lung volumes and loops quiz

Why is it important to measure lung volumes?

Provides a tool for understanding normal function of the lungs as well as disease state

FEV1/FVC

Ratio that is useful in distinguishing between restrictive & obstructive diseases

Maximal inspiration (how)

Results from contraction of the diaphragm downward and the movement of ribs upward and outward, both of which expand the chest cavity

Inspiratory Reserve Volume (IRV) (what is it, what is it measured in, average amount)

The additional volume of air that can be inhaled with maximum effort after a normal inspiration -about 3000 mL -mL or L

Expiratory Reserve Volume (ERV) (what is it, what is it measured in, average amount)

The additional volume that can be forcibly exhaled after normal exhalation -1200 mL -mL or L

What is a breathing cycle initiated by?

The breathing cycle is initiated by the expansion of the chest.

Spirometry

A valuable tool for analyzing the flow rate of air passing into and out of the lung

Four examples of obstructive disorders

Asthma, Bronchitis, Heavy smokers, decreased airflow by bronchoconstriciton

Obstructive disorders

Diseases that interfere with the patency (open, expanded, or unobstructed) of airways resulting in a increase in airflow resistance. -Forced expiratory volumes are used to asses obstructive disorders

If someone can exhale forcefully for a short moment and then produces a weak stream of air with lots of wheezing the

FEF25-75 will be low

If someone can exhale forcefully 70 to 90 of FVC in 1 second, which of the following is true?

FEV 1% is normal

Looking at the lab data you collected during the pulmonary function tests, which do you think is a better predictor of a patients' diagnosis: lung volumes or flow volume loops?

I-flow volume loops would be a better predictor of a patients diagnosis. -While lung volume loops are a great resource, they do not always pick up on a obstructive disorder (they come back normal), while flow volume loops indicated a disorder. -if a patient who is sick takes a lung volume loop test it might come back normal, since they still have a normal lung volume. -if the patient took a flow volume loop test it will most likely com back abnormal.

Forced expiration

Is the result if the rapid contraction of chest and abdominal muscles, as well as the relaxation of diaphragm

Forced Vital Capacity (FVC)

The total exhaled air, from maximum inhalation to maximum exhalation -how vital capacity is measured

Vital Capacity (VC)

The total volume of air that can be exhaled after a maximum inhalation -cm^3 or L

Minute ventilation

The volume of air breathed in 1 minute: TV x RR = MV (L/Min)

tidal volume (TV) (what is it, what is it measured in, average amount)

The volume of air breathed in and out without conscious effort -about 500 mL -(L or mL)

Forced Expiratory Volume (FEV1)

The volume of air expelled in the first second of a forced exhalation -the percentage of the FVC that is expired in 1 second

Residual Volume (RV) (what is it, what is it measured in, average amount)

The volume of air remaining in the lungs after maximum exhalation (the lungs can never be completely emptied) -about 1300 mL -mL or L

Describe the difference between lung volumes for males and females. What might account for this?

Women on average have smaller thoracic cages compared to men. So because of this men have much more room for there lungs to expand compared to women, making there lung volumes much bigger.

respiratory cycle

a single inspiration followed by a single expiration

At rest, how much of the total lung capacity is used?

approximately 1/10th of the total lung capacity is used. (greater is needed for exercise etc.)

Your patient has below normal airflow out of the lungs, yet a normal value for vital capacity. Which of the below listed may be the underlying cause?

asthma

chronic obstructive pulmonary disease (COPD) examples

bronchitis and emphysema

Besides oxygen exchange, the respiratory system also functions to eliminate...

carbon dioxide

Flow volume loops will confirm?

confirm the diagnosis of an obstructive or restrictive disease

Too much of CO2 can cause a .... in blood pH, compromising homeostasis

decrease (becomes more acidic)

Your patient has normal airflow out of the lungs, yet a below normal value for vital capacity. Which of the below listed may be the underlying cause?

degenerative muscle disease

characteristics of a normal flow volume loop

in normal lungs air is rapidly expelled early in the process of forced expiration, with a tapering of flow rate as the lungs are emptying -latter part of expiration curve represents the emptying of small always (terminal bronchioles) -inspiration shows a maximum airflow occurring half-way through the cycle

Restrictive disorder

include any disease that affects the expansion of lung tissue resulting in a reduction in vital capacity

Which of the following may cause restrictive lung disorder?

lung fibrosis

A patient who has a low FEV1% and a low FEF25-75 in a spirometry test should be diagnosed with

obstruction

Two classes of respiratory disorders that can be diagnosed through spirometry

obstructive and restrictive

normal exhalation

passive, resulting from recoil of chest wall, diaphragm, and lung tissue

How to calculate functional residual capacity?

residual volume + expiratory reserve volume

Obstructive flow volume loop

short and wide loop

Restrictive flow volume loop

skinny and tall loop

Which of the following may cause obstructive lung disorder?

smoking

peak expiratory flow (PEF)

the highest point on the exhalation graph

Respiratory Rate (RR)

the number of breaths taken in one minute -(breaths/min)

How to calculate vital capacity?

tidal volume + inspiratory reserve volume + expiratory reserve volume

flow rate

vary over the course of a respiratory cycle and are dependent upon a variety of factors

Total Lung Capacity (TLC)

vital capacity (VC) + residual volume (RV) -L

steps of expansion of the chest for inspiration

-Contraction of the diaphragm causes it to flatten downward. -if chest muscles are used, the ribs expand outward -resulting increase in chest volume creates a negative pressure to draw air in

Four examples of Restrictive Disorders

-Neuromuscular disorders -Fibrosis caused by coal dust -weakening of respiratory muscles -tuberculosis

FEF25-75

-forced expiratory flow 25-75 -the average flow rate of the middle half of the FVC -measure of the ease of the flow of air through small bronchi

With COPD, there is a decreased air flow from the lungs. This could be caused by which reasons?

-inflammation of major and small airways -destruction of the walls between your lungs' air sacs -excessive mucus production

Flow volume loop

-lung flow rates graphed -airflow is graphed as a function of volume -volume is on x axis, so volume is increased with inspiration and decreased with expiration, making it form a loop

Pulmonary volume tests will confirm?

-used in conjunction flow tests to differentiate obstructive and restrictive lung diseases