Pulmonary Part 2 Flashcards
1
Q
The normal automatic process of breathing from the __________
The ________can override these centers if voluntary control is needed
A
from the brainstem; cortex
2
Q
Neurons in medulla oblongata and pons control ______
A
Unconscious breathing
3
Q
The automatic rhythmic is controlled by neurons located in the ___________
A
medullary rhythmicity center
4
Q
•Respiratory nuclei in medulla -rhythm –
2 respiratory and what are they involved in ?
A
inspiratory center (dorsal respiratory group)
- frequent signals, you inhale deeply
- signals of longer duration, breath is prolonged –
expiratory center (ventral respiratory group) •involved in forced respiration
5
Q
*****Medullary respiratory center is in the
A
*****Medullary respiratory center is in the reticular formation of the medulla beneath the floor of the fourth ventricle
6
Q
***Pre-BotzingerComplex (partof VentralGroup) =
A
essential for generation of the respiratory rhythm
7
Q
***Dorsal Respiratory Group:
A
sets the basic respiratory
8
Q
Ventral Respiratory Group = associated with forced respiration •
A
These groups of cells have intrinsic periodic firing abilities and are responsible for basic rhythm of ventilation –Even when all afferent stimuli is abolished, these cells generate repetitive action potentials that send impulses to the diaphragm and other respiratory muscles
9
Q
The expiratory area is normally quiet during normal breathing, but will _______
A
become activated with forceful breathing
10
Q
Pneumotaxic center in the _______pons –
A
UPPER
Inhibits inspiration –Limits the burst of action potentials in the phrenic nerve, effectively decrease the tidal volume and regulating the respiratory rate –“Fine tuning” of respiratory rhythm because a normal rhythm can exist in the absence of this center
11
Q
•Apneustic center in the _______ pons –
A
LOWER
Impulses have an excitatory effect on the Dorsal Respiratory Group in the medulla –Promotes inspiration –Sends signals to the Dorsal Respiratory Group in the medulla to delay the “switch off” signal provided by the pneumotaxic center
12
Q
Impulses from the _____ and ___________ do what?
A
Vagus (X); Glossopharyngeal (IX); nerves
modulate the output of inspiratory cells
13
Q
The cycle of inspiration: –Latent period of several seconds
A
Crescendo of action potentials leading to a ramp of strengthening inspiratory muscles
–Inspiration action potentials cease and inspiratory muscle tone falls
–Expiration occurs due to elastic recoil of lung tissues and chest wall
14
Q
From limbic system & hypothalamus –•
A
respiratory effects of pain& emotion
15
Q
From airways and lungs
–irritant receptors in respiratory mucosa •stimulate vagal signals to medulla results in_______and_______
stretch receptors in airways:_________reflex •excessive inflation triggers_______ of ______
J-receptors are ______ ______Receptors - what do they do?
A
bronchoconstriction and coughing
inflation; stop of inspiration
Juxtapulmonary capillary receptors. They increase rapid, shallow breathing
16
Q
Stimulate vagal signals to medulla results in
A
bronchoconstriction/ coughing
17
Q
From chemoreceptors –
A
monitor blood pH, CO2and O2 levels
18
Q
stretch receptors in airways -inflation reflex
A
•excessive inflation triggers stop of inspiration
19
Q
Rate and depth of breathing adjusted to maintain levels of:
A
–pH
–pH –PCO2
–PO2
20
Q
Rate and depth of breathing adjusted to maintain levels of:
A
–pH
–PCO2
–PO2
21
Q
______primary stimulus for central chemoreceptors) •–
A
pH of CSF
22
Q
Respiratory acidosis (pH < 7.4)
A
caused by ↓ ↓↓ ↓ pulmonary ventilation –hypercapnia: PCO> 45 mmHg –hypercapnia: PCO 2 > 45 mmHg •CO2 easily crosses blood-brain barrier •in CSF the CO2 reacts with water and releases H+ •central chemo receptors strongly stimulate inspiratory center
23
Q
“blowing off ” CO2pushes reaction to the left
A
CO2(expired) + H2O ← ←← ←H2CO3 ← ←← ←HCO3-+ H+ –so hyperventilation reduces H+
24
Q
•Respiratory alkalosis (pH > 7.4)
A
–hypocapnia: PCO 2 < 35 mmHg –Hypoventilation (↑ ↑↑ ↑CO2), pushes reaction to the right ↑ ↑↑ ↑CO+ HO → →→ →HCO→ →→ →HCO-+ H+
↑ ↑↑ ↑CO2+ H2O → →→ →H2CO3 → →→ →HCO3-+ H+ –↑ ↑↑ ↑H+lowers pHto normal
25
•pH imbalances can have metabolic causes –
Ex: uncontrolled diabetes mellitus •ketoacidosis, may be compensated for by Kussmaul respirations
26
Where are peripheral found?
Peripheral –found in major blood vessels •aortic bodies –signals medulla via C.N. X
27
Where are carotid bodies
carotid bodies –signals medulla by C.N. IX
28
Central –in medulla •
primarily monitor pHof CSF •↑ ↑↑ ↑[H+] stimulates ventilation •↓ ↓↓ ↓[H+] inhibits it
29
Ventilatory responses what percentage is mediated by central chemoreceptors?
80% mediated by central chemoreceptors
30
Ventilatory responses what percentage is mediated by peripheraL chemoreceptors?
20% mediated by peripheral chemoreceptors.
31
Central receptors monitor
CSF
32
The normal pH of CSF is ______ and it has much _______buffering capacity compared to blood, resulting in greater change in pH with changes in PCO2
•Changes can be compensated by –Example:
7.33,less
active transport of HCO3-into the CSF HCO3-into the CSF
A patient with chronic lung disease will have CO2 retention, but may have a near normal CSF pH and a resulting low ventilation for his or her PCO2 level
33
With severe lung disease, the hypoxic drive to ventilation becomes very important –Chronic CO2 retention results in the __________
What become the chief stimulus of ventilation?
compensation of CSF pH to nearly normal range
These patients have lost most of their increase in the stimulus for ventilation from CO2 –By this point, the kidney should have already metabolically compensated for the respiratory acidosis, so the peripheral chemoreceptors have no pH stimulus to increase ventilation
-Under these conditions, arterial hypoxemia (PaO2) becomes the chief stimulus of ventilation •If a high O2 mixture is given to relieve the hypoxemia, the ventilation may be grossly depressed.
34
The cortex can _________these centers if _______Control is needed
Can override; voluntary
35
Medullary Rhythmicity area : dorsal group is the ______ group and the Ventral group is the _______Group
Inspiratory Group; expiratory
36
Inspiratory group is the
| Expiratory group is the
Dorsal group
| Ventral group
37
Respiratory Center in pons :
pneumotaxic area
| Apneustic area
38
The pons regulate
rate and depth
39
What does the pneumotaxic center of the pons do?
Pneumotaxic center: Sends continual inhibitory impulses to inspiratory center, as impulse frequency rises, breaths shorter, faster and shallower.
40
What does the Apneustic Center of the pons do
Apneustic center: Promotes maximal lung inflation and long deep breaths
Inspiration & expiration
41
Vagus nerve : type of receptors (3)
Stretch
Irritant
J receptors
42
Central control impulses from the_______and ________
VAGUS; GLOSSOPHARYNGEAL nerves modulate the output of inspiratory cells
43
The cycle of inspiration
- latent period of several seconds
- Crescendo of action potentials leading to a ramp of strengthening inspiratory muscle
- Inspiration action potential cease and inspiratory muscle tone falls
Expiration occurs due to elastic recoil of lung tissues and chest wall
44
Central Control
Medullary respiratory center is in the reticular formation of the medulla beneath the floor of the fourth ventricle.
45
Pre-Botzinger Complex
Part of the ventral group= essential for generation of the respiratory rhythm
46
Dorsal respiratory Group sets what?
sets the basic respiratory rhythm
47
Ventral respiratory Group
associated with forced respiration
48
Ventral resp group, These groups of cells have i
- intrinsic period firing abilities and are responsible for basic rhythm of ventilation.
- Event when all afferent stimuli is abolished, these cells generate repetitive action potentials that send impulses to the diaphragm and other respiratory muscles.
49
Central control; The expiratory area is normally quiet during normal breathing but
will become activated with forceful breathing
50
PNEUMOTAXIC CENTER:located where ? does what? what mechanism
in the upper pons
-inhibits inspiration
- Limits the burst of action potentials in the phrenic nerve, effectively decrease the tidal volume and regulating the respiratory rate
Fine tuning of respiratory rhythm because a normal rhythm can exist in the absence of this center.
51
Apneustic center
in the lower pons
Impulses have an excitatory effect on the DORSAL RESPIRATORY group in the medulla
Promotes inspiration
sends signals to the respiratory group in the medulla to delay the "switch off" signal provided by the pneumotaxic center.
52
INPUT to RESPIRATORY CENTERS
From limbic system & hypothalamus
| respiratory effects of pain & emotion
53
INPUT from airways to lungs
From airways & lungs
Irritant receptors in respiratory mucosa
stimulate vagal signals to medulla, result in bronchoconstriction / coughing
54
INPUT to stretch receptors in airways
irritation reflex
excessive inflation triggers stop of inspiration
J-receptors - Juxtapulmonary capillary receptors. - increase rapid, shallow breathing
55
Input to respiratory from chemoreceptors
monitor blood pH, CO2 and O2 levels.
56
Blood chemistry and respiratory rhythm : Rate and depth breathing adjusted to maintain levels of
pH
PCO2
PO2
57
******Effects of Hydrogen IONS'
primary stimulus for what kind of chemoreceptors?
Respiratory________caused by a_________pulmonary ventilation
```
***pH of CSF (primary stimulus for central chemoreceptors)
Respiratory acidosis (ph<7.40 ) caused by decreased pulmonary ventilation
```
58
Respiratory Acidosis (ph is ________) caused by Decreased pulmonary ________
Hypercapnia -->
CO2 easily crosses______
In CSF, the ________reacts with _____and releases____
Central chemoreceptors strongly stimulates _______Center
______CO2 pushes reaction to the left
What does HYPERVENTILATION do?
PCO2 >45 mmHg
CO2 easily crosses BBB
In CSF, the CO2 reacts with water and releases H+
Central chemoreceptors strongly stimulate inspiratory center
Blowing off CO2 pushes reaction to the left
CO2 (expired ) + H2O
Reduces H+
59
```
Respiratory alkalosis (ph_______-)
Hypo__________: PCO2______
Hypo________Increased______pushes reaction to the right
______H+lowers pH to normal
pH imbalances can have metabolic causes
```
```
>7.4
PCO<35mmHg
Hyperventilation--> Increased CO2
↑CO2+H20-->H2CO3 --> HCO3- + H+
↑ ph _________to normal
```
60
Ph imbalances can have metabolic causes ex
uncontrolled DM
| Ketaacidosis ,compensated by Kussmaul Respirations.
61
What is the normal ph of the CSF? between blood and CSF which one possess LESS buffering capacity? what does that mean?
7.33, CSF ; Greater change in pH with changes in PCO2
62
****Which monitor CSF
Central receptors
63
How is change in the CSF compenesated
Active transport of HCO3- into the CSF
64
A patient with chronic lung disease will have
CO2 retnetion , but may have a normal CSF ph and a resulting low ventilatio for his or her PCO2 level.
65
*******Chemoreceptors types
Peripheral and Central.
66
****Chemoreceptors Peripheral
Found where?
2 Types? and does what ?
****Found in major blood vessels
Aortic bodies - Signals medulla via CN X
Carotid bodies - Signals medulla by CN XI
67
```
****Chemoreceptors Central
Found where?
2 Types? and does what ?
What inhibits ventilation?
What stimulates ventilation?
```
In medulla
Primarily monitor pH of CSF
↑ [H+] stimulates ventilation
↓ [H+] inhibits it
68
*****Ventilator responses 80% mediated by ______
central chemoreceptors
69
*****Ventilator responses 20% mediated by _
Peripheral chemoreceptors
70
****if a high O2 mixture is given the relieve the hypoxemia, the ventilation may be
****Grossly depressed
71
Chronic O2 retention results in the compensation of CSF ph to _______
These patients have lost most of their __________
nearly normal range
Increase in the stimulus for ventilation from CO2
BY THIS POINT, THE KIDNEYS ALREADY METABOLICALLY COMPENSATED FOR THE respiratory acidosis, so the peripheral chemoreceptors have no pH stimulus to increase ventilation.
Under these conditions, arterial HYPOXEMIA (PaO2) becomes the chief stimulus or ventilation
72
****Peripheral chemoreceptors located in the _________ at the __________ of the ________ arteries and in the __________above the _______
Located in the carotid bodies at the bifurcation of the
common carotid arteries, and in the aortic bodies
above the aortic arch
73
***Which of the bodies are more important?
Afferent nerve is the ___________ (CN__).Contain glomus cells --sites of ___________ -modulate ___________ ___________ by physiological and chemical stiumuli
Carotid bodies;
GLOSSOPHARYNGEAL XI;
site of CHEMORECEPTION
neurotransmitter release by
74
***Peripheral CHEMORECEPTORS respond to :
- The response of the peripheral chemoreceptors to arterial PCO2 is _________ than that of the _______chemoreceptors even though peripheral responses are __________ but ________
* ******Decrease in arterial PO2 and pH, and increases in arterial PCO2
- LESS IMPORTANT; CENTRAL; FASTER but Weaker
75
CAROTID receptors respond to drop in
pH (IX)
76
AORTIC receptors response to
PCO2 (X)
77
Conditions that affect ventilation
Receptors can be_______or _______
What are factors that enhanced ventilation?
```
enhanced or suppressed
MLE
Metabolic acidosis
Low PO2(<60mmHg)
Elevated temperature
```
78
Conditions that affect ventilation
| What are factors that SUPPRESSED ventilation?
```
MANC
MA (Metabolic alkalosis)
A (any cns depressant)
N (cold)
N (Narcotics)
```
79
Integrated responses
| - Decreasing arterial PCO2 is ________ in reducing the __________ to Ventilation
very effective
| stimulus
80
The main stimulus to increase ventilation when arterial _________ rises comes from the ______receptors which respond to the increases _____ in CSF , and also from peripheral receptors responding to both the rise in _______ and decrease in ______
PCO2; Central ; {H+}; pCO2 , pH
81
1.Just review: Drug effects on ventilation
Amnestics : _______CNS leading to a decrease ____
Affect _______ and _______
At high doses may cause _______
```
OPIODs
Affect___________Center
Decrease _______
Mildly increase __________
Decrease _________over all
```
Suppress; RR
Muscle tone and upper airway
Apnea
Respiratory drive center
Respiratory Rate
Tidal Volume
minute ventilation
82
2.Just review: Drugs effects on Ventilation
Volatile Anesthetics :
Suppresses _______ ______relaxes _________ including leading to what kind of breathing?
Nitrous Oxide:
Supportive of _______
resulting in an ______in RR
-suppresses neural activation
all muscles including the diaphragm, leading to fast and shallow breathing
Suppresses response to PCO2 (abolishes response to PO2)
- Ventilation; increase
83
Pressure and flow: What drives respiration? _______Pressur
Atmospheric pressure
84
What 2 things are inversely proportional?
Intrapulmonary pressure and LUNG volume
85
Just review :Physical Pressure drive_____
| Partial Pressure drive _____
Conduction
| Gas exchange
86
Flow governed by
Poiseuilles' s Law
| Turbulent flow occurs with increased velocity, tube diameter, and gas density.
87
Describe transitional flow
A mixture of laminar and turbulent , occurs at branch point of the airways,
In Trachea and larger airways either turbulent or transitional
88
Found in smallest airway is________Flow
laminar
89
REVIEW Pressure in the potential space between the parietal and visceral pleura is___________
• Pressures are generated by the movement between the lung and chest wall
– The lung tends to________ its volume due to inward elastic recoil
– The chest wall tends to________its volume due to outward elastic recoil
normally subatmospheric around -3 to -5 cm H2O
| decrease; increase
90
****difference in volume & compliance leads to a
****Difference in ventilation
91
***** Difference in ventilation can be due to
difference in volume and compliance
92
Are all alveoli in the lower lung ventilated equally?
| which alveoli receive more ventilation per breath?
NO
| Base receive more ventilation than the alveoli in the upper regions of the lungs.
93
The influence of gravity on a supported structure is called
Dependency
94
Dependency accounts for
Regional differences in alveolar ventilation (dependent vs nondependent)
95
Effective gas exchange depends on what
Approximately even distribution of gas (ventilation) and blood (perfusion) in all portions of the lungs (V/Q)
96
Ventilation and perfusion depend on
body position.
97
If a standing individual assumes a supine or side lying position--> which are best ventilated?
The areas of the lungs that are the most dependent becomes the best ventilated and perfused?
98
If a standing individual assumes a supine or side lying position--> which are best ventilated?
The areas of the lungs that are the most dependent becomes the best ventilated and perfused
99
Distribution of perfusion in the pulmonary circulaton also is affected by
ALVEOLAR PRESSURE (gas pressure in the alveoli)
100
how does the pulmonary capillary bed differs from systemic capillary bed?
It is surrounded by gas containing alveoli.
101
what happens when the gas pressure in the alveoli exceeds the blood pressure in the capillary
the capillary collapses and flow ceases.
102
Zone I
PA>Pa>Pv
103
Zone II
Pa>PA>Pv
104
Zone III
Pa>Pv>PA
105
PA
Alveolar pressure
106
Pa
arterial pressure
107
Pv
venous pressure
108
Zone 1 =
Increased Pa, compressed arterioles = V without Q deadspace.
109
__________Determine rate of diffusion of each gas and
| gas exchange between blood and alveolus
Partial pressures (as well as solubility of gas)
110
******What is elasticity
| When lungs are inflated, there is a tendency to _________
Tendency of the lung tissue to return to its original position after an applied force has been removed
- When inflated, there is a tendency to recoil to a smaller unstressed volume
111
*****To keep the lungs inflated
an opposing pressure difference is required, provided by chest wall and respiratory muscles,
112
The difference between the two curves is called
hysteresis
113
The lung always retains some residual air, and even in forced expiration, ________would prevent further air loss
small airway closure and trapping
114
Accentuates collapse Airway
Bernouilli effect
115
When air enters a constriction, the linear velocity _____and pressure _______
increases; decreases
116
****COMPLIANCE : opposite of _______
It is a measure of __________ of the lung
Mathematically it is the change in _________divided by the change in ______Pressure . Volume in ____and pressure is in _______
Chest wall compliance is the opposite of elasticity, it is a measure of the distensibility of the lung. Mathematically it is the change in lung volume divided by the change in recoil pressure, where change
in volume is in liters and change in pressure is in cm H20
117
1 cm H2O
98.07 Pa= 0.735559 mmHg
118
Factors reducing compliance
Low volume
Fibrous tissue
Atelectasis and
Increases in surface tension
119
Factors affecting Airway resistance
Diameter
Flow
Density
Poseuilles Law
120
______or ______That affect recoil include _______
Age, pathologies (pulmonary fibrosis)
121
How do you calculate MINUTE VENTILATION (Ve)?
```
Ve = Vt x f
Ve = minute ventilation
Vt= Tidal volume
f = frequency or RR
```
122
Calculatons - Alveolar minute ventilation (VA) formula
V(A) = (Vt - VDs) x RR
V(A)= alveolar ventilation
Vt =Tidal volume
V ds = Physiologic dead space 1ml per POUND of IDEAL body weight
123
anatomic ds =__________
mechanical ds =_________
alveolar ds =________
physiologic ds =________
conducting airway
ventilator machine circuit, ET tube, etc
nonperfused alveoli (usually nominal)
the sum of anatomic & alveolar ds
124
If you want to increase alveolar ventilation, should you
increase respiratory rate or tidal volume?
Which is more affective at increasing alveolar ventilation? increasing TV or increasing frequency? why?
Increasing frequency while maintaining a constant volume results in proportional increase of both alveolar ventilation and dead space
Increasing tidal volume while maintaining constant frequency results in no change to dead space but an increase in alveolar ventilation
Answer: increasing tidal volume is more effective to increase VA than increasing breathing frequency
125
Age effects
Decreased alveolar elasticity/ lung compliance
higher residual volume
Loss of alveolar surface area
Decreased pulmonary perfusion.
126
Pathological Disorders : RESTRICTIVE (PISAM)
```
Decrease compliance and vital capacity
PISAM
Pulmonary fibrosis
sarcoidosis
Interstitial lung disease
Myasthenia Gravis
ALS
```
127
Pathological Disorders : OBSTRUCTIVE
```
interfere with airflow, expiration requires more effort o ris less complete
ACE
Asthma
COPD
Emphysema
```
128
REVIEW Composition of air is a mixture of gases and
| At sea level?
each contributes to its partial pressure
At sea level 1 atm of pressure = 760 mmHg
Nitrogen constitutes 78.6% at the atmophere
129
REVIEW Partial pressures as well as _____________ determine ____________of each gas and __________between blood and alveolus
solubility of gas
Rate of diffusion
Gas exchange.
130
Henry's law: amount of gas that dissolve in _______is determined by its _________in water and its __________
– amount of gas that dissolves in water is
determined by its solubility in water and its
partial pressure in air
131
Factors affecting gas exchange
```
Concentration gradient
Gas solubility
Membrane thickness
Surface area
Ventilation perfusion coupling --> are
O2 has increased conc. gradient
CO2 has increased solubility
```
132
Ventilation perfusion coupling
Areas of good ventilation need good perfusion
133
Oxygen transport: Concentration in arterial blood
98. 5% bound to hemoglobin
| 1. 5% dissolved
134
Explain binding to hemoglobin
each heme group of 4 globin chains my bind O2
Oxyhemoglobin (HbO2)
Deoxyhemoglobin (HHb)
135
Oxygen Transport : Oxyhemoglobin Dissociation curve
Relationship between hemoglobin saturation and PO2 is not a simple linear one
after binding with O2, the shape of hemoglobin change to make it easier for further UPTAKE (which is a positive feedback cycle)
136
Factors decreasing affinity (RIGHT SHIFT)
```
CADET face Right
C increased PCO2
A Acidosis (decreases pH)
D 2,3 DPG high
E Exercise
T Temperature, High
```
137
Curve: x axis and y-axis is
PaO2; SaO2
138
Factors increasing affinity (left shift)
```
Alkalosis
Decreased PCO2
Low level 2,3 DPG
Carboxyhemoglobin
Methemoglobin
Abnormal hemoglfon
```
139
CO2 transport
Carbonic acid - 70%
Carbaminohemoglobin - 23%
Dissolved gas 7%
140
Review CO2 loading GAS exchange at tisses systemic
```
Carbonic anhydralase in RBC catalyzes
• CO2 + H2O →H2CO3 → HCO3- + H+
Chloride shift: Keep reaction proceeding
O2 unloading : H+ binding to HbO2, decreased affinity for O2 (hb arrives 97% saturated, leaves 75% saturates, venous reserve
Amount of O2 released in 22%
```
141
Review Gas Exchange at lung (alveolar)
– as Hb loads O2 its affinity for H+ decreases,
H+ dissociates from Hb and bind with HCO3-
• CO2 + H2O ←H2CO3 ← HCO3- + H
-Reverse Chloride shift
• HCO3- diffuses back into RBC in exchange
for Cl-, free CO2 generated diffuses into
alveolus to be exhaled
142
What is essential for the generation of the respiratory rhtynm? it is part of what respiratory group?
Pre Botzinger complexv
| ventral respiratory group
143
FRC (functional residual capacity)
is the volume remaining in the lungs at the end of a normal tidal expiration.
144
Compliance
Change in V / Change in P
145
What affects recoil
Age and pathologies
