Module 8 - Respiration

Question 1

Describe the path that oxygen follows from inhalation to bining to hemoglobin

Answer 1

First inspiration:

• – contract intercostal muscles and diaphragm -> ribcage opens
• – creates under pressure in alveoli, overpressure mouth,, so air flows in
• – gas exchange happens in the alveoli

Question 2

Describe anatomical deadspace and the types of physiological dead space

Answer 2

Anatomic dead space
- volume conducting airway segment with no alveoli

Physiological deadspace

• Shunt situation
• — There is perfusion but ventilation is zero. ventilation perfusion ratio is 0
• Dead space situation
• — There is ventilation but perfusion is zero, infinite ventilation perfusion ratio

Question 2

Describe anatomical deadspace and the types of physiological dead space

Answer 2

Anatomic dead space
- volume conducting airway segment with no alveoli

Physiological deadspace

• Shunt situation
• — There is perfusion but ventilation is zero. ventilation perfusion ratio is 0
• Dead space situation
• — There is ventilation but perfusion is zero, infinite ventilation perfusion ratio

Question 3

Mechanics of breathing with labels

Answer 3

Lungs are like a balloon. Connected to rib cage via pleural fluid

If the diaphragm contracts, and the intercostal muscles contract, then the lungs will open up.

Inspiration is an active process; contract intercostal muscles, and diaphragm

Expiration is a passive process; relaxation of the muscles leads to thorax falling back into place and breathing out

Question 4

Sketch the pressures of the thorax as a function of time with correct axis

DRAW TABLET

Answer 4

Pressures; alveolar pressure and pleural pressure

Alveolar starts at 0 goes down a bit until halfway, then goes up again and to middle again

Pleural (thorax) pressure is always negative. Starts at -5 ish, goes down to -10 in the middle, and goes up to -5 again

In: cmH20

Question 5

What is lung compliance?

Answer 5

The willingness of the lungs to distend, and elastance as the willingness to retugn to a resting position

ALSO:
Pulmonary volume change per unit pressure change

Question 6

Draw pressure volume curve with correct axis and inhalation and exhalation

Give axis, eenheden. Also explain what you see

DRAW TABLET

Answer 6

Volume; tot 600 ml
Pressure van 5 cmH2O tot 30 cmH2O

When inhaling, overcome the lungs. Exhaling; overcome the airway resistance

Question 7

DRAW TABLET

Draw the electrical analogue of lung compliance

Answer 7

resistance, capacitor, and circle arrow thing haha

Question 8

Give the methods to measure lung compliance:

Answer 8

Super syringe method

• – step in volume and measure the pressure difference
• – you can use a balloon catheter for this

On ventilator

• – often used with mechanical ventilation
• – by stepping the pressure you measure changes in volume

Question 9

Describe the most common lung diseases and if they are linked to increased or decreased compliance if you can

Answer 9

1. Asthma (obstructive disease), increased compliance
   - — inflammation of the airways, leads to swelling in airway lining. thorax increases because air is trapped in the lungs
2. COPD (obstructive disease), increased compliance
   - —obstruction of small airways, difficult to exhale air
   - – emphysema
   - – bronchitis
3. Infectious lung diseases (destructive diseases), decreased compliance?
   - — fluid in alveoli makes gas exchange and diffusion difficult
4. lung cancer (destructive disease), decreased compliance?
   - — reduces the usable lung volume

Lasly there are also exchange problems; only influence exchange between the air sac and the capillary

Question 10

for what do you use the water clock?

DRAWING ON TAB of waterclock

Answer 10

For tidal volume

Detect restrictive diseases; reduced lung volume

Question 11

What is tidal volume?

Answer 11

the volume that one person breaths during regular in and exhalation

Question 12

What three methods are there for residual volume?

Answer 12

Gas dilution tests; helium and nitrogen washout

Bodybox

Question 13

Explain the nitrogen washout method, what is it used for?

DRAWING ON TABLET

Answer 13

To measure residual volume.
Need to make a full exhalation so that only residual volume is left in the lungs. then breathing pure oxygen until the exhaled air flow contains less than 2% nitrogen. Then all nitrogen is in the water clock, and the lungs only have oxygen.

Volume in lungs is then Vol in the spirometer * concentration of nitrogen, divided by nitrogen at the start

Question 14

What is the helium gas dilution test used for and how does it work?

DRAWING ON TABLET

Answer 14

Measures residual volume

Helium is not going into the circulation so not through alveoli!

spirometer filled with helium. Start breathin through the closed system until there is no more change in helium. Then we know it is fully distributed over both lungs and the clock

Question 15

What does the body box measure, and how does it work?

DRAWING ON TABLET

Answer 15

Body box also measures residual volume in the lungs.

As you enter the box you do not know the volume in the box anymore. Therefore need to calibrate the box with the shutter closed. Use a pump and apply low amount of volume and measure the pressure difference that occurs due to it. By P*V = constant you determine the volume in the box when the person is inside

Step 2: do forced breathing against a closed shutter. Then determine volume of the lungs by determining the volume, pressure changes in the box, and the initial volume of the box

Question 16

Ways to establish dynamic flow volume measurement

• Pneumotachs
• Turbine
• Heated wire

Answer 16

1. Fleish, Lilly, Variable orifice
2. Turbine
3. Heated wire

Question 17

Explain what the Fleish type measures, and how it does it.

Answer 17

Fleish has the tubes. Measures pressure difference over known resistance (small tubes from which we can measure pressure difference)

Question 18

Explain what the Lilly type measures, and how it does it

Answer 18

Pressure difference over screen (with known resistance)

Flow is determined by the pressure difference over the known resistance

Question 19

Explain what the variable orifice type measures, and how it does it
and advantage and disadvantage

Answer 19

Changes the resistance if the flow gets higher -> the tube then opens
Better for patients since they do not feel pressure while breathing. However, difficult to calibrate

Question 20

Name advantages and disadvantages of the pneumotachometers

Answer 20

They are easy, light and reliable (especially Fleish and Lilly)

Problems with humidity however
Differences in inspiration and expiration, since the gas mixture is changing and hence the temperature

Question 21

Explain the turbine flowmeter.

Name advantages and disadvantages

Answer 21

It is a wind meter.
Turbine rotates. The faster the flow the faster the rotation. Counting the pulses to determine the flow

Adv.
not sensitive to turbulence and humidity

DisAdv.
Inertia of system is a downside

Question 22

Explain the heated wire flowmeter

Answer 22

The more flow, the more cooling. From this determine what flow is corresponding to what temperature

Disadv.
- only local measurement, fragile

Adv.
- fast and low resistance

Question 23

How does spirometry to flow-volume curve work?

Answer 23

You inhale and then exhale as fast as you can. You start at volume of 0L. Then start exhaling until you cannot anymore. THen you are asked to inhale again, getting the curve back to 0L

Question 24

What are normal values in a flow volume curve? And how do you see the pathologies?

DRAW TABLET

Answer 24

NORMAL: Flow volume, x-axis: 4/5 Liters volume, y-axis: 8 L/s
RESTRICTIVE: x-axis 2 Liter volume, y-axis: below 0 =4 L/s, boven 8L/s
OBSTRUCTIVE: x-axis 2 liter volume, y-axis, 4 en 4

Question 25

What is the single breath method?

Answer 25

Expire fully with 0.3% CO and 10% He from rseidual volume to the total lung capacity. Hold breath for 10 seconds. then exhale again to residual volume.

CO enters the circulation, He will not. At the beginning CO in the capillaries is 0.