the alveoli (4)?
- Central chemoreceptors are stimulated frequently
- Person will breathe faster and more strongly
- Muscles (diaphragm, external intercostals) will build up
- Person will become BARREL CHESTED
98
Why is an emphysema patient (pink puffer) usually lean?
They expend a lot more energy to breathe (more effort) and the muscles for breathing (are built up) and require a lot of energy
99
True or False:
| Emphysema patient’s (pink puffers) usually develop cyanosis
FALSE – they DON’T usually develop cyanosis because they are NOMOXIC (they don’t lack oxygen) – they just can’t get RID of CO2
100
What are the S/S of a pink puffer (emphysema) (6)?
- Increase RR to maintain oxygen levels
- Dyspnea (increased ventilator effort)
- Increase use of accessory muscles
- Pursed-lip breathing
- Unequal chest expansion
- DRY COUGH
101
Why does a pink puffer purse their lips?
Allows them to inhale and exhale more deeply
102
What is the body positioning of a pink puffer?
Usually sit leaning a little forward (increases the ability for the chest to expand)
103
What is the normal breadth:depth ratio of the chest? What is it in a pink puffer?
Normal = 2:1 (breatdth:depth)
| Pink puffer = 1:2 = VERY deep chest, instead of a wide chest
104
What is chronic bronchitis?
Chronic irritation of the airways
| - Patients will WHEEZE
105
What does chronic irritation of the airways cause (4)?
1. Increased number of mucus cells
2. Mucus hypersecretion
3. Inflammatory infiltration of bronchiolar wall
4. Fibrosis of bronchiolar wall (scarring)
106
What is chronic bronchitis characterized by (2)?
1. PRODUCTIVE cough
| 2. Cough over 3 consecutive months for 2 consecutive years
107
What are the S/S of a blue bloater (chronic bronchitis) (6)?
- Excessive airway secretions
- Cannot increase RR enough to maintain oxygen levels
- CYANOSIS
- Polycythemia
- Cor pulmonale
- Obesity
108
Why are blue bloaters (chronic bronchitis) typically obese?
- Because of respiratory distress, they are not physically active
- Because of hypoxia, they have less oxygen to facilitate burning of energy
109
Why do blue bloaters experience polycythemia?
- Kidneys sense reduced oxygen in the blood and release EPO
- EPO increases the # of RBCs in circulation
- If they have TOO many RBCs, the heart has to work harder to push the thick blood
110
What is cor pulmonae and why is it seen in blue bloaters (chronic bronchitis)?
- Increase in polycythemia = thick blood
- COR PULMONALE is the difficulty in pushing thick blood through the lungs (heart failure arising from lung failure)
- Patient might experience RIGHT sided heart failure because the heart is not strong enough to push the thick blood through the small capillaries in the lungs
111
What are 4 clinical features of emphysema (pink puffers)?
- Progressive loss of lung tissue
- Weight LOSS
- Mild hypoxemia, no hypercarbia
- Few secretions
112
What are 6 clinical features of chronic bronchitis (blue bloater)?
- Chronic airway inflammation
- Obese
- Hypoxemia and hypercarbia
- Increased hematocrit
- Cor pulmonale
- Lots of secretions
113
What triggers central chemoreceptors to increase RR?
HIGH CO2 levels
114
What triggers peripheral chemoreceptors to increase RR?
LOW O2 levels
115
What is bronchiectasis?
Infection and inflammation that destroy smooth muscle in airways, causing permanent damage
Classified under COPD
- Could be congenital or result from a tumor or infection
116
What are the clinical features of bronchiectasis (6)?
- Cough
- Purulent sputum
- Hemoptysis
- Chronic sinusitis
- Clubbing of fingers
- Coarse crackles
117
What is hemoptysis?
Bloody saliva
118
What is cystic fibrosis caused by?
A recessive disorder in chloride transport proteins
| - Cystic fibrosis transport regulator (CFTR)
119
What is the average life expectancy of a patient with cystic fibrosis? What is the typical maximum age of life?
- Most people don’t live to be 40 years old
| - Life expectancy is 28 years old
120
Explain the pathophysiology behind cystic fibrosis.
- High concentrations of NaCl in the sweat
- Less Na+ and water in respiratory mucus and in pancreatic secretions
- Results in thick, sticky mucus
- Patient gets airway obstructions and respiratory infections (recurrent)
- Could lead to obstruction of pancreatic and biliary ducts
121
Explain the relationship between the watery fluid and CFTR in cystic fibrosis
- Epithelial cells in bronchi tree secrete mucus (traps foreign particles)
- Watery fluid covers surface of epithelial cells to prevent mucus from sticking
- Fluid is rich in chloride (Na+ follows, and water follows Na+)
- If there is not enough CFTR (transport proteins), then not able to transport enough chloride
- Watery fluid becomes sticky --> mucus is even stickier
Bacteria will feed on the mucus, individuals get a LOT of respiratory infections
122
If a person has cystic fibrosis, what other areas of the body are affected (instead of the lungs) (3)?
- Pancreas (Pancreatic duct blockage)
- GI tract (GI infections)
- Sweat glands
123
What is the management for patients with cystic fibrosis (4)?
- Patient lies on their belly, back is tapped to release some of the mucus
- Anti-biotics
- Early and good management increase life expectancy
- Gene therapy – insert correct gene
124
How is the GI system affected if a person has cystic fibrosis (4)?
1. Pancreatic duct may become blocked
2. Not able to secrete digestive enzymes into the GI tract
3. Ineffective digestion/absorption of nutrients
4. Pancreatic enzymes digest the PANCREAS!
125
What 4 things do restrictive pulmonary disorders include?
1. Chest wall (stiffness and deformity)
2. Pleural (inflammation or space-occupying processes)
3. Parenchymal (fibrosis, atelectasis)
4. Acute respiratory distress syndrome (ARDS)
126
In restrictive pulmonary disorders, __________ is usually normal
FEV1
127
What is a parenchymal disorder?
Something is wrong with the alveoli themselves
128
What is ARDS (acute respiratory distress syndrome) triggered by?
Injury to the respiratory membrane
| - Inflammation follows leading to changes to the respiratory membrane
129
What does ARDS result in?
Reduced diffusion of gases across the respiratory epithelium
130
What is meconium and how does it affect newborn breathing?
Fetal feces
- If there is hypoxia in the uterus the fetus will produce a lot of fecal matter (into the amniotic fluid)
- Going to cause injury to the membranes of the fetal lungs
= Infant respiratory distress syndrome
131
How is adult respiratory distress syndrome different than fetal?
Happens when adults are working in an industry with a lot of particles in the air (dust, glass)
- Causes injury to the membranes of the lungs
- Thickens alveolar membrane, results in less diffusion
132
What are the characteristics of ARDS (3)?
- Injury to respiratory membrane leads to fibrosis
- Pulmonary capillaries become leaky (leads to pulmonary edema)
- Surfactant synthesis decreases (leads to atelectasis)
133
What are the clinical results of ARDs (3)?
1. Higher WOB
2. Shunting of blood
3. Hypoxemia
134
What gets inflamed with pneumonia (2)?
1. Alveoli
| 2. Bronchioles
135
What are the two major forms of pneumonia?
1. Typical
| 2. Atypical
136
Describe typical (alveolar) pneumonia
- Usually resulting from bacteria in the alveoli
| - Fluid collects in the alveoli
137
Describe atypical (interstitial) pneumonia
- Occurs as a result of viral or mycoplasma infections
| - Alveolar septum or interstitium thickens
138
What makes up the thickness of the alveolar membrane? How thick is it?
1. Thin film of fluid
2. Type 1 cells (alveolar membrane)
3. Basement membrane
4. Endothelial cells of the capillaries
- Approx. 0.5 micrometers in thickness
139
During pneumonia, what happens to the thickness of the membrane and the diffusion ability of the gases?
```
Membrane = thickens
Diffusion = decreases
```
140
Describe how atypical pneumonia is different from typical pneumonia
- NO fluid in the alveoli
- Caused by viruses and mycoplasma (smallest type of bacteria, no cell wall)
- Agents affect the basement membrane
- Inflammation causes the basement membrane to thicken
- Harder for gases to diffuse
141
What 4 things can cause pneumonia?
1. Bacteria
2. Viruses
3. Fungi
4. Bacteria-like organisms
142
True or False:
| WBCs are found in the lumen of typical (alveolar) pneumonia
TRUE!
143
True or False:
| RBCs do not escape into the lumen in typical pneumonia
False!
| RBCs DO escape into the lumen of the alveolus in typical pneumonia
144
What happens to the secretions of typical pneumonia if RBCs escape into the lumen of the alveolus?
Sputum will be tinged red
145
In atypical pneumonia where are WBCs found?
Alveolar septum
146
Why is fibrinous exudate formed in atypical pneumonia?
From damage being done to septum
- fibrin is a by-product of bleeding
- this coats the alveolar membrane increasing it's thickness
147
What are the manifestations of pneumonia (3)?
1. Lobar
2. Bronchopneumonia
3. Interstitial
148
What is affected in lobar pneumonia?
Affects an entire lobe of the lung
149
What is the distribution pattern in bronchopneumonia?
Patchy distribution over more than one lobe
150
What thickens in interstitial pneumonia?
Alveolar septum or interstitium thickens
151
What are the manifestations of bronchopneumonia?
- decreases overall function of the alveoli of the lungs
- SOB
- not ALL of the alveoli are affected
152
How many lobes does the right lung have? Left lung?
Right lobe = 3 lobes
| Left lobe = 2 lobes
153
During lobar pneumonia, which lobe is usually affected the most?
INFERIOR LOBE of RIGHT lung
154
Why is the inferior lobe of the right lung most often affected in lobar pneumonia?
Right bronchi is STEEPER than the left one
| - objects (infectious agents) are more likely to fall into right lobe more easily
155
What does it mean for a lung to get consolidated?
It gets sticky
- alveoli are not able to receive much air
- then alveoli don't receive much blood
- Patient's feel SOB because of no gas exchange
156
True or False:
| In lobar pneumonia, the whole bunch (group) of alveoli are affected
True
| - the whole bunch will solidify or consolidate
157
What is affected in interstitial pneumonia?
Alveoli septum
| - entire lung is affected
158
Why do patient's experience SOB and WOB in interstitial pneumonia?
Alveolar walls are thicker - gas exchange is impaired
| - alveoli are CLEAR (not fluid filled)
159
Describe the pathogenesis of typical pneumonia
1. Infection
2, Inflammation
3. Serous exudate
4. Congestion; productive cough
160
What are the S/S of pneumonia?
- fever, chills, malaise, prostration
- cough
- SOB (dyspnea)
- rapid breathing (tachypnea)
161
What is prostration?
Extreme exhaustion
162
What is empyema?
Collection of pus in a cavity of the body
| example: lungs!
163
What are the 6 complications of pneumonia?
1. Pleural fibrosis
2. Empyema
3. Abscesses
4. Bronchiectasis
5. Interstitial fibrosis
6. Cysts
164
What is a long term complication of inflammation in the lungs?
Fibrosis
- can spread into pleural membranes (makes them fuse together)
- HARD to breathe
165
What are abscesses in the lungs?
Large areas of inflammatory tissue
| - can become a restrictive lung disease
166
What is parenchyma?
The functional tissue of an organ
167
Is bronchiectasis a restrictive or obstructive lung disease?
Obstructive
- bronchioles get eaten away, they can collapse
- alveoli that serve these bronchioles will lack oxygen
168
What happens to the alveolar membrane in interstitial fibrosis?
Increase in thickness
169
Why do cysts occur in the lungs?
Inflammation has destroyed tissue and is replaced by fluid
| - those areas are not available for gas exchange
170
What are the systemic effects of pneumonia?
- affects appetite
- temperature regulation
- muscles get broken down b/c of all of the cytokines
171
What is the world's foremost cause of death from a single infectious agent (besides HIV)?
Tuberculosis
172
What is tuberculosis caused by?
Mycobacterium tuberculosis hominis
173
What communities in BC have big problems with TB?
First nations communities
174
What are the characteristics of the agent of TB that make it hard to fight (3)?
1. Protective waxy capsule
2. Can stay alive in "suspended animation" for years
3. Drug-resistant forms have developed
175
What are the steps in an initial TB infection?
1. TB bacteria inhaled
2. Bacteria are ingested by macrophages in lungs
3. Macrophages present them to T cells
4a. Activated T cells kill bacteria
4b. Activated T cells stimulate macrophages to kill bacteria more efficiently
176
How long does it take to develop a (+) TB test after the initial infection?
3 - 6 weeks
| - detectable IN BLOOD
177
What is formed after the initial TB infection?
Granulomatous lesion (Ghon Focus)
178
What does a Ghon Focus contain (3)?
1. Macrophages
2. T cells
3. Inactive TB bacteria
179
If a patient has a Ghon Focus in their lung, are they contagious?
Not necessarily
| - if the patient does not have any ACTIVE TB, then they are NOT contagious
180
When is it possible for a Ghon focus to resolve?
If the patient is a child and the child fights off the infection
- adults cannot fight it off
181
What is sometime deposited into the Ghon focus that would make it easy to see on an x-ray?
Calcium deposits
| - surrounded by fibrous capsule
182
What are the 3 stages of TB?
1. Primary TB
2. Miliary TB
3. Secondary TB
183
When is Primary TB seen in patients?
When they have not been previously exposed
| - seen in infants and children under the age of 5 (most often)
184
When is Miliary TB seen in patients?
Rarely
| - in primary and post-primary TB in individuals with compromised immune systems
185
What happens during secondary TB?
Lung is getting destroyed
| - other organs are destroyed too (they travel throughout the body)
186
What two things can happen after a primary TB infection?
1. Bacteria are isolated in Ghon foci (inactive and not contagious)
2. If immune response is inadequate, bacteria multiply in the lungs (leads to progressive primary TB)
187
What do Miliary TB lesions look like in the body?
Like grains of millet in the tissues (stuff you feed budgies)
188
How does Miliary TB affect other body tissues?
Bacteria may erode blood vessels and spread throughout the body
189
What stage of TB is the stage of active infection?
Secondary TB
190
Why may a secondary TB infection occur?
Follows reinfection of previously healed primary lesions
191
Signs of _____ accompany secondary TB.
Chronic pneumonia
192
What are the clinical manifestations of secondary TB?
- productive cough (with purulent sputum - often bloody)
- anorexia
- malaise
- fatigue
- weight loss
- fever and night sweats
193
What is main cause behind the clinical manifestations of secondary TB?
Release of cytokines
