Summary Clinical Exercise Physiology tm week 10

Clinical exercise physiology tm week 10

• Week 1: Respiration, the basics

When going down in the pulmonary system:
- The amount of cilia decreases.
Cilia is necessary to clear the air and this needs to be done before the alveoli.
- The thickness of the epithelial will decrease.
The smaller the layer, the more simple the gas exchange will be.
- The amount of elastin will increase.
Lower in the pulmonary system there are no bones, so more elastin is necessary.
- The mucus will decrease.
Upper airway → much mucus. Lower airway → les mucus.
Mucus makes gas transport harder.

Lower airways → bronchili and alveoli. The rest: upper part.

Functions of the pulmonary system:
1. Gas transport / conducting
2. Gas exchange (lower airway) (between alveoli – pulmonary capillary)
3. Warming (oro- and nasopharynx; gas exchange is better in body temperature)
4. Moisturizing
5. Defense (filtering)

Ventilation: the breathing pump:
- Respiratory muscles
o Diaphragm → n. Phrenicus
- Chest wall (tends to expand)
- Lungs (tends to collapse, because of the elastic tissue)
- Pleural cavity

Boyle’s law: P1V1 = P2V2 (if volume increases, pressure will decrease)

Expiratory flow occurs when the alveolar pressure (PA) exceeds barometric pressure (Pb)

Inspiration (active):
1. Contraction of the inspiratory muscles (diaphragm, intercostals).
2. Volume thorax increases and Pip decreases (more negative).
3. PA < PB, and air flows from outside into the lungs.

Expiration (passive):
1. Relaxation of inspiratory muscles (Pip increases, less negative).
2. Gravity and elastic recoil of the lung: volume thorax and lungs decrease.
3. If volume decreases, PA increases → PA > Pb.
4. Air flows out of the lungs.

,FRC = extra expiratory volume (this includes: ERV, RV)

Elastic recoil depends on:
- Elasticity / compliance of the tissue
- Surface tension (surfactant decreases this tension)

Functions of surfactant:
- Decreases surface tension
- Avoids airway collapse
- Decreases work of breathing

Diseases that effect elastic recoil:
- Emphysema
- Interstitial lung diseases (fibrosis)
- Neuromuscular diseases
- Newborn respiratory distress syndrome

, A
Fick’s law of diffusion: V gas = D x (p1 – p2) x ----------
T
D = diffusion constant
P1-p2 = pressure difference between the two sites of the membrane
A = membrane surface
T = membrane thickness




Value depends on:
Age, posture, gender, ethnicity




Asthma → medication has a big impact on the flow volume curve.

, Obstructive → problem with the flow.
Restrictive → smaller volume, the flow is quite okay.

Values lung capacity:
Pred predicted value
Pred LL lower limit of the predicted value
Pre Pre-medication
Post Post-medication
%Rev How much better the post-value t.o.v pre-value is.
%pre Percentage t.o.v. predicted value
Tiff FEV1 / VC
Z-score Standard deviation
MEF25 maximum expiratory flow, 25% still has to be exhaled (problem? → low obstruction)
MEF50 maximum expiratory flow, 50% still has to be exhaled (problem? → high obstruction)
DCO diffusion-capacity, independent of the size of the lungs
KCO DCO, dependent of the lung capacity. (so the corrected DCO)
BE base excess (overschot aan base dat aanwezig is)

Under lower limit of normal / z-score isn’t [-1,64 – 1,64 ] : something wrong, not normal!

Cases:
Tiff decreased → obstruction
RV increased → obstruction
TLC decreased → restriction
FRC and ERV increased → hyperinflation
PaO2 low, SpO2 low → hypoxia

PaO2 = alveolaire zuurstofspanning
spO2 = verzadiging, saturatie zuurstof

Height has a larger impact on the values than weight!

Where to look at during these cases:
- Restriction: TLC, VC
- Obstruction: Tiff, MEF 50, MEF 25
- Diffusion: DCO, KCO