Patho Exam 2: Pulm Physiology & Testing (Lecture 1) Flashcards
What is Respiration?
- Cellular level
- Exchange of O2 and CO2
Note: Respiration is NOT Ventilation
What is Ventilation?
- “Breathing”
- air movement
- ventilation is PART of respiration
-Importance: keep balance in acid-base scale (measured in arterial blood gas, ABG)
Note: Respiration is NOT Ventilation
What is Diffusion?
- Transfer of gases between air-filled spaces and the blood
What is Perfusion?
- Blood flow through lungs
- Responsible for organs and tissues to receive O2-rich and CO2 poor blood.
The lung functions are controlled by multiple systems. List the systems that contribute…
- CNS
- Respiratory
- Cardiovascular
Conducting airways
DO NOT participate in gas exchange
Gas exchange airways
Hint: smaller more detail oriented section of the lungs
- Bronchioles
- Alveolar ducts
- Alveoli
What is the role/importance of surfactant?
- immune function to protect alveoli
- lines alveolar surface and acts as “grease”/ lubricant to reduce surface tension.
- too much surface tension = fluid in alveoli
What are the 2 properties that contribute to the “Elasticity” of the lung?
- Recoil: lung’s ability to rebound after being stretched
- Compliance: lungs ability to stretch with ease.
-These factors are opposites of each other
NEGATIVE is normal lung pressure. What does NEGATIVE pressure maintained by?
- elasticity (recoil and compliance)
- osmotic force (pressure gradient)
- lymphatic pump (filter blood)
Which is the MECHANICAL control of ventilation?
Lung and chest wall
Which is the NEUROLOGICAL control of ventilation?
Brain – respiratory center – chemoreceptors: senses changes in partial pressure of CO2, O2, and pH
What is Dead Space?
Space of trachea, bronchi, bronchioles
- no air contact with capillaries (no O2/CO2 exchange)
What is V/Q relationship?
V - ventilation
Q - perfusion
- Ratio between air in lungs and perfusion in capillaries
What are the ways O2 is transported
Hint: 2 ways
- Dissolved state in plasma - PO2
2. Combined with Hgb
Describe PO2 & is it efficient? Runner or car?
“RUNNER on highway”
PO2 - partial pressure of oxygen (how much O2 in in plasma
NOT efficient but useful during CO-poisoning; Hb is stuck on CO and O2 becomes useless transport
Describe OxyHgb & is it efficient? Runner or car?
“CAR on highway”
OxyHgb - O2 bound to hemoglobin
MOST and VERY efficient
Describe the OxyHgb transport system…
O2 ultimately binds with RBC through AC-membrane then…
RBC + Hgb = OxyHgb
Oxygen moves from capillaries to meet tissue needs
(OxyHgb dissociation and 2,3 DPG important!!!)
When is it significant to have a Right Shift?
- states where body wants easier O2-Hgb dissociation/come off easier
i. e: Exercising or hemorrhagic shock
When is it significant to have a Left Shift?
- states where bod O2 sticks onto HgB and it is difficult to unbind O2 from HgB
i. e: Septic shock
Increase in 2,3-DPG means…
Right Shift
Decrease in 2,3-DPG means…
Left Shift
What are the 3 major types of pulmonary function testing?
- Lung volumes
- Lung capacities
- Diffusion capacities
What do PFTs delineate/show?
Delineates pathology of …
RESTRICTIVE (expansion issue)
OBSTRUCTIVE (blockage/flow issues)
FEV/FVC > 75% is…
good; less risk of obstructive disease
FEV/FVC < 75% is…
bad; more risk of obstructive disease
What is diffusion capacities used for?
Pt inhales CO (controlled amount) to examine gas and calculate diffusion.
This test is important to use to distinguish between COPD and asthma pt’s.
What is the significance behind ABGs
Arterial blood gas will allow you to see how much gas exchange is happening in real time.
- used in acute respiratory issues, hypoxemia, cardiac arrest
- Arterial b/c arteries are oxygenated!
