Respiratory Flashcards
This contains alveoli, the site of gas exchange
Lung parenchyma
Movement of respiratory gases occurs by
Diffusion
This allows for rapid on-loading of oxygen to hemoglobin.
Allosteric modulation
This leads to an increased thickness of the partition between air and blood.
Pulmonary fibrosis
This leads to an increased thickness of the partition between air and blood.
Emphysema or atelectasis
This area of the brain sets the basic rhythm of ventilation.
Medulla
This area of the brain modifies the rhythm of ventilation.
Pons
This is the major signal that sets the rate and depth of ventilation.
CO2
Lung compartments with ventilation but no matching blood supply to participate in gas exchange are referred to as
Dead space
Total dead space equals
Anatomical dead space (conducting airways) + alveolar dead space (occluded blood flow - pulmonary embolism)
Most common cause of hypoxemia
Mismatched ventilation and perfusion
Best measure of alveolar ventilation is
CO2
Most common cause of hypercapnia is
Hypoventilation
Total ventilation generally matches what?
Cardiac output (around 5-6 liters)
Normal range for V/Q is
0.6 to 3
V/Q mismatching, unless very severe, is characterized by this without or far in excess of hypercapnia.
Hypoxia
This is a measure of lung and chest wall dispensability. Determined by alveolar surface tension and the elastic recoil of the long and chest wall.
Compliance
This is the stretchy connective tissue fiber within alveolar walls that contributes to passive deflation of the lungs.
Elastin
Resistance to stretchability.
Collagen
This works against the compliance factor and occurs at any gas-liquid interface. It refers to the tendency for liquid molecules exposed to air to adhere to one another.
Surface tension
This is produced by type-II epithelial cells in alveoli and it acts as a detergent-like substance that helps keep air stretched open.
Surfactant
Surfactant reduces this
Surface tension
Diseases that have loss of compliance are:
- Pulmonary fibrosis- increased collagen
2. Pulmonary edema- increased interstitial fluid
Diseases that increase compliance:
- Emphysema- loss of elastic tissue
Accumulation of air in the pleural space that can result in partial or complete lung collapse.
Pneumothorax
Air enters but does not leave pleural space.
Tension pneumothorax
Air enters pleural space as a result of chest wall injury or punctures.
Secondary (open) pneumothorax
Air-filled blebs/ blisters on lung surface that form and rupture, allowing air to enter the pleural space. It’s most common in smokers.
Spontaneous (closed) pneumothorax
Abnormal collection of fluid in pleural cavity.
Pleural effusion
Accumulation of transudate or fluid coming from different cells.
Hydrothorax
Exudate that comes from inflammatory processes or immune responses.
Empyema
Blood pooling into the pleural cavity.
Hemothorax
Lymph fluid coming into pleural cavity.
Chylothorax
Collapse of previously expanded lung tissue or incomplete expansion of lungs at birth.
Atelectasis.
Lung tissue remains uninflated at birth often due to insufficient surfactant .
Primary atelectasis
Lungs that have been previously been inflated collapse.
Secondary atelectasis
These disorders are characterized by an increased airway resistance.
Obstructive lung disorders
Obstructive lung disorders include:
- Chronic bronchitis
- Asthma
- Emphysema
This is defined by differences between atmospheric pressure and alveolar pressure.
Flow
This is a chronic inflammatory disorder of the airways. It causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, resulting in airway flow obstruction.
Asthma
This is inflammation of the bronchi. The inflammatory responses impair airflow.
Bronchitis
This is abnormal permanent enlargement of gas exchange airways accompanied by destruction of alveolar walls.
Emphysema
Type of emphysema that results from inherited deficiency of a-1 antitrypsin that inhibits the action of proteolytic enzymes.
Primary emphysema
This type of emphysema is caused by inability of body to inhibit proteolytic enzymes in lungs ( from exposure to toxins or cigarette smoke).
Secondary
This is characterized by lungs that are difficult to inflate. Decreased compliance is the best indicator.
Restrictive lung disorder
A condition characterized by excess connective tissue, particularly elastin in the lungs. Symptoms include sob, fatigue, weakness, chest discomfort, loss of appetite, and rapid weight loss.
Pulmonary fibrosis
This is a condition of excess water in the lungs and accumulation of fluid in the extravascular spaces of the lungs.
Pulmonary edema
Infection of the lower respiratory tract caused by microorganisms.
Pneumonia
Occlusion of portion of vascular bed by embolus that can be a thrombus, tissue fragment, lipids, or an air bubble.
Pulmonary embolism
High blood pressure in pulmonary arteries. Often secondary to increased volume or pressure of blood or narrowing/obstruction of vessels.
Pulmonary hypertension
Right ventricular enlargement. Secondary to pulmonary hypertension caused by disorders of lungs or chest wall.
Cor pulmonale
A fulminate form of respiratory failure characterized by acute lung inflammation and diffuse alveolocapillary injury.
Acute respiratory distress syndrome
The amount of air that moves into and out of lungs during normal breath.
Tidal volume TV
The max amount of air that can be inspired in excess of normal TV.
Inspiratory reserve volume IRV
Max amount that can be exhaled in excess of normal TV.
Expiratory reserve volume ERV
Air that remains in lungs after forced expiration. Increases with age bc of more air trapping .
Residual volume RV
Equals the IRV + TV + ERV and is the amount of air that can be exhaled from the point of max inspiration.
Vital capacity VC
TV + IRV and is amount of air a person can breathe in the beginning at the normal expiratory level.
Inspiratory capacity IC
RV + ERV and is the volume of air that remains in the lungs at the end of normal expiration
Functional residual capacity FRC
Sum of all the volumes in the lungs. Total amount of air that the lungs can hold.
Total lung capacity
Max amount of air that can be rapidly and forcefully exhaled from the lungs after full inspiration.
Forced vital capacity
Volume of air expired in the first second of FVC.
Forced expiratory volume achieved in 1s
The gas exchange function of the lungs takes place here
Respiratory lobules
This is the smallest functional unit of the lung and is supplied by a terminal bronchiole, alveoli, and pulmonary blood vessels.
Respiratory lobule
This consists on alveolar ducts and sacs and are the terminal air spaces of the respiratory tract and the actual site of gas exchange between the air and the blood.
Alveoli
In this, blood moves from the venous to the arterial side of the circulation without moving through the lungs. Most often caused by congenital heart defects.
Anatomic shunt
In this, there is mismatching of ventilation and perfusion within the lung, resulting in insufficient ventilation to provide the oxygen needed to oxygenate the blood flowing through the alveolar capillaries. Most often caused from destructive lung disease that impairs ventilation or from heart failure that interferes with movement of blood through sections of lungs.
Physiologic shunt
Persistent abnormal dilation of the bronchi that is frequently associated with bronchitis.
Bronchiectasis
Inflammatory obstruction of the bronchioles.
Bronchiolitis
Chronic bronchitis gives rise to:
COPD