Mechanics Of Breathi

Question 1

Breathing

Answer 1

Function that leads to ventilation - external respiration

Question 2

Ventilation

Answer 2

Moving gasses in (inspiration) and out (expiration) of lungs

Question 3

Diseases affecting respiration types

Answer 3

• restrictive
• obstructive

Question 4

Obstructive ventilation conditions

Answer 4

• asthma
• obstructive pulmonary disease
• lung cancer

Question 5

Restrictive lung conditions affecting ventilation

Answer 5

• intrinsic like pulmonary fibrosis
• extrinsic - pneumothorax, disorders of thoracic skeleton

Question 6

How does gas flow

Answer 6

According to air pressure - always towards an area of more negative pressure

Flows down a pressure gradient

Question 7

Pulmonary fibrosis

Answer 7

When lungs become scarred over time

Symptoms:
- dry cough
- weight loss
- nail clubbing
- shortness of breath

Question 8

Glottis

Answer 8

Airway

Question 9

How is a change in pressure generated - why?

Answer 9

• atmospheric pressure is constant
• so change in pressure is dependent on pressure changes in the chest

Question 10

Expiration - passive or active

Answer 10

Passive - naturally returns to normal size (inspiration is active)

Question 11

When does alveolar pressure change

Answer 11

After thoracic volume changes

Question 12

How does thoracic volume change

Answer 12

Inspiration

Question 13

Quiet breathing inspiratory muscles

Answer 13

Diaphragm contracts and flattens

External intercostals stabilise ribcage

Question 14

Increasing effort breathing inspiritory muscles

Answer 14

Diaphragm contracts and flattens

External intercostals contract (internal relax) - antagonistic pair act to expand ribcage

Neck and shoulder girdle muscles

Question 15

Innervation - nervage - of respiratory muscles

Answer 15

Diaphragm - phrenic nerves C3, C4, C5 - keeps the diaphragm alive

Intercostals - segmental thoracic nerves

Question 16

What are the pleasurable important for in breathing

Answer 16

The pleura are important in transmitting thoracic cage expansion into lung volume expansion

Thoracic cage expansion exerts increasing negative pressure on intrapleural space

Question 17

What conditions affect lung expansion

Answer 17

• pleural effusion
• pneumothorax

Question 18

What does a spriometer do

Answer 18

Measures volume of air moving in and out of lungs in ventilation

Question 19

Tidal volume

Answer 19

Volume of air moved in and our of lungs in normal breathing

Question 20

Typical values of tidal volume during rest

Answer 20

6-7 ml/Kg

Question 21

Typical values of tidal volume during exercise

Answer 21

15 ml/Kg

Question 22

Inspiritory reserve volume typical value

Answer 22

Male 70 kg =3000 ml

Question 23

Expiratory reserve volume

Answer 23

70kg male = 1500 ml

Question 24

Name Lung capacities

Answer 24

• total lung capacity
• vital capacity
• functional residual capacity (amount of air in lungs at end of breath)

Question 25

Chest diseases affecting lung volume and capacity

Answer 25

Restrictive - pulmonary fibrosis Obstructive - asthma, COPD, emphysema

Question 26

What is functional residual capacity dependant on

Answer 26

Compliance of lungs and chest wall Compliance - the change in lung volume per unit change in intrathoracic pressure

Question 27

Compliance definition

Answer 27

Change in lung volume per unit change in intrathoracic pressure C= change in volume / change in pressure

Question 28

How is compliance measured

Answer 28

Spirometers for volume / oesophageal balloon for pressure

Question 29

Functional residual capacity

Answer 29

Relaxation point when chest wasp and lung recoil pressures are equal but opposite - residual volume

Question 30

When is the best compliance?

Answer 30

At the functional residual capacity

Question 31

Diseases associates with reduced compliance

Answer 31

Circumferential burn Pulmonary fibrosis - scarring Kyphoscoliosis

Question 32

Why can’t you measure chest wall curve irl? Why would you measure it?

Answer 32

Difficult unless patient is paralysed. Serious concerns with chest wall compliance.

Question 33

Diseases associated with increased compliance

Answer 33

Emphysema

Question 34

What tissue is scarred in pulmonary fibrosis

Answer 34

Interstitial tissue between alveoli

Question 35

Kyphoscolisis and compliance

Answer 35

Affects compliance as it is a chest wall problem Development of lungs may be affected - lung volumes in particular.

Question 36

Circumferential burn and compliance

Answer 36

Burns heal and scar tissue develops quickly Chest wall issue - scar means less expansion of lungs

Question 37

Emphysema and compliance

Answer 37

Increased compliance because so much of normal lung structure eroded - alveoli structure isn’t close to capillaries Emphysema causes lung structure to be destructed - large air pockets in lungs

Question 38

Is compliance equal throughout the lung - why?

Answer 38

Gravity - alveoli at bottom more squished due to weight of lung above - so can expand more in comparison as more compressed

Question 39

How does lung compliance change with age

Answer 39

Compliance increases

Question 40

What is closing capacity?

Answer 40

Closing volume (volume at which small airways in lungs close start to close) + residual volume

Question 41

What cells in alveoli cells function as gas exchange membranes

Answer 41

Alveolar type 1 cells

Question 42

Alveolar type 2 cells

Answer 42

Produces alveolar surfactant

Question 43

What is alveolar surfactant act as? What does this do?

Answer 43

A detergent to reduce alveolar surface tension - prevents atelelectasis - aids alveolar recruitment - minimises alveolar fluid - increases pulmonary compliance

Question 44

Neonates/ premature babies and surfactant

Answer 44

Don’t produce enough surfactant - infant respiratory distress syndrome - difficulty breathing