Harvard Flashcards
(29 cards)
1
Q
Which of the following acid-base changes is consistent with hypoventilation (decreased respiratory rate)?
A
decreased pH, increased pCO2
2
Q
- Based on the principle of osmotic forces, if the concentration of solute outside of a cell is
148 mmol and the concentration of solute inside of a cell is 160 mmol, how would you expe fluid to move?
A
Fluid will move from outside the cell into the cell.
3
Q
- Upon expiration, the pressure within the thoracic cavity increases. This will___
transmural pressure of the airways and make airway collapse___likely
A
Increase, less
4
Q
- A healthy woman gets into a car accident and her left kidney is injured, requiring remova Compared to her state prior to the accident, the woman’s systemic vascular resistance immediately after the kidney removal is
A
Higher
5
Q
- For a given airflow, narrower airways lead to _-____ making airways more prone to collapse. (fill in the blank)
A
higher velocity airflow, making flow more likely to be turbulent
6
Q
- A patient is admitted to your hospital clinic with a reduced respiratory rate and tidal volur (breath size). You order an “arterial blood gas”, a test where arterial blood is drawn and the levels of oxygen, CO2, bicarbonate, as well as the pH are measured. The results come back and reveal that the patient’s blood pH is not as low as expected given her arterial pCO2 valu Of what might this be an indication? (select two answers)
A
• increased reabsorption of bicarbonate in the kidney
• prolonged duration of the respiratory acidosis
7
Q
- Which of the following statements is true with respect to the perfusion of the myocardium (heart muscle) and skeletal muscle?
Note that systole refers to the phase of ventricular contraction; diastole is the phase of ventricular relaxation.
A
Myocardial perfusion is greatest during diastole, while skeletal muscle perfusion is greatest during systole.
8
Q
- While you are taking care of a patient in the ICU, your supervisor hands you the following set of lab values and asks you to calculate the patient’s cardiac output.
Arterial oxygen saturation (SaO»): 100%
Venous oxygen saturation (SvO2): 70%
Hgb: 15 g/dL
Arterial oxygen content (CaO2): 20.1 mL. 02/dL - Venous oxygen content (CvO2): 14.1 mL O2/dL
Oxygen consumption: 240 mL O-/min
A
Cardiac Output (CO) = 4 L/min
• Enter your answer as a number; do not write in the units.
9
Q
- You inflate a balloon to 1L at sea level where the atmospheric pressure is 760 mmg. You then take this balloon with you as you pilot a spaceship to Mars, where the atmospheric pressure is 6 mmHg. When you step out of your spaceship on Mars, the balloon’s size will__
because the transmural pressure___
A
Decreased : decreased
10
Q
- Sandra, a 20-year-old college runner, is having increasing difficulty keeping up in what used to be “easy” workouts. She sees the team physician, who takes a careful history and performs a physical examination before ordering some standard blood tests. His findings reveal that Sandra is anemic, likely from dietary iron deficiency. Her hemoglobin level (Hgb) is 11.0 grams/100 mL. blood (the normal range is 12.0 - 15.5). How does the partial pressure of oxygen (PO2) in Sandra’s blood at the present time compare to the partial pressure in her blood a year ago, when she had a Hgb of 13.5 grams/100mL.? Assume that she is otherwise healthy.
A
The partial pressure is about the same as it was before
11
Q
- A 55-year-old man arrives in the emergency department in diabetic ketoacidosis (a diabetic
emergency due to insufficient insulin) with a blood sugar of 515 (normal = 80-120 mg/dL) and
an arterial pH of 7.11 (normal = 7.35 - 7.45). Your supervising physician asks you to predict the
effect of the patient’s condition on the activity of the enzymes in his body.
A
the increased proton concentration in the patient’s blood likely impairs enzyme function
12
Q
- An overworked heart that has to generate more force against high blood pressures can eventually develop ventricular hypertrophy, in which the walls of the ventricles of the heart become thicker and stiffer. Compared to a typical heart, a heart with this disease will have ___
A
decreased compliance
13
Q
- The atmospheric pressure at sea level on Earth is 760 mmg; in contrast, the atmospheric pressure on Mars is less than 1% of that, only 5 mmHg. Mars’ atmosphere is 2% N2 gas. What is the partial pressure of N2 in the Mars atmosphere?
Please enter a numeric answer rounded to one decimal point, in units of mmg
A
0.1mm Hg
14
Q
- Below are hypothetical pressures within and round an alveolus in the lung of a healthy adult and a patient with emphysema during a forced expiration. Given that patients with emphysema have “floppy airways” and are more susceptible to airway collapse, match the diagram with the correct diagnosis.
A
Scenario A - healthy adult; Scenario B -patient with emphysema
15
Q
- A 23-year-old woman presents to the emergency department with a four day history of nausea, vomiting, and diarrhea. She reports not being able to eat anything during for the past four days and has had persistent vomiting and diarrhea. In this scenario, the patient’s fluid intake has ___ and her fluid output has___
resulting in a ___ in the patients weight (assume all other factors have remained constant).
A
decreased: increased: decrease
16
Q
- During a long period of fasting, the body is depleted of carbohydrates and relies instead on proteins and fats as fuel sources. How does the respiratory quotient (RQ) change in an individual over the course of fasting (from the time of initiating the fast onward)?
A
RQ decreases during fasting.
17
Q
- Below is the graph of minute ventilation (VE) versus oxygen consumption (VO2) for a healthy person undergoing an exercise physiology test. At a certain point during intense exercise, VE begins to increase at a greater rate than VO2 (the red dot on the graph). Which of the following is a reasonable explanation for why this occurs?
A
to facilitate buffering of protons in the bloodstream resulting from the lactic acid production of anaerobic respiration
18
Q
- Consider a condition in which there is a severe acute aortic stenosis, in which the aortic valve (the valve controlling outflow of the left side of the heart) suddenly becomes narrowed.
In the setting of a sudden, severe narrowing of the valve, which of the following is true?
A
Cardiac output is reduced; oxygen delivery to the body’s tissues is reduced.
19
Q
- Imagine a blood vessel with a vessel wall that is permeable to water but not proteins.
Assuming no change in pressures outside the vessel, how would you adjust the pressures in the vessel to maximize the intravascular volume?
A
Decrease hydrostatic pressure and increase oncotic pressure.
20
Q
20.. All of the following result in the production of metabolic acid except
A
aerobic metabolism.
21
Q
- All of the patients below will have a build-up of respiratory acid (H2CO3) EXCEPT
A
a patient with an aspirin overdose who is breathing rapidly and deeply.
22
Q
- Activation of the baroreceptors in response to hypotension results in sympathetic nervous system activation, including the release of epinephrine, which acts to constrict blood vessels.
It dos not have the same effect on all vessels. Upon which two of the following systems do you predict it exerts the least vasoconstrictive effect? (select two answers)
A
skeletal muscle, brain
23
Q
- A patient is told by his primary care doctor to take a medication every day at the same times three times a day to match the intake and excretion of the drug as closely as possible.
While on vacation, the patient loses track of his medications and takes his meds four times a day by accident. Which of the following statements is true?
A
The drug concentration in the body will increase, and steady state will not be maintained.
24
Q
- A healthy 24-year-old is breathing room air at rest with an oxygen saturation of 100%.
Which intervention would lead to the greatest increase in the oxygen content of his blood?
A
None
25
26. The compliances of two balloons are tested. Balloon A requires pumping air into it to achieve a pressure of 30 cm H2O to inflate it to 1L in size. Balloon B requires pumping air into it to achieve a pressure of 50 cm H2O to inflateit to 1L in size. Which of the following statements describes the compliance of these balloons?
Balloon B is more compliant.?
26
27. Based on the principle of osmotic forces, if the concentration of solute outside of a cells is
160 mmol and the concentration of solute inside of the cell is 148 mmol, how would you expect to change?
The cell will decrease in size
27
28. The atmospheric pressure at the sea level on Earth is 760 mmg; in contrast; th tmospheric pressure on Mars is less than 1% of that, only 5mmHg. Mars' atmosphere is 96°
CO2 gas. What is the partial pressure of CO2 in the Mars atmosphere?
4.8 mmHg
28
29. In the heart disease dilated cardiomyopathy, the walls of the ventricles of the heart become weak, which leads to them filling to a larger volume for any given pressure within the heart. Compared to a typical heart with this disease will have
Increased compliance
29
30. Upon inspiration, the pressure within the thoracic cavity decreses. This will and make airway collapse likely
Increase, less. ?
