PSL301: Respiratory 6

Question 1

what is considered high altitude?

Answer 1

> 1500 m

Question 2

main problem at high altitudes?

Answer 2

hypoxia

Question 3

What is the partial pressure of O2 in dry air?

Answer 3

253 x 0.21 = 53 mmHg

Question 4

How does the peripheral chemoreflex respond to hypoxia?

Answer 4

• Will increase ventilation rate faster
• more dramatic increase
• begin responding at lower pCO2 levels

Question 5

What happens to the hemoglobin saturation curve when hyperventilating?

Answer 5

• CO2 decreases
• H+ decreases
• pH increases (basic)
• more O saturation at tissues (does not release)

Question 6

long term consequences of hypoxia

Answer 6

• release of erythropoietin

- synthesis of 2,3-DPG in RBC

Question 7

What effect does 2,3-DPG have on the hemoglobin saturation curve?

Answer 7

right shift

- Hb has less affinity for O2

Question 8

2,3-DPG is an intermediate of the ___ pathway

Answer 8

glycolysis

Question 9

When does 2,3-DPG degrate?

Answer 9

When blood is stored

Question 10

What conditions are related to high altitude? Which are very serious?

Answer 10

1. mountain sickness
2. high altitude pulmonary edema **
3. high altitude cerebral edema **

Question 11

mountain sickness symptoms

Answer 11

• headache
• irritability
• insomnia
• breathlessness
• nausea
• vomitting

Question 12

symptoms of mountain sickness is caused by…

Answer 12

cerebral autoregulation of blood flow

Question 13

symptoms of high altitude pulmonary edema

Answer 13

• swelling of lungs
• shortness of breath
• cough pink frothy fluid

Question 14

high altitude pulmonary edema

Answer 14

hypertension in the lungs

Question 15

high altitude cerebral edema

Answer 15

swelling of the brain

Question 16

high altitude cerebral edema symptoms

Answer 16

• ataxia
• disorientation
• coma & death (due to capillary leakage)
• brain swelling
• herniation of brain through the tentorium

Question 17

herniation of brain through the tentorium

Answer 17

brain is pushed out through a hole towards the cerebellum if swelling is severe

Question 18

ataxia

Answer 18

cannot control muscles

Question 19

what happens during pulmonary edema?

Answer 19

Normally, lungs vasoconstrict blood vessels around aveoli that have low pO2 and pCO2 to increase efficiency. At high altitudes, all alveoli have low pO2 and pCO2 so all blood vessels become constricted.

• increased blood pressure
• pushes fluid out of vessels
• fluid surrounds alveoli, making it harder for gas exchange

Question 20

prevention of hypoxia

Answer 20

acetazolamide

Question 21

what does acetazolamide do?

Answer 21

• stops CA enzyme
• diuretic: reduce fluid in body
• forces the kidneys to excrete bicarb: want less alkaline conditions

Question 22

treatment for hypoxia

Answer 22

• go to lower altitude

- give O2

Question 23

treatment for cerebral edema

Answer 23

glucocorticoids

- anti-inflammatory

Question 24

treatment for pulmonary edema

Answer 24

Nifedipine: lower pulmonary artery pressure by blocking L-type Ca++ channels

Question 25

what happens to oxygen levels during exercise?

Answer 25

increases (log graph), then plateaus high for duration of exercise

Question 26

What happens to oxygen levels at the end of exercise?

Answer 26

Rapid decrease (hyperbola)

Question 27

what is used to deliver more oxygen to muscles during exercise?

Answer 27

respiratory & cardiovascular systems

Question 28

What is the limiting factor during exercise?

Answer 28

cardiovascular system

Question 29

What components of the respiratory system is affected during exercise?

Answer 29

- TV - breathing frequency - ventilation

Question 30

What components of the cardiovascular system is affected during exercise?

Answer 30

- SV - HR - CO

Question 31

Regulation of blood flow during exercise

Answer 31

21% goes to skeletal muscles @ rest 88% goes to skeletal muscles @ exercise CO: 6 L/min -> 30 L/min

Question 32

How does the respiratory system know to increase ventilation during exercise?

Answer 32

1. motor system tells skeletal muscles to contract -> sends info to medulla, which tells breathing to increase 2. proprioceptors in muscles tell respiratory center to increase breathing 3. chemoreceptors can also cause increased breathing

Question 33

Difference between aerobic -> anaerobic respiration

Answer 33

- arterial pH drops - venous pO2 drops - arterial pCO2 drops a little - ventilation increases

Question 34

what does not change between aerobic & anaerobic respiration?

Answer 34

``` arterial pO2 arterial pCO2 (somewhat) ```

Question 35

What causes the decrease in pH during anaerobic exercise

Answer 35

lactic acid

Question 36

How can ventilation be increased in response to exercise signal? [rapid response]

Answer 36

1. mechanoreceptors & proprioceptors in exercising limbs send info to medulla 2. tells it to increase respiration 3. descending motor commands that go to muscles spill over to medulla

Question 37

How can ventilation be increased in response to exercise signal? [slow response]

Answer 37

1. receptors in muscles & blood vessels send signals to medulla 2. central & peripheral chemoreceptors

Question 38

define: cardio-respiratory fitness

Answer 38

- ability to perform large muscle, dynamic, moderate/high intensity exercise for prolonged periods - ability to transport and use oxygen

Question 39

cardio-respiratory fitness is measured as...

Answer 39

max oxygen consumed during intense whole body exercise (VO2 max)

Question 40

higher VO2max means someone is ___ fit

Answer 40

more

Question 41

VO2max indicates...

Answer 41

max aerobic work that an individual can achieve

Question 42

how to measure VO2max directly?

Answer 42

- make person work at max capacity - measure O2 consumption - units: L/min or mL/kg/min

Question 43

How to normalize VO2 max values?

Answer 43

divide by weight

Question 44

value: VO2 max for young males

Answer 44

3 - 3.5 L/min

Question 45

value: VO2 max for young females

Answer 45

2 - 2.5 L/min

Question 46

value: normalized VO2 max for young males

Answer 46

45 - 50 mL/kg/min

Question 47

value: normalized VO2 max for young females

Answer 47

35 - 45 mL/kg/min

Question 48

what is considered an excellent normalized VO2 max value for males?

Answer 48

>60

Question 49

what is considered an excellent normalized VO2 max value for females?

Answer 49

>55

Question 50

What test is used to estimate VO2 max?

Answer 50

Astrand Fitness Test

Question 51

steps of the Astrand Fitness Test

Answer 51

1. exercise at known work rate for 5-6 min to reach steady state 2. measure heart rate using pulse in the last minute of exercise 3. use tables to look up VO2 max using HR, age, sex

Question 52

assumptions of the Astrand Fitness Test

Answer 52

1. Aerobic work is proportional to oxygen uptake, independent of the type of work 2. oxygen uptake is proportional to CO, which is proportional to HR 3. max heart rate is the same for all individuals of the same age and sex 4. the slope of the HR vs. work is the same for all individuals

Question 53

How to determine the fittest individual looking at the result of an Astrand Fitness Test?

Answer 53

- which has the lowest resting HR? (smaller y axis) | - which has the highest work rate? (bigger x axis)

Question 54

Long-term benefits of aerobic exercise:

Answer 54

- higher oxidative capacity of skeletal muscle - incr. CO - decreased resting HR - incr. max HR - increase blood vlume - decrease BP - increase number of capillaries - increase VO2 max - maintain body weight - improve psychological function - decrease risk of chronic disease - increase life span

Question 55

what are some chronic diseases that are affected by exercise?

Answer 55

- diabetes - osteoporosis - cancer - heart disease - Alzheimer's disease

Question 56

Why might exercise help those with diabetes?

Answer 56

improves glucose tolerance & insulin secretion