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Flashcards in Respiratory System Deck (157)
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1
Q

Process of respiration

A
  • Pulmonary ventilation (breathing)-movement of air into and out of lungs
  • External respiration-O2 and CO2 exchange between lungs and blood
  • Transport-O2 and CO2 in blood
  • Internal respiration-O2 and CO2exchange between systemic blood vessels and tissues
2
Q

Site of gas exchange

A

Respiratory zone

–Microscopic structures-respiratory bronchioles, alveolar ducts, and alveoli

3
Q

Conduits to gas exchange sites

A

Conducting zone

–Includes all other respiratory structures; cleanses, warms, humidifies air

4
Q

Primary respiratory muscles

A

Diaphragm and intercostal muscles that promote ventilation

5
Q

Functions of the nose

A
  1. Provides an airway for respiration
  2. Moistens and warms entering air
  3. Filters and cleans inspired air
  4. Serves as resonating chamber for speech
  5. Houses olfactory receptors
6
Q

Contains olfactory epithelium

A

Olfactory mucosa

7
Q

–Mucous and serous secretions contain lysozyme and defensins
–Cilia move contaminated mucus posteriorly to throat
–Sensory nerve endings trigger sneezing

A

Respiratory mucosa

8
Q

–During inhalation filter, heat, and moisten air

–During exhalation reclaim heat and moisture

A

Nasal conchae - superior, middle, inferior

9
Q

Groove inferior to each conchae

A

Nasal meatus

10
Q

Sinuses in bone that surround the nasal cavity

A

–Frontal
–Sphenoid
–Ethmoid
–Maxillary

*Mnemonic: Fast snakes eat mice

11
Q

Function of sinuses

A

Lighten skull; secrete mucus; help to warm and moisten air

12
Q

Sinusitis

A

Inflamed sinuses

13
Q

Rhinitis

A

–Inflammation of nasal mucosa
–Nasal mucosa continuous with mucosa of respiratory tract –> spreads from nose to throat to chest
–Spreads to tear ducts and paranasal sinuses causing blocked sinus passageways –> sinus headache

14
Q

Pharynx

A

Muscular tube from base of skull to C6
–Connects nasal cavity and mouth to larynx and esophagus
–Composed of skeletal muscle

15
Q

Three regions of the pharynx

A
  1. Nasopharynx
  2. Oropharynx
  3. Laryngopharynx
16
Q

Nasopharynx

A
  • Air passageway posterior to nasal cavity
  • Soft palate and uvula close nasopharynx during swallowing
  • Pharyngeal tonsil (adenoids) on posterior wall •Pharyngotympanic (auditory) tubes drain and equalize pressure in middle ear; open into lateral walls
17
Q

Oropharynx

A
  • Passageway for food and air from level of soft palate to epiglottis
  • Palatine tonsils-in lateral walls of fauces (latin for throat)
  • Lingual tonsil-on posterior surface of tongue
18
Q

Laryngopharynx

A
  • Passageway for food and air
  • Posterior to upright epiglottis
  • Extends to larynx, where continuous with esophagus
19
Q

Larynx

A

•Attaches to hyoid bone; opens into laryngopharynx; continuous with trachea

20
Q

Functions of the larynx

A
  1. Provides patent airway
  2. Routes air and food into proper channels
  3. Voice production - houses vocal folds
21
Q

Epiglottis

A

Elastic cartilage; covers laryngeal inlet during swallowing; covered in taste bud-containing mucosa

22
Q

True vocal cords

A

Vocal folds

23
Q

Falso vocal cords

A

Vestibular folds

24
Q

Glottis

A

Opening between vocal folds

25
Q

Vibrate to produce sound as air rushes up from lungs

A

Vocal folds

26
Q

–Superior to vocal folds
–No part in sound production
–Help to close glottis during swallowing

A

Vestibular folds

27
Q

Voice production

A
  • Speech-intermittent release of expired air while opening and closing glottis
  • Pitch determined by length and tension of vocal cords •Loudness depends upon force of air
  • Chambers of pharynx, oral, nasal, and sinus cavities amplify and enhance sound quality
  • Sound is “shaped” into language by muscles of pharynx, tongue, soft palate, and lips
28
Q

Valsalva’s maneuver

A

–Glottis closes to prevent exhalation
–Abdominal muscles contract
–Intra-abdominal pressure rises
–Helps to empty rectum or stabilizes trunk during heavy lifting
–Used as an orthopedic test for herniated discs (Part of Dejerine’s Triad)

29
Q

May act as sphincter to prevent air passage

A

Vocal folds (Ex: Valsalva’s maneuver)

30
Q

Trachea

A

Windpipe–from larynx into mediastinum

31
Q

Trachealis muscle

A

–Connects posterior parts of cartilage rings

–Contracts during coughing to expel mucus

32
Q

Carina

A

–Last tracheal cartilage

–Point where trachea branches into two main bronchi

33
Q

Bronchial tree

A

Air passages branch about 23 times

34
Q

The trachea branches into …

A

Right and left main (primary) bronchi

–Each main bronchus enters hilum of one lung

35
Q

Each main bronchus branches into …

A

Lobar (secondary) bronchi (three on right, two on left)

–Each lobar bronchus supplies one lobe

36
Q

Each lobar bronchus branches into …

A

Segmental (tertiary) bronchi

–Segmental bronchi divide repeatedly

37
Q

Segmental bronchi become …

A

–Bronchioles-less than 1 mm in diameter

–Terminal bronchioles-smallest-less than 0.5 mm diameter

38
Q

Terminal bronchioles branch into …

A

Respiratory bronchioles –> alveolar ducts –> alveolar sacs

39
Q

Clusters of aveoli

A

Alveolar sacs

40
Q

Make up most of lung volume

A

300 million alveoli

41
Q

Alveolar walls

A

Single layer of squamous epithelium (type I alveolar cells)

42
Q

Secrete surfactant and antimicrobial proteins

A

Scattered cuboidal type II alveolar cells

43
Q

Surfactant

A

Reduces surface tension preventing collapse of alveoli

44
Q

Right lung

A

–3 lobes

–Superior, middle, inferior lobes separated by oblique and horizontal fissures

45
Q

Left lung

A

–Cardiac notch-concavity for heart
–2 lobes
–Separated into superior and inferior lobes by oblique fissure

46
Q

Deliver systemic venous blood to lungs for oxygenation

A

Pulmonary arteries

47
Q

Carry oxygenated blood from respiratory zones to heart

A

Pulmonary veins

48
Q

Bronchial arteries

A

–Arise from aorta and enter lungs at hilum
–Part of systemic circulation
–Supply oxygenated blood to all lung tissue except alveoli
–Bronchial veins anastomose with pulmonary veins

49
Q

Pleurae

A

Thin, double-layered serosa; divides thoracic cavity into two pleural compartments and mediastinum

50
Q

On thoracic wall, superior face of diaphragm, around heart, between lungs

A

Parietal pleurae

51
Q

On external lung surface

A

Visceral pleura

52
Q

Pleural fluid

A

Fills slitlike pleural cavity

–Provides lubrication and surface tension –> assists in expansion and recoil

53
Q

Two phases of pulmonary ventilation

A
  1. Inspiration-gases flow into lungs

2. Expiration-gases exit lungs

54
Q

Atmospheric pressure

A

–Pressure exerted by air surrounding body

–760 mm Hg at sea level = 1 atmosphere

55
Q

Negative respiratory pressure =

A

Less than P atm

56
Q

Positive respiratory pressure =

A

Greater than P atm

57
Q

Zero respiratory pressure =

A

P atm

58
Q

–Pressure in alveoli

–Fluctuates with breathing

A

Intrapulmonary (intra-alveolar) pressure (P pul)

59
Q

–Pressure in pleural cavity
–Fluctuates with breathing
–Always a negative pressure (<p></p>

A

Intrapleural pressure (P ip)

60
Q

Transpulmonary pressure =

A

(P pul – P ip)

–Keeps airways open
–Greater transpulmonary pressure –> larger lungs

61
Q

Lungs collapse if …

A

P ip = P pul or P atm

62
Q

Atelectasis (lung collapse) due to …

A

–Plugged bronchioles –> collapse of alveoli

–Pneumothorax - air in pleural cavity

63
Q

Boyle’s law

A

P1V1 = P2V2

64
Q

Responsible for 75% of air entering lungs during normal quiet breathing

A

Diaphragm

65
Q

Responsible for 25% of air entering lungs during normal quiet breathing

A

External intercostals

66
Q

Process of inspiration

A

–Active process –> inspiratory muscles (diaphragm and external intercostals) contract
–Thoracic volume increases –> intrapulmonary pressure drops (to -1 mm Hg)
–Lungs stretched and intrapulmonary volume increases
–Air flows into lungs, down its pressure gradient, until P pul = P atm

67
Q

Forced inspiration

A

Vigorous exercise, COPD –> accessory muscles (scalenes, sternocleidomastoid, pectoralis minor) –> further increase in thoracic cage size

68
Q

Process of expiration

A

–Normally passive process –> Inspiratory muscles relax
–Thoracic cavity volume decreases
–Elastic lungs recoil and intrapulmonary volume decreases –> pressure increases (P pul rises to +1 mm Hg) –Air flows out of lungs down its pressure gradient until P pul = 0

69
Q

Forced expiration

A

Active process; uses abdominal (oblique and transverse) and internal intercostal muscles

70
Q

Three factors that hinder air passage and pulmonary ventilation; require energy to overcome

A
  1. Airway resistance
  2. Alveolar surface tension
  3. Lung compliance
71
Q

Breathing movements become more strenuous

A

As airway resistance rises

72
Q

–Can prevent life-sustaining ventilation

–Can occur during acute asthma attacks; stops ventilation

A

Severe constriction or obstruction of bronchioles

73
Q

Dilates bronchioles, reduces air resistance

A

Epinephrine

74
Q

The attraction of liquid molecules to one another at a liquid-gas interface

A

Surface tension

75
Q

–Detergent-like lipid and protein complex produced by type II alveolar cells
–Reduces surface tension of alveolar fluid and discourages alveolar collapse

A

Surfactant

76
Q

Infant respiratory distress syndrome

A

Insufficient quantity of surfactant in premature infants, alveoli collapse after each breath

77
Q

Lung compliance

A

The ease with which lungs can be expanded (distensibility)

78
Q

High lung compliance =

A

Easier to expand lungs

79
Q

Three factors that diminish lung compliance

A
  1. Nonelastic scar tissue replacing lung tissue (fibrosis) 2.Reduced production of surfactant
  2. Decreased flexibility of thoracic cage
80
Q

Three homeostatic imbalances that reduce lung compliance

A
  1. Deformities of thorax
  2. Ossification of costal cartilage
  3. Paralysis of intercostal muscles
81
Q

Four respiratory volumes used to assess respiratory status

A

–Tidal volume (TV)
–Inspiratory reserve volume (IRV)
–Expiratory reserve volume (ERV)
–Residual volume (RV)

82
Q

Amount of air inhaled or exhaled with each breath under resting conditions

A

Tidal volume

83
Q

Amount of air that can be forcefully inhaled after a normal tidal volume inspiration

A

Inspiratory reserve volume

84
Q

Amount of air that can be forcefully exhaled after a normal tidal volume expiration

A

Expiratory reserve volume

85
Q

Amount of air remaining in the lungs after a forced expiration

A

Residual volume

86
Q

Maximum amount of air that can be expired after a maximum inspiratory effort

A

Vital capacity

87
Q

Vital capacity (VC) =

A

TV + IRV + ERV

88
Q

Anatomical dead space

A

–No contribution to gas exchange

–Air remaining in passageways; ~150 ml

89
Q

Alveolar dead space

A

Non-functional alveoli due to collapse or obstruction

90
Q

Total dead space

A

Sum of anatomical and alveolar dead space

91
Q

Percentage of tidal volume that reaches respiratory zone

A

70% (30% remains in conducting zone)

92
Q

Flow of gases into and out of alveoli during a particular time

A

Alveolar ventilation rate (AVR)

93
Q

Increases AVR

A

Slow, deep breathing

94
Q

Decreases AVR

A

Rapid, shallow breathing

95
Q

Rate of loading and unloading of O2 regulated to ensure adequate oxygen delivery to cells

A
  1. Decreased P O2 = decreased O2% –> increased unloading O2
  2. Increased P O2 = increased CO2% –> increased unloading O2
  3. Increased H+ = increased acidity = lower pH –> increased unloading O2
  4. Increased temp –> increased unloading O2
96
Q

Instrument for measuring respiratory volumes and capacities

A

Spirometer

97
Q

Spirometry can distinguish between …

A

–Obstructive pulmonary disease

–Restrictive disorders

98
Q

Increased airway resistance (e.g., bronchitis)

A

Obstructive pulmonary disease

99
Q

Reduced TLC due to disease (i.e. TB) or fibrosis

A

Restrictive disorders

100
Q

Dalton’s law of partial pressures

A

Total pressure exerted by mixture of gases = sum of pressures exerted by each gas

101
Q

–Pressure exerted by each gas in mixture

–Directly proportional to its percentage in mixture

A

Partial pressure

102
Q

Henry’s law

A

Gas mixtures in contact with liquid

–Each gas dissolves in proportion to its partial pressure

103
Q

Amount of each gas that will dissolve in liquid depends on …

A
  • Solubility–CO2 20 times more soluble in water than O2; little N2 dissolves in water
  • Temperature–as temperature rises, solubility decreases
104
Q

Blood flow reaching alveoli

A

Perfusion

105
Q

Amount of gas reaching alveoli

A

Ventilation

106
Q

Matched (coupled) for efficient gas exchange

A

Perfusion and ventilation

107
Q

Hb affinity for O2 increases as …

A

O2 binds

108
Q

Hb affinity for O2 decreases as …

A

O2 is released

109
Q

Percentage of bound oxygen that is unloaded during one systemic circulation

A

Only 20-25%

110
Q

If oxygen levels in tissues drop …

A

–More oxygen dissociates from hemoglobin and is used by cells
–Respiratory rate or cardiac output need not increase

111
Q

Hypoxia

A

Inadequate O2 delivery to tissues –> cyanosis (blue tissues)

112
Q

Too few RBCs; abnormal or too little Hb

A

Anemic hypoxia

113
Q

Impaired/blocked circulation

A

Ischemic hypoxia

114
Q

Cells unable to use O2, as in metabolic poisons

A

Histotoxic hypoxia

115
Q

Abnormal ventilation; pulmonary disease

A

Hypoxemic hypoxia

116
Q

Especially from fire; 200X greater affinity for Hb than oxygen

A

Carbon monoxide poisoning

117
Q

A vasodilator that plays a role in blood pressure regulation

A

Nitric oxide (NO)

118
Q

A vasoconstrictor and a nitric oxide scavenger (destroys NO)

A

Hemoglobin

119
Q

As oxygen binds to hemoglobin …

A

–Nitric oxide binds to a cysteine amino acid on hemoglobin

–Bound nitric oxide is protected from degradation by hemoglobin’s iron

120
Q

Released as oxygen is unloaded, causing vasodilation

A

Nitric oxide

121
Q

Picks up carbon dioxide and also binds nitric oxide and carries these gases to the lungs for unloading

A

Deoxygenated hemoglobin

122
Q

CO2 transported in blood in three forms

A

–7 to 10% dissolved in plasma
–20% bound to globin of hemoglobin (carbaminohemoglobin)
–70% transported as bicarbonate ions (HCO3–) in plasma

123
Q

Resists change in blood pH

A

Carbonic acid–bicarbonate buffer system

124
Q

Changes in respiratory rate and depth affecting blood pH

A

–Slow, shallow breathing –> increased CO2 in blood –> drop in pH
–Rapid, deep breathing –> decreased CO2 in blood –> rise in pH

125
Q

Ventral respiratory group (VRG)

A

–Rhythm-generating and integrative center
–Sets eupnea (12–18 breaths/minute)
–Its inspiratory neurons excite inspiratory muscles via phrenic nerve (diaphragm) and intercostal nerves (external intercostals)
–Expiratory neurons inhibit inspiratory neurons

126
Q

Normal respiratory rate and rhythm

A

Eupnea (12-18 breaths/minute)

127
Q

Dorsal respiratory group (DRG)

A

–Near root of cranial nerve IX

–Integrates input from peripheral stretch and chemoreceptors; sends information to VRG

128
Q

Pontine respiratory centers

A
  1. Influence and modify activity of VRG
  2. Smooth out transition between inspiration and expiration and vice versa
  3. Transmit impulses to VRG - modify and fine-tune breathing rhythms during vocalization, sleep, exercise
129
Q

Breathing depth is determined by …

A

How actively the respiratory center stimulates respiratory muscles

130
Q

Breathing rate is determined by …

A

How long the inspiratory center is active

131
Q

Increased blood CO2 levels resulting in increased rate and depth of breathing

A

Hypercapnia

132
Q

Increased depth and rate of breathing that exceeds body’s need to remove CO2

A

Hyperventilation

133
Q

Decreased blood CO2 levels –> cerebral vasoconstriction and cerebral ischemia –> dizziness, fainting

A

Hypocapnia

134
Q

Breathing cessation from abnormally low Pco2

A

Apnea

135
Q

Acidosis may reflect:

A
  1. Carbon dioxide retention
  2. Accumulation of lactic acid
  3. Excess fatty acids in patients with diabetes mellitus
136
Q

Respiratory system controls will attempt to raise the pH by …

A

Increasing respiratory rate and depth

137
Q

Influence of high brain centers

A

1.Hypothalamic controls act through limbic system to modify rate and depth of respiration
–Example-breath holding that occurs in anger or gasping with pain
2.Rise in body temperature increases respiratory rate
3.Cortical controls-direct signals from cerebral motor cortex that bypass medullary controls
–Example-voluntary breath holding

138
Q

Hering-Breuer Reflex (inflation reflex)

A

Stretch receptors in pleurae and airways stimulated by lung inflation
•Inhibitory signals to medullary respiratory centers to end inhalation and allow expiration
•Acts as protective response more than normal regulatory mechanism

139
Q

Increased ventilation (10 to 20 fold) in response to metabolic needs

A

Hyperpnea

140
Q

Remain surprisingly constant during exercise

A

Pco2, Po2, and pH

141
Q

Three neural factors cause increase in ventilation as exercise begins

A
  1. Psychological stimuli—anticipation of exercise
  2. Simultaneous cortical motor activation of skeletal muscles and respiratory centers
  3. Excitatory impulses to respiratory centers from proprioceptors in moving muscles, tendons, joints
142
Q

Symptoms of acute mountain sickness (AMS) - quick travel to altitudes above 2400 meters

A

–Atmospheric pressure and Po2 levels lower
–Headaches, shortness of breath, nausea, and dizziness
–In severe cases, lethal cerebral and pulmonary edema
–Ex: AMS is common in travelers to ski resorts

143
Q

Respiratory and hematopoietic adjustments to long-term move to high altitude

A

Acclimatization

144
Q

Steps of acclimatization

A

1.Chemoreceptors become more responsive to Pco2 when Po2 declines
2.Ventilation increases and stabilizes in a few days to 2–3 L/min higher than at sea level
3.Decline in blood O2 stimulates kidneys to accelerate production of EPO
•RBC numbers increase slowly to provide long-term compensation

145
Q

The time it takes to get the benefit of high altitude training for increased performance

A

3-4 weeks

146
Q

Evidence also suggests that living at _____ and training at _____ seems to produce the best results for increased performance

A
High altitudes (~8000 ft)
Low altitudes (~4000ft)
147
Q

Chronic obstructive pulmonary disease (COPD)

A

–Exemplified by chronic bronchitis and emphysema
–Irreversible decrease in ability to force air out of lungs
–Treated with bronchodilators, corticosteroids, oxygen, sometimes surgery

148
Q

Other common features of COPD

A
  • History of smoking in 80% of patients
  • Dyspnea - labored breathing (“air hunger”)
  • Coughing and frequent pulmonary infections
  • Most develop respiratory failure (hypoventilation) accompanied by respiratory acidosis, hypoxemia
149
Q

Chronic bronchitis

A

Inhaled irritants –> chronic excessive mucus & Inflamed and fibrosed lower respiratory passageways –> Obstructed airways –> Impaired lung ventilation and gas exchange –> Frequent pulmonary infections

150
Q

Emphysema

A

Permanent enlargement of alveoli; destruction of alveolar walls; decreased lung elasticity –> Accessory muscles necessary for breathing –> exhaustion from energy usage

151
Q

Asthma - reversible COPD

A

–Characterized by coughing, dyspnea, wheezing, and chest tightness
–Active inflammation of airways precedes bronchospasms
–Airway inflammation is immune response
–Airways thickened with inflammatory exudate magnify effect of bronchospasms
–~1 in 12 people in N. America suffer from asthma

152
Q

Tuberculosis (TB)

A

–Infectious disease caused by bacterium Mycobacterium tuberculosis
–Symptoms-fever, night sweats, weight loss, racking cough, coughing up blood
–Treatment- 12-month course of antibiotics

153
Q

–Leading cause of cancer deaths in North America
–90% of all cases result from smoking
–Metastasizes rapidly and widely; most victims die within 1 year of diagnosis

A

Lung Cancer

154
Q

Three most common types of lung cancer

A
  1. Adenocarcinoma
  2. Squamous cell carcinoma
  3. Small cell carcinoma
155
Q

Cystic fibrosis

A

–Most common lethal genetic disease in North America
–Abnormal, viscous mucus clogs passageways –> increased bacterial infections
•Affects lungs, pancreatic ducts, reproductive ducts

156
Q

Treatment for cystic fibrosis

A

Mucus-dissolving drugs; manipulation to loosen mucus; antibiotics

157
Q

Development of respiratory system

A
  • By 28th week, premature baby can breathe on its own
  • Two weeks after birth before lungs are fully inflated
  • Respiratory rate is highest in newborns (40-80 respirations per minute and slows until adulthood 12-18 per minute)

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