L06: Surfactant And Resistance

Question 1

What is compliance

Answer 1

Wanting to expand

Question 2

What is elasticity

Answer 2

Wanting to recoil

Question 3

What sets up the total system compliance

Answer 3

Chestwall compliance

Lung compliance

Question 4

Where does surface tension occur

Answer 4

Where air and liquid meet

Question 5

Which structure is surface tension present at

Answer 5

Alveoli

Question 6

What happens to a bubble when surface tension acts down on it

Answer 6

Collapses

Question 7

How does a bubble stop itself from collapsing due to a surface tension

Answer 7

It has a pressure inside that is equal, opposite and and positive

Question 8

What does the laplace’s law describe

Answer 8

As a radius decreases and a bubble gets smaller the pressure increases to keep bubble inflated

Question 9

What is laplace’s law in equation

Answer 9

P=2T/r

Question 10

What is the role of a surfactant

Answer 10

Reduces surface tension in alveoli

Question 11

If there is a high surface tension what happens to the compliance

Answer 11

Compliance decreases

Question 12

With surfactant what happens to the compliance

Answer 12

Compliance increases

Question 13

Which cells in the alveoli secrete surfactant

Answer 13

Alveolar type 2 epithelial cells

Question 14

What is a surfactant made o

Answer 14

DPPC (a phospholipid)
Cholesterol
Other phospholipids
Proteins

Question 15

What happens to the affect of surfactant as the surface area increases

Answer 15

Effect decreases so surface tension is not lowered much

Question 16

When can you get reduced lung compliance

Answer 16

Infant respiratory distress syndrome
Damage to alveolar type 2 epithelial cells
Bronchopulmonary disease

Question 17

What is infant respiratory distress syndrome

Answer 17

In premature baby’s there is a reduction of surfactant
Lungs have low compliance
Small alveoli collapse
Fibrounous membrane form which impairs diffusion across alveoli

Question 18

What is the treatment for infant respiratory distress syndrome

Answer 18

Glucocorticoids

Instill surfactant into trachea

Question 19

Name a syndrome associated with the damage of alveolar type 2 epithelial cells

Answer 19

Adult respiratory distress syndrome

Question 20

Where does resistance come from in the lungs

Answer 20

Friction in airways

Lung tissue friction

Question 21

What happens to the resistance as the radius increases

Answer 21

Resistance decreases

Question 22

Is resistance greater in the lower or upper airway

Answer 22

Upper airway

Question 23

Why is resistance less in the lower airway

Answer 23

Although the radius decreases as you get more branches, the total cross sectional are is highest in the lower airway

Question 24

What are the common causes of increases airway resistance in the upper airways

Answer 24

Airway obstruction 
Bronchospasm (asthma)
Mucus
Oedema
Tongue falling back in sleep/ unconsciousness

Question 25

What is the most common cause of an increased resistance in the lower airway

Answer 25

Chronic obstructive pulmonary disease (COPD)

Question 26

By which nervous system is the smooth muscle in the airways controlled by

Answer 26

Autonomic nervous system (sympathetic and parasympathetic)

Question 27

Does parasympathetic or sympathetic nervous system cause bronchoconstriction

Answer 27

Parasympathetic

Question 28

Which local mediators cause bronchoconstriction

Answer 28

Histamine

Question 29

Does the sympathetic or parasympathetic nervous system crusade bronchodilation

Answer 29

Sympathetic nervous system

Question 30

Which neurotransmitters act on beta2 receptors

Answer 30

Adrenalin or noradrenaline

Question 31

What is oedema

Answer 31

Excess fluid accumulation