Physiology 1

Question 1

What are three forces/ factors which effect breathing

Answer 1

Stiffness of lungs
Surface tention
Friction/resistance to respiritory membrane

Question 2

How does the stiffness of the lungs effect breathing

Answer 2

Lungs are high compliance = high change in volume with pressure change

Pulmonary fibrosis: scaring of lungs
caused: chemical inhilation or chronic inflamation
decreases compliance = less volume when lungs exspand

Question 3

How does surface tention effect breathing

Answer 3

Surface tention = resist change of alveolar memebrane = large effect as membranes are thin

surfactant = lipoprotein = secreated to decrease surface tention

Respiritory distress syndrom:
common in premature infants as they dont produce surfactant = difficulites breathing + less O2

Question 4

How does resistance effect breathing

Answer 4

Increased resistance down the bronchi tree leads to less airflow = less O2 exchanged
Follow: R=1/r^4
Constriction causes increased resistance

Question 5

What is the difference between obstructive and restricted

Answer 5

Obstructive: Decreased flow rate to the lungs
- asthma
- chronic bronchitis

Restricted: decreased lung volume
- low surfactant
- pulmonary fibrosis

Question 6

What is a spirometer and what does it measure

Answer 6

A tool to measure the volume of air breathed, and the flow rate of a breath
- good to check effectivness of a treatment/therpy

Question 7

What are the spriometor trace volumes

Answer 7

Tidal volume = noraml breathing
inspiration reserve volume = increased lung capacity
exspriation reserve volume = increase exhlation volume
residual volume = volume left after expiration reserve
minimal volume = volume when lungs collapse

Question 8

What are the spirometer capacitys

Answer 8

Total capacity = IRV + ERV + TV + RV
vital capctity = IRV + ERV + TV
inspiration capcitry = TV + IRV
function residual capactiy = ERV + RV