Respiration Disease Flashcards
What is the role of the respiratory system
Gas exhange and regulating pH
You need
- To acquire oxygen.
- To remove carbon dioxide
- To control blood pH
The way you do that is through efficient gas exchange between the blood and the atmosphere
Integrated components of the respiratory system
Controller (Sensor of O2, pH, and CO2) => Chest wall (pump-diaphram, ribs, …) => Lung (gas exchanger) => Controller =>
This is the cycle and it keep happening to keep everything undercontrolled
Respiratory Tract Anatomy
Two major components:
- Conduits (airway-just get gas)
–Bronchi
– Bronchioles
– Alveolar ducts
- Blood-gas interface (alveoli)
– Where gas exchange take place
Respiratory Tract
Upper respiratory tract
Lower respiratory tract
Upper Respiratory Tract
Anatomy of the Conduits
- Upper airway
– Nasal Cavity
– Pharynx
– Larynx
Nose => Turbinates => Filter in nose particles deposited and do not enter lungs
Nose => warm up air to room temp
Lower Respiratory Tract
The Respiratory Tree (got more than one gen)
Trachea
Primary bronchi
Lungs (exhange)
Trachea (orign => divide into right and left bronchi)
Primary bronchi: Conducting airways ( At gen 16 it turn into bronchiloes which help with respiration)
- Turn into bronchioles (respiratory airways) and Acini (the gas exchange unit)
Bronchioles gonna turn into alveolus to max surface area
Conduct; differ w/chest being there
Structure of Extrapulmonary Airways (Outside of Lung)
Cross Sectional View of Bronchi
- Cartilagenous ring anterior
- Muscular wall posterior (trachealis mus.)
Longitudinal view of bronchi
- Cartilage on first 2nd - 3rd divisions
– first few branches are semi rigid to prevent collapse during coughing
Airway Structure
- Globlet Cells and Glands: produce mucus for lining
- Ciliated Cells: Move upward => more muscus out (keep lung clear)
– Lose when smoking - Hyaline cartilage: Stiff for Structure
- Smooth muscles: Change amount of air
Respiratory Bronchioles (gen 16 - need to be as thin as possible)
- gonna turn into alveoli (need epitherlia & elastic fiber)
What Gen 16 do to cross sectional area and Resistance
It decrease resistance and drastically increase total cross section area (Gen-15 have high resistance and low to non total cross section area; called conducting zone)
Cells of the Airway
- Large conducting airway
- Small conducting airway
- Alevolus
Large Conducting Airway
Ciliated epithelium; globlet cells; mucous glands; cartilage
- All these try to clear the air and keep it clear
Small Conducting Airway
Ciliated epithelium (type I)
- Also try to filture the air
Alevolus
Non ciliated epithelium
- Where exchange of O2 and CO2 happen with blood
- There is also macrophages that act as last line of defense of phagocytkines (if smokin/breathing kil them)
Surfactant secretion (type II)
- control surface tension
- Cytokines and protein that regulate
Pulmonary Acinus
Blood-gas interface
One terminal bronchiole with associated respiratory bronchioles and alveoli (fixed ad doesn’t regulate airflow)
- Alveolar neck is always open in the absense of disease
Cells of the Alveolus
Components of the Alveolar Wall
- Endothelium (barrier)
- Mesenchymal
- Alveolar type I and Type II
Cells in alveolar lumen
- Pulmonary alveolar macrophage
- Lymphocyte
Surfactant and Alveolar Filling Pressure
T=Surface Tension
R=Radius (smaller R lead to more pressure)
P=Pressure=2T/r
- Surfactant reduces tension as alveoli expand by increasing lipid incorporation
– Without it small alveoli would empty into larger especially at low volume
Alveoli connected so gas can move from one to another
Lung Vasculature
Anatomy of the Circulatory System
Two Systems:
Bronchial
- Supplies the lung
Pulmonary: for gas exchange
- Pulmonary artery (deoxygenated blood)
- Capillary
- Pulmonary vein (oxygenated blood)
Lung Vasculature
Circulation
Pulmonary Circulation:
- Arteries and Bronchi travel together
- Capillaries are designed to maximize gas exchange (move in upper repiratory)
Bronchial Circulation:
- Separate circulation to lung
- Supplies bronchi
- Arises from aorta (carries oxygenated blood)
Anatomy of the Pump
- Right Lung (3 lobes)/Left Lung (2 Lobes)
- Pleural Membrane (surrounds lung and puts it into cavity space)
- Chest wall
– Skeletal (ribs, sternum, vertebrae)
– Muscles (diaphragm (main muscle), Intercostal muscles (internal and external)
Abdomial muscles => used in forced expiration
Chest Wall
Diaphragm, Intercostal Muscles and Ribs
Diaphragm: Main muscle of respiration
- flattens => lungs expand
Intercostal muscles:
- Two types (int. & ext.) used for expiration (internal) and inspiration (external)
Abdominal muscles: used in forced
expiration
Lung Volumes (Statics) and Flow (Dynamics)
Lung Vol: Conducting airway (dead space); alveoli (vol of lung)
Ventilation (ml) & flow (ml/min)
- Tidal volume (Vt); vol of normal breath
- Dead space (Vd); not used in gas exchange
Minute ventilation = Vt * Freq
Alveolar ventilation = (Vt-Vd) * Freq
V/Q = 1
- If too much V or too much Q (flow) is bad
Subdivisions of Lung Volume
- Total Lung Capacity (TLC): Vol in lung at maximal inspiration
- Forced Vital Capacity (FVC): Vol expired from maximal inspiration to maximal expiration
- Functional Residual Capacity (FRC): Vol in lung at resting position (no force applied)
- Expiratory Reserve Volume: Vol of air that can be expired maximally beyond resting position
- RV: mostly dead space
Spirometer
Measure of the Lung Volume
- Measure FVC, ERV
- FRC - ERV = Residual Volume (RV)
Nitrogen washout:
- Measures FRC
Flow Rates
Timed Volumes: Spirometer tracing while the paper is moving
- FEV1: Forced expiratoy volume in one sec (80% of air comes out here)
- Major index of obstruction: FEV1/FVC
- Major index of restriction: reduced lung volume with normal FEV1/FVC ratio
Diffusion Capacity
Measure of the gas transfer across alveolar-capillary epithelium
- Principle: Carbon monoxide (CO) is a gas that is bound irreversibly to hemoglobin ( makes blood red)
- Measurment: Dilute concentration of CO is inhaled, breath is held for 10 sec., and CO uptake is computed
- Interpretation: CO uptake (D(L)CO) is low when BARRIER IS THICKEND or when ALVEOLAR surface area is DECREASED
Control of Ventilation
Respiration is:
- Automatic (paced rate of breathing)
- Continually adjusted to maintain levels of oxygen and carbon dioxide tension within a narrow range
- Can override at any time and decide how much you hold
Respiration is controlled by a feedback system:
- Components: controller, effector, sensor
- Output: ventilation (muscle force & frequency, airway tone)
- Input: levels of acid (pH, H+) and O2
Proprioceptors, Lung and upper airway receptor tell the brain how much the lung is expanded
- CNS medullary signal if breathing is too fast or too slow
CO2 and O2 importance in the Control of Ventilation
Small changes in CO2 are detected better
- Lung control pH
Acid Base Changes
Elements maintaining acid base balance
- Lung: regulate CO2, a weak acid
- Kidney: Regulate HCO3, a base (very slow at changing pH)
- Blood and tissues: buffering capacity
Regulation
- Lung: CO2 levels change quickly
- Kidney: HCO3 takes longer
pH equation
Lung and Kidney
pH = Metabolic (kidney)/Respiratory (Lung)
HCO3-/Pco2
Alveolar Ventilation and pCO2 relationship
They are inversely related
pCO2 =K/V(alv)
K is a constant
Normal Acid base balance
Lung: 1.2 of dissolved CO2
Kidney: 24 of HCO3-
- pH = 7.4
Respiratory Acidosis and Acidemia
Failure in the lung function
- Not blowing off CO2
Lung: 2.4 Dissolved CO2
Kidney: 24 of HCO3-
- pH = 7.2
Compensated Respiratory Acidosis
Kidney Compensate
Lungs: 2.4 dissolved CO2
Kidney: 40 of HCO3-
-pH normal again
Anatomy of the Pulmonary Vessels
Pulmonary arteries are thinner and have less smooth muscle than systemic arteries
- Offer less resistance
- More distensible
Much lower Intervascular Pressure
- More compressible
Located within the Thorax (not outside the chest)
- Subject to pulmonary pressue (alveloar and intrapleural pressure)
Pulmonary Vascular Resistance (PVR) is determined by more than pulmonary vascular tone
Pulmonary and Systemic Circuits
- PAP is much smaller than systemic pressure (1/10)
- Distrubution of pressure through systemic and pulmonary vasculature uneven
- Requirement for systemic head pressure not present in lung
- Differential organ flow systemically
The reason why it’s so much lower is because you really don’t need so much pressure. All what the PAP need to do and send is already in the lung
Determination of Pulmonary Vascular Resistance
Pouseille’s Law: Pi - Po = Q x R
- R= P1-P2/Q
– P1= pressure at beginning of tubles
– P2 = pressure at end of the tubles
– Q = Flow
– R= Resistance
PVP= MPAP(mean pulmonary arterial pressure) - MLAP(mean left atrial pressure)/PBF (pulmonary blood flow)