Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FHB - Pulmonary & Renal - Exam 2 > Pulmonary 9 - Lecture 31 > Flashcards

Pulmonary 9 - Lecture 31 Flashcards

1
Q

What is the affect of High Altitude on

  1. Barometric pressure
  2. PO2
A

Both decrease!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the PiO2 at a Barometric Pressure of 255 mmHg (high altitude)?

What is the PAO2?

A

PiO2: 0.21 x (255-47mmHg) = 44 mmHg

PCO2 = 40 mmHg, respiratory ratio = 1

PalveolarO2 = 43 – 40/1 = 3 mmHg !

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is acclimatization achieved at high altitudes where the PO2 is low?

A

Acclimitization via Hyperventilation

  • 5 fold increase in PO2!

PalveolarO2 = 43 – 8/1 = 35 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do people achieve hyperventilation in high altitudes with PaCO2 of 33 mmHg?

A

HYPOXIC STIMULATION of peripheral chemoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens initially at high altitudes due to hyperventilation?

A

Respiratory Alkalosis due to low PaCO2 and high pH

  • this initially inhibits further ventilation, but is adjusted within several days & hyperventilation is further increased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does Polycythemia normalize O2 concentration? How is polycythemia achieved?

A
  1. Increases RBC concentration
    - via erythropoietin from Kidney (takes days/weeks)
  2. Increase Hb/O2 carrying capacity
    - although Saturation may decrease, the total Oxygen per dL of blood is relatively high due to the increased Hematocrit

(higher Hb = more Oxygen can build up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the normal Hb, SO, and Oxygen content per ml/dl

A

normal Hb = 15 g/dL
SO = 95%
19.1 mL O2/dl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the only blood at high altitude that has relatively similar PO2 to sea level?

A

Mixed Venous Blood!

  • only 7 mmHg difference
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the initial affect of 2,3- DPG because of high altitudes? What is the secondary affect?

A
  1. RIGHTWARD shift of O2 binding curve
    - O2 dissociates easier
  2. LEFTWARD shift once alkalosis occurs, due to hyperventilation (low CO2 - better loading of Oxygen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the affect of alveolar hypoxia on Pulmonary Vasculature? (2 clinical correlates)

A
  1. Pulmonary Vasocontriction
  2. Pulmonary Edema
  3. Right Heart Hypertrophy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Because the air is less dense at high altitudes, what happens to the breathing capacity?

A

Maximal Breathing Capacity Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Acute Mountain Sickness? What 2 clinical cases can this progress into?

A
  1. Headache, fatigue, dizziness, nausea
  2. Pulmonary Edema
  3. Cerebral Edema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Chronic Mountain Disease?

A

Polycethemia, Fatigue, Reduced Exercise TOlerance, Hypoxemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the increase in pressure for every 10 m/33ft depth increase ?

A

Pressure doubles!

  • lung is compressed, so volume decreases (breathing is reduced)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the primary and secondary responses of the DIVING REFLEX? What is it induced by?

A

INDUCED BY APNEA

  1. Primary - Peripheral Vasoconstriction due to Sympathetic Activity
    = initial hypertension
  2. Secondary - Vagal induced Bradycardia & reduction of CARDIAC OUTPUT

= slow HR to spare oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the primary purpose of Bradycardia within the context of the diving reflex?

A

Slow HR = decrease CO and decrease Oxygen Use

17
Q

What are the 3 important affects of the diving reflex?

A
  1. Sympathetic Peripheral Vasoconstriction = increase BP
  2. Decrease HR (vagally induced bradycardia)
    - O2 saturation is maintained
  3. Increase Hb by splenic contraction
18
Q

What is the pO2 that hypoxic loss of consciousness occurs at?

A

PO2 of 20-25 mmHg

19
Q

How does Hyperventilation lead to LOC? What input is overridden?

A
  1. Reduces CO2 drive to breath (low CO2 = less of a stimulus to increase ventilation)
  2. Weak Respiratory Stimulus from Hypoxia is OVERRIDDEN voluntarily by low CO2

(the low CO2 has a greater affect than the low O2)

20
Q

How does Ascent Blackout occur?

A

Reduction of Water Pressure & Gas Pressure causes a decrease in pO2 content

(due to lower pressure = lower O2 partial pressure)

  • need to slowly ascend to avoid LOC at 20-25 mmHg of PO2
21
Q

How does carbohydrate depletion lead to Hypoxic Loss of Consciousness?

A

Less CO2 produced by metabolism

  • reduces CO2 drive to breath
22
Q

What are the 3 reasons that LOC can occur in Breath Holders?

A
  1. Hyperventilation - low CO2
  2. Ascent Blackout - low PO2
  3. Carbohydrate Depletion - Low CO2

1 and 3 have a common theme = LOW CO2! = loss of CO2 drive to breath

23
Q

What is the affect of barotrauma of descent?(2) Why does this happen?

A
  1. Lung Edema
  2. Damage
    - Atelectasis
    - Capillary Rupture

Pressures redistribute & increase in certain areas
ex: Capillary Hydrostatic pressure increases and causes pulmonary edema

Pressures redistribute because LUNG VOLUME redistributes (occurs at low PRESSURES
ex: submerging head underwater)

24
Q

What is maintained in Barotrauma of Descent & what is lost?

A
  1. Compression of lung
  2. Redistribution of blood volume

LOST:

  1. Atelectasis
  2. Edema
  3. Capillary Rupture
25
Q

What is Decompression Sickness?

A

Nitrogen content increases in the tissues as the pressure increases (when diving)

  • since more Nitrogen pushed into the tissues, the blood needs time to equilibrate since it is poorly soluble

Nitrogen Diffuses out as you ascend to lower pressures
- causes the formation of NITROGEN BUBBLES

  • can function like emboli and lead to pain in joints etc..
26
Q

What is Inert Gas Narcosis?

A

High levels of N2 in the blood due to diving to HIGH PRESSURES

at 50 m: EUPHORIA

at deeper levels: Loss of Coordination/Coma

27
Q

What affects to N2 and O2 have at high pressures?

A

N2 and O2 affect the CNS

O2 affects the Lung

28
Q

What is the affect of oxygen toxicity in the CNS? (Hyperbaric O2)

In the lung? What levels must it reach to cause damage in the lung?

A
  1. Vomiting, Dizziness, Vision Impairment, seizures
    - HIGH LEVELS OF OXYGEN
  2. Must reach FiO2 > 0.4 - 0.5

Damage of endothelial cells of
pulmonary capillaries

Substernal pain during breathing

Impaired gas exchange

Reduction of vital capacity

Atelectasis

Retrolental fibroplasia in premature
infants  fibrotic tissue due to increased O2

29
Q

What is Hyperbaric O2 therapy used for?

A
  1. CO poisoning
  2. Anemic Crisis
  3. Gas Gangrene (anaerobic bacteria)
  4. Impaired bone/wound healing
  • use dissolved Oxygen for CO poisoning
30
Q

What is the most important problem at high altitude? How can this be resolved?

A

Low PO2

  • HYPERVENTILATION
31
Q

How does high altitude lead to the formation of Pulmonary Vasoconstriction, Right Heart Hypertrophy, and Pulmonary Edema?

A

via ALVEOLAR HYPOXIA

32
Q

What is the main purpose of the Diving Response?

A

SPARE OXYGEN

FHB - Pulmonary & Renal - Exam 2 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions