Respiratory I Flashcards

Question

Thorax: Thoracic Cage: Chest wall

Answer 1

muscles in chest cavity internal and external intercostal muscles connect the 12 rib pairs sternocleidomastoids and scalenes connect the head and neck to the first 2 ribs

Answer 2

dome-shaped skeletal muscle separates thoracic cavity from the abdominal cavity

Answer 3

* separates each lung from the thoracic wall * double walled closed sac * visceral covers surface of lung * parietal on inside of thorax * Space within sac contains * intrapleural fluid (1.5 mL) * secreted by surfaces of the pleura * lubricates pleural surfaces * causes pleural surfaces to adhere together (lung and thorax)

Answer 4

intrapleural fluid creates a slippery surface allowing lungs to slide against thoracic wall pleural fluid = a lubricant

Answer 5

when chest expands → lungs are compelled to follow Pleural Fluid = lungs and chest expand as a single unit

Answer 6

subject to gravity pressure exerted by the weight of the air in the atmosphere (760 mm Hg at sea level)

Answer 7

pressure inside the alveoli when compared to atmospheric pressure it is 0 (B/C they are the same)

Answer 8

pressure in pleural fluid; normally \< intraalveolar pressure normally less than what is in lungs

Answer 9

pressure difference across the lungs transpulmonary = across lung wall; P_alveolar - P_intrapleural

Answer 10

important reason lungs follow chest makes it easier to expand pushes alveoli out as pressure goes down the gradient

Answer 11

tendency to pull in

Answer 12

tends to pull out

Answer 13

transmural pressure gradient and intrapleural fluid's cohesiveness

Answer 14

creates a vacuum because fluid cannot expand to fill the slightly larger volume

Answer 15

negative during quiet breathing more negative during deep inspiration

Answer 16

during forced expiration → blowing out

Answer 17

air in chest

Answer 18

shortness of breath fatigue increased HR chest pain blue lips/fingers

Answer 19

opening in the chest wall → air enters pleural space → P_ip equilibrates with P_B → transplum pressure gradient is lost → lungs and thorax separate and assume their natural positions

Answer 20

Pressure, tension, or Partial Pressure of gas

Answer 21

volume of gas

Answer 22

functional concentration of a gas

Answer 23

volume of blood

Answer 24

barometric

Answer 25

dead space

Answer 26

expiratory

Answer 27

inspiratory

Answer 28

carbon dixoide

Answer 29

nitrgrogen n

Answer 30

denotes a rate → V_eCO₂ → volume of CO₂ in expired and as you rotate

Answer 31

* Respiratory muscles to change size of thoracic cavity * overcome tissue elastance * overcome surface tension within alveoli

Answer 32

down a pressure gradient from higher to lower

Answer 33

air enters lungs

Answer 34

air exits lungs

Answer 35

changing the volume of the lungs

Answer 36

the pressure and volume of a gas are inversely related P₁V₁ = P₂V₂ ½ volume → double pressure double volume → ½ pressure

Answer 37

decreases proportionately

Answer 38

* as the lungs expand in volume, pressure goes down * expand chest wall → ⇡ volume → ⇣ pressure → air flows in * as the lungs shrink in volume, pressure goes up * expiration → ⇣ volume → ⇡ pressure → air flows out

Answer 39

the active phase of the breathing cycle

Answer 40

Respiratory muscles relaxed no air is flowing → P_A = P_B

Answer 41

* motor impulses from brainstem activate muscle contraction * thoracic cavity expands → P_A and P_ip to drop

Answer 42

Fresh air to flow in until pressures are equalized

Answer 43

⇡ transpulmonary pressure gradient needed to overcome increased elastic recoil force of stretched lungs

Answer 44

sheet of skeletal muscle forms the floor of the thoracic cavity major muscle of inspiratory effort (75%) Normal inspiration: Diaphragm moves 1 cm Forced inspiration: Diaphragm can move 10 cm

Answer 45

dome shape protrudes upward into thorax

Answer 46

innervated by phrenic nerve it increases thoracic cavity by descending downward ribs forward

Answer 47

responsible for 25% of inspiratory effort lie on top of internal intercostal activated by intercostal nerves contraction: elevate ribs an thus sternum → upward and forward ie. “bucket-handle” fashion

Answer 48

help increase dimensions of thoracic cavity pump handle movement bucket handle movement

Answer 49

assist with forces inspiration → eg. exercise Scalene Muscles → elevate the first 2 ribs Sternocleidomastoid Muscle → raises the sternum both cause even greater drops in P_A and P_ip

Answer 50

using neck muscles to breath

Answer 51

positive because machine forces air into you

Answer 52

The passive phase of breathing cycle

Answer 53

inspiratory muscles relax lungs recoil due to elastic properties pleural and alveolar pressures rise → P_A = 761 mmHg gas flows passively out of lung due to elastic recoil

Answer 54

abdominal and internal intercostals

Answer 55

* need to ⇡ P_A even more * need more force than accomplished by simple relaxation * exercise and disease states such as asthma

Answer 56

⇡ intra-abdominal pressure

Answer 57

* Unable to expand * hard to increase volume, difficult to decrease pressure and breathe in * unable contract lung * hard to decrease volume, difficult to increase pressure and breathe out

Answer 58

Scar tissue reduced surfactant mucus fluid

Answer 59

Laminar Turbulent flow changes: laminar to turbulent when Reynolds # \>200

Answer 60

air flows in the same direction parallel to walls low flow rates → requires less pressure to flow gas in center travels most rapidly

Answer 61

As air flow rate increases → air moves irregularly → creates resistance to flow which requires higher pressures

Answer 62

Re = 2rvd/n r = radius, v = average velocity, d = density, n = viscosity

Answer 63

Average velocity is high and radius is large Trachea: large diameter (3 cm) and gas flow: 1L/sec gas flow in larger airways (nose, mouth, trachea, bronchi) is turbulent

Answer 64

F = ΔP/R F = flow rate, ΔP = pressure difference, R = resistance of airway high pressure difference = fast flow

Answer 65

R = ( 8\*L\*n) / (π \* r⁴) R = resistance, L = length of tube, n = viscosity of fluid π = 3.14, r = radius of tube to the fourth power

Answer 66

it will increase R 16-fold

Answer 67

the larger the lung volume the lower the resistance diameter of airways change with lung volume airways supported by radial traction of surrounding lung CT as lung expands, it pulls open airways as lung volume decreases, smaller airways may be compressed at low lung volumes → ⇡ R

Answer 68

contraction of airways ⇡ R bronchoconstriction → ⇣ radius, ⇡ resistance to airflow bronchodilation → ⇡ radius, ⇣ resistance to airflow

Answer 69

* Pathological: allergy-induced spasm of airways * Physical blockage: mucus, airway collapse * \*neural control: PNS - during quiet relaxed situations, demand not high * Ach on M receptors * \*local control: low CO₂

Answer 70

* Pathological: none * Neural (minimal effect): SNS * \*Hormonal: EPI when demand high * Beta-2 adrenergic agonists (cause dilation) * \*Local control: high CO₂

Answer 71

Elevated gas density (deep sea diving) ⇡ R for every 10 m you go down, you ⇡ 1 atm

Answer 72

airway compression ⇡ resistance significantly P_ip is positive P_A = P_ip + P_{elastic recoil} as elastic recoil decreases, P_A decreases exhaling air loses pressure as it hits R

Answer 73

the point when P_airway = P_ip If P_ip \> than P_airway , collapse of the airway can occur occurs in larger airways in healthy lungs, the EPP occurs normally where cartilage is present and prevents closure of the airway influenced by lung elastic recoil

Answer 74

the loss of alveoli and thus elastic recoil, lowers P_A further during forced expiration EPP occurs closer to the alveoli, where the cartilage cannot prevent airway collapse

Answer 75

Recoil → ⇡ P_A → EPP established in larger airways; collapse is minimal

Answer 76

Low recoil → ⇣P_A → EPP established in small airways; easily compressed

Answer 77

* umbrella term used to describe chronic lung diseases that cause limitations in lung airflow → ⇡ R * when R ⇡s, larger pressure gradient needed to maintain normal flow rate * Two main forms: * chronic bronchitis * emphysema

Answer 78

* Chronic bronchitis * alveolar walls are destroyed * alveoli lose their ability to recoil * Emphysema * airways walls become thickened and inflames * airways become clogged with mucus

Answer 79

a series of tests that evaluate how well lungs are working used to diagnose, stage, and monitor pulmonary diseases

Answer 80

Spirometry → 1st test performed → screening test Formal lung volume measurement diffusing capacity for CO → assess diffusion barrie and Hb Arterial Blood gases

Answer 81

* Lung volumes and capacities * determine the amount (volume) of air someone can move in and out compared to normal population * Flow/Volume loops * determine speed (flow) → how fast can air escape

Answer 82

* Anatomic measurements that vary with age (⇣ capacity with age) , weight (larger the weight, ⇣ capacity), height (⇡ capacity with taller height), sex (men have higher capacity than women), and race * can be altered by disease/trauma * seated subject breaths into closed system * old: an air filled drum floating in water filled chamber * New: Pneumotachometer

Answer 83

Volume of air entering or leaving lungs during a single breath avg value = 500 mL

Answer 84

extra volume of air that can be maximally inspired over and above the typical resting tidal volume

Answer 85

extra volume of air that can be actively expired by maximal contraction beyond the normal volume of air after a resting tidal volume

Answer 86

maximum volume of air that can be inspired at the end of a normal quiet expiration IC = IRV + VT

Answer 87

minimum volume of air remaining in the lungs even after a maximal expiration

Answer 88

volume of air in lungs at the end of normal passive expiration resting equilibrium point FRC = ERV + RV

Answer 89

maximum volume of air that can be moved out during a single breath following a maximal inspiration VC = IRV + VT + ERV avg value = 4800 mL

Answer 90

Maximum volume of air that the lungs can hold TLC = VC = RV avg value = 6000 mL

Answer 91

* into 4 volumes that give 4 capacities * IRV = 3.1 L * VT = 0.5 L * ERV = 1.2 L * RV = 1.2 L * TLC = IRV + VT + ERV + RV = 6.0 L * IC = IRV + VT = 3.6 L * VC = IRV + VT + ERV = 4.8 L * FRC = ERV + RV = 2.4 L

Answer 92

spirometry measures the amount of air entering and leaving the lungs but cannot provide info about absolute lung volumes need to use things like gas dilution and body plethysmography

Answer 93

⇣ capacity to get air out ⇡ RV ( \> 120% predicted) ⇡ static lung volumes: RV, FRC, TLC slow flow rates; hyperinflation; ⇣ recoil characteristic of COPD

Answer 94

⇣ capacity to get air in ⇣ TLC ( \< 80% predicted) ⇣ static lung volumes: RV, FRC, VT, VC ⇡ recoil, ⇣ volume

Answer 95

FVC: forced vital capacity; the volume of air forcibly blown out after full inspiration → volume of air drops in the lungs FEV1: forced expiratory volume in 1 sec FEV1/FVC: proportion of FVC expired in 1st second of expiration

Answer 96

if the issue is obstructive or restrictive \< 80% = obstructive \> 80% = restrictive

Answer 97

elastic properties → once stretched it recoils to its unstretched position

Answer 98

how easily the lung is stretched (distensibility) ΔV/ ΔP → Δ in lung volume resulting from a Δ in distending pressure (transmural pressure gradient)

Answer 99

large change in V for a given change in P easy to stretch low lung volume stretches further for a given ⇡ in pressure

Answer 100

Emphysema → disappearing lung tissue → easy to inflate → larger increases in volume for a given change in pressure → low elastic recoil :

Answer 101

small change in V for a given change in P hard to stretch high lung volume a large transmural pressure gradient is needed to expand lungs

Answer 102

Pulmonary fibrosis → collagen deposition in response to injury → more work required → smaller increases in volume for a given change in pressure → “stiff lung” → lacks stretchability

Answer 103

the base compliance of the base \> apex a greater portion of tidal volume goes to the base, resulting in greater ventilation the base is relatively compressed but expands better due to smaller resting volume

Answer 104

gravity causes weight of lung to pull down on alveoli → results in alveoli in apex to be more expanded → P_ip is more negative allowing for greater initial expansion lower compliance in distended alveoli

Answer 105

loss or gain of connective tissue

Answer 106

* Distensibility and elastic recoil are inversely related * lung that is easily inflates has less elastic recoil * lung that is hard to inflate has high elastic recoil * elastic recoil is directly related to lung stiffness * the stiffer the lung, the greater the recoil → coiled spring

Answer 107

Normal: balanced Obstructive: emphysema: FRC ⇡: chest elastic recoil wins Restrictive: Fibrosis: FRC ⇣ → lung elastic recoil wins

Answer 108

* elastin and collagen fibers * smoking destroys CT (⇡ compliance) * \*Alveolar surface tension * ⅔ of total elastic force in lung is due to surface tension due to inspiration * thin liquid film lines each alveolus → produces as inwardly directed force (collapsing force) → resists being stretched

Answer 109

in alveoli fluid and reduces surface tension increases compliance gets in between water molecules and breaks up cohesiveness making it easier for lungs to expand secreted by Type II alveolar cells

Answer 110

oxygen consumption how much oxygen do we have to take in to use to make ATP → tells what work is for breathing

Answer 111

O₂ cost of quiet breathing: 5% of total oxygen consumption Heavy exercise increases O₂ cost to 20%

Answer 112

compliance is decreased → more work required to expand lungs airway resistance is increased → more work to achieve pressure gradients to overcome resistance elastic recoil is decreased → passive expiration inadequate (need abs)