cardiopulmonary: physiology of the Pulmonary system Flashcards
(27 cards)
What are the steps of gas transportation from the atmostphere to tissues
- inspiration to alveoli (ventilation)
- alveolar to arterial = respiration
- gas transport via blood (transportation)
- gas exchnage at capillaries (cellular respiration)
What happens with partial pessure of O2 and CO2 with alveolar hyperventilation
- more O2 is supplied and more CO2 is removed than metabolis rates require
- Po2 Increases
- Pco2 decreases
What happens to partial pressure of O2 and CO2 with alveolar hypoventilation
- less O2 is suppled and less CO2 is removed than metabolic rate requires
- Po2 decreases
- Pco2 increases
TV
- tidal volume
- air inhaled and exhaled during quiet breathing
IRV:
air that can be forcefully inhaled over normal breathing
ERV:
air that can be forcefully exhaled over normal breathing
RV:
the amount of air that cannot be forcefully exhaled
Capacities:
TLC:
the total amount of air that the lungs can hold (IRV+TV+ERV+RV)
IC:
maximum amount of air that can be inhaled following a normal expiration
VC:
amount of air that can be forcefully exhaled following max inspiration
FRC:
amount of air remaining in the lungs following a normal expiration
Minute ventilation
- norms
= respiratory rate x tidal volume
- normal 4-6 L/min
- tidal volume can increase more than RR
Describe pressures in the lungs during
1) resting
2) inspiration
3) expiration
1) atmospheric pressure = intrapulmonic pressure and intrapleural pressure is lower than atmospheric pressure
2) Atmospheric pressure>intrapulmonic pressure (air flows in) intrapleural pressure becomes more negative
3) atmospheric pressure <intrapulmonic pressure (air pushed out) intrapleural pressure remains negative
Primary inhalation muscles
- diaphragm
- external intercostals
Accessory inhalation muscles
- SCM
- scalene
- serratus anterior
- pectoralis
expiratory muscles
- abdominals
- internal intercostals
accessory
- serratus posterior inferior
exhalation is mostly passive
What is and what contributes to lung distensibility
- compliance: distensibility/ease of which the lung can inflate
- less complaint as you get closer to TLV
- pressure difference between alveolar pressure and intrapleural pressure must be maintined
- lungs want to recoil inwards
What contributes to the elastic characteristic of the lungs
- network of collagen and elastin
- surface tension: watery surfactant allows for elastic recoil
surfactant
- synthesized by alveolar type 2
- maintains surface tension and keeps compliance normal and alveoli open
What is pleural pressure
- negative pressure that must be maintained to pevent pneumothorax
How is O2 carried in the blood
- desolved in plasma to bound to Hg
- 100 mmHg is dissolved in each 100 mL of plasma
- hemoglobin can bind 4 O2 molecules
- as 1 O2 molecule binds the Hg affinity for O2 increases (same for when 1 O2 molecule dissociates)
How is CO2 carried in the blood
- dissolved in plasma
- bound to plasma proteins
- bound to hemoglobin
- bicarbonate
Ventilation/perfusion ratio
- Ratio of the amount of air entering the alveoli and the blood flowing available to the alveoli
- Norm is 0.8 or greater
- Alterations result in hypoxia
Types of barriers in V/Q
- dead space
- shunt
