Bryan - Respiratory Physiology - Spring 2010

Front 1

What is the most important muscle for inspiration (in most animals)?

Back 1

Diaphragm

Front 2

T or F:
Expiratory muscles are used during exercise or with respiratory distress.

Back 2

True!

Front 3

Which muscles are used for expiration?

Back 3

Intercostal
Abdominal

Front 4

T or F:
In a healthy animal, intrapleural pressure is always positive.

Back 4

False! It is always negative!

Front 5

What is the approximate intrapleural pressure at rest? At full inspiration?

Back 5

-3mm Hg
-6mm Hg

Front 6

What is the formula for compliance?

Back 6

C = V/P
C = compliance
V = volume
P = pressure

Front 7

Compliance is inversely related to what other variable (other than pressure)?

Back 7

Elastance

Front 8

T or F:
At high expanding pressure, the compliance is high.

Back 8

False! Compliance and pressure are inversely related.

Front 9

What is the main contributing factor to the negative intrapleural pressure?

Back 9

Lymphatic vessel action

Front 10

If a patient is in respiratory distress, what is the first thing to do?

Back 10

Give O2!!

Front 11

The normal volume of air inspired or expired is the...

Back 11

...tidal volume

Front 12

What is the volume that can be inspired OVER AND ABOVE the tidal volume?

Back 12

Inspiratory reserve volume

Front 13

T or F:
The total lung capacity minus the vital capacity would equal the expiratory reserve volume.

Back 13

False!
This equals the Residual volume

Front 14

What is the volume that can be expired after the expiration of the tidal volume?

Back 14

Expiratory reserve volume

Front 15

T or F:
All aspects of the vital capacity can be measured by spirometry.

Back 15

True!

Front 16

T or F:
All aspects of the total lung capacity can be measured by spirometry.

Back 16

False!

Front 17

What are the two types of dead space?

Back 17

Anatomic and physiologic

Front 18

Inspiratory capacity is the sum of which two volumes?

Back 18

Inspiratory reserve volume and tidal volume.

Front 19

Functional residual capacity is the sum of which two volumes?

Back 19

Expiratory reserve volume and residual volume

Front 20

Which equation describes the collapsing pressure of an alveolus due to its surface tension?

Back 20

Laplace's Law
P = 2T/r
P = collapsing pressure
T = surface tension
r = radius

Front 21

What is the primary component of alveolar surfactant?

Back 21

DPPC (Dipalmitoyl Phosphatidylcholine)

Front 22

Which cell produces alveolar surfactant?

Back 22

Type II alveolar cells

Front 23

Who's law describes the resistance of an airway? What is the equation?

Back 23

Poiseuille's law
R = (8nl)/(pi r^4)
n = gas viscoscity
l = airway length
r = radius
pi = pi

Front 24

Which level of the bronchi have has the most resistance?

Back 24

Medium sized bronchi

Front 25

T or F:
Parasympathetic stimulation decreases airway resistance.

Back 25

False! Parasympathetic stimulation decreases airway radius and INCREASES airway resistance.

Front 26

Stimulation of which type of sympathetic receptor dilates the airways?

Back 26

Beta-2 receptors

Front 27

Which domestic species have complete lobular separation of the lungs?

Back 27

Pigs and cattle

Front 28

Which domestic species have no lobular separation?

Back 28

Dogs and cats

Front 29

Which two substances are measured to determine fetal lung maturity? What is their target ratio?

Back 29

Lecitin:sphingomyelin (2:1)

Front 30

T or F:
Patients with chronic asthma have high lung volumes.

Back 30

True!

Front 31

T or F:
The resting tidal volume of horses and cattle is approximately the same.

Back 31

False!
Horse 7.5L
Ox 4.2L

Front 32

T or F:
The resting tidal volume of a dog is 10x that of a cat.

Back 32

True!
Dog 0.3L and cat 0.03L

Front 33

If a dog breathes through the mouth, how does this affect the dead space? Which dead space is impacted?

Back 33

Decreases anatomical dead space

Front 34

If tidal volume is increased, what must increase in order to compensate?

Back 34

Respiratory rate

Front 35

Confluent alveoli is a symptom of which respiratory disease?

Back 35

Emphysema

Front 36

What is the condition characterized by collapsed alveoli known as?

Back 36

Atelectasis

Front 37

T or F:
Alveolar surfactant increases compliance.

Back 37

True!

Front 38

T or F:
If a cow has an obstructed mid-bronchial airway, the entire distal lobe becomes dead space.

Back 38

True!

Front 39

T or F:
If a dog has an obstructed mid-bronchial airway, the entire distal lobe becomes dead space.

Back 39

False! Dogs and cats have no separation between lobes, thus they have collateral ventilation

Front 40

Where does gas exchange occur in the avian lung?

Back 40

Air capillaries

Front 41

What keeps the trachea from collapsing?

Back 41

Cartilagenous rings

Front 42

What keeps the bronchi from collapsing?

Back 42

Cartilagenous plates

Front 43

What keeps the bronchioles expanded?

Back 43

Smooth muscle

Front 44

T or F:
The musculature of the bronchioles is strongly controlled by sympathetic nervous stimulation.

Back 44

False! It is weakly controlled.

Front 45

What adrenergic substances cause dilation of the bronchial tree? How do these substances reach the bronchi?

Back 45

Epinephrine and norepinephrine reach the bronchi via the blood

Front 46

What effect does histamine have on the bronchi? What releases histimine?

Back 46

Histimane causes bronchoconstriction and is released by mast cells.

Front 47

Which of the following can be measured by spirometry?
Total lung capacity
Vital capacity
Physiologic dead space
Functional residual capacity
Residual volume

Back 47

Vital capacity

Front 48

A dog presents that is lethargic, febrile, and has high pulse and respiratory rates. Auscultation reveals diffuse crackling and tests show mild normochromic anemia and left-shift leukocytosis. What is the best differential dx?

Back 48

Pneumonia

Front 49

Which has the lower pressure, pulmonary or systemic circulation?

Back 49

Pulmonary

Front 50

Which has the lower resistance, pulmonary or systemic circulation?

Back 50

Pulmonary

Front 51

T or F:
Since the pulmonary resistance and pressure is lower, the cardiac output to the lungs is less than that going to the rest of the body.

Back 51

False! CO is same on both sides!

Front 52

T or F:
Hydrostatic pressure in the lungs has no effect on the majority of domestic species.

Back 52

True! This only effects primates.

Front 53

Let's play pulmonary vasodilator or vasoconstrictor!
What does Angiotensin II do?

Back 53

Vasoconstriction!

Front 54

Let's play pulmonary vasodilator or vasoconstrictor!
What does Histamine do?

Back 54

usually vasoconstriction

Front 55

Let's play pulmonary vasodilator or vasoconstrictor!
What does NE do?

Back 55

vasodilation

Front 56

Let's play pulmonary vasodilator or vasoconstrictor!
What does isoproterenol do?

Back 56

vasodilation! (it's a beta 1 and beta 2 agonist)

Front 57

Approximately what % of total blood carried to the lung is borne by the brachial arteries? The pulmonary arteries?

Back 57

2% brachial (oxygenated)
98% pulmonary (no O2)

Front 58

T or F:
As cardiac output increases, pulmonary pressure increases at the same rate.

Back 58

False!
Dilating vasculature decreases resistance causing pressure to rise at a much slower rate.

Front 59

What is the assumed pressure in pulmonary capillaries? What it is in the peripheral tissue capillaries?

Back 59

~7mmHg
~17mmHg peripherally

Front 60

About how long does a RBC stay in a pulmonary capillary? How about with increased cardiac output?

Back 60

0.8sec (normal)
0.3sec (increased CO)

Front 61

What is the net filtration pressure in a normal pulmonary capillary?

Back 61

+1 mmHg (toward interstitum)

Front 62

If the plasma colloid osmotic pressure is 25mmHg and the pulmonary capillary pressure in a dog is 7mmHg, at what is the "safety factor" against edema before which the lymphatic pump can no longer keep up?

Back 62

18mmHg

Front 63

T or F:
In cases of chronic pulmonary hypertension, the lymphatic pump enlarges concurrently.

Back 63

True!

Front 64

What are three main causes of pleural edema?

Back 64

Lymph obstructions
Left sided heart failure
Anything removing proteins in blood (liver failure)

Front 65

T or F:
If the oxygen concentration falls below 70% of normal, bronchodilation occurs.

Back 65

False, dummy!
VASOCONSTRICTION happens in the alveolar vessels!

Front 66

T or F:
A right to left shunt has little impact on blood oxygenation.

Back 66

False! This is bad as unoxygenated blood is shunted back into the system.

Front 67

T or F:
A left to right shunt has little impact on blood oxygenation.

Back 67

True! This has oxygenated blood from the lungs going back to the lungs which isn't all that bad.

Front 68

What four features characterize the Tetralogy of Fallot?

Back 68

Ventricular foramen patent
PDA
R ventricle hypertrophy
Aortic displacement

Front 69

Above what pulmonary capillary pressure does edema occur in dogs?

Back 69

>25mmHg

Front 70

If the radius of a bronchiole becomes constricted so that its radius is one-half its original value then what does this do to the final resistance?

Back 70

Resistance is 16x greater

Front 71

If the radius of a bronchiole becomes dilated so that its radius is twice its original value then what does this do to the final resistance?

Back 71

Resistance is 16x less

Front 72

Which volume remains in the lungs after a maximal expiration?

Back 72

Residual volume

Front 73

Which volume remains in the lungs after the tidal volume is expired?

Back 73

Functional residual capacity (expiratory reserve volume + residual volume)

Front 74

What is the general makeup of atmospheric air?

Back 74

79% N2
21% O2
<1% CO2 and other gases

Front 75

If air pressure is 760mmHg (dry) then what are the partial pressures of O2 and N2?

Back 75

600mmHg N2 (.79 * 760)
160mmHg O2 (.21 * 760)

Front 76

T or F:
CO2 and O2 diffuse at the same rate.

Back 76

False! CO2 diffuses much faster

Front 77

What is Henry's Law?
Hint: has to do with partial pressure and solubility of the gas...

Back 77

Partial pressure = (conc. of dissolved gas/(solubility))

Front 78

What are some of the factors that can affect the rate of gas diffusion in a fluid?

Back 78

Pressure difference
Solubility of the gas in the fluid
Cross sectional area of the fluid
The distance through which the gas must diffuse
Molecular wt. of the gas
Temp of fluid

Front 79

How long does it take for O2 equilibrium to be achieved between a capillary and alveolus?

Back 79

0.25sec

Front 80

What are some conditions where diffusion-limited gas exchange is an issue?

Back 80

Strenuous exercise
Fibrosis (thickening alveolar membrane)
Emphysema (alveolar surface area decreased)

Front 81

T or F:
If an area of the lung is not ventilated because of bronchial obstruction, the pulmonary capillary blood serving that area will have a PaO2 that is equal to the atmospheric PO2.

Back 81

False!
It would be equal to the venous PaO2 due to no diffusion going on in the blocked area.

Front 82

T or F:
Increasing breathing rate will decrease alveolar PCO2.

Back 82

True!

Front 83

What is the ideal ventilation-perfusion ratio (V/Q)? What is the more normal V/Q value?

Back 83

1 is ideal
0.8 is more normal

Front 84

What is the normal PaO2 and PaCO2 at a V/Q of 0.8?

Back 84

PaO2 100mmHg
PaCO2 40mmHg

Front 85

If there is a diffusion abnormality, which decreases first, PO2 or PCO2?

Back 85

PO2

Front 86

What are some factors affecting diffusion across a respiratory membrane?

Back 86

Thickness of membrane
Surface area of membrane
Diffusion coefficient of gas
Partial pressure difference of gas

Front 87

T or F:
PaCO2 is the main indicator for alveolar gas exchange.

Back 87

True! If the CO2 isn't changing, then there is a problem with alveolar exchange.

Front 88

What is the V/Q of an airway obstruction?

Back 88

Zero!

Front 89

What is the V/Q of an area of pulmonary embolus?

Back 89

Infinite (dividing by zero)

Front 90

What is the Bohr equation?

Back 90

(VDphys/VT) = (PaCO2 - PECO2)/PaCO2

Where VDphys = physiological dead space
VT = tidal volume
PaCO2 = partial pressure of CO2 in arteries
PECO2 = partial pressure of CO2 expired

Front 91

T or F:
Supplemental O2 is more helpful in a situation with a low V/Q vs. a high V/Q.

Back 91

True! Low V/Q means that there is less ventilation and more O2 would help out!

Front 92

T or F:
When the physiologic dead space is great, much of the work of ventilation is wasted effort.

Back 92

True

Front 93

T or F:
In alveoli with no ventilation but adequate blood flow the PaO2 is 100mm Hg and the Pa CO2 is 45mm Hg.

Back 93

False!
PaO2 will go down and PaCO2 will stay the same or go up!

Front 94

T or F:
Oxygen diffusion is normally perfusion limited.

Back 94

True

Front 95

Which law deals with the diffusion of a gas through a membrane?

Back 95

Fick's law!

Front 96

What is Fick's law?

Back 96

V = (AD*(P1-P2))/T
Where:
V = volume of gas diffusing/min
A = surface area
D = diffusion constant (inversely proportional to square root of gas molecular wt)
T = membrane thickness
P1-P2 = partial pressure difference across membrane

Front 97

T or F:
According to Fick's law, as membrane thickness increases, the rate of gas diffusion increases concurrently.

Back 97

False! Diffusion rate and membrane thickness are inversely proportional!

Front 98

T or F:
Myoglobin has considerable homology with the four subunits of hemoglobin.

Back 98

False!
Myoglobin has homology with the Beta subunit of hemoglobin

Front 99

What are the subunits of hemoglobin? Of fetal hemoglobin?

Back 99

Alpha and Beta
Alpha and Gamma in fetal

Front 100

T or F:
The O2 partial pressure of myoglobin at P50 is greater than that of hemoglobin.

Back 100

False! Myoglobin has a much greater affinity for O2 and, thus, is saturated at a lower partial pressure than Hb is.

Front 101

Which has a higher O2 affinity? Fetal Hb or adult Hb?

Back 101

Fetal Hb

Front 102

T or F:
2,3-DPG binds more avidly to fetal Hb than adult Hb.

Back 102

False! It has less affinity for fetal Hb, thereby giving adult Hb a lower O2 affinity than fetal Hb.

Front 103

T or F:
Iron is in the ferric state in hemoglobin.

Back 103

False! Ferric is methemoglobin! Remember, METH is ICK!!

Front 104

T or F:
The affinity of the hemoglobin tetramer for the first molecule of O2 is much higher than for the fourth molecule.

Back 104

False! Affinity for the 4th molecule is the highest (due to heme-heme interactions)

Front 105

T or F:
Hb is 100% saturated at 100mm of Hg and 50% saturated at 50mm Hg.

Back 105

False!
It is P50 is 40mmHg

Front 106

Pick Right or Left shift...
Increased H+

Back 106

RIGHT SHIFT = decreased O2 affinity

Front 107

Pick Right or Left shift...
Increased pH

Back 107

LEFT SHIFT = increased O2 affinity

Front 108

Pick Right or Left shift...
Decreased temp

Back 108

LEFT SHIFT = increased O2 affinity

Front 109

Pick Right or Left shift...
Increased 2,3-DPG

Back 109

RIGHT SHIFT = decreased O2 affinity

Front 110

Pick Right or Left shift...
Change from fetal to adult Hb

Back 110

RIGHT SHIFT = decreased O2 affinity

Front 111

Pick Right or Left shift...
Decreased PCO2

Back 111

LEFT SHIFT = increased O2 affinity (PCO2 increases H+ which decreased pH)

Front 112

T or F:
The Bohr Effect is named after Niels Bohr's dad.

Back 112

Yup. Dr. Christian Bohr himself fathered the genius who gave us the concept of electron energy shells.

Front 113

The right shift and subsequent decrease of Hb affinity for O2 is called the _________ effect.

Back 113

Bohr

Front 114

T or F:
The Bohr effect facilitates the unloading of O2 in peripheral tissues.

Back 114

True!

Front 115

T or F:
Ruminants and Elephants have little to no response to 2,3-DPG.

Back 115

True! What weirdos.

Front 116

T or F:
Hb affinity for CO is ~200x greater than O2.

Back 116

True!

Front 117

Between hypoxemia and hypoxia, which is more commonly caused by lung issues?

Back 117

Hypoxemia.

Front 118

T or F:
Hypoxemia describes a decrease in PaO2.

Back 118

True!

Front 119

T or F:
Hypoxia describes a decrease in PaO2.

Back 119

False! This describes a decrease in the DELIVERY of O2 to tissues (PaO2 can be just fine)

Front 120

How many heme groups are bound to O2 at P50?

Back 120

2 of 4 heme groups

Front 121

How can one determine the O2 delivery? (think of using the heart as a pump to deliver O2 to tissues)

Back 121

O2 delivery = Cardiac Output x PaO2

Front 122

What is the alveolar gas equation?

Back 122

PAO2 = PIO2 - (PACO2/R)
Where:
PAO2 = alveolar PO2
PIO2 = inspired PO2
PACO2 = alveolar PCO2
R = respiratory exchange ratio

Front 123

T or F:
Residing at high altitude will result in increased 2,3-DPG concentration.

Back 123

True (unless you're a high altitude elephant)

Front 124

T or F:
Residing at high altitude will cause a left shift of the Hb-O2 dissociation curve.

Back 124

False! Increased CO2 will increase H+ which will decrease pH, causing a RIGHT SHIFT!

Front 125

What is the major form of CO2 in the blood?

Back 125

HCO3-

Front 126

CO2 bound to Hb is known as...

Back 126

...carbaminohemoglobin

Front 127

What buffers H+ inside erythrocytes?

Back 127

Deoxyhemoglobin

Front 128

HCO3- leaving erythrocytes in exchange for Cl- is known as the _____________ phenomenon.

Back 128

HAMBURGER

Front 129

What is the major factor causing the Bohr effect?

Back 129

increased CO2 increases H+ which decreases pH shifting curve to R and unloads O2 into tissues

Front 130

What is the opposite of the Bohr effect?

Back 130

Haldane effect.

Front 131

In the transport of CO2 from the tissues to the lungs, which of the following occurs in the venous blood?
A. conversion of CO2 and H2O to H+ and HCO3- in the RBCs.
B. buffering of H+ by oxyhemoglobin
C. shifting of HCO3- into the RBCs from plasma in exchange for Cl-
D. Binding of HCO3- to Hb
E. Alkalinization of the RBCs

Back 131

A. conversion of CO2 and H2O to H+ and HCO3- in the RBCs

Front 132

What is the Henderson-Hasselbalch equation?

Back 132

pH = pKa + log(10) ([base]/[acid])

Front 133

T or F:
Emphysema and asthma are both characterized by an EXCESS of air in the lungs.

Back 133

True!

Front 134

T or F:
One of the effects of chronic emphysema is pulmonary hypotension caused by weakening of the capillary walls.

Back 134

False!
Capillary numbers actually decrease leading to pulmonary HYPERtension

Front 135

When alveoli become filled with fluid and/or blood in pneumonia, what is the effect on the V/Q ratio?

Back 135

Decreases it (due to reduced ventilation)

Front 136

How do you say increased CO2 in greek?

Back 136

Hypercapnia

Front 137

What happens to the permeability of the blood-alveolar barrier during pneumonia?

Back 137

Permeability increases

Front 138

Why is arterial O2 concentration higher in a case of unilateral pneumothorax than in a case of unilateral pneumonia?

Back 138

In pneumothorax, affected lung collapses and the perfusion AND ventilation both decrease. Other lung takes over. In pneumonia, perfusion is unaffected.

Front 139

CN- poisoning blocks what enzyme?

Back 139

Cytochrome c oxidase

Front 140

Name some conditions where O2 therapy is worthless.

Back 140

R to L shunt
Abnormal Hb O2 transport
Circulatory deficiency
Anemia

Front 141

What is normal blood pH?

Back 141

7.40

Front 142

T or F:
Ventilation is the key to respiratory control of pH.

Back 142

True!

Front 143

Crap! Your stupid dog ate a ton of asprin! Whats-a-gonna happen?

Back 143

Salycilate intoxication causes metabolic acidosis AND respiratory alkalosis (mostly metabolic acidosis though)

Front 144

What acid/base effect can severe diarrhea cause?

Back 144

Metabolic acidosis due to lost HCO3-

Front 145

Severe and chronic vomiting can cause what acid/base condition?

Back 145

Metabolic alkalosis due to lost H+

Front 146

Which experiences the greater increase in H+, going from 7.4 to 7.3 or from 7.1 to 7.0?

Back 146

From 7.1 to 7.0

Front 147

What is the respiratory compensation for metabolic acidosis?

Back 147

Hyperventilation

Front 148

What is the compensation mechanism for metabolic alkalosis?

Back 148

Increase HCO3- excretion
(laxatives maybe???)

Front 149

T or F:
There is no way to compensate for respiratory alkalosis via respiration.

Back 149

True!

Front 150

What size particles can make it all the way to the alveoli?

Back 150

<1um

Front 151

What kind of epithelium is found in the large and small conducting airways of the lung?

Back 151

Pseudostratefied columnar epithelium w/cilia

Front 152

What is the serous fluid layer covering the lumenal surface of bronchial respiratory epithelium?

Back 152

Pericilliary fluid

Front 153

T or F:
Periciliary fluid is produced by active ion transport of Na+ and Ca++.

Back 153

False! It is Na+ and Cl-

Front 154

What layer lies on top of the periciliary fluid layer?

Back 154

Mucus layer (comfy mucous blanket)

Front 155

T or F:
B-adrenergic agonists open Cl- channels in the respiratory epithelium by increasing cAMP.

Back 155

True!

Front 156

The propulsion of mucus toward the trachea by cilia is called...

Back 156

...ESCALATOR MOTION

Front 157

Which respiratory cells produce mucus?

Back 157

Goblet, Clara, Mucous, and serous cells

Front 158

What are the regenerative cells of the bronchi?

Back 158

Clara cells

Front 159

What cell type is seen in bronchial airways in COPD cases?

Back 159

Goblet cells

Front 160

The coordinated, bi-phasic beating of respiratory cilia is known as...

Back 160

...METACHRONISM

Front 161

Where is Angiotensin I converted to Angiotensin II and what enzyme does this?

Back 161

In the endothelium of the lungs, angiotensin converting enzyme

Front 162

T or F:
The lung endothelium metabolizes angiotensin and bradykinin

Back 162

True!

Front 163

Which is the most efficient APC?

Back 163

Dendritic cells

Front 164

When ascending to high altitude, would you expect respiratory alkalosis or acidosis and why?

Back 164

Respiratory alkalosis
Increased respiration to compensate for decreased O2; eliminates more CO2 causing increase of pH.

Front 165

What region(s) of the brain controls respiration?

Back 165

Pons and medulla

Front 166

What does transection at the level of the low medulla do to breathing rates?

Back 166

Apnea! Comadeath

Front 167

What are the four respiratory centers or groups in the pons and medulla?

Back 167

Apneustic center
Ventral respiratory group
Dorsal respiratory group
Pneumotaxic center

Front 168

Which respiratory centers or groups are responsible for inspiration?

Back 168

Ventral and dorsal respiratory groups

Front 169

Which respiratory centers or groups are responsible for expiration?

Back 169

Ventral respiratory group

Front 170

Which respiratory center or group controls rate and depth of respiration?

Back 170

Pneumotaxic center

Front 171

T or F:
The dorsal and ventral respiratory groups send signals to the phrenic nerve.

Back 171

False! It's only the dorsal respiratory group.

Front 172

Which complex or nucleus inhibits the dorsal and ventral respiratory groups?

Back 172

Botzinger complex

Front 173

Which nucleus, group, or complex is the pacemaker of respiration?

Back 173

NONE HAS BEEN IDENTIFIED DUMBBO (but it might be the Botzinger complex)!!

Front 174

Why not have all inspiratory neurons fire simultaneously?

Back 174

Allows for inspiratory ramp; gradual lung inflation; captures more O2

Front 175

T or F:
Expiratory neurons begin to fire at the end of an inspiration.

Back 175

False! They begin to fire mid-inspiration! Helps with inspiratory ramp and stopping inspiration.

Front 176

The stretch-receptors in the lung smooth muscle generate what reflex that controls inspiration?

Back 176

Hering-Breurer Inflation Reflex

Front 177

T or F:
The Hering-Breurer reflex is generated during quiet as well as labored breathing.

Back 177

False! It is only generated with large tidal volumes (not quiet breathing)

Front 178

T or F:
The Hering-Breurer DEFLATION reflex triggers the lung to deflate after maximal inspiration.

Back 178

False! It triggers inflation once the lung is deflated.

Front 179

What would happen if the pneumotaxic area and the respiratory stretch receptors were somehow disabled?

Back 179

Your lungs a-splode! (uncontrolled inflation without deflation)

Front 180

T or F:
The Hering-Breuer reflex may prevent alveolar collapse by periodic deep sighs.

Back 180

False!
This is HEAD's REFLEX (Head's Paradoxical Effect)

Front 181

What effect does cooling the Vagus n. have on the Hering-Breuer reflex?

Back 181

Lung hyperinflation causes a FURTHER increase in inspiratory effort

Front 182

What are some responses to stimulation of irritant receptors in the respiratory tract?

Back 182

Bronchoconstriction
Coughing
Sneezing
Tachypnea
Vagovagal reflex

Front 183

Irritant receptors can cause the vagovagal reflex. What are effects of this reflex?

Back 183

Laryngospasm
Bronchospasm
Cough
Bradycardia

Front 184

Respiratory receptors stimulated by inflammatory processes are called...

Back 184

J-Fibers (Justacapillary fibers)

Front 185

T or F:
Stimulation of justacapillary fibers causes inspiratory activity.

Back 185

True!
Causes tachypnea

Front 186

What effect will clumsy tracheal suction of a dog have?

Back 186

Stimulate the irritant receptors causing vagovagal reflex - bradycardia and drop in BP

Front 187

How does coughing cause a decrease in BP?

Back 187

Increases chest pressure, decreases blood return to heart which decreases CO

Front 188

T or F:
Medullary chemoreceptors respond directly to H+ and CO2 concentrations.

Back 188

False! They respond directly to H+ but INDIRECTLY to CO2

Front 189

What effect does changing O2 concentration have on carotid chemoreceptors?

Back 189

Decreased O2 increases H+ sensitivity