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)
