Lab 4-- Respiratory Flashcards
Conducting portion
Nasal Cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
functional components
The airways
Alveoli
Blood vessels of the lungs
Tissue of the chest wall
Diaphragm
Respiratory control neurons in the brain stem
Respiratory portion
- alveoli (site of gas exchange)
- blood gas barrier is ideal because very thin and large surface area
- composed of alveolar epithelium, basement membranes, interstitium and capillary
endothelium
receptors in respiratory system
- B2 adrenergic
- M3 muscarinic
- smooth muscle tissue and epithelial tissue
Ventilation
- transport of air from the environment to the gas exchange surface in the alveoli
oxygen diffusion
- from the
alveolar air space across the
alveolar-capillary membrane to
the blood and to the
tissues
removal of carbon dioxide
- diffusion from the tissues to the
alveoli
Active process
Inspiration
Diaphragm: Convex at rest, flattens during contraction elongating the thoracic
cavity
- External Intercostals: Contraction lifts the ribs upwards and outwards,
expanding thoracic cavity, important for deep inhalations
- Accessory muscles of respiration: scalene, sternocleidomastoid
Passive process
Expiration
- Chest wall and lungs are elastic and naturally return to their resting state
- Expiratory muscles used only during exercise, forced expiration and disease states
- Abdominal muscles: rectus abdominis, internal and external obliques increases the abdominal pressure and pushes the diaphragm up, drawing air out of lungs
- Internal intercostals muscles: pull the ribs down and inwards decreasing the thoracic volume.
Mechanism of pulmonary ventilation
- When no movement (pressure inside and outside is equal)
- inhale (pressure inside decreases so air flows in)
- exhale ( pressure inside increases so air flows out)
Lung volumes
- tidal volume
- inspiratory reserve volume
- expiratory reserve volume
- residual volume
Tidal volume (Vt)
- volume of air in one inspired or expired normal breath
Inspiratory reserve volume (IRV)
- volume of air that can be inspired in excess of tidal volume
Expiratory reserve volume
- extra amount of air that can be expired after a normal tidal expiration
Residual volume
- volume of gas that remains after maximal expiration
Lung capacities
- total lung capacity
- vital capacity
- functional residual capacity
- inspiratory capacity
Total lung capacity
volume of gas that can be contained within a maximally inflated lung
vital capacity
maximal volume that can be expelled after maximal inspiration
functional residual capacity
- volume remaining in the lungs after normal tidal expiration
inspiratory capacity
- volume that can be taken into lungs after maximal inspiration after normal expiration
COPD pulmonary parameters
FVC: Normal/decreased
FEV1: decreased
FEV1:FVC ; decreased
FEF 25-75: decreased
Restricitve pulmonary disease
FVC: decreased
FEV1: decreased
FEV1:FVC ; normal/increased
FEF 25-75: normal/increased/ decreased
FEF 25-75
forced epiratory flow at 25-75% of FVC
FEV1:
forced expiratory volume in the first second of exhalation
Restrictive pulmonary disease
chest wall deformities, interstitial processes due
to collagen-vascular disease, hypersensitivity pneumonitis, and interstitial fibrosis
Obstructive pulmonary disease
asthma
chronic bronchitis
cystic fibrosis
emphysema
bronchiactasis
Spirometry patterns
Normal: ~80% FEV1:FVC
Obstructive: <80%
Restrictive: >80%
Asthma
- spastic contraction of the smooth muscle in the
bronchioles - chronic inflammatory disorder
- causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly
at night and in the early morning
Intermittent asthma
Normal FEV1 between exacerbations; FEV1
> 80% predicted; FEV1/ FVC normal.
Mild asthma
FEV1 ≥ 80% predicted; FEV1/ FVC normal
Moderate asthma
FEV1 > 60% but < 80% predicted; FEV1/ FVCreduced 5%.
Severe asthma
- FEV1 < 60% predicted; FEV1/ FVC reduced > 5%
Drugs for asthma
- inhaled B2 agonist (bronchodilator)
- SABA (albuterol)
- LABA + inhaled corticosteroids
corticosteroids
- Block inflammatory reaction and effective in reducing asthma symptoms.
- prednisone
Anticholinergics
- Block acetylcholine from causing smooth muscle contraction and producing excess mucus in the bronchi.
- Ipratropium
- tiotropium
ADR of B2 agonist
tachycardia, skeletal muscle tremor and hypokalemia.
ADR of corticosteroids
short-term use – weight gain, hypertension.
long-term use – diabetes, muscle weakness
ADR of anticholinergic
Vision changes, dry mouth, heart rhythm disturbance, postural hypotension,
and cognitive problems (confusion)
Emphysema
- Refers to the distention of the air spaces distal to the terminal bronchiole with destruction of alveolar septa.
- Associated with cigarette smoking, urban living and pollution
chronic bronchitis
- persistent cough with sputum production for at least 3 months for 2 consecutive years.
- Associated with Infections cigarette smoking, air pollution and genetic factors
Bronchiectasis
abnormal permanent dilatation of airways due to chronic necrotizing infection and obstruction
Pulmonary fibrosis
- replacement of lung tissue with fibrous connective tissue, making the lungs stiff and difficult breathing
- Caused by exposure to asbestos, silica, coal dust etc.
Cystic fibrosis
- Is an autosomal recessive disorder caused by defects in the gene for cystic fibrosis transmembrane conductance regulator (CFTR)
- Lack of ion transport prevents water from entering the mucus making it viscous and thus increasing likelihood of infections
- Sweat of CF patients contains high level of NaCl
Pneumonia
- Lung parenchyma/alveolar inflammation and abnormal alveolar filling with fluid.
- Caused by bacteria like Strep. Pneumonia, H. influenza, Klebsiella, staph viruses
Restrictive pulmonary disease
- cannot fully fill their lungs with air. Their
lungs are restricted from fully expanding - results from a condition causing stiffness in
the lungs themselves.
COnditions that can cause restrictive lung disease
- Interstitial lung disease, such as idiopathic pulmonary fibrosis
- Sarcoidosis, an autoimmune disease
- Obesity, including obesity hypoventilation syndrome
- Scoliosis
- Neuromuscular disease, such as muscular dystrophy or amyotrophic lateral sclerosis (ALS)
