Nokea
The optimum pH for trypsin and chymotrypsin is about
- A. 1-3.
- B. 5-7.
- C. 7-9.
- D. 10-12.
Correct Answer: C
Rationale: The correct answer is C (7-9) because trypsin and chymotrypsin are proteolytic enzymes that function optimally in slightly basic environments. At pH 7-9, these enzymes maintain their structural integrity and catalytic activity. Choices A, B, and D are incorrect because trypsin and chymotrypsin are not acidic enzymes, so pH ranges 1-3 and 10-12 would denature and inactivate them, while pH 5-7 is still on the acidic side, not optimal for these enzymes.
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A sudden decrease in blood volume would be met by increases in epinephrine, antidiuretic hormone (vasopressin) and angiotensin II. What EFFECT would the increase in these three hormones ALL HAVE IN COMMON?
- A. increased heart rate
- B. increased fluid retention and blood volume
- C. increased PNS activity
- D. vasoconstriction and increased total peripheral resistance
Correct Answer: D
Rationale: The correct answer is D: vasoconstriction and increased total peripheral resistance. Epinephrine, antidiuretic hormone, and angiotensin II all act to increase vasoconstriction, leading to an increase in total peripheral resistance. This response is crucial during a sudden decrease in blood volume to maintain blood pressure and ensure adequate perfusion to vital organs.
Choice A (increased heart rate) is not correct because while epinephrine can increase heart rate, antidiuretic hormone and angiotensin II do not directly affect heart rate.
Choice B (increased fluid retention and blood volume) is not correct because antidiuretic hormone and angiotensin II can increase fluid retention, but epinephrine does not have this effect.
Choice C (increased PNS activity) is not correct because these hormones actually stimulate the sympathetic nervous system (SNS) leading to vasoconstriction and increased blood pressure, not the parasympath
Which of these processes occurs in the mouth?
- A. ingestion
- B. mechanical digestion
- C. chemical digestion
- D. all of the above
Correct Answer: D
Rationale: In the mouth, ingestion occurs when food is taken in. Mechanical digestion occurs through chewing and mixing food with saliva. Chemical digestion begins with enzymes in saliva breaking down carbohydrates. Therefore, all processes (ingestion, mechanical digestion, and chemical digestion) occur in the mouth. Other choices are incorrect because they do not encompass all the processes that happen in the mouth.
A hiatal hernia is a weakness in the _____ muscle, which allows a portion of the digestive tract to enter the thoracic cavity.
- A. diaphragm
- B. stomach
- C. intestinal
- D. thoracic wall
Correct Answer: A
Rationale: The correct answer is A: diaphragm. The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities. A hiatal hernia occurs when the stomach pushes through the opening in the diaphragm known as the esophageal hiatus, allowing a portion of the stomach to enter the thoracic cavity. The other choices, B: stomach, C: intestinal, and D: thoracic wall, are incorrect because a hiatal hernia specifically involves a weakness in the diaphragm muscle, not in these other structures. The stomach is the organ affected by the hernia, but the primary issue lies in the diaphragm's weakness. The intestinal and thoracic wall choices are not directly related to the development of a hiatal hernia.
Priority Decision: In instituting a bowel training program for a patient with fecal incontinence, what should the nurse first plan to do?
- A. Teach the patient to use a perianal pouch.
- B. Insert a rectal suppository at the same time every morning.
- C. Place the patient on a bedpan 30 minutes before breakfast.
- D. Assist the patient to the bathroom at the time of the patient's normal defecation.
Correct Answer: D
Rationale: The correct answer is D because assisting the patient to the bathroom at the time of their normal defecation helps establish a routine for bowel movements, which is crucial in bowel training. This step maximizes the chances of success by utilizing the body's natural cues. Teaching the patient to use a perianal pouch (A) does not address the underlying issue of incontinence. Inserting a rectal suppository (B) may provide temporary relief but does not promote long-term bowel control. Placing the patient on a bedpan (C) at a specific time does not actively involve the patient in the process of bowel training.
The hydrogen ions that form hydrochloric acid of the stomach come from
- A. lactic acid.
- B. carbonic acid.
- C. citric acid.
- D. acetic acid.
Correct Answer: B
Rationale: The correct answer is B: carbonic acid. Carbonic acid is produced when carbon dioxide reacts with water in the stomach, forming hydrogen ions that combine with chloride ions to create hydrochloric acid. Lactic acid (A), citric acid (C), and acetic acid (D) do not directly contribute to the formation of hydrochloric acid in the stomach. Therefore, they are incorrect choices for this question.