SF3 2 Lecture Material Flashcards
Obstructive Sleep Arpnea
Inspiratory process intact but upper airway obstructed due to fat around pharynx. Also can happen due to enlarged tonsils or too much tissue at back of throat (uvula/soft palate). Larger than average tongue or deviated septum in nose.
Pharyngeal muscles do not contract properly
Pressure Inequalities: Zone 1
PA > Pa > PV
Dorsal Respiratory Groups (DRGs)
Chiefly inspiratory neurons to diaphragm and external intercostal muscles. Responsible for basic rhythm of breathing (12-15 breaths per min)
Input from both chemoreceptor types, stretch receptors, and higher brain centers
Dead Space Volume
Air which a person breathes but is not used for gas exchanges. Fills respiratory passages like nose, pharynx, and trachea (150 mL)
Pressure Inequalities: Zone 3
Pa > PV > PA
Adult Respiratory Distress Syndrome (ARDS)
Severe form of lung injury marked by persistent lung inflammation and increased capillary permeability -> Permeability edema.
X-ray shows airspaces and bilateral alveolar infiltrates.
Diagnosed by Methacholine Test
1) Asthma (main)
2) COPD
3) Allergic Rhinitis
Variable Extrathoracic Lesion
Region of trachea outside thoracic cage. Difficulty during inspiration.
Ex: Fat deposits, vocal chord paralysis, obstructive sleep apnea
Ear Drum Rupture
occurs with hyperbaric descent. Ear canal blocked by cerumen, ear plugs, etc.. Pressure change can rupture ear drum
Vital Capacity
Maximal amount of air which can be inhaled/exhaled by a person. Difference with FVC/TLC is it’s done slowly
Eupnea
normal spontaneous breathing
Functional Residual Capacity
Volume of air in the lung when the lung and chest wall have equal recoil force (2300 mL)
Central Sleep Apnea
Pattern of breathing characterized by normal deep inspiratory cycle interchanged with complete cessation of breathing. Problem with how brain controls breathing
Dyspnea
difficulty breathing that individual is aware of
P-Value Definition
Likelihood to observe data as extreme as the data you actually collected (if null true)
Apnea
complete absence of spontaneous breathing
Biot’s Respiration
Rhythmic but deep respiratory movement which alternate at regular intervals with long respiratory pause. Associated with damage to respiratory center from (1) trauma, (2) stroke, and (3) opioid use
Meningitis patients and disorders of cerebral circulation
Bronchitis
Inflammation of mucous membranes of the bronchi. Primarily a disease of the upper airways
Left-Right Order of Characteristics: Left-Tailed/Skewed Distribution
Mean, median, mode
Pulmonary Angiography
Measured blood flow distribution. Radiopaque substance is injected into pulmonary artery and its movement is monitored by X-rays
Congenital Center Hypoventilation Syndrome (CCHS)
Rare congenital disorder. Central pattern generator inoperative. Insensitivity of chemoreceptors, both to CO2 (pH) and O2.
No automatic control of respiration. Voluntary breathing.. Management via permanent tracheostomy
Kussmaul’s Respiration
Hyperventilation, gasping, and deep and labored respiration. State characterized by high degree of acidosis (diabetic ketoacidosis, kidney failure, diabetic coma)
Centrolobular Emphysema (or Centriacinar)
Most common. Affects superior part of lungs/lobes. Begins in respiratory bronchioles and spread.
Associated with long-term smoking, exposure to chemicals/dust, etc.
Respiratory Centers in the Pons
1) Apneustic Center
2) Pneumotaxic Center
Oxygen Consumption per minute
250 mL/min
Measurable by Spirometer
1) TV
2) FVC
3) FEV1
4) FEF25-75
Statistical Power
Chance an experiment or study finds a positive result assuming that the alternative hypothesis is really true
= 1 - β (aim for 80%)
Change to breathing in Kyphoscoliosis
Underventilation of lungs. FRC and RV are lower
Tension Pneumothorax
More and more air accumulates in the pleural cavity with each breath
Treatment for Right Heart Failure
Nitric Oxide causes smooth muscle relaxation. Nitroglycerin and Nitroprusside are other options but they cause vasodilation everywhere
Required concentration for medication 20 ppm. Toxic at high concentrations
Passive Influence on Pulmonary Vascular Resistance
Reason for only modest rises in pressured with increased cardiac ouput
1) Recruitment of unperfused capillaries
2) Distension of existing pulmonary capillaries
Panacinar Emphysema
Entire alveolus destroyed uniformly; predominant in lower half.
Observed in patients with Alpha1-antitrypsin deficiency or ritalin induced lung emphysema
Non-Tension Pneumothorax
There is air in the pleural cavity but it does not accumulate with each breath
Silicosis/Asbestosis
Restrictive Diseases. Pulmonary fibrosis caused by long-term exposure to silica and asbestos.
Line entire respiratory tract..
mucus-covered Ciliated Epithelium
Apneustic Center
Continually sends neural impulses to stimulate inspiratory neurons of DRG/VRG
“Normal Respiration Cut-Off Switch”
Where do you see Perihilar Patchy Infiltrates and Kerley B lines on X-ray?
Hydrostatic/Cardiogenic Edema
Mask Squeeze
Occurs with hyperbaric descent. Negative pressure in mask causes capillary rupture and conjunctiva hemorrhage
Hyperpnea
Increase depth/volume of breathing with or without increased frequency
Fixed Intra/Extrathoracic Lesion
Foreign bodies/scarring which makes airway too stiff to be affected by transmural pressure gradient. Inspiration/expiration both affected
ex: fixed tumor in airway, fibrotic lesion, or tracheal stenosis
Bronchiectasis
Scarring of airways seen in Immotile Cilia Syndrome
Normal Hb levels
15 g / 100 mL blood
Ventral Respiratory Groups (VRGs)
Both inspiratory and expiratory neurons. Control muscles of upper airways expanding during inspiration. Controls muscles of exhalation and accessory muscles of inspiration (stress/heavy exercise)
Variable meaning False Positive
α
Difference between % by vol of oxygen in Arterial-Venous blood (systemic)
approximately 5%
Normal DLCO
20-30 mL/min per mmHg
Apneustic Breathing
Respiratory cycle holds in inspiration, periodically interrupted by expiration. Caused by cutting pneumotaxic center out of pons
Specific Compliacnce
Compliance / FRC
PC20
In methacholine test; concentration of methacholine in which you produce 20% reduction in FEV1
68-95-99 Rule
Normal Distribution.
- 68% of values within 1 sd of mean
- 95% of values within 2 sd of mean
- 99.7% of values within 3 sd of mean
Total Pulmonary Compliance
1/Total Pulmonary Compliance = 1/lung Compliance + 1/chest wall compliance
High Altitude Cerebral Edema
Ataxia and inability to walk heel-to-toe. Swelling causes brain ischemia and herniation
Pulse Oximeter
Measures SATURATION of hemoglobin.
Shines photons of light: 650 nm (HbO2) and 900 nm (deoxyHb)
Orthopnea
dyspnea which occurs when lying flat
Non-Respiratory Functions of the Lung
1) Defense Mechanism
2) Air-Conditioning
3) Olfaction
4) Filtration and Removal of Particles
5) Blood Filter
6) Blood Reservoir
7) Metabolism of Circulating Substances
Forced Vital Capacity
Amount of air that can be exhaled quickly during forced exhalation (4600 mL)
What level of PC20 is considered clinically important
less than 8 mg/mL
133Xe Technique
Measured blood flow distribution. Xe injected intravenously. Amount of soluble Xe in pulmonary artery blood gives regional blood flow. Not very soluble in blood so it comes out of solution in lungs and enters alveoli and is expelled out.
Left-Right Order of Characteristics: Right-Tailed/Skewed Distribution
Mode, median, mean
Normal P50
~26 mmHg PaO2
Residual Volume
Amount of air in lungs which can’t be exhaled (1-2 L)
Type II Error
Null hypothesis really is false; experiment fails to yield a p-value below threshold. False negative
High Altitude Pulmonary Edema
Real altitude killer! Aggravated by physical exercise, most commonly seen in athletic young males. End stage sign is hemoptysis
Variable Intrathoracic Lesion
Obstruction inside thoracic cage; expiration affected
Ex: Tumor of Lower Trachea
Pneumotaxic Center
Major Functions: Prevent aneupsis and enhance/fine-tune rhythmicity of breathing
Associated issue with Acute Mountain Sickness
Fluid retention. Treated with diuretic
FEV1/FVC Ratio: Obstructive Disease
Lower than 70%
Coefficient change for capillary hydrostatic permeability increase
Kf increases
Muscles of Inhalation
1) Diaphragm (Main)
2) External Intercostal Muscles
3) Accessory Muscles of Shoulder Girdle (exercise/patholoy)
Bradypnea
Decrease of respiratory rate
Cheyne-Stokes Breathing
10-30 seconds of apnea followed by gradual increase in volume and frequency until another period of apnea. Pulmonary changes in CO2 before neuronal; depth of respiration corresponds with PCO2 in brain.
Hyperventilation and waning of ventilation with periods of no ventilation.
Found in cardiac failure or brain damage
Mediastinum Shift: Pneumothorax
Opposite side of collapse
Z-Score Formula
Z = (chi - mu) / sigma
chi - variable sampled
mu - mean
sigma - sd
Wegener’s Granulomatosis
Presence of pulmonary nodules (Coin Lesions) in lungs
Respiratory Exchange Ratio
Rate CO2 output / Rate O2 uptake
FEV1/FVC Ratio: Restrictive Disease
Normal or Higher (>80%)
CO2 Production per minute
200 mL/min
Primary Surfactant
Dipamitoyl Phosphatidyl Choline (DPPC)
Mediastinum Shift: Atelectasis
Side of collapse
Lung Elastic Forces
1) Lung Tissue Elastic Recoil
2) Surface Tension Forces (main)
1 g hemoglobin binds to ____ mL O2
1.34 mL O2
Immotile Cilia Syndrome
More susceptible to respiratory disease due to increase entry of foreign particles into the lung. Mucus not pushed back up. Bronchiectasis
Secretes Surfactant
Type II Alveolar Cells
Alveolar Vessels
Elongated during alveolar expansion (inspiration). Resistance to blood flow increases at high lung volume
Way(s) to measure FRC
1) Helium Dilution Technique
2) Body Box Plethysmography (if high airway resistance)
FEV1
Amount exhaled in the first second of FVC. Should be 80% of FVC (3800 mL)
Change in PCO2 from Arterial to Venous Blood
6 mmHg
Microaggregates of Albumin
Measured blood flow distribution. Labeled with 131-I or 99m-Tc and injected into peripheral vein. Trapped in small pulmonary vessels as enter lungs. Patient stands in front of gamma detector.
Dark regions - few capilaries working
Light regions - working
Systolic/Diastolic Mean Pulmonary Arterial Pressure
25 mmHg / 8 mmHg
Middle Ear Squeeze
Occurs with hyperbaric descent. Failure to equalize pressure can caused middle third of Eustachian tube to colapse
What does symmetry tell you about the data set?
position of line of symmetry equal to both mean and median
Partial Pressure of H20 at 37 C
47 mmHg
Pulmonary Fibrosis
Chronic disease causing swelling and scarring of alveoli and interstitial tissues of the lungs. Scar tissue replaces healthy tissue. Causes inflammation, stiffened lungs and breathing difficulty
Coefficient change for capillary protein permeability increase
sigma decreases
Type I Error
Null hypothesis really is true, just happened to get a p=value below threshold. False positive
Tachypnea
rapid rate of breathing
Normal CO2 production per day
15 mol / day
Total Lung Capacity
Volume of air in the lungs after a maximal inspiratory effort (6000 mL)
Esophageal balloon
measures lung compliance (only)
Muscles of (Forced) Exhalation
1) Abdominal Muscles (internal obliques, rectus abdominus, transverse abdominus)
2) Internal Intercostal Muscles
Pressure Inequalities: Zone 2
Pa > PA > PV
Atelectasis
Partial or total collapse of the lung without air entering pleural space.
Extralveolar Vessels
Exposed to intrapleural pressure. Distend as Transmural Pressure gradient increases (intrapleural pressure more negative). As lung volume increases, resistance decreases.
Tidal Volume
Volume or air inspired or expired with each breath (500 mL)
Problems from Expansion on Ascent in Hyperbaric conditions
1) Pneumothorax
2) Dissection of Mediastium (Cardiovascular issues)
3) Gas Emboli
4) Death
Variable Meaning False Negative
β
Bronchial smooth muscle mechanism
Low PACO2 causes bronchial smooth muscle contraction in order to divert ventilation away from over-ventilated regions
Physiological conditions leading to high amounts of Zone 1
Hemorrhage or general anesthesia (low pulmonary systolic pressure)
Sarcoidosis
Restrictive disease. Abnormal collections of chronic inflammatory cells (granulocytes) form as nodules (granulomas) in lungs/lymph nodes.
