Respiration physiology course pack Flashcards

1
Q

What is the main function of respiration?
What happens during expiration?
What are gases transported by?

A

-gas exchange
-Co2 is produced and exhaled from the lungs
-transported by blood

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2
Q

What cleans the air of dust particles?
Where does the moistened air pass through?
what does air pass through to reach lungs

A

the nose which is nasal septum+nasal turbinates
-the pharynx then continues to larynx
-reaches lungs via trachea and bronchi

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3
Q

How many bronchi lobes are on each side of body?
Where does gas exchange occur?

A

-left side has 2 lobes (2 lobes)
-right side has 3 bronchi (3 lobes)
-alveoli, since they are surrounded by capillaries

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4
Q

what is the visceral pleura
-what is parietal pleura

A

-visceral pleura=space between ribcage
-parietal pleura=thoracic lung space

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5
Q

what is in the conducing zone vs the respiratory zone?

A

-conducting zone has trachea, bronchi, bronchioles, terminal bronchioles
-respiratory zone has respiratory bronchioles, alveolar ducts, alveolar sacs

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6
Q

What does the pleural space do to the lungs when inhaling?
what is the pressure in the pleural space?

A

-pleural space pulls on lungs to open, causing respiratory muscle and lung volume to increase
-pleural space is stuck to ribcage and has a negative pressure

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7
Q

why is there a negative pressure in pleural space?

A

-Lungs always want to generate a pressure to collapse, and ribcage wants to expand causing a neg. pressure

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8
Q

What does the conducting zone do vs the respiratory zone?

A

-conducting zone does not contribute to gas exchnage and thus composes the anatomical dead space
-respiratory zone has gas exchange in the alveolar regions of the lungs (smalles unit of lung is acinus)

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9
Q

what is difference between bronchioles and bronchi?

A

-bronchioles are smaller and do not have cartilage plaques

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10
Q

What are the main 4 functions of conducting airways?

A
  1. defense against bacterial infection due to cilia in the bronchi, and due to epithelial gland which secrete mucous
    2.warm and moistens air
    3.sound and speech produced by air moving over vocal cords
    4.regulation of air flow- SM contracts or relaxes around air ways
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11
Q

What is main function of respiratory zone?

A

-site of gas exchange between air in the alveoli and blood in the pulmonary capillaries, around 1000 capillaries per alveolus

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12
Q

What are the 2 types of blood supply?

A

-pulmonary circulation and bronchial circulation

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13
Q

what does pulmonary circulation do vs bronchial circulation?

A

-pulmonary circulation brings mixed venous blood to the lungs allowing blood to get oxygenated, and back to the left heart
-supplying oxygenated blood from the systemic circulation to the tracheobronchial tree (always airways to get oxygenated)

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14
Q

What vessel supplies blood in pulmonary circulation?
How does oxygenated blood get returned back to heart

A

-blood in pulmonary capillaries is supplied via pulmonary arteries which orginates from the right ventricle, which supply blood to respiratory surface where gas exchange occurs
-then oxygenated blood leaves lungs and returns to left heart via pulmonary veins

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15
Q

what supplies blood in bronchial circulation?

A

-bronchial arteries from the aorta supply the airway walls (part of systemic circulation)

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16
Q

What lines alveoli and what do they secrete?

A

-epithelial type I and Type II pneumocytes
-type II secretes surfactant (decreases surface tension)

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17
Q

What do endothelial cells line?
What do alveolar macrophages do?

A

-endothelial cells line pulmonary capillaries
-they remove foreign particles from the alveoli

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18
Q

What causes surface tension in lungs?
What is laplace’s law?

A

-tension arises because the molecules want to arrange themselves in the lowest energy configuration which makes them tightly bound
-P=4T/R (4 tension/radius) (smaller radius=larger pressure)

19
Q

what are the 2 types of lung tissue?

A

-inspiratory and expiratory muscles because the lung tissue is elastic and unable to expand/contract on its own

20
Q

What are the inspiratory muscles?

A

-main one is diaphragm, external intercostal muscles and the parasternal intrcartilaginous muscle, and neck muscle

21
Q

when is expiratory muscle active?

A
  • at higher levels of ventilation (excercise, or during increased expiratory resistance
22
Q

what is used to measure lung volumes?
What can this machine measure?
What cant the machine measure

A

-spirometer, which measures te volume of air inhaled during inspiration
-can measure inhaled/exhaled gas like tidal volume, vital capacity, inspiratory capacity, expiratory reserve volume, and inspiratory reserve volume
-cant measure, functinal residual capacity, total lung capacity or residual capacity

23
Q

How do you measure Vital capacity?

A

VC=TLC-RV (total lung capacity-residual volume)
can also be measured by VC=ERV+TV+IRV (expiratory reserve volume+tidal volume+inspiratory reserve volume)

24
Q

How is FRC (functional residual capacity measured)

A

FRC can be measured by helium dilution in a spirometer
FRC= (c1*v1/c2)-V1

25
Q

Minute ventilation formula (Ve), what is the formula and what are the typical values

A

Ve=Vtf (tidal volumebreathing frequency)
typically 6000ml/min since Vt=500ml and f=12

26
Q

what is the amount of air that reaches the respiratory zone?
How many ml is the anatomical dead space?

A

dead space is 150ml (typically subjects weight in lbs)
-alveolar ventilation (Va)=(500-150ml)12=4200ml/min
Va=(tidal volume-anatomical dead space)
breathing frequency

27
Q

physiological deadspace formula (Vd)

A

Vd=Ve-Va

28
Q

3 types of alveolar ventilation, what are they and what occurs in each?

A
  1. normal alveolar ventilation:Va keeps PaCO2 at a constant level (alveolar ventilation keeps partial arterial pressure co2)
    -solubility of Co2 is higher than O2
    2.Alveolar hyperventilation- Co2 in blood decreases causing vasconstriction which can lead to fainting since PAO2 rise and PaCO2 decreases
  2. alveolar hypoventilation: PAO2 falls and PACO2 rises, blood in pulmonary capillary is less oxygenated, causing PaO2 to decrease
29
Q

What is diffusion rate proportional to?
How many times faster does Co2 diffuse than o2
in what direction does O2 diffuse vs Co2

A

-surface area, partial pressure gradient and 1/thickness
-20x faster, that is why there is higher PCO2 in alveoli than PO2
-O2 diffuses from alveolar gas to blood and CO2 goes from blood to alveolar gas

30
Q

How much time is required for equilbrium between alveolar air and capillary blood?

A

-it is approximately the same for the 2 gases since the difference in PCO2 is 10x smaller between the 2 sides of the alveolar capillary membrane than O2, but PCO2 has higher diffusion rate

31
Q

How long is the transit time for both CO2 and O2 equilbrium?
What happens in personw with impaired diffusion if blood flow increases?

A

-it can occur within 1/3 of the RBC transit time
-transit time becomes shorter so arterial PO2 may decrease and arterial PCO2 may increase

32
Q

How long is the transit time for both CO2 and O2 equilbrium?
What happens in personw with impaired diffusion if blood flow increases?

A

-it can occur within 1/3 of the RBC transit time
-transit time becomes shorter so arterial PO2 may decrease and arterial PCO2 may increasewhat

33
Q

what is difference between pulmonary and systemic circulation
What is the MAP in pulmonary artery vs left atrium

A

-BP is lower and pulmonary capillaries are thinner in pulmonary circulation than in systemic circulation vessels/BP
-15mmhg while left atrial pressure is about 5mmhg

34
Q

WHat is the MAP in pulmonary artery vs systemic artery?

A

-pulmonary MAP=15mmhg
-systemic MAP=100mmhg since systole is 120 and diastole is 80mmhg

35
Q

What is the resistance in pulmonary vs systemic circulation?
What is the low vascular resistance in pulmonary circulation causes by?

A

-pulmonary resistance is 1/10 that of systemic circulation when pulmonary goes from pulmomary artery to left atrium compared to systemic artery to right atrium
-due to high compliance

36
Q

How can you increase cardiac output without changing the pressure?

A

-you open up more capillaries or distend vessles which increase cross secrional area causing resistance to drop and blood flow to increase

37
Q

What drugs increase pulmonary vascular resistance and which drugs decrease pulmonary vascular resistance

A

seratonin, histamine and norepinephrine cause contraction of Sm increase resiatance in larger pulmonary arteries
-AcH, and isoproteranol relax SM and can decrease resistance

38
Q

What else can cause vasocontriction/vasodilation?

A

-vasonctriction can occur in regions of lungs with poor oygentation
-vasodilatoin can occur when nitric oxide is produced by endothelial cells since it relaxes SM

39
Q

How does gravity effect blood flow?

A

-when we stand up blood flow increases from top to bottom of lungs (vessels more distended at bottom since gravity increases vascular pressure and near top capillaries are more compressed)

40
Q

What are the effects of gravity on zone 1, zone 2 and zone 2

A

zone 1: PA>pa>Pv (alveolar>arterial>venous)
zone2:Pa>PA>Pv
zone 3: Pa>PV>PA

41
Q

How can distribution of ventilation be measured, what is used in the test?

A

-it can be measured with inhaled xenon instead of infused in the blood (ventilation at the bottom of lung is higher)

42
Q

How does ventilation and blood flow change from top to bottom of lung?
Where is the ventilation perfusion ratio high/low?

A

-ventilation increases slowly from top to bottom of lung, but blood flow increases rapidly from top to bottom
-ventilation perfusion ratio is high at the top and much lower at the bottom of lung

43
Q

What is pulmonary blood flow equal to (Q)?

A

it is equal to Vo2/(CaO2-CvO2)
-O2 conusmption per minute/ (blood leaving lungs-blood entering lungs)