Ventilation and perfusion

Question 1

Restrictive lung disease, a decrease in the total volume of air that the lungs are able to

Answer 1

hold

Question 2

Restrictive lung disease is often due to

Answer 2

a decrease in the elasticity of
the lungs themselves or caused by a problem related to the expansion
of the chest wall during inhalation.

Question 3

In the obstructed lung diseases, respiration ends prematurely, thus
increasing

Answer 3

RV and FRC

Question 4

. In the restricted lung, volumes

Answer 4

volumes are small
because inspiration is limited due to reduced compliance

Question 5

V̇ or V — ventilation

Answer 5

the air that reaches the alveoli.

Question 6

the blood that reaches the alveoli via the capillaries

Answer 6

perfusion Q

Question 7

V/Q mismatch can be caused by anything which increases or decreased

Answer 7

ventilation of the lungs or increases or decreases perfusion of the
lungs.

Question 8

Anything that interferes with the ability of fresh air to get to the alveoli, or
anything that prevents blood flow to the capillaries will impact the

Answer 8

V/Q ratio

Question 9

It is the ratio of alveolar ventilation and the amount of blood that perfuse the alveoli

Answer 9

V/Q ratio

Question 10

 Joe is suffering from a large pulmonary embolus which is partially
blocking the circulation to his lungs by 50%. His ventilation is normal.
What will happen to his ventilation/perfusion ratio?

Answer 10

4200/2500 =1.68, it will increase reflecting the decreased circulation.
 The dead space of the lung is increased

Question 11

Four lung diseases illustrate the problems associated with shifts in the
V/Q ratio. These are:

Answer 11

• Asthma
  -Emphysema
  -COPD (chronic obstructive pulmonary disease)
  -ARDS (Acute Respiratory Distress Syndrome)& Lung Fibrosis

Question 12

a chronic disease of the airways that makes breathing
difficult.

Answer 12

asthma

Question 13

symptoms of asthma

Answer 13

coughing, wheezing,
shortness of breath, and chest tightness

Question 14

inflammation of the air passages that results in a
temporary narrowing of the airways that carry oxygen to the lungs

Answer 14

asthma

Question 15

Asthma Types

Answer 15

Exercise-Induced Asthma. Exercise commonly
makes asthma symptoms worse.

• Nocturnal Asthma. Worsening of asthma at night is very common and
  treatment of underlying causes can help greatly
  .
• Occupational Asthma.
• Steroid-Resistant Asthma (Severe Asthma)
  -Allergic Asthma

Question 16

Describe the type of ventilation/perfusion ratio change that you would
see with an asthma attack.

Answer 16

Ventilation would be affected more than perfusion. The V/Q ratio
would get smaller.
- This is termed a shunting of blood.
- Moreover pulmonary arteries constrict with hypoxia to shift blood to
more oxygenated areas