Brainscape's Knowledge GenomeTM

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


See full index

Respiratory Medicine Midterm > HY Respiratory Phys + Karius review > Flashcards

HY Respiratory Phys + Karius review Flashcards

1
Q

Ratio of what molecules produced by the lungs is a marker for lung maturity?

A

Lecithin:sphingomyelin ratio. Usually greater than 2

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

Diameter of airways depends upon the balance between what two molecules produced in the lung

A

prostaglandins (bronchodilation) and Histamine (bronchoconstriction)

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

Which molecule is produced by the lung such that when inhibited produces a build up product that causes a dry cough

A

Angiotensin Converting enzyme

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

What important coagulation cascade cofactor is produced in the lung?

A

Kallikrein

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

What is residual volume (RV)?

A

volume that remains in lungs after a maximal expiration

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

What is tidal volume (TV)?

A

Volume inspired with each normal breath

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

What is inspiratory reserve volume (IRV)?

A

volume that can be inspired over and above the tidal volume. Used during exercise

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

What is expiratory reserve volume (ERV)?

A

Air that can still be breathed out after normal expiration

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

What is inspiratory capacity?

A

IRV + TV

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

What is functional residual capacity

A

RV + ERV. Volume of gas in lungs after normal expiration; includes RV, cannot be measured on spirometry

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

What is vital capacity?

A

TV + IRV + ERV = max volume of gas that can be expired after a maximal inspiration

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

What is total lung capacity?

A

IRV + TV + ERV + RV = volume of gas present in lungs after a maximal inspiration. (notice it includes RV which cannot be measured by spirometry)

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

Differentiate between anatomic vs physiologic dead space and alveolar dead space.

A

Dead space is area of the respiratory system that do not participate in gas exchange. Anatomic dead space = conducting zones of respiratory system. Physiologic dead space = anatomic dead space in a non diseased state; in a disease state physiologic dead space = anatomic dead space + functional (alveolar) dead space. Alveolar dead space = alveoli which receive ventilation but are poorly perfused (apex of lung biggest contributor to alveolar dead space)

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

How is physiologic dead space calculated?

A

Vd/Vt = (PaCO2 - PeCO2) / PaCO2

Vd = phys dead space+anatomic dead space + alveolar dead
Vt = Tidal volume 
PaCO2 = arterial PCO2
PeCO2 = expired air PCO2

Taco, Paco, Peco, Paco (refers to orer of variable )

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

What is minute ventilation and how is it calculated?

A

Total volume of gas entering lungs per minute

Ve = VT x RR

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

What is alveolar ventilation and how is it calculated?

A

volume of gas per unit time that reaches alveoli.
Va = (Vt-Vd) x RR

Normal values: Vt = 500/breath; Vd = 150 mL/breath; RR = 12-20

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

Elastic recoil is the tendency of lungs to collapse inward and chest wall to spring outward. These two recoils equals to zero at what point?

A

FRC (functional residual capacity)

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

At FRC, indicate at what level of each of these factors are in:
A. Airway and alveolar pressure
B. Intrapelural pressure
C. PVR (pulmonary vascular resistance)

A

A. 0
B. Negative value
C. At minimum resistance

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

What is lung compliance defined as?

A

Change in lung volume for a change in pressure; expressed as deltaV/deltaP and is inversely proportional = lung easier to full at high compliance; lung harder to fill at low compliance

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

What are some diseased states in which lung compliance:
A. decreased
B. Increased

A

A. pulmonary fibrosis, pneumonia, pulmonary edema

B. emphysema, normal aging

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

What is hysteresis?

A

The combo of inhalation and deflation curve of pressure volume curve). The transpulmonary pressure vs Volume curve of inhalation is different from the Pressure vs Volume curve of exhalation, the difference being described as hysteresis. Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation.

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

with decreased O2 explain the difference between pulmonary blood flow and systemic blood flow

A

Decreased O2 levels leads to vasodilation of peripheral arteries thus increased blood flow and the opposite is true for pulmonary circulation: with decrease O2 –> vasoconstriction –> decreased flow –> shunting of blood from poorly ventilated areas to more to well ventilated areas. In sum: increase PaO2 blood flow increase in the lungs, but decrease blood flow systemically

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

Differentiate difference pulmonary circulation and systemic circulation

A 
Pulmonary = low pressure system 24/12 mmHg
Systemic = high pressure system 120/80 mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Gases must diffuse from air to blood. The rate of diffusion depends on what factors?

A
  • Pressure difference (air - blood)
  • area of alveoli for diffusion
  • Thickness of alveolar tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the Fick’s Law of diffusion?

A

V(gas) = (A/T) x D x (P1-P2) aka Vgas = Area x D x pressure difference / thickness

Vgas = rate of gas diffusion
A= surface area for exchange
T = thickness of membrane between alveolar gas and capillary blood
- (p1-P2) = gas partial pressure difference alvolar gas and capillary blood
D = diffusion constant

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

Diffusion is impacted by diseased states. State what variable in Fick’s Law of diffusion is altered due to the following diseased states:
A. Emphysema
B. Pulmonary fibrosis

A

A. decreased Area

B. Increased thickness

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

How long does RBC remain in pulmonary capillary, and how long does it take for equilibrium for the exchange of CO and O2 to take place?

A

RBC remains in caps for 0.75 sec and equilibrium is reached in .25s in normal lung at resting state. Exercise reduces equilibrium time, but there is still enough reserve for full equilibrium of oxygen in a healthy individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Diffusion and perfusion are factors for a gas to reach max level in circulation. For the each of the following gases indicate and explain the their limitations in reaching max in circulation:
A. CO
B. N20
C. O2

A

A. Diffusion limited. The barrier from alveoli to capillary (diffusion thickness) retards their diffusion
B. N20 is perfusion limited. They are able to easily diffuse across the diffusion barrier, thus their max level in circulation will be depended on blood flow (perfusion)
C. O2 is perfusion limited. Similar idea as N20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is pulmonary vascular resistance calculated?

A

PVR = P (pulm artery) - P (left atrium) / CO

30
Q

At what point is pulmonary vascular resistance the lowest?

A

At FRC.

31
Q

What happens to pulmonary vascular resistance during inspiration? during expiration?

A

Resistance during both

32
Q

Hemoglobin is a 4 polypeptide subunits with 2alpha and 2 beta and usually exists in what two forms?

A
  1. Taut: deoxygenated = low affinity for O2, promotes release/unloading of O2
  2. Relaxed: oxygenated = high affinity for O2 and exhibits positive cooperativity and negative allosteric ;
33
Q

what factors favors the taut form of hemoglobin and thus shifts the oxygen-hemoglobin dissociation curve tot he right.

A

remember by: right shift —> ACE BAT’s right handed

  • Acid (increased H+)
  • CO2
  • Exercise
  • 2,3 BPG
  • Altitude
  • Temp
34
Q

Is hemoglobin in the taut form or relaxed form in peripheral tissues?

A

Taut form in tissues and relaxed form in lung.

Taut in Tissues; Relaxed in Respiratory area

35
Q

Carboxyhemoglobin is Hb bound to CO instead of O2 and shifts the curve to _

A

left. Decrease O2 unloading in tissues. CO binds Hb 200x with greater affinity than O2. Treat with 100% O2 in hyperbaric chamber

36
Q

How is O2 content in blood calculated?

A

O2 content = (O2 binding capacity) x (% sat) + Dissolved O2

O2 content = 1.34 x Hb x OaO2 + 0.003

  • O2 binding capacity is determined by Hb = 20.1 mL O2/dL
  • % saturation is determined by measuring via pulse oximetry
  • Dissolved O2 is 0.003 ( negligible since number is so small)
37
Q

What is A-a gradient?

A

The difference in pressure in alveoli and in blood

PAO2 - PaO2 = 10-15mmHg

38
Q

How is alveolar gas pressure calculated?

A

PAO2 = PIO2 - (PaCO2/R)

aka
150mmHg^a - (paCO2/.8)

PAO2 = alvolar PO2
PIO2 = PO2 in inspired air
PaCO2 = PCO2 in arteries
R = respiratory quotient: CO2 produced/O2 consumed. normallly it's 0.8
39
Q

Increased A-a gradient can be seen in what clinical situations?

A

Hypoxemia as due to shunting, V/Q mismatch, fibrosis

40
Q

What does it mean when A-a gradient is normal, but pt is hypoxemic?

A

Since A-a gradient is normal that means alveoli and pulmonary vasculature are working properly but pt is not inhaling enough O2 which can be due to hypoventilation as seen in narcotics, neuromuscular weakness, obesity, high altitude. Can be treated with giving O2.

41
Q

What is the implication of high A-a gradient hypoxemia?

A

High A-a gradient means alveoli can’t get O2 to blood, in other words blood is not going to working alveoli. Most lung diseases usually has high A-a gradient.

42
Q

What are the three main mechanism that which produces a high A-a gradient?

A
  1. Fibrosis: loss of alveoli for diffusion, increased A-a gradient and hypoxemia
  2. Shunt: blood not flowing past alveoli with O2 (anatomic and physiologic shunting)
  3. Altered VQ mismatch
43
Q

Ideally V/Q ratio should be 1, but due to anatomy and physics, what is “normal” V/Q ratio?

A

0.8 and depends on normal RR, TV, and CO.

It reaches 1 during exercise cuz CO is increased.

44
Q

What is the V/Q ratio at the apex of the lung vs base of the lung?

A

Apex V/Q = 3 (wasted ventilation) high ventilation with high O2, low CO2

Base: 0.6 (wasted perfusion) low ventilation with low O2, high CO2.

45
Q

What makes up the conducting zone and respiratory zones?

A

Conducting zone: trachea; bronchi; bronchioles; terminal bronchoioles

Respiratory zone: Respiratory bronchioles; alveolar ducts; alveolar sacs

46
Q

which type of alveoli are responsible for surfactant production

A

Type II alveolar cells (aka type II pneumocytes)

47
Q

What is approximate pressure inside the alveoli during inspiration and expiration?

A

Inspiration: about -1mmHg

Expiration: about +1mmHg

48
Q

When is the intrapleural pressure the lowest?

A

Right after inspiration and beginning of expiration. It’s -6mmHg. Normally it’s -2.5mmHg at the start of inspiration.

49
Q

Which lung volume cannot be exhaled out?

A

RV

50
Q

Which lung volume cannot be measured via spirometry

A

Residual volume and any capacity that includes it

51
Q

What is forced vital capacity (FVC)?

A

Largest amount of air that can be expired after a maximal inspiratory effort. It’s frequently measured clinically as an index of pulmonary function

52
Q

What is FVC1?

A

The fraction of the vital capacity expired during first second of a forced expiration

53
Q

In a normal lung, what is the FEV1, FVC, and FEV1/FVC ratio?

FEV=Forced expiratory volume
FVC = Forced vital capacity

A 
FEV1 = 3.3L
FVC = 4.0L
FEV1/FVC = 83%

In normal lung, most of FVC can be expired within 2sec.

54
Q

In obstructive lung diseases, describe how FEV1, FVC, and FEV1/FVC ratio changes

A 
FEV1 = 1 L (significantly lower than normal) 
FVC = 2 L (half of normal)
FEV1/FVC = 50% (about 30% less than that normal)

Notice both FEV1 and FVC is significantly reduced. Further more, even in that reduced FVC, it takes almost twice as much time (about 4 sec) to expire the FVC

55
Q

In a restrictive lung disease, explain what changes are seen in FEV1, FVC and FEV/FVC ratio.

A 
FEV1 = 1.8
FVC = 2.0
FEV1/FVC = 90%
56
Q

The pressure volume curve takes different paths in inspiration and expiration (they do not follow the same path). Why?

A

The surface tension (between the air inhaled and the tissue (which is essentially water) is what makes the curve to be different

57
Q

What is the role of surfactant and how does it prevent the alveoli from collapsing during expiration?

A

The low surface tension when alveoli are small are due to surfactant in the fluid lining the alveoli. If the surface tension is not kept low when the alveoli become smaller during expiration, they collapse in accordance with law of Laplace. In spherical structures like the alveolus, the distending pressure (P) equals two times the tension (T) divided by the radius. (P=2T/r); if T is not reduced as r is reduced, the tension overcomes the distending pressure. Surfactant

58
Q

what drives net flow of O2 into the blood and CO2 out of the blood in the pulmonary system?

A

partial pressure difference between air and blood for O2 and CO2.

59
Q

what are the major ways O2 is carried in blood?

A

Most are bound to Hb, and small amounts are dissolved.

60
Q

How is CO2 carried in blood?

A

CO2 in blood is rapidly converted into H2CO3 due to activity of carbonic anhydrase. CO2 also readily forms carbamino compounds with blood proteins (including HB0. the rapid net loss of CO2 allows more CO2 to dissolve in blood

61
Q

what is the role of Pre botzinger complex in respiratory control?

A

Located on either side of medulla, contains synaptically coupled pacemaker cells that allow for rhythmic generation of breathing. the spontaneous activity of these neurons can be altered by neurons in pneumotaxic center

62
Q

Peripheral chemorecetpros are located on _ and are sensitive to changes in _

A

Aortic an carotid bodies.

PaO2, PaCO2, and pHa

63
Q

What kind of breathing patterns is seen in patient with diabetic acidosis?

A

Kussmaul

64
Q

Where are central chemoreceptors located and what are they sensitive to?

A

Located on ventral surface of medulla and sensitive to CO2.

65
Q

Rapidly-adapting pulmonary stretch receptors trigger _ in response to various irritants.

A

Cough

66
Q

Slowly adapting pulmonary stretch receptors are important for _

A

telling the brain how much air is in the lungs which then would trigger expiration/ decrease inspiration.

67
Q

Which pulmonary stretch receptors are important in babies to control respiratory rate.

A

slowly adapting pulmonary stretch receptors.

68
Q

In adults, during exercise which receptors allows to increase tidal volume?

A

slowly adapting pulmonary stretch receptors.

69
Q

J receptors are located _ and are important in detecting _ which produces _ breathing pattern.

A

Located on juxtaalveolar wall and detects fluid flow. Important in detecting edema, and produces rapid shallow breathing as seen in pts with restrictive disease

70
Q

Pt takes a breathe in as deeply as possible and exhales forcefully into a spirometer until all possible air has been expelled. What volume/capacity was measured?

A

Vital capacity

71
Q

An increase in what will decrease the amount of oxygen that crosses the alveolar barrier in one minute?

A

The diffusion distance across the alveolar barrier

Respiratory Medicine Midterm (7 decks)

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