Chapter 23 Flashcards
3 stages of breathing
- Ventilation
- Diffusion
- perfusion
Ventilation, perfusion, deffusion
V- movement of air into lungs
P- movement of O2 and CO2 into and out of circulation
D- movement of blood through the pulmonary circualtion.
Decrease in amount of O2 in blood
Hypoxemia
Hypoxemia
- effects are due to compensatory mechanisms of body
- SNS ^ = ^HR, ^BP, vasoconstriction
- ^ serum lactate from anaerobic respiration
- ^ respiratory rate, cyanosis, mental status changes
- ^ RBC production
Hypercapnia
PCO2 greater than 50 mm Hg
too much CO2 in circulation
causes of hypercapnia
hypoventilation
changes in metabolic rate
^ carbohydrate diet
treatment for hypercapnia
- improvement of respiratory muscles (gas exchange)
- provide supplemental O2
Hypercapnia (PCO2 ____)
Hypoxemia (PO2 ____)
PCO2 > 50 mm Hg
PO2 < 60 mm Hg
Bronchia are surrounded by ___
Bronchioles are surrounded by ___
- cartilage & smooth muscle
- smooth muscle only
Autonomic NS controls ___ in breathing
Parasympathetic ____
Sympathetic ___
smooth muscle
- Constriction- through vagus nerve (epi and norepi)
- Dilation- through B2 adrenergic receptor during sress and exercise
Inflammatory disease that causes obstruction to flow of air in/out of lungs
asthma
Asthma is caused by:
overreaction of the airways to irritants
In Asthma, the irritant exposure triggers immune response by: (1st thing)
- Bronchoconstriction (^ inflammatory mediators do this)
- ^ vascular permeability
- ^ mucus production
In Asthma, the irritant exposure triggers immune response by: (2nd thing)
- TH2 cell involvment-
- binds to allergen and triggers B cells to secrete IgE
- IgE binds to mast cells
- Mast cells initiate inflammatory response (mucus & asthma attack)
Asthmatics have more ___ cells that increase their chance to pick up more potential allergens
Th2 cells
Their are 2 types of Asthma:
- Extrinsic (Atopic) Asthma- allergy
2. Intrinsic (Nonatopic) Asthma- Irritation
Extrinsic (Atopic) Asthma
- Hypersensitivity to allergen
- initiated by allergic response
Steps in Atopic Asthma
- mast cells release inflammatory mediators
- this causes an ACUTE response within (10-20 mins)
- Bronchospasm, ^ vessel permeability, ^ mucus production.
- WBC’s enter area, release more inflammatory med.
- Airway inflammation causes LATE-PHASE response (4-8 h later)
Intrinsic (Nonatopic) Asthma is caused by:
- Respiratory Infections- epithelial damage, IgE produc
- Exercise, Hyperventilation, cold air
- Inhaled Irritants- inflammation, vagus reflex
Their are 2 types of Chronic Obstructive Pulmonary Disorder, what are they?
- Emphysema
2. Chronic Obstructive Bronchitis
Emphysema is characterized by:
- destruction of alveoli and capillary beds
- Neutrophils in the alveoli secrete proteases (breaks down elastin)
- can have genetic defect in a1-antitrypsin
a1-antitrypsin deactivates ____ which deactivates ____
elastase (which is used to breakdown elastin)
which deactivates
elastin which destroys alveoli ability to expand and contract
Emphysema main symptoms:
- barrel chested- air constantly getting trapped and can’t escape the lungs, so its distended
- Pink Puffer- ppl purse lips to create more resistance in air so their airways don’t collapse
Emphysema creates ___ of airways that then ___ on exhale. This contributes to the inability of a person to breathe fully.
overextension of the airways that then collapses on exhale.
Chronic bronchitis has 3 main characteristics:
- Chronic irritation of airways
* ^ mucous cells, ^ mucus hypersecretion - Productive cough- lasting at least 3 months
- Blue Bloaters
- can’t ^ respiration enough to maintain O2 levels
- cyanosis and polycthemia
Chronic Bronchitis can be diagnosed from emphysema by it’s distinctive: (3)
- tripod position to use accessory muscles in breathing
- wheezing and crackling in lungs
- Productive cough
Pulmonary Embolism signs and symptoms:
- severe, crushing chest pain
2. loss of consciousness
How to diagnose pulmonary embolism:
- Pulmonary Angiography- passing of catheter directly into pulmonary arteries
Most common causes of COPD:
- Smoking
- Exposure to occupational dusts and chemicals
- Airway infections
- Asthma
- Airway hypersensitivity
The term chronic obstructive pulmonary disease encompasses 2 types of obstructive airway disease:
- Emphysema
2. Chronic Obstructive Bronchitis
Asthma
Enlargement of air spaces and destruction of lung tissue
Chronic Obstructive Bronchitis
^ in mucus production, obstruction of small airways, chronic productive cough
Emphysema is characterized by:
Loss of lung elasticity and abnormal enlargement of air spaces distal to the terminal bronchioles, with destruction of alveolar walls and capillary beds.
2 causes of emphysema
- Smoke- kills lung tissue
2. Deficiency in a1-antitrypsin: antiprotease enzyme that protects the lung from injury
Emphysema results from:
Breakdown of elastin and other alveolar wall components by an enzyme called proteases
Mechanisms of COPD (4)
- Inflammation and fibrosis of the bronchial wall
- Hypertrophied mucous glands—- lead to excess mucus and obstructed airways
- Loss of alveolar tissue—- decreased surface area for gas exchange
- Loss of elastic lung fibers—- airway collapse, obstructed exhalation, air trapping
Elastase
Breaks down fibers and elastin in lungs
Antiprotease (alphatripsin)
Protects the lungs from protease ingestion but smoking and other irritants signal neutrophils to secrete more proteases, overpowering the antiprotease enzymes
Asthmatics are called “pink puffers” because:
Lack of cyanosis
Use of accessory muscles “pursed-lips” breathing
-loss of lung elasticity and hyperinflation of the lungs causes airways to collapse during expiration because of pressure in the surrounding lung tissues exceeding airway pressure.
Emphysema pt’s often have “barrell chest”, why?
-air becomes trapped in alveoli and lungs, producing an increase in the anteroposterior dimensions of the chest.
Those with chronic bronchitis are called “blue bloaters”, why?
In reference to their cyanosis and fluid retention associated with R-sided heart failure.
COPD symptoms for both emphysema and chronic bronchitis
- respiratory impairment on exhale
- increased work of breathing but decreased effectiveness
- exertional dyspnea
- labored breathing even at rest
- crackles and exploratory wheezing lung sounds
- accessory muscle use (tripod stance)
Pursed lips breathing does what for those with COPD
Enhances air flow bc it increases the resistance to the outflow of air and helps to prevent airway collapse by increasing airway pressure
Pulmonary emboli originate from where?
Most arise from deep vein thrombosis int he large veins in the lower leg.
A congenital defect in a1-antitrypsin in a patient who is also a long-term smoker is likely to lead to which of the following conditions:
emphysema
