Resp Flashcards
1
Q
What are the primary functions of the respiratory system?
A
Supply the body with oxygen and remove carbon dioxide.
2
Q
Which structures comprise the upper respiratory system?
A
Nose, nasal cavity, paranasal sinuses, and pharynx.
3
Q
What is the role of the nasal conchae?
A
Increase mucosal surface area and enhance air turbulence to filter, warm, and moisten air.
4
Q
Which structures are part of the lower respiratory system?
A
Larynx, trachea, bronchi, and lungs.
5
Q
What is the function of the epiglottis?
A
Prevents food and liquids from entering the airway during swallowing.
6
Q
What are the four processes of respiration?
A
Pulmonary ventilation, external respiration, transport of respiratory gases, and internal respiration.
7
Q
Define pulmonary ventilation.
A
The movement of air into and out of the lungs (breathing).
8
Q
What is external respiration?
A
The exchange of gases between the lungs and the blood.
9
Q
How is oxygen transported in the blood?
A
Primarily bound to hemoglobin in red blood cells; a small amount is dissolved in plasma.
10
Q
What factors influence hemoglobin’s affinity for oxygen?
A
Partial pressure of oxygen (PO₂), temperature, blood pH, and concentration of BPG.
11
Q
Where are the respiratory control centers located?
A
In the medulla oblongata and pons of the brainstem.
12
Q
What is the role of the medullary respiratory centers?
A
Set the basic rhythm of breathing.
13
Q
How do chemoreceptors influence breathing rate?
A
They detect changes in CO₂, O₂, and pH levels in the blood and adjust breathing rate accordingly.
14
Q
What is hypercapnia?
A
An elevated level of carbon dioxide in the blood.
15
Q
How does the body respond to hypercapnia?
A
Increases the rate and depth of breathing to expel more CO₂.
16
Q
What is tidal volume (TV)?
A
Air moved in or out during normal breathing (~500 mL).
17
Q
Define inspiratory reserve volume (IRV).
A
Air inhaled beyond normal inspiration.
18
Q
What is expiratory reserve volume (ERV)?
A
Air exhaled beyond normal expiration.
19
Q
Explain residual volume (RV).
A
Air remaining in lungs after maximal exhalation.
20
Q
How is vital capacity (VC) calculated?
A
VC = TV + IRV + ERV.
21
Q
What is the primary driving force for oxygen diffusion in the lungs?
A
The partial pressure gradient of oxygen between the alveoli and the blood.
22
Q
How is carbon dioxide transported in the blood?
A
Dissolved in plasma, chemically bound to hemoglobin, and as bicarbonate ions in plasma.
23
Q
What is the chloride shift?
A
The exchange of chloride and bicarbonate ions across red blood cell membranes to facilitate CO₂ transport.
24
Q
What effect does a rightward shift of the oxygen-hemoglobin dissociation curve have?
A
Decreases hemoglobin’s affinity for oxygen, facilitating oxygen release to tissues.
25
What conditions can cause a rightward shift in the oxygen-hemoglobin dissociation curve?
Increased CO₂, increased H⁺ concentration (decreased pH), increased temperature, and increased BPG levels.
26
27
What are the functions of the nasal cavity?
Warms and humidifies air, filters particles, houses olfactory receptors.
28
Which bones contain sinuses?
Frontal, ethmoid, sphenoid, and maxillary bones.
29
Which part of the pharynx is lined with pseudostratified ciliated columnar epithelium?
Nasopharynx.
30
Which structure connects the nasal cavity to the nasopharynx?
Internal nares.
31
What structure is known as the 'windpipe'?
Trachea.
32
What is the function of the epiglottis?
Prevents food from entering the trachea during swallowing.
33
What are the vocal cords and their function?
True vocal cords are elastic folds that produce sound; false cords do not.
34
What is the glottis?
The space between the vocal cords.
35
What structure bifurcates into the larynx and esophagus?
Laryngopharynx.
36
What are the three branches of the bronchial tree?
Primary, secondary (lobar), and tertiary (segmental) bronchi.
37
What are the lobes of the lungs?
Right: 3 lobes; Left: 2 lobes with cardiac notch.
38
What is the hilum?
The area on the lung where bronchi, blood vessels, and nerves enter/exit.
39
40
What are the two types of alveolar cells?
Type I (gas exchange) and Type II (secrete surfactant).
41
What is the function of surfactant?
Reduces surface tension in alveoli to prevent collapse.
42
What is the respiratory membrane composed of?
Type I alveolar cell, basement membrane, and capillary endothelium.
43
What is the pleural cavity?
A fluid-filled space between visceral and parietal pleura that reduces friction and keeps lungs inflated.
44
What is Boyle's Law?
Pressure is inversely related to volume (P=1/V).
45
What happens during inhalation?
Diaphragm contracts, thoracic volume increases, intrapulmonary pressure drops, air flows in.
46
What happens during exhalation?
Diaphragm relaxes, thoracic volume decreases, intrapulmonary pressure rises, air flows out.
47
What muscles are used in forced expiration?
Internal intercostals and abdominal muscles.
48
What is tidal volume (TV)?
Air moved in or out during normal breathing (~500 mL).
49
What is inspiratory reserve volume (IRV)?
Air inhaled beyond normal inspiration.
50
What is expiratory reserve volume (ERV)?
Air exhaled beyond normal expiration.
51
What is residual volume (RV)?
Air remaining in lungs after maximal exhalation.
52
53
What is vital capacity (VC)?
IRV + TV + ERV.
54
What is total lung capacity (TLC)?
VC + RV.
55
Where does external respiration occur?
At the alveoli between air and blood.
56
Where does internal respiration occur?
At the tissues between blood and cells.
57
How is oxygen transported in the blood?
1.5% in plasma, 98.5% bound to hemoglobin.
58
What factors weaken O2-Hb bond?
Increased CO2, increased temperature, decreased pH, increased DPG.
59
How is carbon dioxide transported?
7% in plasma, 23% bound to Hb, 70% as bicarbonate (HCO3-).
60
What enzyme converts CO2 + H2O to H2CO3?
Carbonic anhydrase.
61
What is the Bohr effect?
Low pH enhances O2 unloading from Hb.
62
What is the chloride shift?
Exchange of HCO3- and Cl- to maintain ionic balance in RBCs.
63
What are the respiratory centers in the brain?
Medullary rhythmicity center (VRG, DRG) and pontine respiratory centers.
64
What is the most powerful respiratory stimulus?
Increased CO2 levels.
65
66
Where are central chemoreceptors located?
In the medulla, monitoring pH of CSF.
67
Where are peripheral chemoreceptors located?
In the carotid and aortic bodies, monitoring O2 and CO2 in blood.
68
69
What is the primary function of the upper respiratory system?
Warms, humidifies, and filters air
70
What structures support the nose?
Bone and hyaline cartilage
71
What are the nostrils also known as?
External nares
72
What is the nasal cavity lined with?
Pseudostratified ciliated columnar epithelium
73
What divides the nasal cavity on the midline?
Nasal septum
74
What are the bony foundations of the nasal septum?
* Perpendicular plate of the ethmoid bone
* Vomer
75
What are the ridges found on the lateral walls of the nasal cavity called?
Nasal conchae
76
Name the three types of nasal conchae.
* Superior nasal conchae
* Middle nasal conchae
* Inferior nasal conchae
77
What are the functions of the nasal cavity?
* Warms and humidifies incoming air
* Entraps dust and small particles
* Contains olfactory receptors
78
Where are the sinuses located?
* Frontal bone
* Ethmoid bone
* Sphenoid bone
* Maxillary bones
79
What are the functions of the sinuses?
* Reduce the weight of the skull
* Affect the sound of the voice
80
What is the pharynx commonly known as?
Throat
81
What are the three regions of the pharynx?
* Nasopharynx
* Oropharynx
* Laryngopharynx
82
What type of epithelium lines the nasopharynx?
Pseudostratified ciliated columnar epithelium
83
What does the oropharynx contain?
Palatine and lingual tonsils
84
What is the function of the larynx?
Guards the entrance of the airway and produces sound
85
What is another name for thyroid cartilage?
Adam’s apple
86
What shape is the epiglottis?
Pringle potato chip shaped
87
What are the two pairs of vocal cords called?
* Vestibular folds (false vocal cords)
* True vocal cords (create sound)
88
What is the glottis?
The vocal cords and the open space of the lumen between them
89
What does the trachea consist of?
15-20 incomplete rings of tracheal cartilage connected by annular ligaments
90
What does the trachea bifurcate into?
Primary bronchi
91
What are the components of the bronchial tree?
* R and L primary bronchi
* Secondary (lobar) bronchi
* Tertiary (segmental) bronchi
* Bronchioles
92
How many lobes does the right lung have?
3 lobes
93
What is the cardiac notch?
A notch in the left lung
94
What are the two layers of pleura?
* Visceral pleura
* Parietal pleura
95
What is the function of the alveoli?
Gas exchange
96
What are the two cell types that make up the alveoli?
* Type I cells (simple squamous epithelium)
* Type II cells (secrete surfactant)
97
What is Boyle’s law?
Pressure is inversely related to volume (P=1/V)
98
What is intrapulmonary pressure?
Pressure inside the airway
99
What is the Hering-Brauer reflex?
Stretch receptors inhibit further inhalation when lungs are stretched
100
What is tidal volume (TV)?
Volume of air moved in or out during normal, quiet breathing
101
What is vital capacity (VC)?
Maximum amount of air that can be controlled consciously
102
What is minute respiratory volume (MRV)?
Amount of new air moved into the respiratory passageways per minute
103
What is external respiration?
Gas exchange between the lungs and blood
104
What is Dalton’s Law?
Total pressure of a gas equals the pressures exerted independently by each gas in the mixture
105
What is the primary way oxygen is transported in the blood?
Bound to hemoglobin (oxyhemoglobin)
106
What factors can weaken the O2-Hb bond?
* Increased PCO2
* Decreased pH
* Increased temperature
107
What is the O2-Hb dissociation curve?
Describes the relationship between oxygen saturation of hemoglobin and the partial pressure of oxygen
108
How does fetal hemoglobin differ from adult hemoglobin?
Fetal hemoglobin has a higher affinity for O2
109
What shape does the oxygen-hemoglobin dissociation curve take?
An S shaped curve
## Footnote
This shape indicates the cooperative binding of O2 to hemoglobin.
110
What does a rightward shift in the oxygen-hemoglobin dissociation curve indicate?
Decreased affinity for O2 (weaker bond)
## Footnote
This means hemoglobin is less likely to hold onto oxygen.
111
What does a leftward shift in the oxygen-hemoglobin dissociation curve indicate?
Increased affinity for O2 (stronger bond)
## Footnote
This means hemoglobin is more likely to hold onto oxygen.
112
How does fetal hemoglobin compare to non-fetal hemoglobin in terms of O2 affinity?
Fetal Hb has a higher affinity for O2 than non-fetal Hb
113
How much CO2 is transported dissolved in plasma?
7%
114
What percentage of CO2 is bound to hemoglobin in the form of carbaminohemoglobin?
23%
115
What percentage of CO2 is transformed into bicarbonate ion (HCO3-)?
70%
116
What enzyme combines water with CO2 to form carbonic acid?
Carbonic anhydrase
117
What is the reaction that forms carbonic acid from CO2 and water?
CO2 + H2O ------carbonic anhydrase----→ H2CO3
118
What happens to carbonic acid in a watery solution?
It dissociates, eliciting H+
## Footnote
This process decreases pH and makes the solution more acidic.
119
What is the Bohr effect?
Facilitates O2 unloading from Hb due to a decrease in pH
120
What is the chloride shift?
A counter transport mechanism that imports one Cl- for each HCO3- exported
121
What are the two processes involved in external respiration?
* O2 loading
* CO2 unloading
122
What percentage of O2 enters the RBC and binds to hemoglobin during external respiration?
98.5%
123
What is the main function of the medullary rhythmicity center?
Control basic inspiratory drive
124
What are the two groups of neurons in the medullary rhythmicity center?
* Ventral respiratory group (VRG)
* Dorsal respiratory group (DRG)
125
What does the ventral respiratory group (VRG) innervate?
The diaphragm
126
What does the dorsal respiratory group (DRG) innervate?
Intercostal muscles
127
Which group of neurons fine-tunes the length of inspiration and expiration?
Pontine respiratory centers
128
What does the peripheral chemoreceptors monitor?
O2 levels
129
What is the main factor that stimulates breathing according to blood monitoring?
O2 must be significantly low
130
What does a higher PCO2 in arterial blood stimulate?
Increased respiratory rate
131
What is the relationship between PCO2 and pH?
Higher PCO2 causes a decrease in pH
132
What does H+ concentration increase lead to in terms of respiratory rate?
Immediate increase in respiratory rate
133
What percentage of the response due to H+ concentration is due to peripheral chemoreceptors?
25%
134
What percentage of the response due to H+ concentration is due to central chemoreceptors?
75%
135
What is the reaction that leads to increased H+ concentration due to CO2?
CO2 + H2O → H2CO3 → H+ + HCO3-
136
137
Which structure is not lined with pseudostratified columnar epithelial tissue?
Oropharynx
## Footnote
The pseudostratified columnar epithelial tissue lines the nasopharynx, trachea, and bronchioles, but not the oropharynx.
138
Which of the following describes the glottis?
Opening between the vocal cords
## Footnote
The glottis is the space between the vocal cords that plays a crucial role in sound production.
139
Which of the following bones do not contain a sinus?
Nasal
## Footnote
The nasal bone does not contain any sinus cavities, unlike the frontal, ethmoid, and maxillary bones.
140
Which structure penetrates the lungs?
Primary bronchi
## Footnote
The primary bronchi are the main passageways that lead into the lungs from the trachea.
141
What is the function of surfactant?
Ease surface tension
## Footnote
Surfactant reduces surface tension in the alveoli, preventing collapse and aiding in gas exchange.
142
The pleural cavity:
Is a fluid filled cavity
## Footnote
The pleural cavity contains serous fluid that reduces friction and allows for smooth lung movement.
143
Which of the following rules pertains to the relationship between volume and pressure of a gas?
Boyle’s law
## Footnote
Boyle's law states that the pressure of a gas is inversely related to its volume.
144
If atmospheric pressure= 100 mm Hg, and O2 makes up 30% of air, what is the partial pressure of O2?
30 mm Hg
## Footnote
The partial pressure of a gas is calculated by multiplying the total pressure by the fraction of that gas in the mixture.
145
If PCO2 in the alveolus= 50 mm Hg, and the PCO2 in the blood= 75 mm Hg, which direction will CO2 move?
Blood Lungs until blood=50 mm Hg
## Footnote
CO2 will diffuse from the blood (higher concentration) to the alveolus (lower concentration).
146
Gas exchange between the lungs and blood is known as:
External respiration
## Footnote
External respiration involves the exchange of gases in the lungs, primarily oxygen and carbon dioxide.
147
Which of the following rules pertains to the movement of a gas between a gas and liquid state?
Henry’s law
## Footnote
Henry’s law states that the amount of gas dissolved in a liquid is proportional to its partial pressure.
148
Which gas is most soluble in blood?
Carbon dioxide
## Footnote
Carbon dioxide is more soluble in blood than oxygen, which influences gas transport and exchange.
149
Which part of hemoglobin binds to oxygen?
Heme group
## Footnote
The heme group contains iron, which is essential for oxygen binding in hemoglobin.
150
In which scenario would Hb be most saturated with O2 at a PO2=40 mm Hg?
10 degrees celsius
## Footnote
Lower temperatures generally increase hemoglobin's affinity for oxygen.
151
In which scenario would Hb be least saturated with O2 at a PO2=40 mm Hg?
43 degrees Celsius
## Footnote
Higher temperatures decrease hemoglobin's affinity for oxygen, leading to lower saturation.
152
Which of the following situations enhance Hb’s affinity for O2?
Increased pH
## Footnote
An increase in pH typically enhances hemoglobin's ability to bind oxygen.
153
What is the primary mode of transport for CO2?
HCO3-
## Footnote
The majority of carbon dioxide is transported in the form of bicarbonate ions (HCO3-) in the plasma.
154
Where is HCO3- produced?
Inside RBC’s
## Footnote
Bicarbonate is formed in red blood cells during the conversion of carbon dioxide.
155
A decrease in pH enhances O2 release from Hb. This is called:
Bohr effect
## Footnote
The Bohr effect describes how lower pH levels promote oxygen release from hemoglobin.
156
What is the most powerful stimulus to increase breathing?
Increased CO2
## Footnote
Elevated levels of carbon dioxide are the primary driver for stimulating respiration.
157
Which of the following is the most sensitive area regulating respiration?
Central chemoreceptors
## Footnote
Central chemoreceptors in the brain respond primarily to changes in CO2 levels in the blood.
158
Where can gas exchange occur?
Bronchioles
## Footnote
While the primary site of gas exchange is in the alveoli, gas exchange can also occur in the bronchioles.
159
What is the function of the nasal cavity? Select all correct answers.
• Warms and humidifies incoming air
• Sensation of smell
• Dividing the incoming air into two distinct volumes
## Footnote
The nasal cavity plays multiple roles in respiratory function, including olfaction.
160
Which sinus is not continuous with the nasal cavity?
All sinuses open into the nasal cavity
## Footnote
This statement is incorrect; all sinuses typically drain into the nasal cavity.
161
Which part of the pharynx is lined with pseudostratified ciliated columnar epithelium?
Nasopharynx
## Footnote
The nasopharynx is the only part of the pharynx lined with this type of epithelium.
162
Which region of the pharynx bifurcates?
Laryngopharynx
## Footnote
The laryngopharynx is the region that leads to both the esophagus and trachea.
163
Which region produces sound?
Larynx
## Footnote
The larynx contains the vocal cords and is responsible for sound production.
164
The ____ is known as the windpipe.
Trachea
## Footnote
The trachea is the main airway leading to the lungs.
165
Which type of conducting air passageway is always patent? Select all correct answers.
• Trachea
• Primary bronchi
## Footnote
These passageways maintain their structure and remain open under normal conditions.
166
What structure protects the lungs from inhaled food and fluid?
Epiglottis
## Footnote
The epiglottis covers the larynx during swallowing to prevent food from entering the airways.
167
Identify the connection between the nasal cavity and nasopharynx.
Internal nares
## Footnote
The internal nares are the openings that connect the nasal cavity to the nasopharynx.
168
Where is the aorta located?
Mediastinum
## Footnote
The aorta runs through the mediastinum, the central compartment of the thoracic cavity.
169
The lungs are organized into 3 ___ on the right and ___ on the left:
Lobes
## Footnote
The right lung has three lobes while the left lung has two lobes.
170
What is the best description of the pleural cavity?
Fluid filled cavity that separates the lungs
## Footnote
The pleural cavity is essential for lung function, facilitating movement during breathing.
171
What is the best description of the pleural cavity?
fluid filled cavity that separates the lungs
## Footnote
The pleural cavity is crucial for lung function as it allows for movement during breathing.
172
What cell type performs the primary function of the lungs?
Type I cells
## Footnote
Type I cells are crucial for gas exchange in the alveoli.
173
What is the function of surfactant?
reduces surface tension within an alveolus
## Footnote
Surfactant prevents alveolar collapse during exhalation.
174
If the visceral pleura separates from the parietal pleura:
the lung collapses
## Footnote
This condition is known as pneumothorax.
175
According to Boyle's law, pressure changes are related to:
volume of the container
## Footnote
Boyle's law states that pressure and volume are inversely related.
176
The intrapulmonary pressure could be described as:
pressure inside the alveoli
## Footnote
It is critical for determining airflow during breathing.
177
When the alveolar volume increases:
intrapulmonary pressure decreases
## Footnote
This decrease allows air to flow into the lungs.
178
Identify the factors that affect inspiration: Select all correct answers.
* diaphragm contraction
* contraction of external intercostal muscles
## Footnote
These factors increase thoracic cavity volume.
179
Contraction of muscles are used to increase the size of the thoracic cavity. Which muscles?
* external intercostals
* diaphragm
* sternocleidomastoid
## Footnote
These muscles work together to facilitate inhalation.
180
Which muscles are used to blow up a balloon?
* internal intercostals
* abdominal muscles
## Footnote
These muscles help force air out during exhalation.
181
When the diaphragm contracts:
intrapulmonary pressure decreases and air moves in
## Footnote
This process is essential for inhalation.
182
Which pressure is always lower than atmospheric pressure?
intrapleural pressure
## Footnote
This negative pressure is crucial for lung expansion.
183
In order for the lung to increase volume:
* air must be moved into the lung
* lung must be compliant
* lung must be adhered to the parietal pleura
## Footnote
These conditions are necessary for effective breathing.
184
What forces are responsible for normal exhalation? Select all correct answers.
* normal elasticity of the lungs
* relaxation of the diaphragm
## Footnote
These factors help expel air from the lungs.
185
When atmospheric pressure > intrapulmonary pressure:
air moves into the lungs
## Footnote
This is the basic principle of inhalation.
186
The amount of air that can be inhaled in addition to a normal inhalation is:
IRV
## Footnote
IRV stands for Inspiratory Reserve Volume.
187
The amount of air that we consciously control is the:
VC
## Footnote
VC stands for Vital Capacity.
188
The vital capacity is: Select all correct answers.
* IRV + TV + ERV
* TLC - RV
## Footnote
Vital capacity measures the maximum amount of air a person can exhale after a maximum inhalation.
189
Which of these values is a relatively constant number?
anatomic dead space
## Footnote
Anatomic dead space refers to areas in the respiratory system where no gas exchange occurs.
190
The alveolar ventilation rate is the total amount of air that a person inhales per minute.
false
## Footnote
Alveolar ventilation rate accounts for air that reaches the alveoli and is available for gas exchange.
191
Gas exchange between the lungs and the blood is called:
external respiration
## Footnote
This process occurs in the alveoli.
192
In order to predict the movement of CO2, you must know:
* the partial pressures of CO2
* the solubility of CO2
## Footnote
These factors influence gas diffusion across membranes.
193
Atmospheric pressure can be calculated using:
Dalton's law
## Footnote
Dalton's law relates to the partial pressures of gases in a mixture.
194
If the total air pressure = 500 mm Hg, and the PO2 = 50 mm Hg, then:
oxygen makes up 10% of air
## Footnote
This is calculated using the formula PO2 / total pressure.
195
If the PO2 in the lungs = 100 mm Hg and the PO2 in the blood = 100 mm Hg, then:
there would be no net movement of oxygen
## Footnote
This indicates equilibrium between the lungs and blood.
196
If the PCO2 at the tissues = 50 mm Hg and the PCO2 in the blood = 60 mm Hg, then:
CO2 will diffuse into the blood until tissue PCO2 = 60 mm Hg
## Footnote
This reflects the principles of gas exchange based on partial pressures.
197
Henry's law pertains to internal gas exchange, but not external gas exchange.
false
## Footnote
Henry's law applies to both internal and external gas exchanges.
198
Gas exchange depends on: Select all correct answers.
* presence of a concentration gradient
* presence of a pressure gradient
* solubility of the gas
## Footnote
These factors influence the efficiency of gas exchange.
199
What factors permit oxygen to diffuse across the respiratory membrane? Select all correct answers.
* thickness of the respiratory membrane
* oxygen pressure gradient
## Footnote
These factors are essential for effective oxygen transfer.
200
What factors affect gas exchange?
• presence of a concentration gradient
• presence of a pressure gradient
• molecular weight of the gas
• solubility of the gas
## Footnote
These factors influence the efficiency of gas exchange in the lungs.
201
What factors permit oxygen to diffuse across the respiratory membrane?
• thickness of the respiratory membrane
• oxygen pressure gradient
• carbon dioxide pressure gradient
• lipid solubility
## Footnote
These factors determine how effectively oxygen can move from the alveoli into the blood.
202
Where is oxygen found in the blood?
• bound to the globin portions of Hb
• bound to the iron atoms of Hb
• dissolved in the plasma
## Footnote
Oxygen is primarily transported bound to hemoglobin but also in a dissolved form.
203
How many molecules of oxygen can one Hb molecule transport?
4
## Footnote
Each hemoglobin molecule can carry up to four oxygen molecules.
204
What is the primary factor that facilitates oxygen binding to Hb?
an oxygen pressure gradient
## Footnote
The gradient influences the uptake of oxygen by hemoglobin.
205
What is a factor that determines how long RBCs remain effective?
• metabolic rate
• temperature
• oxygen pressure in environment
• amount of CO2 being transported
## Footnote
These factors can affect the lifespan and functionality of red blood cells.
206
Which of these factors weakens the O2-Hb bond?
• increased temperature
• decreased pH
• increased DPG
• increased PCO2
## Footnote
These conditions promote the release of oxygen from hemoglobin.
207
Which of these factors increases the affinity between O2 and Hb?
• decreased temperature
• increased pH
• decreased DPG
## Footnote
These conditions enhance hemoglobin's ability to hold onto oxygen.
208
Which of these factors could cause the O2-Hb dissociation curve to shift to the right?
• increased PCO2
## Footnote
A rightward shift indicates a decreased affinity of hemoglobin for oxygen.
209
At a P02 = 40mm Hg, the blood is:
75% saturated with oxygen
## Footnote
This saturation level indicates how much oxygen is bound to hemoglobin at this partial pressure.
210
If the PO2 at the tissues = 40 mm Hg, then it makes sense for the PO2 at the placenta to be:
20 mm Hg
## Footnote
A lower PO2 at the placenta allows for oxygen transfer from maternal to fetal circulation.
211
CO2 enters the blood during:
• internal respiration
## Footnote
This process refers to the exchange of gases between blood and tissues.
212
CO2 movement is dependent on which gradients?
• PCO2 gradient
• PO2 gradient
## Footnote
These gradients drive the diffusion of CO2 in and out of the blood.
213
CO2 is more soluble in blood compared to O2.
true
## Footnote
CO2 has a higher solubility in plasma than oxygen.
214
CO2 is transported in all of these ways, except:
bound to iron in Hb
## Footnote
CO2 binds to globin, not iron, in hemoglobin.
215
Carbonic acid is formed in:
• the tissues
• inside of RBCs
## Footnote
Carbonic acid formation occurs as CO2 reacts with water, primarily in red blood cells.
216
Acids in solution will dissociate to elicit:
H+
## Footnote
This dissociation leads to a decrease in pH.
217
Most CO2 travels in the blood in the form of:
HCO3-
## Footnote
Bicarbonate is the primary form of CO2 transport in the bloodstream.
218
When H+ are generated in a solution, they _____ the pH.
decrease
## Footnote
The introduction of H+ ions lowers the pH, making the solution more acidic.
219
When CO2 enters the blood, how much of it will enter a RBC?
70%
## Footnote
A significant portion of CO2 is taken up by red blood cells for transport.
220
CO2 unloading from the blood is facilitated by:
• PCO2 gradient
• acidic pH
• increased temperature
## Footnote
These conditions promote the release of CO2 from hemoglobin.
221
The neurons that innervate the diaphragm originate in the:
ventral respiratory group
## Footnote
This group is crucial for controlling respiration.
222
What is the most important factor affecting respiration?
carbon dioxide levels
## Footnote
CO2 levels are the primary driver for the regulation of breathing.
223
Oxygen is detected by:
• chemoreceptors in the aorta
• chemoreceptors in the common carotid arteries
## Footnote
These chemoreceptors monitor oxygen levels in the blood.
224
Which of these changes will elicit the most rapid response?
increase in arterial carbon dioxide levels
## Footnote
Changes in CO2 levels prompt quick adjustments in ventilation.
225
pH changes in the body are due to:
• excess expiration of CO2
• accumulation of CO2
## Footnote
These factors influence the acid-base balance in the body.
226
Which of these can cross the BBB?
dissolved CO2
## Footnote
Only certain molecules, like dissolved CO2, can pass through the blood-brain barrier.
227
Decreased body CO2 levels can be caused by:
• hyperventilation
## Footnote
Hyperventilation can lead to a drop in CO2 levels, affecting respiratory drive.
228
The medullary rhythmicity center is made up of:
• ventral respiratory group
• dorsal respiratory group
## Footnote
These groups are essential for the rhythmic control of breathing.
229
Holding your breath is regulated by:
Medullary rhythmicity center
## Footnote
This center manages the involuntary aspects of respiration.
230
Which centers are involved in the regulation of breathing?
VRG, DRG, Medullary rhythmicity center, Pons, Primary motor cortex
231
Holding your breath is regulated by which centers?
VRG, DRG, Medullary rhythmicity center, Pons, Primary motor cortex
232
Which condition would make the LEAST difference in the breathing rate?
decline in oxygen availability
233
Which condition would make the LEAST difference in the breathing rate?
increase in blood PCO2
234
Which condition would make the LEAST difference in the breathing rate?
change in the pH of the CSF
