Page 1 of 54
USPS EXAM 421 WINDOW CLERK FOR THE UNITED
STATES POSTAL SERVICE TEST EXAM NEWEST
2026 ACTUAL EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) ALL
ANSWERED/ ALREADY GRADED A+ | BRAND NEW!
| 100% GUARANTEED PASS
Which statement is true regarding respiratory physiology?
1. Ventilation is the process of moving gases into and out of the
lungs.
2. The diaphragm is the major expiratory muscle of respiration.
3. Ventilation requires muscular properties irrespective of the
elastic properties of the lungs.
4. The diaphragm is innervated by the phrenic nerve that exits
the cranium. - ANSWER: 1. Ventilation is the process of moving
gases into and out of the lungs
Which condition causes bluish discoloration of the skin and mucous
membrane?
3|Page
1. Hypoxia
2. Dehydration
,Page 2 of 54
3. Hyperlipidemia
4. Right sided cardiac failure - ANSWER: 1. Hypoxia
Which condition causes decreased tissue oxygenation
because of the decreased oxygen-carrying capacity of the
blood?
1. Obesity
2. Anemia
3. Pregnancy
4. Neuromuscular disease - ANSWER: 2. Anemia
A nurse is taking a health history of a newly admitted patient
with a diagnosis of possible fecal impaction. Which question is
the priority to ask the patient or caregiver?
1. Have you eaten more high fiber foods lately
2. Have you taken antibiotics recently
3. Do you have gluten intolerance
4. Have you experienced frequent, small liquid stools recently -
ANSWER:
Have you experienced frequent, small liquid stools recently?
Which information is correct regarding physiological factors that
affect oxygenation?
1. Metabolic rate decreases normally in pregnancy,
wound healing, and exercise.
2. The physiological response to chronic hypoxemia is an
increase in white blood cell production.
,Page 3 of 54
3. Carbon monoxide (CO) poisoning decreases the oxygen-
carrying capacity of the blood.
4. The oxygen-carrying capacity of the blood increases when
there is a decline in inspired oxygen concentration. - ANSWER:
3. Carbon monoxide (CO) poisoning decreases the oxygen-
carrying capacity of the blood.
Which skills can the nurse delegate to assistive personnel (AP)?
(Select all that apply.)
, Page 4 of 54
2|Page
1. Initiate oxygen therapy via nasal cannula.
2. Perform nasotracheal suctioning of a patient.
3. Educate the patient about the use of an incentive spirometer.
4. Assist with care of an established tracheostomy tube.
5. Reposition a patient with a chest tube. - ANSWER: 4.
Assist with care of an established trach tube
5. Reposition a patient with a chest tube
The nurse is caring for a patient with pneumonia. On entering the
room, the nurse finds the patient lying in bed, coughing, and
unable to clear secretions. What should the nurse do first?
1. Start oxygen at 2L/min via nasal cannula
2. Elevate the head of the bed to 45 degrees
3. Encourage the patient to use incentive spirometer
4. Notify the health care provider - ANSWER: 2. Elevate the
head of the bed to 45 degrees
Hyperkalemia - ANSWER: higher than 5
causes: burns, acute kidney failure, excessive potassium
supplements
Hyperkalemia s/s - ANSWER: Muscles weakness
hypotension diarrhea
hyperactive bowel sounds flat P wave
USPS EXAM 421 WINDOW CLERK FOR THE UNITED
STATES POSTAL SERVICE TEST EXAM NEWEST
2026 ACTUAL EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) ALL
ANSWERED/ ALREADY GRADED A+ | BRAND NEW!
| 100% GUARANTEED PASS
Which statement is true regarding respiratory physiology?
1. Ventilation is the process of moving gases into and out of the
lungs.
2. The diaphragm is the major expiratory muscle of respiration.
3. Ventilation requires muscular properties irrespective of the
elastic properties of the lungs.
4. The diaphragm is innervated by the phrenic nerve that exits
the cranium. - ANSWER: 1. Ventilation is the process of moving
gases into and out of the lungs
Which condition causes bluish discoloration of the skin and mucous
membrane?
3|Page
1. Hypoxia
2. Dehydration
,Page 2 of 54
3. Hyperlipidemia
4. Right sided cardiac failure - ANSWER: 1. Hypoxia
Which condition causes decreased tissue oxygenation
because of the decreased oxygen-carrying capacity of the
blood?
1. Obesity
2. Anemia
3. Pregnancy
4. Neuromuscular disease - ANSWER: 2. Anemia
A nurse is taking a health history of a newly admitted patient
with a diagnosis of possible fecal impaction. Which question is
the priority to ask the patient or caregiver?
1. Have you eaten more high fiber foods lately
2. Have you taken antibiotics recently
3. Do you have gluten intolerance
4. Have you experienced frequent, small liquid stools recently -
ANSWER:
Have you experienced frequent, small liquid stools recently?
Which information is correct regarding physiological factors that
affect oxygenation?
1. Metabolic rate decreases normally in pregnancy,
wound healing, and exercise.
2. The physiological response to chronic hypoxemia is an
increase in white blood cell production.
,Page 3 of 54
3. Carbon monoxide (CO) poisoning decreases the oxygen-
carrying capacity of the blood.
4. The oxygen-carrying capacity of the blood increases when
there is a decline in inspired oxygen concentration. - ANSWER:
3. Carbon monoxide (CO) poisoning decreases the oxygen-
carrying capacity of the blood.
Which skills can the nurse delegate to assistive personnel (AP)?
(Select all that apply.)
, Page 4 of 54
2|Page
1. Initiate oxygen therapy via nasal cannula.
2. Perform nasotracheal suctioning of a patient.
3. Educate the patient about the use of an incentive spirometer.
4. Assist with care of an established tracheostomy tube.
5. Reposition a patient with a chest tube. - ANSWER: 4.
Assist with care of an established trach tube
5. Reposition a patient with a chest tube
The nurse is caring for a patient with pneumonia. On entering the
room, the nurse finds the patient lying in bed, coughing, and
unable to clear secretions. What should the nurse do first?
1. Start oxygen at 2L/min via nasal cannula
2. Elevate the head of the bed to 45 degrees
3. Encourage the patient to use incentive spirometer
4. Notify the health care provider - ANSWER: 2. Elevate the
head of the bed to 45 degrees
Hyperkalemia - ANSWER: higher than 5
causes: burns, acute kidney failure, excessive potassium
supplements
Hyperkalemia s/s - ANSWER: Muscles weakness
hypotension diarrhea
hyperactive bowel sounds flat P wave
