Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Body Systems > Mechanics of Breathing > Flashcards

Mechanics of Breathing Flashcards

1
Q

what proportion of the deaths are attributable to respiratory disease

A

36%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the definition of breathing

A

the bodily function that leads to ventilation of the lungs also known as external respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define ventilation

A

the process of moving gases in and out of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define mechanics of breathing

A

decries the structural and physiological bases of ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the two types of disease affecting ventilation and what are some examples

A

obstructive conditions:
asthma, COPD, lung cancer
restrictive conditions: intrinsic: pulmonary fibroids
extrinsic - pneumothorax, disorders of the thorax skeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the difference in barometric pressure during inspiration and expiration between the atmosphere and the alveoli

A

inspiration: Pb (atmospheric pressure) > Pa (alveolar pressure)
expiration: Pa > Pb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is 1 atm of pressure equal to in terms of kPa, bar, mmhm and cmH20

A

1 atm = 101.3 kPa
= 1.013 bar
= 760 mmHg
= 1033 cmH2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a change in pressure dependant on

A

cycle of pressure changes in the chest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

according to boyles law what happens after thoracic volume changes

A

alveolar pressure changes

P = 1/V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the difference sin muscle groups between quiet breathing and increasing effort

A

quiet = diaphragm and external intercostal muscle (inspiration)

increasing effort: accessory muscles involved such as neck muscles (pull rib cage up) and shoulder girdle muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens in quiet breathing during expiration and increasing effort

A

quiet breathing = elastic recoil of tissue

increasing effort = internal intercostal muscles and abdominal muscle walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what innervates intercostals

A

segmenta thoracic nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where does the diaphragm originate from

A

the neck and becomes a muscle therefore innervated by the cervical nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what happens to the intrapleural space during thoracic cage expansion

A

causes an increasing negative pressure meaning air comes into lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does a traditional spirometer work

A

Measurement of the basic lung volumes and capacity
Counterbalanced using a weight
Cylinder down pen up
Breathes in pen moves up and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is tidal volume and its typical values

A

the volume of air moved in or out of the lungs during normal breathing
at rest: 6-7 ml/kg
exercise: 15 ml/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the inspiratory reserve volume and what is its typical value

A

after normal expiration take as deep a breath as possible

70kg male - 3,000ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the expiatory reserve volume

and its typical value

A

after normal inspiration, breath out as deeply as possible

70 kg male - 1,500 ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which values on a spirometer do restrictive lung diseases affect

A

reduced RV, FRC, VC, TLC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what do obstructive lung diseases such as asthma, COPD and emphysema affect

A

increased RV
TLC may be reduced in COPD but reduced in emphysema
FRC increased in emphysema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is FRC

A

functional residual capacity - dependant on the compliance of the lungs and chest wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is compliance

A

defined as the change in lung volume per unit change in intrathoracic pressure
C = change in V/ change in pressure
if something is very compliant it means it doesn’t take much effort to stretch it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the normal tendency of the lung

A

to collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the calculation for recoil pressure of the lung

A

Palv - Ppl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the recoil pressure of the lung at maximal expiration

A

0 - - 3 = +3 cmH2O

26
Q

what is the recoil pressure of the lung at peak inspiration

A

+ 30cmH2O

27
Q

what is the recoil pressure of then lung during tidal breathing

A

+5 cmH2O

28
Q

how do you calculate the recoil pressure of the chest wall

A

Ppl - Pbs (body surface)

29
Q

what are the three steps for measuring and calculating the recoil pressure of the chest wall

A

maximal expiration, close glottis, relax muscles

Ppl - Pbs = -30 - 0 = -30cmH2O

30
Q

what happens when we maximally expire in terms of the chest wall and intrapleural pressure

A

generates very negative intrapleural pressure and therefore chest wall wants to spring out for inspiration to occur

31
Q

describe the graph of a composite chest wall and lung compliance

A

at FRC the recoil pressure is 0

FRC is the relaxation point of the respiratory system when chest wall and lung recoil pressures are equal but opposite

32
Q

what surgery is formed during circumferential burn

A

escharotomy

33
Q

how does scoliosis affect compliance

A

reduces compliance as ribs don’t expand as well as they normally should

34
Q

what happens to compliance during emphysema

A

increases compliance as elastic tissue is destroyed meaning less want to recoil

35
Q

describe how gravity affects compliance throughput the length of the lungs

A

Spaces at the bottom are more closed off than those at the top
Alveoli even at the bottom are not completely shut
According to position in the lung alveoli have a difference in compliance – steeper curve at the bottom of the graph then flattens off at the top
bigger change in the basal alveoli compared to the upper alveoli – upper don’t open that much – better ventilation at the bottom of the lungs
ie when you breath the top alveoli don’t stretch that much as they are already quite open

36
Q

what is closing capacity

A

The closing capacity is the volume in the lungs at which its smallest airways, the respiratory bronchioles, collapse

37
Q

what happens if the closing capacity exceeds FRC

A

alveoli independent lung regions will be poorly ventilated

38
Q

what happens to alveoli when FRC is smaller than closing capacity

A

you get closure of some of the alveoli

39
Q

does closing capacity ever change

A

no

40
Q

what is the equation for the law of laplace

A

Pressure = (2 x Thickness x Tension)/Radius

41
Q

how can tension within a sphere be decreased at constant pressure

A

increasing the thickness of the sphere wall

42
Q

how does surface tension work

A

potential energy is minimised through reducing surface area to volume ratio by formation of a sphere

43
Q

what specifically is the role of surfactant

A 
Acts as a detergent to reduce alveolar surface tension
Increases pulmonary compliance
Prevents atelectasis
Aids alveolar recruitment
Minimises alveolar fluid
44
Q

which syndrome causing less surfactant

A

infant respiratory distress

45
Q

what cells produce surfactant

A

type 2 alveolar cells

46
Q

what is the composition of surfactant

A

90% phospholipid 10% protein

47
Q

what happens to surfactant as alveolar volume increases

A

becomes more dispersed which equalises pressure between alveoli of different sizes
ie there is less tension from spread out surfactant in larger sized alveoli

48
Q

what is it called when the relationship between he intrathoracic pressure and the lung volume during tidal breathing

A

hysteresis

49
Q

what causes hysteresis

A

at small lung volumes:
reduced compliance
airway calibre

50
Q

what is the equation for flow in the lungs

A

Flow = (k.change in P.r^4)/L

51
Q

define laminar and terminal flow

A

Laminar flowis where the air is flowing through the tube in parallel layers, with no disruption between the layers, and the central layers flowing with greater velocity. Turbulentflowis when the air is not flowing in parallel layers, but direction, velocity and pressure within theflowof air become chaotic.

52
Q

which flows are where in the lungs

A

upper alveoli more turbulent flow

laminar flow in lower branches

53
Q

what does a vitalograph spirometer do

A

measures the forced vital capacity FVC

the forced expiratory volume in 1 second (FEV1)

54
Q

what does a peak flow meter measure

A

PEFR

55
Q

what causes reduction in FVC and FEV1

A

COPD (obstructive defect)

Restrictive defect such as pulmonary fibrosis

56
Q

what does the FEV1/FVC ratio distinguish between

A

obstructive and restrictive conditions
ratio < 0.7 = obstructive
ration > 0.7 = restrictive

57
Q

what is the difference between asthma and chronic obstructive lung disease

A

asthma airways are reversible via B adrenorecpetor agonist salbutamol
COPD is irreversible

58
Q

what is the work of breathing

A

the energy used in inspiration to overcome elastic forces is stored as potential engird which is dissipated in expiration
work is expended in the form of heat during inspiration and expiration to overcome resistance forces

59
Q

what is the equation for work

A

volume x pressure

60
Q

what happens to minimal work of breathing in restrictive and obstructive conditions

A

restrictive: work is minimised with rapid volume small volume breaths
obstructive work is minimised with large volume slow breaths

Body Systems (77 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions