Brainscape's Knowledge GenomeTM

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


See full index

Physiology And Pharmacology Of Systems > Introduction to the respiratory system and lung mechanics > Flashcards

Introduction to the respiratory system and lung mechanics Flashcards

1
Q

Definition of internal respiration

A

Exchange of cases between blood, interstitial fluid and cells

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

Definition of external respiration

A

Exchange of gases (O2, CO2) between blood and the external environment

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

Definition of pulmonary ventilation

A

Physical movement of air into and out of the lungs.

Movement of air needs pressure gradient to be generated along the airways

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

Definition of functional residual capacity

A

Volume of lung at end of a normal expiration

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

Definition of transmural pressure

A

Pressure differences between the inside compartment minus the outside compartment

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

Definition of respiratory cycle

A

Single cycle of inhalation and exhalation

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

Definition of tidal volume

A

Amount of air moved in 1 cycle (500ml)

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

Definition of dead space

A

Airway volume with no gas exchange

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

Definition of dyspnoea

A

Breathlessness

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

Definition of elastic resistance

A

Resistance to stretch of lung tissues and air liquid interface lining alveoli

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

Definition of airway resistance

A

Resistance due to friction between layers of flowing air and between the air and airway walls

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

Definition of compliance

A

∆V/∆P, the measure of elastic resistance (stiffness)

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

What is the difference between external and internal respiration

A

Internal
Exchange of gases between blood, interstitium and cells

External
Exchange of gases between blood and lungs

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

Describe step 1 of inspiration

-muscle contraction (obligate and accessory)

A

Inspiratory muscles contract => expands cage

Obligate

  • ext intercostals
  • diaphragm
  • scalenes

Accessory
-sternocleidomastoid

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

Describe step 2 of inspiration

-how does cage expansion affect the pleural cavity

A

Cage expands => pulls on the pleural cavity => pleural cavity pressure gets more -ve => lungs expand

PC starts -ve due to natural cage recoil out and lung recoil in

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

Describe step 3 of inspiration

-how does the change in Ppl affect the Pl

A

Pl gets more +ve => holds lungs open => Pa becomes more -ve

Pl = -Pa – Ppl
Pl starts +ve due to both recoils in equilibrium => lungs held open

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

Describe step 4 of inspiration

-how does the change in Pa affect the movement of gas

A

More +ve Pl => more -ve Pa

As Pa is more negative than Pb => bulk air flow into lung

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

Describe step 1 of expiration

-muscle contraction (obligate and accessory)

A

Expiratory muscles contract => shrinks cage

Obligate

  • Int intercostals
  • Passive process

Accessory

  • RA, EO, IO, TA
  • Chest wall, limb girdle muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe step 2 of expiration

  • pleural cavity
  • what can happen in forced expiration
A

PC becomes more +ve => lungs recoil

PC can become +ve if expiration is forced

20
Q

Describe step 3 of expiration

  • how does the change in Ppl affect the Pl
  • what happens in end expiration
A

Pl pressure becomes more -ve => lungs recoil => Pa increases

At the end of expiration, Pl is +ve to keep the lungs open

21
Q

Describe step 4 of expiration

-how does the change in Pa affect bulk air flow

A

Pa is more +ve than Pb => bulk air flow out of lungs

22
Q

What happens in a pneumothorax

A

Chest wall punctured => Ppl = Pb

Lung recoils in, cage recoils out

23
Q

What is the respiratory cycle?

What is the typical tidal volume

A

Single cycle of inhalation and exhalation

Tidal volume, amount of air moved in 1 cycle = 500ml

24
Q

What is the tidal volume at rest for a typical person

A

500ml

25
Q

What is the vital capacity for a typical person

A

5500ml

26
Q

What is the inspiratory reserve volume for a typical person

A

3300ml

27
Q

What is the expiratory reserve volume for a typical person

A

1700ml

28
Q

What is the inspiratory capacity for a typical person

A

3800ml

29
Q

What is the total lung capacity in a typical person

A

7300ml

30
Q

What is the functional residual capacity in a typical person

A

3500ml

31
Q

What is the residual volume for a typical person

A

1800ml

32
Q

What is dead space (Vd)

A

Airway volume with no gas exchange

33
Q

What is anatomical dead space

What volume of the lung makes up anatomical Vd

A

All except alveoli and respiratory bronchioles

150ml

34
Q

What is physiological dead space
How much physiological dead space is normally present in a healthy individual
How much physiological dead space is present in others?

A

Anatomical plus areas with dysfunctional gas exchange
Normally in healthy people, PVd=AVd

In others PVd=AVd + AlvVd

35
Q

What volume does the alveoli take up in the lung is a typical person

A

3000ml

36
Q

What volume of blood is present in the pulmonary capillary beds

A

70ml

37
Q

What is the rate of total ventilation in a typical person

How would you calculate this value

A

7500ml/min

7500 = 15 x 500

38
Q

What is the typical frequency of ventilation

A

15/mins

39
Q

What is the rate alveolar ventilation

How would you calculate this value

A

5250ml/min

5250 = 7500 - (15 x 150)

40
Q

What is the rate of pulmonary blood flow

What is the rate of alveolar ventilation

A 
PBF = 5000ml/min
AV = 5250ml/min
41
Q

What are the sources of resistance in breathing and what equations are they determined by

If R increases, what can happen?

Why is high resistant flow dangerous in asthma

A

Elastic resistance of lung

  • Inverse of compliance = ∆V/∆Pl
  • If compliance low => R is high

Airway resistance

  • R = Pa-Pb/F
  • Determined by F = r4 , R = 1/r4, R = 8VL/πr4
  • Increased flow, sharp bends (decreased r) => turbulent flow => increased R and noise

Can lead to dysnpoea

If airway r too small => can’t generate noise => ominous silent wheeze

42
Q

Where are the main sites of airway resistance in the lungs

A

Nose, larynx, pharynx
3rd gen bronchi
More distal bronchi have high R, but net R is low due to parallel flow

43
Q

What factors can affect the airway in airway resistance

SM tone

  • Bronchodilation
  • Bronchoconstriction

Inflammation

A 
SM tone
Bronchodilation
-CO2
-NANC (VIP NO)
-B2 agonists

Bronchoconstriction

  • Histamine, prostaglandins
  • NANC (SP, neurokinins)
  • Ach M3 due to irritants

Inflammation
-gland hypertrophy => mucus prod

44
Q

What factors can affect the pressure across the airway wall in airway resistance

A

Normally, Pl = -ve to keep lungs open

However in forceful expiration, Pl can become +ve => dynamic compression of gen 3-4 bronchi

45
Q

What are the effects off effort on expiratory flow

A

Dynamic compression occurs in forceful expiration
-Effort independent

Occurs in everyone, more likely in those with higher airway resistance

Physiology And Pharmacology Of Systems (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions