Chapter 22: Respiratory System Flashcards
1
Q
respiratory system
A
organ system that takes in air and expels it from the body
2
Q
respiration refers to
A
ventilation of the lungs (breathing)
3
Q
functions of the respiratory system
A
- gas exchange
- communication (speech)
- olfaction
- acid base balance
- blood pressure regulation
- blood and lymph flow
- platelet production
- expulsion of abdominal contents
4
Q
blood pressure regulation
A
assists with synthesis of angiotensin II, a hormone that regulates blood pressure
5
Q
blood and lymph flow
A
breathing creates pressure gradients between thorax and abdomen that promote flow of lymph and blood
6
Q
platelet production
A
more than half of platelets are made by megakaryocytes in lungs (not in bone marrow)
7
Q
expulsion of abdominal contents
A
breath-holding assists in urination, defecation, and childbirth
8
Q
principal organs of respiratory system
A
nose, pharynx, larynx, trachea, bronchi, and lungs
9
Q
conducting zone
A
-passages that serve only for airflow (no gas exchange)
-Nostrils through major bronchioles
10
Q
upper respiratory tract
A
airway from nose through larynx
11
Q
lower respiratory tract
A
regions from trachea through alveoli
12
Q
respiratory zone
A
-regions that participate in gas exchange
-Alveoli and nearby structures
13
Q
nose
A
-warms, cleanses, and humidifies inhaled air; detects odors; and serves as a resonating chamber that amplifies voice
-Extends from nostrils (nares) to posterior nasal apertures (choanae)—posterior openings
-Facial part is shaped by bone and hyaline cartilage
14
Q
superior half of nose
A
nasal bones and maxillae
15
Q
inferior half of nose
A
lateral and alar cartilages
16
Q
ala nasi
A
flared portion at lower end of nose shaped by alar cartilages and dense connective tissue
17
Q
what divides nasal cavity into right and left nasal fossae?
A
nasal septum
18
Q
structure of nasal septum
A
-Vomer forms inferior part
-perpendicular plate of ethmoid forms superior part
-septal cartilage forms anterior part
-Paranasal sinuses and nasolacrimal duct drain into nasal cavity
19
Q
Superior, middle, and inferior nasal conchae (turbinates) project from
A
lateral walls toward septum
20
Q
nose epithelium
A
-Ciliated pseudostratified columnar epithelium
-Olfactory epithelium is involved in the sense of smell
21
Q
goblet cells (ciliated cells)
A
have motile cilia that propel the mucus posteriorly toward pharynx to be swallowed
22
Q
epithelia of pharynx
A
-Nasopharynx passes only air and is lined by pseudostratified columnar epithelium
-Oropharynx and laryngopharynx pass air, food, and drink and are lined by stratified squamous epithelium
23
Q
muscles of the pharynx assist in
A
swallowing and speech
24
Q
larynx
A
-Cartilaginous chamber about 4 cm (1.5 in.) long
-Primary function is to keep food and drink out of airway
-involved in production of sound, so commonly called the “voice box”
25
epiglottis
flap of tissue that guards superior opening of larynx
26
3 big solitary cartilages
-Epiglottic cartilage
-Thyroid cartilage
-Cricoid cartilage
27
3 smaller paired cartilages
-Arytenoid cartilages
-Corniculate cartilages
-Cuneiform cartilages
28
vocal cords (vocal folds)
-produce sound when air passes between them
-Contain vocal ligaments covered with stratified squamous epithelium, suited to endure vibration and contact
29
glottis
the vocal cords and the opening between them
30
trachea
-Lined by ciliated pseudostratified columnar epithelium
-Contains mucus-secreting cells, ciliated cells, and stem cells
31
mucocillary escalator
-mechanism for debris removal
-Mucus traps inhaled particles, upward beating cilia moves mucus to pharynx to be swallowed
32
trachealis
muscle spans opening in rings; contracts or relaxes to adjust airflow *internal median ridge—the carina
33
tracheotomy
-to make a temporary opening in the trachea and insert a tube to allow airflow
-Prevents asphyxiation due to upper airway obstruction
34
intubation
-when a patient is on a ventilator, air is introduced directly into trachea
-Air must be filtered and humidified
35
base
broad concave portion resting on diaphragm
36
apex
tip that projects just above the clavicle
37
costal surface
pressed against the ribcage
38
mediastinal surface
faces medially toward the heart
39
hilum
-slit through which the lung receives the main bronchus, blood vessels, lymphatics, and nerves
-Structures near hilum constitute root of lung
40
right lung
-Has three lobes—superior, middle, and inferior lobes
-Horizontal fissure separates superior and middle lobes, and oblique fissure separates middle and inferior lobes
41
left lung
-Has indentation to accommodate heart—cardiac impression
-Has two lobes—superior and inferior lobes, separated by a single oblique fissure
42
bronchial tree
-a branching system of air tubes in each lung
-Extends from main bronchus to 65,000 terminal bronchioles
43
main (primary) bronchi
-divide into lobar (secondary) bronchi
-A Lobar bronchi branch into segmental (tertiary) bronchi
44
bronchioles
continuations of airway that lack supportive cartilage and are 1 mm or less in diameter
45
pulmonary lobule
-portion of lung ventilated by one bronchiole
-terminal bronchioles
-respiratory bronchioles
-alveolar ducts
-End in alveolar sacs—clusters of alveoli around a central space (atrium)
46
alveoli
-microscopic air pouches in the lungs
-for gas exchange
47
cells of the alveoli
-Squamous (type 1) alveolar cells
-Great (type 2) alveolar cells
-Alveolar macrophages (dust cells)
48
Squamous (type 1) alveolar cells
-Thin cells allow rapid gas diffusion between air and blood
-Cover 95% of alveolus surface area
49
Great (type 2) alveolar cells
-Repair the alveolar epithelium when the squamous (type 1) cells are damaged
-Secrete pulmonary surfactant
50
pulmonary surfactant
mixture of phospholipids and proteins that coats the alveoli and prevents them from collapsing during exhalation
51
respiratory membrane
-thin barrier between the alveolar air and blood
-Gases exchanged across respiratory membrane, which consists of three layers:
Squamous alveolar cells
Endothelial cells of blood capillary
Their shared basement membrane
52
pleura
serous membrane that lines thoracic wall and forms surface of lung
53
visceral pleura
forms surface of lung
54
parietal pleura
Adheres to mediastinum, inner surface of the rib cage, and superior surface of the diaphragm
55
pleural cavity
potential space between pleurae-Fluid layer
56
pleural effusion
pathological seepage of fluid into the pleural cavity
57
functions of pleurae and plural fluid
-reduction of friction (allow lungs to move with minimal friction)
-creation of a pressure gradient (assist with lung inflation)
-compartmentalizatin (prevents spread of infection)
58
Boyles law
-governs air flow into and out of the lungs:
-At a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume
59
if lung volume decreases then intrapulmonary pressure
rises
60
if the pressure rises above atmospheric pressure then air
moves out of the lungs
61
if the pressure falls below atmospheric pressure then air
moves into the lungs
62
atmospheric (barometric) pressure
-the weight of the air above us
-lower at higher elevations
63
intrapulmonary pressure
-air pressure within lungs
-changes with lung volume according to Boyles law
64
pulmonary compliance
-ease with which the lungs can expand; change in lung volume relative to a given pressure change
-reduced with degenerative lung diseases
65
Infant respiratory distress syndrome (IRDS)
premature babies lacking surfactant are treated with artificial surfactant until they can make their own
66
principal muscles of respiration
diaphragm and intercostal muscles
67
diaphragm
prime mover of respiration
68
internal and external intercostal muscles
assist diaphragm
69
Valsalva maneuver
breathing technique used to help expel contents of certain abdominal organs
70
Ventral respiratory group (VRG)
-In medulla
-Primary generator of the respiratory rhythm
71
Dorsal respiratory group (DRG)
-In medulla
-Modifies the rate and depth of breathing
72
Pontine respiratory group (PRG)
-In pons
-Modifies rhythm of VRG by outputs to both VRG and DRG
73
Automatic, unconscious breathing is controlled by
respiratory centers
74
Central chemoreceptors
-Brainstem neurons that respond to changes in pH of cerebrospinal fluid
-Ensures stable C O2 level in blood
75
Peripheral chemoreceptors
-Carotid and aortic bodies
-Respond to the O2 and C O2 content and the pH of blood
76
Stretch receptors
Inflation (Hering–Breuer) reflex—triggered by excessive inflation; protective reflex that inhibits inspiratory neurons and stops inspiration
77
Irritant receptors
-Respond to smoke, dust, pollen, chemical fumes, cold air, and excess mucus
-Trigger protective reflexes such as bronchoconstriction, shallower breathing, breath-holding (apnea), or coughing
78
Pneumothorax
presence of air in pleural cavity
79
Bronchodilation
-increase in diameter of bronchus or bronchiole
-Epinephrine and sympathetic stimulation
-Increase airflow
79
what 2 factors influence airway resistance
bronchiole diameter and pulmonary compliance
80
Bronchoconstriction
-decrease in diameter of bronchus or bronchiole
-Histamine, parasympathetic nerves, cold air, and chemical irritants
-Decrease airflow
81
how many mL fills the conducting zone of the airway?
about 150
82
anatomical dead space
where there is no gas exchange
83
Physiological (total) dead space
sum of anatomical dead space and any pathological dead space
84
Alveolar ventilation rate (AVR)
-amount of air ventilating alveoli per minute
-crucially relevant to the body’s ability to get oxygen to the tissues and dispose of carbon dioxide
85
residual volume
leftover air that cannot be exhaled, even with maximum effort
86
Spirometry
-measuring pulmonary ventilation
-Assess severity of a disease, monitor improvement or deterioration
87
Spirometer
device used to make measurements; recaptures expired breath and records rate and depth of breathing, speed of expiration, and rate of oxygen consumption
88
Tidal volume (TV)
volume of air inhaled and exhaled in one cycle of breathing (500 mL)
89
Inspiratory reserve volume (IRV)
air in excess of tidal volume that can be inhaled with maximum effort (3,000 mL)
90
Expiratory reserve volume (ERV)
air in excess of tidal volume that can be exhaled with maximum effort (1,200 mL)
91
Residual volume (RV)
-air remaining in lungs after maximum expiration (1,300 mL)
-Allows some gas exchange with blood before next breath of fresh air arrives
92
Vital capacity (VC)
-total amount of air that can be inhaled and then exhaled with maximum effort
-VC = E R V + TV + IRV (4,700 mL)
93
Inspiratory capacity
-maximum amount of air that can be inhaled after a normal tidal expiration
-IC = TV + IRV (3,500 mL)
94
Functional residual capacity
-amount of air remaining in lungs after a normal tidal expiration
-F R C = RV + E R V (2,500 mL)
95
total lung capacity
-maximum amount of air the lungs can contain
-TLC = RV + VC (6,000 mL)
96
what aids in diagnosis and assessment of restrictive and obstructive lung disorders?
spirometry
97
restrictive disorders
-Reduction in pulmonary compliance, limit how much lungs can inflate
-Any disease that produces pulmonary fibrosis
-black lung disease, tuberculosis
98
Obstructive disorders
-Interfere with airflow by narrowing or blocking the airway
-Make it harder to inhale or exhale a given amount of air
-asthma, chronic bronchitis
99
what combines elements of restrictive and obstructive disorders?
emphysema
100
Forced expiratory volume (FEV)
- percent of vital capacity that can be exhaled in a given time interval
- Healthy adult reading is 75% to 85% in 1 second
101
peak flow
-maximum speed of expiration
- measure with spirometer
102
Minute respiratory volume (MRV)
amount of air inhaled per minute
103
Maximum voluntary ventilation (MVV)
-MRV during heavy exercise
-May be as high as 125 to 170 L/min
104
Eupnea
relaxed, quiet breathing
105
apnea
temporary cessation of breathing
106
Dyspnea
labored, gasping breathing; shortness of breath
107
Hyperpnea
increased rate and depth of breathing in response to exercise, pain, or other conditions
108
Hyperventilation
increased pulmonary ventilation in excess of metabolic demand
109
Hypoventilation
reduced pulmonary ventilation leading to an increase in blood C O2
110
Kussmaul respiration
deep, rapid breathing often induced by acidosis
111
Orthopnea
dyspnea that occurs when person is lying down
112
Respiratory arrest
permanent cessation of breathing
113
Tachypnea
accelerated respiration
114
Henry’s law
the amount of gas that dissolves in the water is determined by its solubility in water and its partial pressure in air
115
pressure gradient of PO2
104 mm Hg in alveolar air versus 40 mm Hg in blood
116
pressure gradient of PCO2
46 mm Hg in blood arriving versus 40 mm Hg in alveolar air
117
Hyperbaric oxygen therapy
treatment with oxygen at greater than 1 atm of pressure
118
how is partial pressure affected at high elevations?
gases are lower; pressure gradient for oxygen is lower so less diffuses into blood
119
Ventilation–perfusion coupling
- Air flow and blood flow are matched to each other
- Pulmonary blood vessels change diameter depending on air flow to an area of the lungs
-Bronchi change diameter depending on blood flow to an area of the lungs
120
gas transport
the process of carrying gases from the alveoli to the systemic tissues and vice versa
121
what is specialized for oxygen transport?
hemoglobin
122
Arterial blood carries about
20 mL of O2 per deciliter
123
Oxyhemoglobin (HbO2)
O2 bound to hemoglobin
124
Deoxyhemoglobin (HHb)
hemoglobin with no O2
125
Oxyhemoglobin dissociation curve
-illustrates relationship between hemoglobin saturation and ambient P O2
-Not a linear relationship
126
90% of the C O2 is hydrated (reacts with water) to form
carbonic acid
127
Carbon monoxide (C O)
colorless, odorless gas in cigarette smoke, engine exhaust, fumes from gas furnaces
128
Systemic gas exchange
unloading of O2 and loading of C O2 at systemic capillaries
129
Chloride shift
bicarbonate pumped out of RBC in exchange for chloride ion from plasma
130
Venous reserve
amount of O2 remaining in the blood after it passes through the systemic capillary beds
131
Ambient PO2
-active tissue has decreased PO2
-O2 is released from Hb
132
temperature
active tissue has high temp, promotes O2 unloading
133
ambient pH
-active tissue has high CO2
- lowers pH of blood
-promotes O2 unloading called the Bohr effect
134
BPG
when RBCs produce a metabolic intermediate of anerobic metabolism
135
Haldane effect
Deoxyhemoglobin binds more hydrogen ions than oxyhemoglobin
136
acidosis
blood pH lower than 7.35
137
alkalosis
blood pH higher than 7.45
138
hypocapnia
PCO2 less than 37 mm Hg, most common cause of alkalosis
139
hypercapnia
PCO2 greater than 43 mm Hg; most common cause of acidosis
140
Respiratory acidosis and respiratory alkalosis
pH imbalances resulting from a mismatch between the rate of pulmonary ventilation and the rate of CO2 production
141
what can be a corrective homeostatic response to acidosis?
hyperventilation
142
what can be a corrective homeostatic response to alkalosis?
hypoventilation
143
Chronic hypoxemia
-PO2 less than 60 mm Hg
-Can significantly stimulate ventilation
144
hypoxic drive
-Caused by long-term hypoxemia
-Respiration driven more by low P O2 than by C O2 or pH
145
hypoxia
-deficiency of oxygen or the inability to use oxygen
-marked by cyanosis
146
cyanosis
blueness of the skin
147
Hypoxemic hypoxia
High altitude, drowning, hypoventilation
148
Ischemic hypoxia
-Inadequate circulation of blood
-Congestive heart failure
149
anemic hypoxia
Due to inability of the blood to carry adequate oxygen
150
Histotoxic hypoxia
Metabolic poisons (for example, cyanide) prevents O2 use in tissue
151
Chronic obstructive pulmonary diseases (COPDs)
-long-term obstruction of airflow and substantial reduction in pulmonary ventilation
-usually associated with smoking
152
major COPDs are
chronic bronchitis and emphysema
153
emphysema
-alveolar walls break down
-lungs fibrotic and less elastic
-air passages collapse
-weaken thoracic muscles
154
3 major forms of lung cancers
squamous cell carcinoma, adenocarcinoma, and small cell (oat cell) carcinoma
