RESPIRATORY PT. 1 Flashcards
(500 cards)
1
Q
contributes to homeostasis by providing for the exchange of gases— oxygen and carbon dioxide—among the atmospheric air, blood, and tissue cells. It also helps adjust the pH of body fluids.
A
Respiratory System
2
Q
What do your body’s cells continually use for the metabolic reactions that generate ATP from the breakdown of nutrient molecules?
A
Oxygen (O2)
3
Q
What is released as a waste product during these metabolic reactions?
A
Carbon dioxide (CO2)
4
Q
Why must excess CO2 be eliminated quickly and efficiently?
A
Because an excessive amount of CO2 produces acidity that can be toxic to cells.
5
Q
Which two systems cooperate to supply O2 and eliminate CO2?
A
The cardiovascular and respiratory systems.
6
Q
What does the respiratory system provide for?
A
Gas exchange—intake of O2 and elimination of CO2.
7
Q
What is the role of the cardiovascular system in gas exchange?
A
It transports blood containing the gases between the lungs and body cells.
8
Q
What happens if either the cardiovascular or respiratory system fails?
A
It disrupts homeostasis by causing rapid death of cells from oxygen starvation and buildup of waste products.
9
Q
Besides gas exchange, in what other functions does the respiratory system participate?
A
Regulating blood pH, containing receptors for the sense of smell, filtering inspired air, producing sounds, and ridding the body of some water and heat in exhaled air.
10
Q
In which other systems is there an extensive area of contact between the external environment and capillary blood vessels, similar to the respiratory system?
A
The digestive and urinary systems.
11
Q
What do your body’s cells continually use for the metabolic reactions that generate ATP from the breakdown of nutrient molecules?
A
Oxygen (O2)
12
Q
What is released as a waste product during these metabolic reactions?
A
Carbon dioxide (CO2)
13
Q
Why must excess CO2 be eliminated quickly and efficiently?
A
Because an excessive amount of CO2 produces acidity that can be toxic to cells.
14
Q
Which two systems cooperate to supply O2 and eliminate CO2?
A
The cardiovascular and respiratory systems.
15
Q
What does the respiratory system provide for?
A
Gas exchange—intake of O2 and elimination of CO2.
16
Q
What is the role of the cardiovascular system in gas exchange?
A
It transports blood containing the gases between the lungs and body cells.
17
Q
What happens if either the cardiovascular or respiratory system fails?
A
It disrupts homeostasis by causing rapid death of cells from oxygen starvation and buildup of waste products.
18
Q
Besides gas exchange, in what other functions does the respiratory system participate?
A
Regulating blood pH, containing receptors for the sense of smell, filtering inspired air, producing sounds, and ridding the body of some water and heat in exhaled air.
19
Q
In which other systems is there an extensive area of contact between the external environment and capillary blood vessels, similar to the respiratory system?
A
The digestive and urinary systems.
20
Q
What is the process of supplying the body with O2 and removing CO2 called?
A
Respiration
21
Q
How many basic steps does respiration have?
A
Three
22
Q
What is pulmonary ventilation also known as?
A
Breathing
23
Q
What does pulmonary ventilation involve?
A
The inhalation (inflow) and exhalation (outflow) of air and the exchange of air between the atmosphere and the pulmonary alveoli of the lungs.
24
Q
What does inhalation permit?
A
O2 to enter the lungs.
25
What does exhalation permit?
CO2 to leave the lungs.
26
What is external (pulmonary) respiration?
The exchange of gases between the pulmonary alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane.
27
What happens to pulmonary capillary blood during external respiration?
It gains O2 and loses CO2.
28
What is internal (tissue) respiration?
The exchange of gases between blood in systemic capillaries and tissue cells.
29
What happens to blood during internal respiration?
It loses O2 and gains CO2.
30
What are the metabolic reactions that consume O2 and give off CO2 during the production of ATP called?
Cellular respiration
31
What do your body’s cells continually use for the metabolic reactions that generate ATP from the breakdown of nutrient molecules?
Oxygen (O2)
32
What is released as a waste product during these metabolic reactions?
Carbon dioxide (CO2)
33
Why must excess CO2 be eliminated quickly and efficiently?
Because an excessive amount of CO2 produces acidity that can be toxic to cells.
34
Which two systems cooperate to supply O2 and eliminate CO2?
The cardiovascular and respiratory systems.
35
What does the respiratory system provide for?
Gas exchange—intake of O2 and elimination of CO2.
36
What is the role of the cardiovascular system in gas exchange?
It transports blood containing the gases between the lungs and body cells.
37
What happens if either the cardiovascular or respiratory system fails?
It disrupts homeostasis by causing rapid death of cells from oxygen starvation and buildup of waste products.
38
Besides gas exchange, in what other functions does the respiratory system participate?
Regulating blood pH, containing receptors for the sense of smell, filtering inspired air, producing sounds, and ridding the body of some water and heat in exhaled air.
39
In which other systems is there an extensive area of contact between the external environment and capillary blood vessels, similar to the respiratory system?
The digestive and urinary systems.
40
What is the process of supplying the body with O2 and removing CO2 called?
Respiration
41
How many basic steps does respiration have?
Three
42
What is pulmonary ventilation also known as?
Breathing
43
What does pulmonary ventilation involve?
The inhalation (inflow) and exhalation (outflow) of air and the exchange of air between the atmosphere and the pulmonary alveoli of the lungs.
44
What does inhalation permit?
O2 to enter the lungs.
45
What does exhalation permit?
CO2 to leave the lungs.
46
What is external (pulmonary) respiration?
The exchange of gases between the pulmonary alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane.
47
What happens to pulmonary capillary blood during external respiration?
It gains O2 and loses CO2.
48
What is internal (tissue) respiration?
The exchange of gases between blood in systemic capillaries and tissue cells.
49
What happens to blood during internal respiration?
It loses O2 and gains CO2.
50
What are the metabolic reactions that consume O2 and give off CO2 during the production of ATP called?
Cellular respiration
51
What does the respiratory system consist of?
The nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, and lungs.
52
How can the parts of the respiratory system be classified?
By structure or function.
53
What are the two structural parts of the respiratory system?
The upper respiratory system and lower respiratory system.
54
What does the upper respiratory system include?
The nose, nasal cavity, pharynx, and associated structures.
55
What does the lower respiratory system include?
The larynx, trachea, bronchi, and lungs.
56
What are the two functional parts of the respiratory system?
The conducting zone and the respiratory zone.
57
What does the conducting zone consist of?
A series of interconnecting cavities and tubes both outside and within the lungs, including the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
58
What is the function of the conducting zone?
To filter, warm, and moisten air and conduct it into the lungs.
59
What does the respiratory zone consist of?
Tubes and tissues within the lungs where gas exchange occurs, including the respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
60
What are the main sites of gas exchange between air and blood?
The respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
61
What is the branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat (ENT)?
Otorhinolaryngology
62
What does the term 'otorhinolaryngology' mean?
Oto- = ear, -rhino- = nose, -laryngo- = voice box, -logy = study of.
63
During respiration, the body is supplied with ___ and ___ is removed.
O2; CO2
64
includes the nose, nasal cavity, pharynx, and associated structures; the lower respiratory system includes the larynx, trachea, bronchi, and lungs.
Upper respiratory system
65
What are the functions of the respiratory system?
1. Provides for gas exchange: intake of O2 for delivery to body cells and removal of CO2 produced by body cells. 2. Helps regulate blood pH. 3. Contains receptors for sense of smell, filters inspired air, produces vocal sounds (phonation), and excretes small amounts of water and heat.
66
What do your body’s cells continually use for the metabolic reactions that generate ATP from the breakdown of nutrient molecules?
Oxygen (O2)
67
What is released as a waste product during these metabolic reactions?
Carbon dioxide (CO2)
68
Why must excess CO2 be eliminated quickly and efficiently?
Because an excessive amount of CO2 produces acidity that can be toxic to cells.
69
Which two systems cooperate to supply O2 and eliminate CO2?
The cardiovascular and respiratory systems.
70
What does the respiratory system provide for?
Gas exchange—intake of O2 and elimination of CO2.
71
What is the role of the cardiovascular system in gas exchange?
It transports blood containing the gases between the lungs and body cells.
72
What happens if either the cardiovascular or respiratory system fails?
It disrupts homeostasis by causing rapid death of cells from oxygen starvation and buildup of waste products.
73
Besides gas exchange, in what other functions does the respiratory system participate?
Regulating blood pH, containing receptors for the sense of smell, filtering inspired air, producing sounds, and ridding the body of some water and heat in exhaled air.
74
In which other systems is there an extensive area of contact between the external environment and capillary blood vessels, similar to the respiratory system?
The digestive and urinary systems.
75
What is the process of supplying the body with O2 and removing CO2 called?
Respiration
76
How many basic steps does respiration have?
Three
77
What is pulmonary ventilation also known as?
Breathing
78
What does pulmonary ventilation involve?
The inhalation (inflow) and exhalation (outflow) of air and the exchange of air between the atmosphere and the pulmonary alveoli of the lungs.
79
What does inhalation permit?
O2 to enter the lungs.
80
What does exhalation permit?
CO2 to leave the lungs.
81
What is external (pulmonary) respiration?
The exchange of gases between the pulmonary alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane.
82
What happens to pulmonary capillary blood during external respiration?
It gains O2 and loses CO2.
83
What is internal (tissue) respiration?
The exchange of gases between blood in systemic capillaries and tissue cells.
84
What happens to blood during internal respiration?
It loses O2 and gains CO2.
85
What are the metabolic reactions that consume O2 and give off CO2 during the production of ATP called?
Cellular respiration
86
What does the respiratory system consist of?
The nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, and lungs.
87
How can the parts of the respiratory system be classified?
By structure or function.
88
What are the two structural parts of the respiratory system?
The upper respiratory system and lower respiratory system.
89
What does the upper respiratory system include?
The nose, nasal cavity, pharynx, and associated structures.
90
What does the lower respiratory system include?
The larynx, trachea, bronchi, and lungs.
91
What are the two functional parts of the respiratory system?
The conducting zone and the respiratory zone.
92
What does the conducting zone consist of?
A series of interconnecting cavities and tubes both outside and within the lungs, including the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
93
What is the function of the conducting zone?
To filter, warm, and moisten air and conduct it into the lungs.
94
What does the respiratory zone consist of?
Tubes and tissues within the lungs where gas exchange occurs, including the respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
95
What are the main sites of gas exchange between air and blood?
The respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
96
What is the branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat (ENT)?
Otorhinolaryngology
97
What does the term 'otorhinolaryngology' mean?
Oto- = ear, -rhino- = nose, -laryngo- = voice box, -logy = study of.
98
What is the nose?
A specialized organ at the entrance of the respiratory system.
99
What are the two portions of the nose?
The external nose and the internal nose (nasal cavity).
100
What is the external nose?
The portion of the nose visible on the face.
101
What forms the bony framework of the external nose?
The frontal bone, nasal bones, and maxillae.
102
What forms the cartilaginous framework of the external nose?
The nasal septal cartilage, lateral nasal cartilages, and alar cartilages.
103
What are the two openings on the undersurface of the external nose called?
The nostrils (external nares).
104
What do the nostrils lead into?
The nasal vestibules.
105
What are the three functions of the interior structures of the external nose?
Warming, moistening, and filtering incoming air, detecting olfactory stimuli, and modifying speech vibrations.
106
What is resonance?
Prolonging, amplifying, or modifying a sound by vibration.
107
What do your body’s cells continually use for the metabolic reactions that generate ATP from the breakdown of nutrient molecules?
Oxygen (O2)
108
What is released as a waste product during these metabolic reactions?
Carbon dioxide (CO2)
109
Why must excess CO2 be eliminated quickly and efficiently?
Because an excessive amount of CO2 produces acidity that can be toxic to cells.
110
Which two systems cooperate to supply O2 and eliminate CO2?
The cardiovascular and respiratory systems.
111
What does the respiratory system provide for?
Gas exchange—intake of O2 and elimination of CO2.
112
What is the role of the cardiovascular system in gas exchange?
It transports blood containing the gases between the lungs and body cells.
113
What happens if either the cardiovascular or respiratory system fails?
It disrupts homeostasis by causing rapid death of cells from oxygen starvation and buildup of waste products.
114
Besides gas exchange, in what other functions does the respiratory system participate?
Regulating blood pH, containing receptors for the sense of smell, filtering inspired air, producing sounds, and ridding the body of some water and heat in exhaled air.
115
In which other systems is there an extensive area of contact between the external environment and capillary blood vessels, similar to the respiratory system?
The digestive and urinary systems.
116
What is the process of supplying the body with O2 and removing CO2 called?
Respiration
117
How many basic steps does respiration have?
Three
118
What is pulmonary ventilation also known as?
Breathing
119
What does pulmonary ventilation involve?
The inhalation (inflow) and exhalation (outflow) of air and the exchange of air between the atmosphere and the pulmonary alveoli of the lungs.
120
What does inhalation permit?
O2 to enter the lungs.
121
What does exhalation permit?
CO2 to leave the lungs.
122
What is external (pulmonary) respiration?
The exchange of gases between the pulmonary alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane.
123
What happens to pulmonary capillary blood during external respiration?
It gains O2 and loses CO2.
124
What is internal (tissue) respiration?
The exchange of gases between blood in systemic capillaries and tissue cells.
125
What happens to blood during internal respiration?
It loses O2 and gains CO2.
126
What are the metabolic reactions that consume O2 and give off CO2 during the production of ATP called?
Cellular respiration
127
What does the respiratory system consist of?
The nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, and lungs.
128
How can the parts of the respiratory system be classified?
By structure or function.
129
What are the two structural parts of the respiratory system?
The upper respiratory system and lower respiratory system.
130
What does the upper respiratory system include?
The nose, nasal cavity, pharynx, and associated structures.
131
What does the lower respiratory system include?
The larynx, trachea, bronchi, and lungs.
132
What are the two functional parts of the respiratory system?
The conducting zone and the respiratory zone.
133
What does the conducting zone consist of?
A series of interconnecting cavities and tubes both outside and within the lungs, including the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
134
What is the function of the conducting zone?
To filter, warm, and moisten air and conduct it into the lungs.
135
What does the respiratory zone consist of?
Tubes and tissues within the lungs where gas exchange occurs, including the respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
136
What are the main sites of gas exchange between air and blood?
The respiratory bronchioles, alveolar ducts, alveolar saccules (sacs), and pulmonary alveoli.
137
What is the branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat (ENT)?
Otorhinolaryngology
138
What does the term 'otorhinolaryngology' mean?
Oto- = ear, -rhino- = nose, -laryngo- = voice box, -logy = study of.
139
What is the nasal cavity also known as?
Internal nose
140
What structure divides the nasal cavity into right and left sides?
Nasal septum
141
What forms the anterior portion of the nasal septum?
Hyaline cartilage
142
What bones form the remainder of the nasal septum?
The vomer, perpendicular plate of the ethmoid, maxillae, and palatine bones.
143
What openings connect the nasal cavity to the pharynx?
Choanae (internal nares)
144
What ducts open into the nasal cavity?
Paranasal sinuses ducts and nasolacrimal ducts.
145
What bones contain the paranasal sinuses?
Frontal, sphenoid, ethmoid, and maxillae.
146
What are the two regions of the nasal cavity?
Respiratory region and olfactory region.
147
What type of epithelium lines the respiratory region?
Ciliated pseudostratified columnar epithelium with goblet cells.
148
What are the three nasal conchae?
Superior, middle, and inferior nasal conchae.
149
What do the nasal conchae create?
Superior, middle, and inferior nasal meatuses.
150
What is the function of the nasal conchae and meatuses?
Increase surface area and trap water droplets during exhalation.
151
What happens to inhaled air as it moves through the nasal cavity?
It is warmed, moistened, and filtered.
152
Where are olfactory sensory neurons located?
Near the superior nasal conchae and adjacent septum.
153
What type of epithelium makes up the olfactory region?
Olfactory epithelium.
154
What is the process of supplying the body with O2 and removing CO2 known as?
Respiration
155
How many basic steps does respiration have?
Three
156
What is pulmonary ventilation also known as?
Breathing
157
What does pulmonary ventilation involve?
The inhalation (inflow) and exhalation (outflow) of air and the exchange of air between the atmosphere and the pulmonary alveoli of the lungs.
158
What permits O2 to enter the lungs?
Inhalation
159
What permits CO2 to leave the lungs?
Exhalation
160
What is external (pulmonary) respiration?
The exchange of gases between the pulmonary alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane.
161
What happens to pulmonary capillary blood in external respiration?
It gains O2 and loses CO2.
162
What is internal (tissue) respiration?
The exchange of gases between blood in systemic capillaries and tissue cells.
163
What happens to blood in internal respiration?
It loses O2 and gains CO2.
164
What are the metabolic reactions that consume O2 and give off CO2 during ATP production called?
Cellular respiration
165
What does the respiratory system consist of?
The nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, and lungs.
166
How can the respiratory system be classified?
According to structure or function.
167
What does the upper respiratory system include?
The nose, nasal cavity, pharynx, and associated structures.
168
What does the lower respiratory system include?
The larynx, trachea, bronchi, and lungs.
169
What is the function of the conducting zone?
To filter, warm, and moisten air and conduct it into the lungs.
170
What structures are included in the conducting zone?
The nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.
171
What is the function of the respiratory zone?
Gas exchange.
172
What structures are included in the respiratory zone?
Respiratory bronchioles, alveolar ducts, alveolar sacs, and pulmonary alveoli.
173
What is otorhinolaryngology?
The branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat (ENT).
174
What does the nose consist of?
A visible external portion (external nose) and an internal portion inside the skull (nasal cavity).
175
What is the external nose made of?
A supporting framework of bone and hyaline cartilage covered with muscle and skin and lined by a mucous membrane.
176
What forms the bony framework of the external nose?
The frontal bone, nasal bones, and maxillae.
177
What forms the cartilaginous framework of the external nose?
The nasal septal cartilage, lateral nasal cartilages, and alar cartilages.
178
What are the openings on the undersurface of the external nose called?
Nostrils (external nares).
179
What are the functions of the internal structures of the external nose?
Warming, moistening, and filtering incoming air; detecting olfactory stimuli; modifying speech vibrations.
180
What is resonance?
Prolonging, amplifying, or modifying a sound by vibration.
181
What divides the nasal cavity into right and left sides?
The nasal septum.
182
What bones form the nasal septum?
The vomer, perpendicular plate of the ethmoid, maxillae, and palatine bones.
183
What are the posterior openings of the nasal cavity called?
Choanae (internal nares).
184
What bones contain the paranasal sinuses?
Frontal, sphenoid, ethmoid, and maxillae.
185
What are the functions of the paranasal sinuses?
Producing mucus and serving as resonating chambers for sound.
186
What does the nasal vestibule contain?
Coarse hairs that filter out large dust particles.
187
What are the projections inside the nasal cavity called?
Superior nasal conchae, middle nasal conchae, and inferior nasal conchae.
188
What do the conchae and meatuses do?
Increase surface area and prevent dehydration by trapping water droplets during exhalation.
189
What warms inhaled air?
Blood in the capillaries.
190
What moistens inhaled air?
Mucus secreted by goblet cells and drainage from the nasolacrimal ducts.
191
What removes trapped dust particles from the respiratory tract?
Cilia moving the mucus toward the pharynx to be swallowed or spit out.
192
What makes up the olfactory epithelium?
Olfactory sensory neurons, supporting epithelial cells, and basal epithelial cells.
193
What is rhinoplasty?
A surgical procedure in which the shape of the external nose is altered.
194
What are the reasons for performing rhinoplasty?
Cosmetic reasons, repairing a fractured nose, or correcting a deviated nasal septum.
195
How is rhinoplasty performed?
With local and general anesthetics, instruments inserted through the nostrils, reshaping of the nasal cartilage, and fracturing and repositioning of nasal bones.
196
What helps keep the nose in the desired position after rhinoplasty?
Internal packing and a splint.
197
As air passes through the nose, it is warmed, filtered, and moistened, and ___ occurs
olfaction
198
has a cartilaginous framework and a bony framework.
external nose
199
What are the bony framework of the external nose?
Frontal bone, nasal bones, and maxilla
200
What are the cartilaginous framework of the external nose?
Lateral nasal cartilage, Nasal septal cartilage, Minor alar cartilages, and Major alae cartilages
201
Superior attachment of the nose to the frontal bone
Root
202
Tip of nose
Apex
203
Bony framework of nose formed by nasal bones
Bridge
204
External opening into nasal cavity
Nostril
205
What is tonsillectomy?
Tonsillectomy is surgical removal of the tonsils.
206
Under what type of anesthesia is a tonsillectomy usually performed?
A tonsillectomy is usually performed under general anesthesia.
207
Where is a tonsillectomy usually performed?
A tonsillectomy is usually performed on an outpatient basis.
208
In which individuals are tonsillectomies performed?
Tonsillectomies are performed in individuals who have frequent tonsillitis.
209
What is tonsillitis?
Tonsillitis is inflammation of the tonsils.
210
What are other conditions that may require a tonsillectomy?
A tonsillectomy may be required if the tonsils develop an abscess or tumor, or if they obstruct breathing during sleep.
211
What is the pharynx?
The pharynx is a funnel-shaped tube about 13 cm (5 in.) long that starts at the choanae and extends to the level of the cricoid cartilage.
212
Where does the pharynx lie in relation to other structures?
The pharynx lies posterior to the nasal and oral cavities, superior to the larynx, and anterior to the cervical vertebrae.
213
What is the composition of the pharyngeal wall?
The pharyngeal wall is composed of skeletal muscles and lined with a mucous membrane.
214
What helps keep the pharynx patent?
Relaxed skeletal muscles help keep the pharynx patent.
215
What assists in deglutition (swallowing)?
Contraction of the skeletal muscles assists in deglutition (swallowing).
216
What are the functions of the pharynx?
The pharynx functions as a passageway for air and food, a resonating chamber for speech sounds, and houses the tonsils for immunological reactions.
217
What are the three anatomical regions of the pharynx?
The three anatomical regions of the pharynx are nasopharynx, oropharynx, and laryngopharynx.
218
What are the two muscle layers of the pharynx?
The muscles of the entire pharynx are arranged in an outer circular layer and an inner longitudinal layer.
219
Where is the nasopharynx located?
The nasopharynx is the superior portion of the pharynx, lying posterior to the nasal cavity and extending to the soft palate.
220
What is the function of the soft palate?
The soft palate is an arch-shaped muscular partition between the nasopharynx and oropharynx, lined by a mucous membrane.
221
How many openings are in the wall of the nasopharynx?
There are five openings: two choanae, two auditory (eustachian) tube openings, and the opening into the oropharynx.
222
What tonsil is located in the posterior wall of the nasopharynx?
The pharyngeal tonsil (adenoid) is located in the posterior wall of the nasopharynx.
223
How does the nasopharynx receive air?
The nasopharynx receives air from the nasal cavity through the choanae.
224
What type of epithelium lines the nasopharynx?
The nasopharynx is lined with ciliated pseudostratified columnar epithelium.
225
What is the function of the cilia in the nasopharynx?
The cilia move mucus down toward the most inferior part of the nasopharynx.
226
How does the nasopharynx help equalize air pressure?
The nasopharynx exchanges small amounts of air with the auditory tubes to equalize air pressure between the tympanic cavity and the atmosphere.
227
Where is the oropharynx located?
The oropharynx is the intermediate portion of the pharynx, lying posterior to the oral cavity and extending from the soft palate to the upper border of the epiglottis.
228
What is the only opening into the oropharynx?
The only opening into the oropharynx is the fauces (throat), which is the opening from the mouth.
229
What functions does the oropharynx serve?
The oropharynx serves as a common passageway for air, food, and drink.
230
What type of epithelium lines the oropharynx?
The oropharynx is lined with nonkeratinized stratified squamous epithelium.
231
Which tonsils are found in the oropharynx?
The palatine and lingual tonsils are found in the oropharynx.
232
Where does the laryngopharynx begin?
The laryngopharynx begins at the level of the hyoid bone.
233
What does the laryngopharynx open into?
The laryngopharynx opens into the esophagus (food tube) posteriorly and the larynx (voice box) anteriorly.
234
What functions does the laryngopharynx serve?
The laryngopharynx serves as both a respiratory and a digestive pathway.
235
What type of epithelium lines the laryngopharynx?
The laryngopharynx is lined by nonkeratinized stratified squamous epithelium.
236
What is the larynx also known as?
voice box
237
What is the larynx?
A short passageway that connects the laryngopharynx with the trachea.
238
Where is the larynx located?
It lies in the midline of the neck anterior to the esophagus and the fourth through sixth cervical vertebrae (C4–C6).
239
How many pieces of cartilage make up the wall of the larynx?
Nine pieces
240
What are the three single cartilages of the larynx?
Thyroid cartilage, epiglottic cartilage, and cricoid cartilage
241
What are the three paired cartilages of the larynx?
Arytenoid, cuneiform, and corniculate cartilages
242
Which paired cartilage is the most important for speech?
Arytenoid cartilages
243
What do the extrinsic muscles of the larynx do?
They connect the cartilages to other structures in the throat.
244
What do the intrinsic muscles of the larynx do?
They connect the cartilages to one another.
245
What is the laryngeal cavity?
The space that extends from the entrance into the larynx down to the inferior border of the cricoid cartilage.
246
What is the portion of the laryngeal cavity above the vestibular folds called?
Laryngeal vestibule
247
What is the portion of the laryngeal cavity below the vocal folds called?
Infraglottic cavity
248
What is another name for thyroid cartilage?
Laryngeal prominence or Adam’s apple
249
What is the function of thyroid cartilage?
Forms the anterior wall of the larynx and gives it a triangular shape.
250
Why is thyroid cartilage usually larger in males?
Due to the influence of male sex hormones on its growth during puberty.
251
What ligament connects the thyroid cartilage to the hyoid bone?
Thyrohyoid membrane
252
What is the epiglottic cartilage?
A large, leaf-shaped piece of elastic cartilage.
253
What is the epiglottis?
The epiglottic cartilage and its mucous membrane covering.
254
What is the function of the epiglottis?
Moves down to cover the glottis during swallowing, preventing food or liquid from entering the airways.
255
What is the glottis?
A pair of folds of mucous membrane, the vocal folds (true vocal cords), and the space between them called the rima glottidis.
256
What happens if small particles pass into the larynx?
A cough reflex occurs, usually expelling the material.
257
What is the cricoid cartilage?
A ring of hyaline cartilage that forms the inferior wall of the larynx.
258
What ligament attaches the cricoid cartilage to the first ring of the trachea?
Cricotracheal ligament
259
What ligament connects the thyroid cartilage to the cricoid cartilage?
Cricothyroid ligament
260
What is the significance of the cricoid cartilage?
It is the landmark for making an emergency airway called a tracheotomy.
261
Where are the arytenoid cartilages located?
At the posterior, superior border of the cricoid cartilage.
262
What type of joints do the arytenoid cartilages form with the cricoid cartilage?
Synovial joints
263
What is the function of the corniculate cartilages?
They are horn-shaped pieces of elastic cartilage located at the apex of each arytenoid cartilage.
264
What is the function of the cuneiform cartilages?
They are club-shaped elastic cartilages that support the vocal folds and lateral aspects of the epiglottis.
265
What type of epithelium lines the larynx superior to the vocal folds?
Nonkeratinized stratified squamous epithelium
266
What type of epithelium lines the larynx inferior to the vocal folds?
Ciliated pseudostratified columnar epithelium
267
What are the three types of cells found in the ciliated pseudostratified columnar epithelium of the larynx?
Ciliated columnar cells, goblet cells, and basal cells
268
What is the function of the mucus produced by goblet cells?
Helps trap dust not removed in the upper passages.
269
Where do the cilia in the upper respiratory tract move mucus?
Down toward the oropharynx
270
Where do the cilia in the lower respiratory tract move mucus?
Up toward the laryngopharynx
271
is composed of nine pieces of cartilage.
Larynx
272
What does the mucous membrane of the larynx form?
Two pairs of folds
273
What is the superior pair of folds in the larynx called?
Vestibular folds (false vocal cords)
274
What is the inferior pair of folds in the larynx called?
Vocal folds (true vocal cords)
275
What is the space between the vestibular folds known as?
Rima vestibuli
276
What is the lateral expansion of the middle portion of the laryngeal cavity called?
Laryngeal ventricle
277
Where is the laryngeal ventricle located?
Inferior to the vestibular folds and superior to the vocal folds
278
Do the vestibular folds function in voice production?
No
279
What function do the vestibular folds serve when brought together?
Holding the breath against pressure in the thoracic cavity
280
What are the principal structures of voice production?
Vocal folds
281
What type of epithelium covers the vocal folds?
Nonkeratinized stratified squamous epithelium
282
What is deep to the mucous membrane of the vocal folds?
Bands of elastic ligaments
283
What do intrinsic laryngeal muscles attach to?
Both the rigid cartilages and the vocal folds
284
What happens when the intrinsic laryngeal muscles contract?
They move the cartilages, pulling the elastic ligaments tight and stretching the vocal folds
285
What happens when air passes through the larynx?
It vibrates the vocal folds and produces sound (phonation)
286
What determines the variation in the pitch of sound?
The tension in the vocal folds
287
What happens when there is greater air pressure?
A louder sound is produced by the vibrating vocal folds
288
What happens when the intrinsic muscles of the larynx contract?
They pull on the arytenoid cartilages, causing them to pivot and slide
289
What happens when the posterior cricoarytenoid muscles contract?
They move the vocal folds apart (abduction), opening the rima glottidis
290
What happens when the lateral cricoarytenoid muscles contract?
They move the vocal folds together (adduction), closing the rima glottidis
291
What controls the pitch of sound?
The tension on the vocal folds
292
What happens if the vocal folds are pulled taut by muscles?
They vibrate more rapidly, producing a higher pitch
293
What happens if the muscular tension on the vocal folds decreases?
They vibrate more slowly, producing lower-pitched sounds
294
Why do males generally have a lower range of pitch than females?
Due to the influence of androgens (male sex hormones), vocal folds are usually thicker and longer in males
295
Where does sound originate from?
The vibration of the vocal folds
296
What structures help convert sound into recognizable speech?
The pharynx, mouth, nasal cavity, and paranasal sinuses
297
What do the pharynx, mouth, nasal cavity, and paranasal sinuses act as?
Resonating chambers that give the voice its human and individual quality
298
How do we produce vowel sounds?
By constricting and relaxing the muscles in the wall of the pharynx
299
What muscles help us enunciate words?
Muscles of the face, tongue, and lips
300
How is whispering accomplished?
By closing all but the posterior portion of the rima glottidis
301
Why is there no pitch in whispering?
Because the vocal folds do not vibrate
302
How can intelligible speech still be produced while whispering?
By changing the shape of the oral cavity
303
What happens as the size of the oral cavity changes?
Its resonance qualities change, imparting a vowel-like pitch to the air
304
consists of a pair of folds of mucous membrane in the larynx (the vocal folds) and the space between them (the rima glottidis).
Glottis
305
What is laryngitis?
Laryngitis is an inflammation of the larynx that is most often caused by a respiratory infection or irritants such as cigarette smoke.
306
What causes hoarseness or loss of voice in laryngitis?
Inflammation of the vocal folds causes hoarseness or loss of voice by interfering with the contraction of the folds or by causing them to swell to the point where they cannot vibrate freely.
307
What is a consequence of long-term smoking on the vocal folds?
Many long-term smokers acquire a permanent hoarseness from the damage done by chronic inflammation.
308
In whom is cancer of the larynx almost exclusively found?
Cancer of the larynx is found almost exclusively in individuals who smoke.
309
What are the symptoms of cancer of the larynx?
The condition is characterized by hoarseness, pain on swallowing, or pain radiating to an ear.
310
What are the treatments for cancer of the larynx?
Treatment consists of radiation therapy and/or surgery.
311
What is the trachea?
The trachea (windpipe) is a tubular passageway for air that is about 12 cm (5 in.) long and 2.5 cm (1 in.) in diameter.
312
Where is the trachea located?
The trachea is located anterior to the esophagus and extends from the larynx to the superior border of the fifth thoracic vertebra (T5), where it divides into right and left primary bronchi.
313
What are the layers of the tracheal wall from deep to superficial?
The layers of the tracheal wall are the (1) respiratory mucosa, (2) submucosa, (3) hyaline cartilage, and (4) adventitial layer.
314
What does the respiratory mucosa of the trachea consist of?
The respiratory mucosa consists of an epithelial layer of ciliated pseudostratified columnar epithelium and an underlying layer of lamina propria that contains elastic and reticular fibers.
315
What does the submucosa of the trachea consist of?
The submucosa consists of areolar connective tissue that contains seromucous glands and their ducts.
316
How many hyaline cartilage rings are found in the trachea?
The hyaline cartilage rings in the trachea are 16–20 incomplete, horizontal rings.
317
What is the shape of the hyaline cartilage rings in the trachea?
The hyaline cartilage rings resemble the letter C and are stacked one above another.
318
What structure spans the open part of the C-shaped cartilage rings?
The open part of each C-shaped cartilage ring faces posteriorly toward the esophagus and is spanned by the membranous wall of the trachea.
319
What muscle is found within the membranous wall of the trachea?
The trachealis muscle is found within the membranous wall of the trachea.
320
What is the function of the trachealis muscle?
The trachealis muscle allows the diameter of the trachea to change subtly during inhalation and exhalation, which is important in maintaining efficient airflow.
321
What is the function of the C-shaped cartilage rings?
The C-shaped cartilage rings provide a semirigid support to maintain patency so that the tracheal wall does not collapse inward (especially during inhalation) and obstruct the air passageway.
322
What does the adventitial layer of the trachea consist of?
The adventitial layer consists of areolar connective tissue that joins the trachea to surrounding tissues.
323
is anterior to the esophagus and extends from the larynx to the superior border of the fifth thoracic vertebra.
Trachea
324
consists of macroscopic airways that begin at the trachea and continue through the terminal bronchioles.
Bronchial Tree
325
What are the two zones of the respiratory system?
Conducting zone and Respiratory zone
326
What are the conducting zones of the respiratory system?
Trachea, Main Bronchi, Lobar Bronchi, Segmental Bronchi, and Bronchioles and terminal bronchioles
327
What are the respiratory zones of the respiratory system?
Respiratory bronchioles, alveolar ducts, and alveolar saccules
328
What is the name of the branch at generation # 0?
Trachea
329
What is the name of the branch at generation # 1?
Main bronchi
330
What is the name of the branch at generation # 2 left and generation # 3 right?
Lobar bronchi
331
What is the name of the branch at generation # 10?
Segmental bronchi
332
What is the name of the branches found between generation # 11–16?
Bronchioles and terminal bronchioles
333
What is the name of the branches found between generation # 17–19?
Respiratory bronchioles
334
What is the name of the branches found between generation # 20–22?
Alveolar ducts
335
What is the name of the structure found at generation # 23?
Alveolar saccules
336
What are two methods used to reestablish airflow when the trachea is obstructed?
Tracheostomy and Endotracheal intubation
337
What is another name for a tracheostomy?
Tracheotomy
338
Where is the incision made during a tracheostomy?
Below the cricoid cartilage
339
What is inserted into the trachea during a tracheostomy?
Endotracheal tube
340
What are some indications for a tracheostomy?
Mechanical ventilator use, vocal cord paralysis, throat cancer, severe neck or mouth injuries, airway burns, foreign body obstructions, and difficulty coughing up secretions
341
What is the alternative procedure to a tracheostomy for maintaining an open airway?
Endotracheal intubation
342
What instrument is used to visualize the larynx during intubation?
Laryngoscope
343
What are some uses of an endotracheal tube?
Permit air passage, connect to a ventilator, introduce anesthesia, medications, and oxygen, and suction respiratory secretions
344
What is a mechanical ventilator?
A machine that supports ventilation (breathing)
345
What are some functions of a mechanical ventilator?
Oxygenate the lungs, remove carbon dioxide, help people breathe, and ventilate individuals who cannot breathe on their own
346
How does a mechanical ventilator deliver air to the lungs?
Through a tube placed into the trachea via tracheostomy or endotracheal intubation
347
What is a noninvasive type of ventilation?
Continuous Positive Airway Pressure (CPAP)
348
How does CPAP work?
A machine draws in air, humidifies it, pressurizes it, and delivers it through a hose connected to a mask over the nose and/or mouth
349
What is CPAP used to treat?
Sleep-related disorders such as sleep apnea
350
Where does the trachea divide into the right and left main bronchi?
At the superior border of the fifth thoracic vertebra (T5)
351
Which main bronchus is more vertical, shorter, and wider?
Right main bronchus
352
Why are aspirated objects more likely to enter the right main bronchus?
Because it is more vertical, shorter, and wider than the left main bronchus
353
What is the carina?
An internal ridge at the tracheal bifurcation, formed by the last tracheal cartilage
354
Why is the carina clinically significant?
Widening or distortion may indicate carcinoma of nearby lymph nodes
355
What are the secondary bronchi called?
Lobar bronchi
356
How many lobar bronchi are there in each lung?
Three in the right lung, two in the left lung
357
What are tertiary bronchi called?
Segmental bronchi
358
How many segmental bronchi are in each lung?
10 in the right lung, 8 in the left lung
359
What is the smallest conducting airway?
Terminal bronchioles
360
What special cells are found in terminal bronchioles?
Exocrine bronchiolar (Clara) cells
361
What are the functions of Clara cells?
Protect against inhaled toxins, produce surfactant, act as stem cells
362
What is the bronchial tree?
The extensive branching of airways from the trachea to the terminal bronchioles
363
What comes after terminal bronchioles?
Respiratory bronchioles and alveolar ducts
364
How many generations of branching occur from the trachea to alveolar ducts?
23 generations
365
How does the epithelium change as bronchi branch into bronchioles?
Ciliated pseudostratified columnar → ciliated simple columnar → ciliated simple cuboidal → nonciliated simple cuboidal
366
What removes inhaled particles in areas without cilia?
Macrophages
367
How does cartilage change as airways branch?
Incomplete rings → plates → disappears in distal bronchioles
368
How does smooth muscle change as airways branch?
Increases as cartilage decreases
369
What happens during an asthma attack?
Muscle spasms in bronchioles close off the airways
370
How does the sympathetic nervous system affect bronchioles?
Releases epinephrine and norepinephrine, causing bronchodilation
371
How does the parasympathetic nervous system affect bronchioles?
Causes bronchoconstriction
372
What chemical mediators cause bronchoconstriction?
Histamine and other allergic mediators
373
What is a pulmonologist?
A specialist in the diagnosis and treatment of lung diseases
374
Why are lungs called "lightweights"?
Because they float
375
What separates the two lungs?
The mediastinum, which contains the heart and other structures
376
What is the function of the mediastinum in relation to lung collapse?
If one lung collapses, the other can remain expanded
377
What is the pleural membrane?
A double-layered serous membrane enclosing and protecting each lung
378
What are the two layers of the pleura?
Parietal pleura (lines the thoracic cavity) and visceral pleura (covers the lungs)
379
What is the pleural cavity?
The space between the parietal and visceral pleurae, containing lubricating pleural fluid
380
What are the functions of pleural fluid?
Reduces friction during breathing and creates surface tension to keep the membranes together
381
What is pleurisy (pleuritis)?
Inflammation of the pleural membrane, causing pain due to friction between layers
382
What is pleural effusion?
Excess fluid accumulation in the pleural cavity
383
What is the base of the lung?
The broad inferior portion that fits over the diaphragm
384
What is the apex of the lung?
The narrow superior portion, slightly above the clavicles
385
What is the costal surface of the lung?
The surface that matches the curvature of the ribs
386
What is the hilum?
A region on the mediastinal surface where bronchi, blood vessels, lymphatics, and nerves enter/exit
387
What is the root of the lung?
The bronchi, blood vessels, lymphatics, and nerves held together by pleura and connective tissue
388
What is the cardiac notch?
A concavity in the left lung where the heart lies
389
Why is the left lung smaller than the right?
It is about 10% smaller due to space occupied by the heart
390
Why is the right lung shorter than the left?
The diaphragm is higher on the right side due to the liver
391
What is the only palpable part of the lungs?
The apex, superior to the medial third of the clavicles
392
What are the lung surface landmarks?
Base extends from the 6th costal cartilage anteriorly to T10 posteriorly
393
What is thoracentesis?
A procedure to remove excess pleural fluid using a needle
394
Where is a thoracentesis needle inserted?
Through the 7th intercostal space, along the superior border of the lower rib
395
Why is the needle passed along the superior border of the lower rib?
To avoid damaging intercostal nerves and blood vessels
396
What is the risk of inserting a needle below the 7th intercostal space?
Penetrating the diaphragm
397
lines the thoracic cavity, and the visceral pleura covers the lungs.
Parietal pleura
398
divides the left lung into two lobes. The oblique and horizontal fissures divide the right lung into three lobes.
Oblique fissure
399
What is pneumothorax?
Air in the pleural cavities
400
What is hemothorax?
Blood in the pleural cavities
401
What is the cause of pneumothorax?
Air entering the pleural cavity due to a surgical opening, stab wound, or gunshot wound
402
What happens when air enters the pleural cavity?
The lung may collapse
403
What is atelectasis?
Partial or complete lung collapse due to incomplete expansion
404
What is the goal of treatment for pneumothorax or hemothorax?
Evacuation of air or blood from the pleural cavity to allow the lung to reinflate
405
Can a small pneumothorax resolve on its own?
Yes, in some cases
406
What is often needed to assist in evacuation of air or blood from the pleural cavity?
Insertion of a chest tube
407
What divides each lung into sections called lobes?
One or two fissures
408
What type of fissure do both lungs have?
Oblique fissure
409
What additional fissure does the right lung have?
Horizontal fissure
410
What does the oblique fissure in the left lung separate?
The superior lobe from the inferior lobe
411
In the right lung, what does the superior part of the oblique fissure separate?
The superior lobe from the inferior lobe
412
In the right lung, what does the inferior part of the oblique fissure separate?
The inferior lobe from the middle lobe
413
What is the middle lobe bordered superiorly by?
The horizontal fissure
414
What does each lobe receive?
Its own lobar bronchus
415
What does the right main bronchus give rise to?
Three lobar bronchi
416
What are the names of the three lobar bronchi in the right lung?
Superior, middle, and inferior lobar bronchi
417
What does the left main bronchus give rise to?
Two lobar bronchi
418
What are the names of the two lobar bronchi in the left lung?
Superior and inferior lobar bronchi
419
What do the lobar bronchi give rise to within the lung?
The segmental bronchi
420
What is constant in both origin and distribution?
The segmental bronchi
421
How many segmental bronchi are in each lung?
10
422
What is the portion of lung tissue that each segmental bronchus supplies called?
A bronchopulmonary segment
423
What may be surgically removed without seriously disrupting the surrounding lung tissue?
Bronchial and pulmonary disorders (such as tumors or abscesses) that are localized in a bronchopulmonary segment
424
What does each bronchopulmonary segment of the lungs have?
Many small compartments called lobules
425
What is each lobule wrapped in?
Elastic connective tissue
426
What does each lobule contain?
A lymphatic vessel, an arteriole, a venule, and a branch from a terminal bronchiole
427
What do terminal bronchioles in a lobule subdivide into?
Microscopic branches called respiratory bronchioles
428
What buds from the walls of respiratory bronchioles?
Pulmonary alveoli
429
What do pulmonary alveoli participate in?
Gas exchange
430
What do respiratory bronchioles begin?
The respiratory zone of the respiratory system
431
As respiratory bronchioles penetrate more deeply into the lungs, what does the epithelial lining change from?
Simple cuboidal to simple squamous
432
What do respiratory bronchioles subdivide into?
Several (2–11) alveolar ducts
433
What do alveolar ducts consist of?
Simple squamous epithelium
434
What is the terminal dilation of an alveolar duct called?
Alveolar saccule or alveolar sac
435
What is an alveolar saccule analogous to?
A cluster of grapes
436
What are the outpouchings that compose each alveolar saccule called?
Pulmonary alveoli
437
What are pulmonary alveoli analogous to?
Individual grapes
438
How many alveolar saccules are at the end of each alveolar duct?
About 100
439
How many pulmonary alveoli does each alveolar saccule contain?
About 20–30
440
What is the diameter of pulmonary alveoli?
200–300 µm (0.2–0.3 mm)
441
How many types of alveolar epithelial cells does the wall of each pulmonary alveolus consist of?
Two
442
What is the more numerous type of alveolar epithelial cells (about 95%)?
Pneumocyte type I (type I alveolar cell)
443
What type of epithelium forms pneumocyte type I?
Simple squamous epithelial cells
444
What do pneumocytes type I form in the pulmonary alveolar wall?
A nearly continuous lining
445
What is another name for pneumocyte type II?
Septal cells
446
Where are pneumocyte type II found?
Between pneumocytes type I
447
What is the main function of pneumocytes type I?
The main sites of gas exchange
448
What is the shape of pneumocytes type II?
Rounded or cuboidal epithelial cells
449
What do pneumocytes type II secrete?
Pulmonary alveolar fluid
450
What does pulmonary alveolar fluid do?
Keeps the surface between the cells and the air moist
451
What is included in the pulmonary alveolar fluid?
Surfactant
452
What type of mixture is surfactant?
A complex mixture of phospholipids and lipoproteins
453
What does surfactant do to the surface tension of pulmonary alveolar fluid?
Lowers it
454
What does surfactant reduce the tendency of pulmonary alveoli to do?
Collapse
455
What does surfactant help maintain?
Patency
456
What type of cells are also present in the pulmonary alveolar wall?
Alveolar macrophages
457
What do alveolar macrophages do?
Remove fine dust particles and other debris
458
What type of cells produce reticular and elastic fibers?
Fibroblasts
459
What lies underneath the layer of pneumocytes type I?
An elastic basement membrane
460
What disperses into a network of blood capillaries on the outer surface of the pulmonary alveoli?
The lobule’s arteriole and venule
461
What do blood capillaries consist of?
A single layer of endothelial cells and basement membrane
462
How does the exchange of O₂ and CO₂ between air spaces in the lungs and the blood take place?
By diffusion
463
What forms the respiratory membrane?
Pulmonary alveolar and capillary walls
464
How many layers does the respiratory membrane consist of?
Four
465
What is the first layer of the respiratory membrane?
A layer of pneumocytes type I and type II and associated alveolar macrophages that constitutes the alveolar wall
466
What is the second layer of the respiratory membrane?
An epithelial basement membrane underlying the pulmonary alveolar wall
467
What is the third layer of the respiratory membrane?
A capillary basement membrane that is often fused to the epithelial basement membrane
468
What is the fourth layer of the respiratory membrane?
The capillary endothelium
469
How thick is the respiratory membrane?
0.5 µm thick
470
How does the thickness of the respiratory membrane compare to the diameter of a red blood cell?
About one-sixteenth the diameter of a red blood cell
471
Why is the respiratory membrane very thin?
To allow rapid diffusion of gases
472
How many pulmonary alveoli do both lungs contain?
300–500 million
473
What is the total surface area provided by pulmonary alveoli for gas exchange?
About 75 m² (807 ft²)
474
What is the size of the total alveolar surface area compared to?
A racquetball court or slightly larger
475
What accounts for the spongy texture of the lungs?
The hundreds of millions of pulmonary alveoli
476
is the terminal dilation of an alveolar duct and is composed of pulmonary alveoli.
Alveoli saccule
477
How is the pathway for microscopic airways?
Respiratory bronchioles > Alveolar ducts > Alveolar saccules > Pulmonary alveoli
478
How many sets of arteries supply blood to the lungs?
Two
479
What are the two sets of arteries that supply blood to the lungs?
Pulmonary arteries and bronchial arteries
480
Through what does deoxygenated blood pass before reaching the pulmonary arteries?
Pulmonary trunk
481
Into which arteries does the pulmonary trunk divide?
Left pulmonary artery and right pulmonary artery
482
Where does the left pulmonary artery enter?
The left lung
483
Where does the right pulmonary artery enter?
The right lung
484
What is unique about pulmonary arteries?
They are the only arteries in the body that carry deoxygenated blood
485
How does oxygenated blood return to the heart?
Via the four pulmonary veins
486
Where do the four pulmonary veins drain?
Into the left atrium
487
What is a unique feature of pulmonary blood vessels?
Their constriction in response to localized hypoxia (low O₂ level)
488
How do blood vessels in all other body tissues respond to hypoxia?
By dilation to increase blood flow
489
How do blood vessels in the lungs respond to hypoxia?
By vasoconstriction
490
Why does vasoconstriction occur in pulmonary blood vessels in response to hypoxia?
To divert pulmonary blood from poorly ventilated areas to well-ventilated regions for more efficient gas exchange
491
What is the phenomenon called where perfusion (blood flow) matches ventilation (airflow) in the lungs?
Ventilation–perfusion coupling
492
What is the function of bronchial arteries?
To deliver oxygenated blood to the lungs
493
From where do bronchial arteries branch?
The aorta
494
What do bronchial arteries mainly perfuse?
The muscular walls of the bronchi and bronchioles
495
What connections exist between branches of bronchial arteries and pulmonary arteries?
Some connections exist, but most blood returns to the heart via pulmonary veins
496
Through which veins does some blood drain from the lungs?
Bronchial veins
497
Bronchial veins are branches of what system?
Azygos system
498
Through which vein does blood return to the heart from bronchial veins?
Superior vena cava
499
The exchange of respiratory gases occurs by ___ across the respiratory membrane.
diffusion
500
What is another name for coryza?
The common cold
