Lecture 17 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

3 basic steps of respiration

A
  1. Pulmonary ventilation
  2. External ventilation
  3. Internal ventilation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is pulmonary ventilation/breathing (inhalation/exhalation)

A

Exchange of air bet atmosphere and alveoli of lungs

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

What is external (pulmonary) respiratory

A

Exchange of gases between air in alveoli and blood in capillaries across respiratory membrane

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

What is internal (tissue) respiration

A

Exchange of gases between blood in systemic capillaries and tissue cells

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

How does flow of air between atmosphere and lungs occur

A

Difference in air pressure (high to low)

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

When diaphragm is relaxed, what is the diff between alveolar air pressure and atm pressure

A

0, both at 760mmHg

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

During inhalation, pressure in lung decr or incr

A

Decrease (more space, same amount of gas)

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

Bc during inhalation pressure lowers in lungs, air moves

A

Into lungs

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

When diaphragm contracts (inhalation), alveolar pressure drops to

A

757 mmHg

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

Body parts during inhalation

A

Thoracic cavity expands, external intercostal muscles and diaphragm contract

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

Why does contraction of diaphragm increases thoracic cavity

A

Bc it flattens and lowers the dome -> more space for lungs

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

When intercostal muscles contract,

A

Elevates ribs

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

Why is inhalation said to be an active process

A

Bc involves muscular contraction

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

Why is exhalation not a passive process

A

Bc no muscular contraction

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

What results from elastic recoil of chest wall and lungs

A

Exhalation

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

Body mvmt during exhalation

A

External IM relax, diaphragm relaxes, ribs are depressed

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

When exhalation decreases thoracic cavity, pressure in lungs increases to

A

763 mmHg

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

During exhalation, atm 760 and lungs 763 so air

A

Flows out

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

Ventilation steps

A
  1. Respiratory center in brain stimulates phrenic and intercostal nerves
  2. Nerves send impulses to resp muscles
  3. IM and D contract
  4. Thoracic cav V incr
  5. Lungs expand so intrapleural and intrapulmonary P decreases
  6. Air sucked in lungs (inhale)
  7. Muscles relax, air out of lungs (exhale)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Negative pressure and positive pressure mean

A

Negative: lower than atm P
Positive: higher than atm P

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

Atm pressure at sea level (normal atm P)

A

760 mmHg

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

Intrapulmonary/intra alveolar P is

A

P of air within alveoli (equalizes atm bet breaths but doesn’t stay there)

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

Intrapleural P

A

P within pleural cav, changes at diff phases of breathing, ALWAYS 4 mmHg LESS than intrapulmonary P

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

If intrapleural P wasn’t negative to lungs, they would

A

Collapse bc air would flow to low P

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

At rest, three P are at

A

Atm: 760
Intra alveolar: 760
Intrapleural: 756

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Lungs tend to get pulled inward bc of the

A

Recoil of elastic tissue in them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

As lungs move away from thoracic wall, cav gets larger so

A

Negative P in cav suctions lungs to stay inflated and not collapse

28
Q

What is trans pulmonary P

A

P difference between inside of lungs (intra alveolar) and outside of lungs (intrapleural)

29
Q

Trans pulmonary P needs to stay how to keep lungs inflated

A

Positive (lungs - cav, 760 - 756)

30
Q

Ventilation depends on 3 types of P:

A

Atm
Intrapulmonary
Intrapleural

31
Q

3 types of P when inhaling

A

Atm: 760
Intra alveolar: 758
Intrapleural: 754

32
Q

3 types of P when exhalation

A

Atm: 760
Intra alveolar: 762
Intrapleural: 758

33
Q

Tidal volume

A

Amount of air moving in/out of lungs each breaths (500ml)

34
Q

Inspiratory reserve volume (IRV)

A

Amount of air that can be forcibly inspired beyond tidal volume (2100-3000ml)

35
Q

Expiratory reserve volume (ERV)

A

Amount of air can be forcibly expelled after normal TV inhalation (1000-1200ml)

36
Q

Residual volume (RV)

A

Amount of air remaining in lungs even after max exhalation (after max, still 1200 ml left to help prevent collapse of alveoli)

37
Q

Vital capacity

A

Total amount of exchangeable air
(IRV + TV + ERV)

38
Q

Total lung capacity

A

Sum all lung volume
(IRV + ERV + TV + RV)

39
Q

Apparatus used to measure air exchange volume when breathing is

A

Spirometer

40
Q

Airway resistance

A

Resistance of respiratory tract to airflow during inhalation and exhaustion

41
Q

Airway resistance is mainly related to

A

Diameter of airways

42
Q

When airway resistance rises

A

Breathing mvmts become more strenuous

43
Q

Alveolar surface tension

A

Amount of H bonds in liquid coating alveoli

44
Q

Water mainly coats alveoli walls so without surfactant, which breaks H bonds,

A

Alveoli would collapse (surfactant reduces surface tension)

45
Q

What is lung compliance

A

Ability to expand lungs

46
Q

Factors affecting lung compliance

A

Surface tension and elasticity from elastin in connective tissue, smoking, emphysema, obesity and pregnancy (reduce volume of chest)

47
Q

Scar tissue caused by infections or low surfactant production decreases lung compliance bc

A

Elastin fibres in lungs are replaced by collagen which is less elastic

48
Q

Major determinants of airway resistance

A

Radii of airways

49
Q

Airway resistance determines

A

How much air flows in lungs at any P diff bet atm and alveoli

50
Q

Lung compliance is determined by

A

Elastic connective tissues of lungs and surface tension of fluid lining alveoli

51
Q

Factors that can affect ventilation

A

Airway resistance, lung compliance, alveolar surface tension and scar tissue

52
Q

Walls of airways, especially ___ offer some resistance to airflow

A

Bronchioles

53
Q

Asthma

A

Chronic, bronchial tubes inflame and narrow -> hard to breathe

54
Q

Asthma is caused by

A

Genetic and eviro factors

55
Q

Asthma symptoms

A

Wheezing, coughing, chest tightness, SOB

56
Q

Chronic obstructive pulmonary disease (COPD)

A

Group of diseases that cause airflow blockage

57
Q

Chronic bronchitis (COPD disease)

A

Irritates bronchial tubes -> swell and mucus builds up -> cilia damaged by disease so can’t help clear mucus

58
Q

Result of emphysema

A

Reduced surface for gas exchange or o2/co2 bet inhaled air and blood traversing lungs

59
Q

Emphysema characterized by

A

Destruction of gas exchanging tissue -> large air space bc loss of alveolar walls are destruction of capillaries

60
Q

Emphysema (COPD) most commonly caused by

A

Smoking

61
Q

Cystic fibrosis (genetic disease)

A

Buildup of thicker and stickier mucus -> bacteria gets more frequently stuck so frequent infections

62
Q

Average lifespan for cystic fibrosis

A

37 yo, death generally from heart failure bc massive chronic bacterial infection to lung

63
Q

Pneumothorax (collapsed lung)

A

Air enters pleural cav-> pressure not - to intrapulmonary, so lung collapses
(Getting air out of pleural cav can reinflate lung)

64
Q

Atelectasis

A

Collapsed of one/more parts of lung specifically alveoli sacs -> alveoli can’t fill o2 so this lung area doesn’t function

65
Q

Compressive atelectasis

A

Something (fluid/air/blood/tumor) around lung pushes it -> collapses

66
Q

Obstructive atelectasis

A

No new air can move in alveoli (airflow obstruction)

67
Q

Contraction atelectasis

A

Lung scarring