Final Flashcards
1
Q
Describe internal respiration
A
Gas exchange that occurs at between the tissues and system capillaries
2
Q
Describe the path of air entering the nose beginning with the nasal cavity and ending with the main stem bronchi
A
Nasal cavity
Nasopharynx
Oropharynx
Hypopharynx/laryngopharynx
Larynx
Trachea
Main stem bronchi
2
Q
Describe external respiration
A
Gas exchange that occurs in the lungs between the pulmonary capillaries and the alveoli
3
Q
What are the functions of the nose?
A
Warm air
Humidify air
Filter air
Smell
Resonance in speech
4
Q
What structure in the nose facilitates the warming and humidification of incoming air? how?
A
Nasal conchae
They increase the surface area of the nasal cavities
5
Q
How many pairs of tonsils are there? What are their names?
A
4 pairs
Lingual
Palatine
Tubal
Adenoid
6
Q
Describe the paranasal sinuses
A
Air filled cavities
4 pairs
Light head
Provide vocal resonance
7
Q
What is the function of the tonsils?
A
Assist immune system with production of antibodies
8
Q
The adenoid tonsils can also be called what?
A
Pharyngeal tonsils
8
Q
what anatomical landmark divides the upper and lower airways
A
Vocal cords
9
Q
What is the cartilage structure below the thyroid cartilage?
A
The cricoid cartilage=
9
Q
What is the structure that connects the thyroid cartilage and the cricoid cartilage?
A
The cricothyroid ligament
10
Q
Where do the lower airways begin?
A
With the true vocal cords
11
Q
What is the difference between conducting airways and respiratory airways?
A
Conducting airways facilitate ventilation
Respiratory airways support external respiration
12
Q
List the conducting airways
A
larynx
Trachea
Main stem bronchi
Lobar bronchi
Segmental bronchi
Subsegemental bronchi
Small bronchi
Bronchioles
Terminal bronchioles
12
Q
List the respiratory airways
A
Respiratory bronchioles
Alveolar ducts
Alveolar sacts
Alveolus
13
Q
What happens to the airways as they branch?
A
Airways become progressively shorter, narrower and more numerous
Cross sectional area enlarges
14
Q
What is the difference between the right and left main stem bronchus?
A
The RMS is shorter, wider and more vertical
The LMS is narrower, longer, and more horizontal
15
Q
The RMS divides into what?
A
Upper lobar bronchus
Middle lobar bronchus
Lower lobar bronchus
16
Q
The LMS divides into what?
A
Upper lobar bronchus
Lower lobar bronchus
17
Q
Describe cartilaginous airways in regards to their function and which airways have cartilage
A
Are strictly conducting airways, no gas exchange
Consist of trachea, main stem bronchi, lobar bronchi, segmental bronchi, and subsegmental bronchi
Small bronchi are the last generation of airways that contain cartilage
18
Q
Describe noncartilaginous airways in regards to their function and which airways do not have cartilage
A
Can be conducting airways and respiratory airways
Small bronchi are the first to not have cartilage
19
Q
What is the main function of cartilage in the airways?
A
Structural integrity
Prevent airway collapse
19
Q
With no cartilage, how do smaller airways stay open?
A
Pressure gradients
Alveoli have surfactant
20
What is the first generation of airways where cartilage is absent?
Bronchioles
21
Describe the cartilage found in small bronchi compared to the cartilage found in larger airways
Smaller airways have cartilage plates whereas larger airways have cartilage rings
22
At what point do cilia and mucous glands such as goblet cells no longer appear?
Terminal bronchioles
23
Where is smooth muscle found in the airways?
From the trachea to the terminal bronchioles
23
What airway marks the beginning of the respiratory zone?
Respiratory bronchioles
23
What airway marks the end of the conducting zone?
Terminal bronchioles
24
Define an acinus
An acinus is the term for the group of structures that arise from a single terminal bronchiole
24
Describe the atrium in terms of the lungs
The space at the entrance from the alveolar duct to an alveolar sac
25
Beginning with the terminal bronchiole, list the subsequent structures ending with the alveoli
Terminal bronchiole
Respiratory bronchiole
Alveolar duct
Alveolar sac
Alveous
26
ow often do cilia strike the gel layer?
About 15 times a second
26
What are the two distinct layers of the mucus blanket?
Sol layer
Gel layer
27
How fast can the mucociliary escalator move the mucus blanket
About 2 cm per minute
28
Describe the sol layer
Low viscosity mucus that allows the cilia to move through it quickly
From submucosal bronchial glands
29
Describe the gel layer
High viscosity mucous on top of the sol layer
Catches particulates for transport and expectoration
From goblet cells
30
Which airways do goblet cells disappear in?
At the end of the terminal bronchioles
31
What environmental factors can inhibit the mucociliary escalator?
Cigarette smoke
Dehydration
Pollutants
32
What iatrogentic effects can inhibit the mucociliary escalator
Hypoxia
General anesthesia
Parasymptholytic drugs
Positive pressure ventilation
Endotracheal suctioning
High FiO2
33
escribe pseudostratified epithelium
Appear to have several layers while being one layer
Each cell touches basement membrane
34
Describe the lamina propria
A thin layer of connective tissue that lies beneath the epithelium
34
Where is pseudostratified columnar epithelia found?
From the trachea until the until the terminal bronchioles
Cilia are absent in the respiratory bronchioles
35
What cells and tissue make up the mucosa?
Epithelium
Cilia
Pseudostratified columnar epithelium
Goblet cells
Basement membrane
Lamina propria
36
Describe the adventitia
A sheath of connective tissue that surrounds the airways
Interspersed with bronchial arteries, bronchial veins, nerves, lymphatic vessels and adipose tissue
37
Describe type 1 pneumocytes
Large flat (squamous) cells that make up the majority of the alveolar wall
Major site of gas exchange
38
Describe type 2 cells
Cuboidal cells that secrete surfactant
Have microvilli
surfactant made by lamellar bodies
39
Describe type 3 pneumocytes
Alveolar macrophages
Remove bacteria and foreign particles
Migrate as monocytes through the blood and into the alveoli
40
List the layers that an oxygen molecule would go through as it traveled from the alveolus to the pulmonary capillary
Surfactant layer
Liquid layer
Type 1 pneumocyte
Epithelial basement membrane
Interstitium
Endothelial basement membrane
Endothelial cell
Plasma
RBC
41
Describe collateral ventilation
Collateral ventilation is the ventilation of alveolar structures through passages or channels that bypass the normal airways when airways are restricted or obstructed
42
What are the three types of collateral ventilation?
Pores of kohn
Canals of lambert
Channels of martin
43
escribe the pores of kohn
Small holes between adjacent alveoli
Alveoli to alveoli ventilation
44
Describe canals of lambert
Collateral airways between respiratory bronchioles and adjacent alveoli
Provide ventilation between various airways within the acinus and between adjacent acini
45
Describe the channels of martin
Found between respiratory bronchioles within the acinus
Found between respiratory bronchioles and terminal bronchioles of adjacent segments
Bronchiole to bronchiole
46
What part of the type 2 cells secrete surfactant
Lamellar bodies
47
Describe the AC membrane
A thin tissue barrier through which gases are exchanged between the alveolar air and the blood in the pulmonary capillaries
48
hat is the role of surfactant in the alveoli?
To reduce surface tension and prevent alveolar collapse
49
What kind of things are located in the interstitial space?
Connective tissue
Collagen fibers
Fibroblasts
Interstitial fluid
Macrophages
Lymphatic vessels
50
What are the structures that form the thoracic cavity?
Ribcage
Intercostal muscles
vertebra l column
Sternum
Diaphragm
51
In basic terms, what does the thoracic cavity contain?
The organs of ventilation, respiration and circulation
52
What are the 3 sections that make up the sternum?
Manubrium
Body
Xiphoid process
53
How many true ribs are there?
Ribs 1-7 are true ribs
54
How many ribs are considered false ribs
8,9,10 are false ribs
55
Which ribs are considered floating ribs?
11 and 12
56
What is the function of the costal groove?
The costal groove serves as a protective channel for nerves, arteries and veins on the underside of the rib
57
When inserting needles into the chest wall, where should they be aimed?
Aimed above the rib to prevent damage to nerves and vessels
58
What is a potential downside of collateral ventilation?
Potentially allows disease to spread quickly through the lung tissue
59
When performing CPR, what are the risks of compressing too low on the sternum?
The xiphoid process projects downward between the ribs. Placing the hands over it during CPR could result in contusions or puncturing of the underlying organs
60
What bones form the sternal angle or angle of louis?
The angle of louis is formed by the articulation of the manubrium with the body of the sternum
61
Where is the angle of louis in relation to costal cartilage?
Lies at the level of the second costal cartilage
62
What is the angle of louis used for?
It is the point from which all costal cartilages and ribs are counted because the first rib is under the clavicle and cannot be felt
63
What is the relative position of the angle of louis to the vertebrae?
Lies opposite of the vertebral disc between T4 and T5
64
What anatomical landmark serves as a reference point for the approximate location of where an ETT should be placed?
Sternal angle or angle of louis
65
Describe pump handle movement of the ribs
Viewing the ribs from the side, the movement of the ribs and the sternum during inspiration is up and out, which mimics the movement of a pump handle
66
Describe bucket handle movement
Viewing from the front, during inspiration the ribs move up and out similar to how a bucket handle would move
66
What do the pump handle and bucket handle movements facilitate?
They facilitate a change in the volume of the thoracic cavity which aids in inspiration and expiration
67
What do you call the opening at the top of the rib cage?
Superior thoracic outlet
Thoracic inlet/outlet
68
What do you call the opening at the bottom of the rib cage?
Inferior thoracic aperture
69
What is the function of the fluid in the pleural space?
To allow frictionless sliding between the pleura during ventilation
69
How is the fluid in the pleural space regulated?
Involves a balance between leakage from systemic and pulmonary capillaries and drainage by lymphatic vessels
70
Define a pneumothorax
An abnormal collection of air in the pleural space between the lung and the chest wall
71
What are the signs of a pneumothorax?
Absent or decreased breath sounds
Tracheal deviation away from affected side
Hyperresonance
Tachycardia
Hypotension
Increased PIP/MAP if on MV
72
What are the symptoms of a pneumothorax?
Acute onset chest pain
Acute onset SOB
73
What is the difference between a tension and a simple pneumothorax
A matter of degree
A tension pneumothorax will have more air infiltrating the pleural space and will be putting pressure on the heart decreasing venous return
74
If you were to look at an xray of a patient with a pneumothorax, the what would it look like?
The side with the pneumo would be black
75
What is a pleural effusion?
A build up of fluid in the pleural space
76
What kinds of fluid can be in the pleural space?
Plasma
Blood
Pus
77
What is transudate a result of?
An imbalance between oncontic and hydrostatic pressure resulting in fluid build up
Can result from congestive heart failure, renal failure or cirrhosis
78
What is exudate a result of?
Typically inflammatory conditions such as infections or pneumonia
79
What is the difference in the content of transudative and exudative fluid
Trasudative = low in protein and LDH
Exudative = high in protein and LDH
79
How do you treat a pleural effusion?
Thoracentesis to drain the fluid
80
List the structures found within the mediastinum
Trachea
Main stem bronchi
Heart
Pericardium
Great vessels leading into and out of the lungs
Esophagus
Vagus and phrenic nerves
thymus , lymph nodes, fat and connective tissue
Azygos and hemiazygos veins
81
What is located in the anterior portion of the mediastinum?
Lymph Nodes, fat, connective tissue, remnants of thymus
82
What is in the middle section of the mediastinum?
Pericardium, heart, bronchi, roots of great vessels
83
What is in the posterior section of the mediastinum?
Esophagus, thoracic aorta, azygos and hemiazygos veins, vagus nerve
84
Describe the hilum
The only place where the lungs are truly attached to the body
Area where main stem bronchi and great vessels enter lungs
85
What is the primary muscle of ventilation?
The diaphragm
86
What bones does the diaphragm attach to?
Vertebrae, ribs, xyphoid process
87
What is the name of the fibers within the diaphragm that form a broad connective sheet?
The central tendon
88
What does the diaphragm do during inspiration? Expiration?
Flatten
Returns to dome shape
88
T/F: The diaphragm is slightly elevated on the right side of the body because of the stomach
False. The diaphragm is slightly elevated on the right side because of the right lobe of the liver
89
What nerve controls the diaphragm?
The phrenic nerve
90
Where does the phrenic nerve exit the spinal column? Why is this relevant?
The phrenic nerve exits at C3-C5
Fractures between C1-C5 are likely to disrupt the phrenic nerve and compromise the ability to breathe
91
The phrenic nerve controls what?
The diaphragm
92
What are the accessory muscles of inspiration?
The external intercostals
Scales
Sternocleidomastoids
Pec major
Traps
93
What are the accessory muscles of exhalation
Internal intercostals
Abdominals (rectus abdominus, ext oblique, int oblique, transverse abdominus)
94
Describe the external intercostals role in inspiration
Lift rib cage causing pump handle and bucket handle movements which increase the volume of the thoracic cavity
95
Where do the scalene muscles attach?
The cervical spine and the first and second rib
96
Where do the sternocleidomastoid muscles attach?
The mastoid process, clavicle and manubrium
97
What are the 4 volumes that make up total lung capacity?
Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Residual volume
98
Describe tidal volume
Normal resting quiet breathing
The volume of air that is inhaled or exhaled in a single breath (usually about 500 mL)
99
Describe inspiratory reserve volume
The maximum amount of additional air that can be drawn into the lungs with best effort after normal inspiration
100
Describe expiratory reserve volume
The additional amount of air that can forcibly be exhaled from the lungs by determined effort after normal expiration
101
Describe reserve volume
The amount of air left in the lungs after a forced exhalation
Note, this volume cannot be directly measured, only calculated
102
What are the 4 lung capacities?
Total lung capacity
Inspiratory capacity
Vital capacity
Functional residual capacity
103
Describe total lung capacity
The volume of air contained in the lungs at the end of maximal inspiration
104
The volume of air contained in the lungs at the end of maximal inspiration is called what?
Total lung capacity
105
What volumes make up total lung capacity?
VT+IRV+ERV+RV
106
Describe inspiratory reserve capacity
The maximum volume of air that can be inspired after reaching the end of a normal quiet expiration
107
The maximum volume of air that can be inspired after reaching the end of normal quiet expiration is called what?
Inspiratory reserve capacity
108
What volumes make up inspiratory reserve capacity
IRC = VT+IRV
109
Describe vital capacity
The great volume of air that can be expelled from the lungs after taking the deepest possible breath
110
What volumes make up vital capacity?
VC = IRV + VT + ERV
110
The greatest volume of air that can be expelled from the lungs after taking the deepest possible breath is called what?
Vital capacity
111
Describe Functional Residual capacity
The volume of air present in the lungs at the end of passive expiration
112
What volumes make up FRC?
FRC = ERV + RV
113
The results of a pulmonary function test are dependent upin what?
The quality of instruction and coaching on the part of the clinician doing the testing
The ability to obtain and document multiple reproducible results
The patient giving their best effort during testing
114
T/F: Exhalation is a passive process in healthy individuals
True
115
Bronchospasms and increased secretions in the airways result in what?
Increased resistance to airflow
Increased work of breathing
116
What disease processes decrease the compliance of the lung tissue?
Interstitial lung diseases
Atelectasis
Fluid build up - pneumonia, pleural effusions
117
Increased resistance to airflow can be caused by what?
Bronchoconstriction
Bronchospasms
Secretions
118
Interstitial lung diseases such as pulmonary fibrosis and pneumonia do what to lung tissue?
Decrease compliance
119
Post op patients who have had major abdominal surgery tend to guard against deep breathing and painful abdominal movements. What can this potentially result in?
Secretion retention
Mucus plugging
Atelectasis
Pulmonary infection
120
The tendency of an object to return to its original shape after being deformed is referred to as what?
Elasticity or elastance
121
Define elasticity
The tendency of an object to return to its original shape after being deformed
122
Why do healthy lungs recoil inward?
Surface tension forces
Elastin in the walls of alveoli and within interstitium
122
Surface tension forces within the alveoli along with elastin in the walls of the alveoli and interstitium result in what?
Elastic recoil of the lungs away from the chest wall
123
At the same time the lungs are recoiling away from the chest wall, what is the chest wall doing?
The chest wall is recoiling away from the lungs
124
What is the point at which the lungs and chest wall balance each other?
End exhalation-
125
What determines FRC?
The balance point between inward lung recoil and outward chest wall recoil
125
The balance point between inward lung recoil and outward chest wall recoil determines what?
The FRC
126
What comprises the FRC?
ERV and RV
Expiratory reserve volume and Residual volume
127
What capacities are affected by a decrease in lung recoil force?
FRC (functional reserve capacity) is decrease
IC (inspiratory capacity) is decreased
128
An increase in FRC and a decrease in IC could be a result of what?
A decrease in lung recoil force
129
What capacities are affected by an increase in lung recoil force?
FRC is decreased
TLC is decreased
VC is decreased
130
Why does decreased FRC translate into and increased WOB?
Low FRC means that the lung volume at the of of normal exhalation is abnormally low implying that some alveoli are airless and collapsed
Collapsed alveoli strongly oppose inflation because of high surface tension
To open alveoli, patients have to breath harder to generate more pressure to expand the alveoli which increases the WOB
131
Why are collapsed alveoli difficult to inflate?
Surface tension is difficult to overcome
132
A decrease in the FRC could mean what?
Collapsed alveoli (atelectasis)
133
Collapsed alveoli do what to compliance?
Decrease compliance
133
Describe ventilation
Ventilation is the movement of gas into and out of the lungs which allows oxygen to enter the body and carbon dioxide to be removed
134
This process involves the movement of gas into and out of the lungs which allows oxygen to enter the body and carbon dioxide to be removed.
Ventilation
135
Describe tidal volume
The normal amount of air moving into and out of the lungs with each breath
Air dis[placed between normal inhalation and exhalation when extra effort is not applied
Healthy adult tidal volume is about 500 mL
136
What is the average tidal volume for a healthy adult?
About 500 mL
137
Describe minute ventilation
Defined as the total amount of air that moves into and out of the lungs in a minutes time
138
How is minute ventilation measured?
Typically measured via exhaled gas
Function of tidal volume x frequency
139
The region of the upper airway and the conducting zone is called what?
Anatomic dead space
140
Anatomic dead space is defined as what?
The region of the upper airway and conducting zone that does not participate in gas exchange
141
How can anatomical dead space be calculated?
Determined by calculating the ideal body weight in pounds
142
The IBW in pounds relates to what?
Anatomical dead space
143
Dead space ventilation is defined as what?
Movement in and out of the upper airways and conducting zone
144
Why are the areas that comprise the upper airways and conducting zone characterized as dead space?
They do not participate in gas exchange
144
What is the formula for IBW?
Males = 110+(5 x height in inches over 5 feet)
Females = 100 + (5 x height in inches over 5 feet)
145
Describe alveolar ventilation
Occurs in the respiratory zone
Movement of gas into and out of the region of the airways that includes the respiratory bronchioles alveolar ducts and alveoli
146
What is the formula for finding alveolar ventilation?
Alveolar ventilation = tidal volume - anatomical dead space
147
Describe the relationship between minute ventilation and carbon dioxide
Increased minute ventilation = decreased carbon dioxide
Decreased minute ventilation = increased carbon dioxide
148
Describe alveolar dead space
Occurs when the blood flow to the pulmonary capillary is compromised and gas exchange cannot take place
The volume of air in the lungs that is ventilated but not perfused
149
In its simplest form, dead space is…
Ventilation without perfusion
150
Obstructions to pulmonary capillaries result in what?
Alveolar dead space
151
Will gas exchange take place if blood flow to a pulmonary capillary is compromised?
No.
This results in alveolar dead space ventilation
152
What could a pulmonary embolus cause?
Obstruction of the pulmonary capillary and the creation of alveolar dead space and alveolar dead space ventilation
153
Alveolar dead space could be caused by what?
Obstruction in the pulmonary capillary-pulmonary embolus
154
Describe physiologic dead space
Anatomical dead space + alveolar dead space
155
The combination of anatomical dead space and alveolar dead space creates what?
Physiologic dead space
Physiologic dead space = anatomical dead space + alveolar dead space
156
The volume of air in the conducting zone that is ventilated but not perfused is called what?
Alveolar dead space
157
How do you calculate anatomical dead space?
By calculating the ideal body weight in pounds
158
How do you calculate tidal volume?
Ideal body weight in kg x 6-8 mL/kg (dependent on patient)
159
What does the alveolar air equation tell us?
The partial pressure of a oxygen in the alveoli
160
Give the formula for the alveolar air equation
PAO2 = FIO2 (PB-PH2O) - PaCO2/RQ
PAO2 = partial pressure of oxygen in alveoli
FiO2 = fraction of inspired oxygen
PB = barometric pressure (usually 760 mmHg)
PH2O = barometric pressure of water (usually 47 mmHg)
PaCO2 = partial pressure of CO2 in arterial blood
RQ = respiratory quotient (0.8)
161
Where the actual fuck does the pulmonary circuit begin and end?
Begins where main pulmonary artery leaves RV
Ends where the 4 pulmonary veins dump blood into the left atrium
162
Where the fuck does the systemic circuit begin and end?
Starts with blood exiting the left atrium and entering the aortic artery
Ends with the superior and inferior vena cava dumping blood into the right atrium
163
What is valve stenosis?
A pathological narrowing or constriction of a valve outlet causing increase pressure in the proximal chamber and vessels leading into the proximal chambers
164
What does mitral valve stenosis cause?
High pressures in the left atrium back up into the pulmonary circulation which can lead to pulmonary edema
165
What does aortic valve stenosis cause?
High pressures in the left ventricle causes thickening of the wall of the left ventricle and eventually heart failure resulting in pulmonary edema
166
What causes rheumatic feve
Certain strains of streptococcal bacteria
Strep throat that isnt properly treated can trigger rheumatic fever
167
What is the risk associated with rheumatic fever?
Rheumatic fever can damage heart muscle and heart valves
167
How does rheumatic fever damage the heart valves? What is this called?
Bacterial growth on the heart valves and myocardium causing damage
Also known as subacute bacterial endocarditis
168
Subacute bacterial endocarditis is being seen in increasing numbers in what populations?
IV substance users
169
What is the term for the first heart sound and what does it indicate?
S1 = lub
Closure of the tricuspid and mitral valves
170
What is the term for the second heart sound and what does it indicate?
S2 = dub
Closure of the semilunar valves
171
Myocardial infarction, compromised electrical conduction in the heart and congestive heart failure could all be generally categorized as what?
Heart attack
172
Heart attack is a colloquial term that could refer to:
Myocardial infarction (most likely)
Compromised electrical conduction in the heart
Congestive heart failure
173
Describe the physiological conditions that lead to coronary artery disease
Occurs when the lumen of one or more coronary arteries narrows limiting the flow of oxygen rich blood to surrounding heart muscle tissue
Can lead to myocardial infarction
174
Narrowing of the lumen in the coronary arteries will reduce the flow of oxygen rich blood to the heart. What is this disease process called and what can it lead to?
Coronary artery disease
Myocardial infarction
175
Describe cholesterol
A waxy substance produced and released into the bloodstream by cells in the liver
176
A waxy substance produced and released into the bloodstream by cells in the liver
Cholesterol
177
Describe plague
Build up of LDL cholesterol and other substances in the walls of the coronary arteries
178
A build up of LDL cholesterol on the walls of the coronary arteries is called what?
Plaque
179
Describe atherosclerosis
Condition that leads to walls of the coronary arteries becoming thick and stiff as a result of the build up of plaque on the artery walls which can lead to the blockage of the artery and myocardial infarction
Can also be called CAD
180
A condition that leads to the walls of the coronary arteries becoming thick and stiff as a result of the build up of plaque on the artery walls
Atherosclerosis
181
Define arteriosclerosis
Loss of elasticity of coronary arteries caused by atherosclerosis
181
The loss of elasticity in the coronary arteries is called what? What is it caused by?
Arteriosclerosis
Atherosclerosis
182
What is a stationary blood clot called?
A thrombus
183
What is a thrombus?
A stationary blood clot
184
What is an embolus?
A mobile blood clot
185
A mobile blood clot is called what?
An embolus
186
Describe myocardial ischemia
Reduced blood and oxygen delivery to the tissue
187
The reduction of blood flow and oxygen delivery to tissues
Myocardial ischemia
188
Describe a myocardial infarction
Blood supply to the heart muscle is totally blocked or severely reduced resulting in the death of heart tissue
189
The death of heart tissue as a result of decreased or blocked blood flow is called what?
A myocardial infarction
190
What is angina?
Chest pain resulting from myocardial ischemia
191
What is a coronary artery bypass CABG?
A surgical intervention which attempts to bypass obstructions caused by CAD
192
A surgical intervention which attempts to bypass obstructions caused by CAD
CABG
193
Pain felt beneath the sternum and radiating the left or right arm, neck or jaw is referred to as what? What is the cause?
Angina pectoris
Results from decrease flow of oxygen to myocardial tissue aka myocardial ischemia
194
When does angina occur?
When the myocardium doesnt get the required blood and oxygen supply necessary to meet its demand, may occur during periods of physical exertion and go away after rest = stable angina
195
What is reversible or stable angina?
Occurs when heart works harder and needs more oxygen and goes away when oxygen demand is decreased
196
What is progressive or unstable angina?
Occurs when a plague in one or more coronary arteries ruptures
197
Describe the initial stages of atherosclerosis
LDL deposits in the artery wall
Macrophages engulf the invading cholesterol
Macrophages become full of cholesterol and as more macrophages collect in the area, they form a fatty streak between the tunica media and tunica intima which can develop into a plaque which pushes the intima into the lumen reducing blood flow
198
What does the plaque develop over time?
A fibrous coating on its outer edge
199
What can happen if cholesterol continues to collect in foam cells?
If cholesterol continues to collect in foam cells, the fibrous outer coating can weaken and eventually rupture resulting in smaller downstream arteries becoming blocked
200
What can happen at the rupture site if the problem is not addressed?
The rough surface of the rupture can cause RBCs to adhere to it and form a clot which could completely block the artery
201
Describe Low density Lipoproteins
LDL cholesterol joins with fats and other substances to build up in the inner walls of your arteries. These are necessary for carrying cholesterol throughout the body, but too many of them can lead to CAD
202
Describe high density lipoproteins
HDL remove cholesterol from the blood stream and the artery walls. A high HDL count is desirable because it reduces you chances of strokes and CAD
203
What is considered a good HDL level?
Ideal is 60 or higher
Men = 40 or higher is acceptable
Women = 50 or higher is acceptable
204
What is considered a good LDL level?
Less than 100, preferably below 70 if coronary artery disease is present
205
What is considered to be a high LDL level?
160 or higher
190 considered to be very high
206
What is a good triglyceride level?
Less than 149, ideal is less than 100
207
What is considered a high triglyceride level?
200 or higher with 500 considered to be very high
208
Where do atherosclerotic plaques form?
Between the tunica media and the tunica intima
209
What comprises a total cholesterol score?
HDL + LDL + Triglycerides
210
What class of drugs are used to lower cholesterol?
Statins
210
How do statins treat high cholesterol?
Statins disrupt the production of cholesterol by blocking an enzyme in the liver cells which decreases the amount of cholesterol being released into the bloodstream
Some statins reduce the inflammatory response process in the vessel wall resulting in fewer macrophages going to phagocytose the invading cholesterol resulting in fewer foam cells and plaque which results in the plaques growth slowing or stopping and preventing the rupture and subsequent formation of a clot
211
When can collateral circulation reduce the risk of myocardial infarction?
If the narrowing or coronary arteries progresses gradually over a long period of time, collateral circulation develops to supply ischemic areas and reduce the risk of MI
Does not have a major effect in cases where narrowing occurs rapidly either due to plaque rupture or clot formation
212
What are non modifiable/internal risk factors for CAD by atherosclerosis?
Age
Gender (women pre menopause have a hormonal advantage)
Family history of coronary artery disease (relative with MI before 40)
Male pattern baldness
213
What are some of the tests that can be performed in order to diagnose CAD?
Electrocardiogram
Echocardiogram
Exercise stress test
Nuclear stress test
Cardiac catheterization and angiogram
Cardiac CT scan
214
Describe an angiogram
A catheter is placed in the coronary arteries via the femoral or brachial artery
One placed, a radio opaque dye is injected via the catheter into the blood stream
Pictures are taken via a specialized xray machine in a process called fluoroscopy which will show areas of narrowing in the arteries
215
What are some modifiable risk factors for CAD caused by atherosclerosis?
Smoking or tobacco use
High cholesterol levels
Diabetes
Hypertension
Obesity
Psychosocial stress
Sedentary lifestyle
Reduced consumption of fruit and vegetables
Poor oral hygeine
Type A personality
Presence of peripheral vascular disease
216
What non-atherosclerotic factors could cause an MI?
Coronary artery occlusion secondary to vasculitis
Cardiomyopathy
Coronary trauma
Primary coronary vasospasm (can be linked to stimulant use)
Coronary anomalies including aneurysms of coronary arteries
Factors that increase oxygen requirement or decrease oxygen deliver
Aortic dissection
217
Describe stenosis
Valve tights and slows blood flow beyond the valve making it harder for the heart to pump blood
Caused by calcium build up or scarring of the valve tissue
218
What is the most common cause of cardiac regurgitation?
Valve prolapse
The leaflets of the mitral valve bulge = prolapse into the left atrium
219
What is regurgitation?
Valve doesnt close tightly enough or is prolapsed allowing blood to leak backward leading to a fluid build up
220
Describe rheumatic heart disease
A condition where the heart valves have been permanently damaged by rheumatic fever
Damage may occur shortly after an untreated streptococcal infection occurs resulting in an inflammatory response by the body which can cause ongoing damage
221
What part of the heart is most commonly rheumatic heart disease?
The mitral valve is most commonly affected valve in 50-60% of cases
Aortic and mitral valves only make up 20% of cases
222
Rheumatic fever can be the cause of what valve pathologies?
Stenosis
Regurgitation
223
A life threatening condition which results in inflammation in the inner lining (endocardium) chambers and valves
Endocarditis
224
Describe endocarditis
A life threatening inflammation of the endocardium chambers and valves
225
What causes endocarditis?
Bacterial infections that enter the bloodstream, travel to the heart and lodge on heart valves or heart tissue
Bacteria form growths called vegetations on the valves that cause leaking and damage
226
What are the risk factors for endocarditis?
IV drug use, poor dentation, in-dwelling catheter, artificial heart valves
227
How does a cardiac catheterization work?
Examines the inside of coronary arteries via angiogram
Catheter is inserted through the femoral or brachial artery and into the coronary arteries via the aorta
One catheter is in place, a radiopaque contrast dye is injected via catheter into the bloodstream
Specialized x ray machine takes a series of images in a process called fluoroscopy which shows areas of narrowing in the arteries
228
Describe what an angioplasty does
Opens blocked arteries and restores normal blood flow to the myocardium
Opens clogged artery by inflating a tiny balloon in it
Often combined with implantation of a stent to help prop open the artery and decrease the chance of another blockage
229
Describe the process of CABG
Creates new pathways for blood and oxygen to be delivered to the myocardium
Done by harvesting arteries or veins (usually mammary or saphenous veins) and using them to reroute blood around blocked coronary arteries
230
What is a coronary artery stent?
A tiny wire mesh tube used to prop open an artery during angioplasty
Stays in permanently
Frequently contain drugs that have a slow release time and are meant to prevent clot formation
231
What are lifestyle changes that reduces the risk of CAD?
Healthy diet
Regular exercise
No smoking
Reduce stress
Lose weight
232
What are medications that treat CAD?
Cholesterol modifiers
Aspirin
Beta blockers
Calcium channel blockers
Angiotensin converting enzyme (ACE) inhibitors
Angiotensin II receptor blockers
Nitroglycerin
Ranolazine
Clot busters
233
What are procedures that can restore and improve blood flow in the coronary arteries?
Cardiac catheterization
Angiogram
Angioplasty
Stent placement
234
What surgical intervention is used to treat CAD?
CABG or angioplasty with stent placement
235
Define total lung capacity
The volume of air in the lungs upon the maximum effort of inspiration
236
What is the TLC in the average health adult?
6 L
236
What volumes make up TLC
Inspiratory reserve volume
Resting tidal volume
Expiratory reserve volume
Residual volume
237
Describe tidal volume
The lung volume representing the normal volume of air displaced between normal inhalation and exhalation when extra effort is not applied
238
What is the average tidal volume in a healthy young adult?
About 500 mL
239
Describe inspiratory reserve volume
The maximal amount of additional air that can be drawn into the lungs with best effort after normal inspiration
240
The maximal amount of additional air that can be drawn into the lungs with best effort after normal inspiration
Inspiratory reserve volume
241
Describe expiratory reserve volume
The additional amount of air that can be forcibly exhaled from the lungs by determined effort after a normal expiration
242
The additional amount of air that can be forcibly exhaled from the lungs by determined effort after normal expiration
Expiratory reserve volume
243
Describe residual volume
The amount of air left in the lungs after a forced exhalation
Note: this volume cant be measured, only calculated
244
What is the amount of air left in the lungs after a forced exhalation?
Residual volume
245
What are the four lung volumes that make up total lung capacity?
Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Residual volume
246
Describe inspiratory capacity
The maximum volume of air that can be inspired after reaching the end of a normal quiet expiration
IC = VT + IRV
247
The maximum volume of air that can be inspired after reaching the end of normal quiet expiration
Inspiratory capacity
247
Describe vital capacity
The greatest volume of air that can be expelled from the lungs after taking the deepest possible breath
VC = IRV + VT + ERV
248
The greatest volume of air that can be expelled from the lungs after taking the deepest possible breath
Vital capacity
249
Describe functional residual capacity
The volume of air present in the lungs at the end of passive expiration
At FRC the opposing elastic recoil forces of the lungs and chest wall are in equilibrium and there is no exertion by the diaphragm or other respiratory muscles
FRC = ERV + RV
250
What volumes make up inspiratory capacity?
IRC = VT + IRV
251
What are the volumes that make up vital capacity?
VC = IRV + VT + ERV
251
What are the volumes that make up Functional residual capacity?
FRC = ERV + RV
252
What effect can obesity have on breathing?
A very large abdomen can impede downward diaphragmatic movement during inspiration, decreasing inspired volume and possible causing chronic underventilation
253
What can shallow breathing in post op patients result in?
Secretion retention
Mucus plugging
Atelectasis
Pulmonary infection/pneumonia
254
What is hemodynamics?
Pressure, flow, and volumes of blood traveling through the vascular system
254
Where does the systemic circuit begin and end?
The systemic circuit begins where aorta leaves the left ventricle
The systemic circuit ends with the superior and inferior vena cava and coronary sinus dump into the right atrium
255
Where does the pulmonary circuit begin
The pulmonary circuit begins as blood leaves the right ventricle and enters the pulmonary arteries
The pulmonary circuit ends where the pulmonary veins dump the blood into the left atrium
256
Define blood pressure
The amount of pressure exerted against the inside walls of the blood vessels as blood travels throughout the systemic and pulmonary circuits
257
Define systolic blood pressure
The amount of pressure exerted against the inside walls of the arteries when the heart contracts
258
What factors control blood pressure?
Heart
Blood
Vessels
258
If there is an increase in heart rate, how will blood pressure be affected?
It will increase
259
If there is a decrease in heart rate, how will blood pressure be affected?
It will decrease
260
How does contractility affect blood pressure?
Increase contractility = increased blood pressure
Decreased contractility = decreased blood pressure
261
How does the blood influence blood pressure?
Amount of blood influences the blood pressure
Can be altered by altering fluid level (IV, diuretics)
262
How do the vessels influence blood pressure?
Vessel diameter influence blood pressure
Vasoconstriction = increased BP
Vasodilation = decreased BP
263
Define diastolic blood pressure
The amount of pressure exerted against the inside walls of the arteries when the heart is at rest
264
What is the formula for mean systemic arterial pressure?
SAP = systolic pressure + 2(diastolic pressure) / 3
265
What is the normal range for mean system arterial pressure?
Normal is about 92 mmHg
266
How do you measure systemic blood pressure?
Blood pressure cuff
Indwelling arterial line
267
What is the normal range for blood pressure?
<120/<80
268
What is the prehypertension range for blood pressure?
120-139 / 80-89
269
What is the Stage 1 hypertension range for blood pressure?
140-159 / 90-99
270
What is the stage 2 hypertension range for blood pressure?
>160 / >100
271
What is the normal range for pulmonary arterial pressure?
30-15 / 15-5
272
What is the normal range for mean PAP?
8 -20 mmHg
272
How can you measure PAP?
Pulmonary artery catheter
Echocardiogram
Transesophageal echocardiogram
273
Describe the ejection fraction?
The percent of the LVEDV that is ejected during systole
274
What is LVEDV?
Left ventricle end diastolic volume
275
What is LVEDP?
Left ventricle end diastolic pressure
276
What is the normal range for the ejection fraction?
50-65%
277
Describe stroke volume
Volume of blood ejected from left ventricle during systole in mL
278
Describe Cardiac output
The amount of blood the heart pumps out per minute
279
What is the normal range for cardiac output?
4-8 L/m
280
Why might we reduce the cardiac output in post op patients?
We want to decrease the amount of pressure being applied to the newly grafted arteries after a CABG surgery
281
What is the cardiac index?
A method that factors in cardiac output and body size to narrow down the acceptable range for a patient
282
What is the formula for cardiac index
CI = Cardiac output / body surface area
283
How do you calculate stroke index?
cardiac index/heart rate
284
How do you calculate stroke volume index?
SV/BSA
285
Describe the path of the action potential as it travels through the heart
Sinoatrial node
Atrioventricular node
Bundle of His
Common bundle branches
Right and left bundle branches
Purkinje Fibers into myocardium
286
What is the “pacemaker” of the heart?
The sinoatrial node
Sets intrinsic rate of contraction of 60-100 BPM
287
If the SA node is compromised, what takes over as the pacemaker?
The atrioventricular node
Sets intrinsic rate of 40-60 BPM
288
What are the SA node and AV node made o
Specialized nodal tissues that can generate impulses and set HR
289
Under normal conditions, the AV node is suppressed by what?
The SA node
Overdrive suppression
290
The AV node slows the intrinsic rate set by the SA node. Why?
Allows time for ventricular filling
291
Sometimes impulses are generated from abnormal regions of the heart. What are these referred to as?
Ectopic foci
292
What is automaticity?
The unique ability of the cardiac muscle to intrinsically initiate a spontaneous electrical impulse
These spontaneously triggered impulses are conducted through the myocardium which triggers the heart muscle to contract
293
What are the four defining features of the heart?
Automaticity
Conductivity
Excitability
Contractility
293
Describe excitability
The ability of cells to respond to electrical, chemical or mechanical stimulation
294
Imbalances in electrolytes as well as certain drugs can increase excitability in myocytes. What can this lead to?
Dysrythmias
295
Why cant cardiac contractions be sustained?
Because they would kill you. Wishful thinking at this point’
Cardiac contractions cannot be sustained because myocardial tissues is characterized by a prolonged period of inexcitability after contraction
296
What is the period during which the myocardial tissue is inexcitable called?
The refractory period
297
What is contractility?
The ability to shorten muscle fibers
298
Define afterload
The amount of resistance offered by the vasculature to the outflow of blood as it tries to leave the the ventricles
299
Define preload
The stretch placed on the myocardium after diastole
300
How do we measure preload in the right heart?
By measuring central venous pressure
301
How do we measure preload in the left heart
By measuring pulmonary capillary wedge pressure
302
How do we determine afterload in the right heart?
Pulmonary vascular resistance
303
How do we determine afterload in the left heart
By calculating vascular systemic resistance
304
How can we influence preload?
By influencing input and output
305
How can we increase preload?
Administer IV fluid
Crystaloids, colloids, blood products
306
How can we decrease preload?
Increase output
307
How can we manipulate afterload?
Give drugs that cause vasodilation/constriction
Introduce or eliminate fluids
308
Define hypoventilation
PaCO2 > 45 mmHg
309
Define Hyperventilation
PaCO2 < 35 mmHg
309
What does the S1 lub sound indicate?
Atrioventricular valves closings = systole
310
What does the S2 dub sound indicate?
Semilunar valve closure = diastole
311
What connects the right and left atrium in the fetal heart?
Fossa olvalis
312
Where does the coronary circuit begin? End?
The coronary os (ostia = plural)
Ends in coronary sinus
313
An abnormal build up of fluid in the pericardial cavity is called what?
Pericardial effusion
314
Between what layers of heart tissue does a pericardial effusion occur?
Parietal pericardium and visceral pericardium
315
The parietal pericardium, the visceral pericardium and the pericardial space make up what?
The serous pericardium
316
If you were to get stabbed in the heart, in what order would the knife penetrate the cardiac tissues starting with the fibrous pericardium
Fibrous pericardium
Parietal pericardium
Pericardial space
Visceral pericardium / epicardium
Myocardium
Endocardium
316
The visceral pericardium is also known as what?
Epicardium
317
A heart murmur could be caused by what?
Defects in the interventricular septum
318
On average, how much CO2 is produced per minute?
200 ml
319
On average, how much O2 is consumed per minute?
250 ml
319
How do we get the respiratory quotient?
CO2 produced/Oxygen consumed
Generally around .8
320
What is the correct term for slow, shallow breathing?
Hypopnea
321
What is the correct term for fast, deep breathing?
Hyperpnea
321
If a change in breathing pattern is said to have a physiologic cause, what does that mean?
Physiologic causes are factors that change respiratory patterns in order to meet metabolic demands of body tissues
Exercise, high altitude….anemia?
322
If a change in breathing pattern is said to have a pathologic cause, what does that mean?
Pathologic causes are factors that change respiratory pattern due to illness
Infection or sepsis
323
How do we determine if ventilation is effective?
Measuring PaCO2 and its effects on pH
324
What is the correlation between a change in pH and a change in PaCO2?
12 mmHg change in PaCO2 is results in a 0.1 change in pH
325
What does the VT/VD ratio tell us?
The VD/VT ratio provides an index of wasted ventilation per breath
326
What is the formula for calculating the VD/VT ratio?
(PaC02 - PECO2)/PaCO2
326
What is a normal VD/VT ratio?
0.2-0.4
327
What does a VD/VT ratio of 0.4-0.6 mean?
Indicates lung compromise
328
What does a VD/VT ratio of greater than 0.6 mean?
Indicates serious lung compromise
328
What is a normal PECO2?
28 mmHg
329
What is bronchial circulation a subset of?
Systemic circulation
330
Where does the bronchial circuit begin?
The descending thoracic aorta
331
What does bronchial circulation supply oxygenated blood to?
Walls of airways from mainstem bronchi down to the respiratory bronchioles
Visceral pleura
Pulmonary nerves
Mediastinal lymph nodes
Walls of pulmonary arteries and veins
332
Describe how 2/3rd of poorly oxygenated bronchial capillary blood returns to the heart
Blood drains in bronchial venules which anastomoses to pulmonary venules that eventually empty into pulmonary veins leading back to the left heart
333
Describe how 1/3rd of poorly oxygenated bronchial capillary blood returns to the heart
Bronchial submucosal and adventitial venules drain into bronchial veins which drain into the azygos and homozygous veins eventually returning to the right atrium
334
What is the significance behind the return route of 2/3rds of bronchial blood?
The poorly oxygenated blood from the bronchial circuit mixes with the well oxygenated blood of the pulmonary circuit which is then sent to the left circuit and then put into systemic circulation
This decreases the oxygen content of the pulmonary venous blood creating an anatomical shunt
335
What is an anatomical shunt?
Blood that does not have the opportunity to participate in gas exchange at the AC membrane
336
What is considered a normal anatomical shunt?
3-5%
337
What is the consequence of anatomical shunting?
Systemic arterial blood can never have the same partial pressure of oxygen as alveolar gas which gives rise to the normal alveolar to arterial oxygen difference
338
What are some examples of abnormal anatomical shunts?
Tetralogy of fallot
Pulmonary atresia
Transposition of the great arteries
Truncus arteriosus
339
What is the connection between bronchial vein depth and blood drainage?
Deep veins drain into the pulmonary veins
Superficial veins drain into the azygos and hemiazygos veins
340
What are thebesian veins?
Small cardiac veins that exist in the muscular walls of the heart and drain directly into the heart cavities
340
What is the impact of thebesian veins?
Thebesian veins drain directly into the heart cavities including the left atrium which means that they constitute an anatomical shunt by diluting the oxygenated blood with poorly oxygenated blood
340
The bronchial circulation begins where the bronchial arteries branch off of/arise from:
The thoracic descending aorta
340
The bronchial circulation is
A subset of the systemic circulation
341
The bronchial arterial circuit contains
Oxygen rich blood
341
When blood passes through the capillary beds of the walls of the bronchi and bronchioles, oxygen diffuses out of the blood and into the tissues of the wall of the airways. The source of this blood is the:
The bronchial arterial circuit
341
Bronchopulmonary-arterial anastomoses are
vascular connections between bronchial venules and pulmonary venules
342
After gas exchange occurs at the tissue level, blood from the bronchial circulation level is directed back to the right atrium via the
Azygos and hemiazygos veins
343
The bronchial arteries deliver blood to all of the following locations EXCEPT
The pulmonary capillaries
344
Where does the bronchial circuit end?
In 2 different locations. The pulmonary venules taking blood back to the left atrium and the azygos or hemiazygos veins taking blood back to the right atrium
344
What are the two normal sources of the normal anatomical shunt?
Bronchial circulation
Thebesian veins
345
An example of alveolar dead space is
An alveolus that is ventilated but not perfused
Remember, for it to be dead space the alveolus cannot be collapsed
346
Describe a pulmonary shunt
When an alveoli is perfused but not ventilated
347
Describe physiologic shunts
Anatomic shunt + pulmonary shunt
348
What is the symbol for physiologic shunt?
QS/QT
Perfusion shunted/perfusion total
349
What is another term for the QS/QT ratio?
Venous admixture
349
How do we calculate physiologic shunt?
QS/QT = CcO2 - CaO2 / CcO2 -CvO2
349
How do you determine a patient's minute alveolar ventilation
Calculate a patient's dead space based on ideal body weight in pounds, then calculate a patient's tidal volume based on their ideal body weight in kilograms multiplied by 6-8 ml/kg. Then dead space from tidal volume and multiply by respiratory rate
350
The percentage of blood being ejected during systole is called what?
The ejection fraction
351
The volume of blood being ejected during systole is called what?
The stroke volume
352
The information obtained from the arterial blood gas also allowed the clinician to calculate an a/A ratio. This value represents:
the percentage of oxygen that has moved from the alveoli into the pulmonary capillaries during gas exchange at the alveolar capillary membrane
352
If a patients PaCO2 goes from 40 mmhg to 52 mmHg, what happens to their pH?
It goes down by 0.1
353
Describe how we get the respiratory quotient
Healthy individuals consume 250 ml of oxygen per minute while producing 200 ml of carbon dioxide. Dividing the carbon dioxide produced by the oxygen consumed gives us the respiratory quotient, 0.8
353
RBCs have a unique, bi-concave design that increases their surface area and facilitates their major function(s), which is to:
to carry oxygen bound with hemoglobin to the tissues
354
The major difference between plasma and serum is
the absence of fibrinogen and other clotting factors in serum
355
A term that can be used interchangeably with "white blood cells" is:
Leukocytes
356
Red blood cells comprise approximately what percentage of total circulating blood volume?
45%
357
Thrombocytes are also known as
Platelets
358
Which component of the blood is the heaviest, occupying the bottom of a test
tube vial that has been centrifuged?
358
Approximately how many hemoglobin protein molecules are contained within a single red blood cell?
Hundreds of millions
359
Someone who has a hematocrit or hemoglobin that is below the normal range is referred to as
Anemic
360
Hemoglobin is expressed in units of "g%" which represents
the weight (in grams) of hemoglobin contained within a sample of 100 mL of blood
361
Deoxyhemoglobin refers to hemoglobin that
is not carrying any oxygen in its heme groups
362
Every hemoglobin protein molecule contains four "hemes" that are capable of binding with one molecule of
Oxygen
363
Given the information that your patient has a hematocrit (Hct) of 18%, you are able to determine that their hemoglobin level is approximately
6%
364
Hematocrit is approximately 3x ________
Hemoglobin
365
A hematocrit test measures what?
Percentage of red blood cells in blood
366
If a person has a hemoglobin count of 15%, what is their hematocrit?
45%
366
What is a normal hematocrit range in men?
40-54%
367
What is a normal hematocrit range in women?
36-48%
368
In reference to the physiology of oxygen transport, the value"1.34" is best described as:
The amount of oxygen in milliliters that is capable of combining with one gram of Hgb
369
In reference to the physiology of oxygen transport, the units of "vol %" describes:
The amount of oxygen in milliliters contained within a 100 ml of blood
370
The "V" in V/Q ratio or V/Q mismatch represents:
minute alveolar ventilation, which can be calculated if you know a person's tidal volume, anatomical dead space and respiratory rate
371
The number 0.0031 represents
the amount of oxygen in mL that dissolves in plasma for each mm Hg of partial pressure of oxygen (PO2)
372
The difference between CaO2 and CvO2 is represented by
C(a-v)O2
373
Which of the following values for CcO2 would be considered typical in a normal, healthy person with a normal Hgb who is breathing room air?
20 vol%
374
How many heme groups are in a single hemoglobin?
4
375
What is at the center of every heme group?
An iron molecule
376
How many oxygen molecules can be carried by a single heme?
4
377
Describe cooperative binding
When an oxygen molecule binds to iron in one heme group, it changes the shape of the molecule in such a way that it makes other subsequent bindings more likely
377
What units are hemoglobin measured in?
Grams percent/ g%
378
What is the normal hemoglobin range for men?
12-17%
379
What is the normal hemoglobin range for women?
12-15%
379
What is it called if someones hemoglobin is too high?
Polycythemia
380
What is CaO2?
The oxygen content in arterial blood
When calculating, take out 2 decimals
381
What is CvO2?
The oxygen content in mixed venous blood
When calculating, take out 2 decimals
382
What is CcO2?
The oxygen content in end capillary blood
When calculating, take out 2 decimals
382
How do you calculate CaO2?
(Hgb x 1.34 x SaO2) + (PaO2 x 0.0031)
Calculate the amount of oxygen bound to hemoglobin and the amount of oxygen dissolved in the plasma and add the two values together
383
What are the units that describe oxygen content in the blood?
Volume percent
mL of oxygen / 100 mL of blood
384
How do you calculate CvO2?
(HgB x 1.34 x SvO2) + (PvO2 x 0.0031)
Calculate oxygen bound to HgB and amount of oxygen dissolved in the plasma
385
What does C(a-v)O2 tell us?
The difference between the amount of oxygen delivered from the left heart to the tissues and the amount of oxygen that is delivered from the tissues back to the right heart
386
How do you calculate CcO2?
(Hgb x 1.34 x SAO2) + (PAO2 x 0.0031)
Note, when calculating CcO2, SAO2 will always be 1
387
What does DO2 stand for?
Oxygen transport
388
How do you calculate oxygen transport? (DO2)
CaO2 x CO x 10
Multiply by 10 because CaO2 is for how much oxygen is in 100 ml of blood
388
What is the P/F ratio?
PaO2/FiO2
A means of determining the amount of oxygen in the blood compared to the FiO2 required to maintain that level
389
What is a normal range for the P/F ratio?
350-500
390
What would a P/F ratio of 200-300 indicate?
Mild respiratory distress syndrome
390
What would a P/F ratio of 100-200 indicate?
Moderate respiratory distress syndrome
391
What would a P/F ratio of <100 indicate?
Severe respiratory distress syndrome
392
What is the formula for calculating the V/Q ratio?
Minute alveolar ventilation / cardiac output
392
What is a normal V/Q ratio?
0.8 - 1
393
What happens if ventilation is greater than perfusion?
Dead space
393
What happens if perfusion is greater than ventilation?
Pulmonary shunting
394
A V/Q ratio of less than 0.8 indicates…
Shunting
395
A V/Q ratio of greater than 1 indicates
The presence of dead space or increase dead space
396
How do we calculate oxygen consumption (VO2)
Not directly measurable
Determined by calculating the difference in DO2 from left heart to tissues and DO2 from the tissues to the right heart
397
How is CO2 carried by the blood for elimination?
As bicarbonate
Dissolved in plasma
Attached to heme protein chains
Attached to plasma proteins
398
Explain the role of bicarbonate in CO2 transport
CO2 enters an RBC which contains water. CO2 combines with water to form carbonic acid. Carbonic acid is unstable and breaks down into bicarbonate and a hydrogen ion. Bicarbonate then moves out of the RBC as part of the chloride shift and is transported in the plasma
399
What happens to the hydrogen ion created by the break down of carbonic acid?
It binds to a heme
400
What is the technical term for a CO2 molecule bound to a protein?
A carbamino compound
401
What is the term for a hydrogen bound to a heme?
Deoxyhemoglobin
402
What allows for the rapid reaction between water and carbon dioxide?
A hydrolysis reaction performed by carbonic anhydrase
403
What happens when venous blood returns to the AC membrane?
Oxygen diffuses into the RBC, kicks the hydrogen ion off of the heme, bicarbonate moves back into the RBC and a reaction takes the now free hydrogen ion and the bicarbonate and creates CO2 and water allowing the CO2 to diffuse out of the blood and into the alveoli
