Nokea
Which form of intestinal smooth muscle contraction does NOT occur in normal health?
- A. peristalsis
- B. weak antiperistalsis
- C. peristaltic rushes
- D. tonic contractions
Correct Answer: C
Rationale: The correct answer is C: peristaltic rushes. Peristaltic rushes are abnormal and excessive contractions that can result in diarrhea or bowel urgency. In normal health, peristalsis (A) is the coordinated contraction and relaxation of intestinal smooth muscles that moves contents along the digestive tract. Weak antiperistalsis (B) refers to reverse contractions that are weaker than normal peristalsis. Tonic contractions (D) are sustained contractions that help maintain muscle tone and control flow. Therefore, peristaltic rushes are the only option that does not occur in normal health due to their abnormal and disruptive nature.
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The posterior pituitary stores and releases .
- A. prolactin and oxytocin
- B. oxytocin and antidiuretic hormone (ADH)
- C. ADH and growth hormone
- D. growth hormone and prolactin
Correct Answer: B
Rationale: The correct answer is B: oxytocin and antidiuretic hormone (ADH).
1. The posterior pituitary stores and releases oxytocin and ADH.
2. Oxytocin is responsible for uterine contractions and milk ejection.
3. ADH regulates water balance by controlling water reabsorption in the kidneys.
Therefore, B is the correct answer.
A, C, and D are incorrect because prolactin, growth hormone, and other hormones are not stored or released by the posterior pituitary.
In relation to noradrenaline, all of the following are true EXCEPT:
- A. It stimulates α and β receptors
- B. It decreases heart rate
- C. It decreases blood pressure
- D. Causes vasoconstriction
Correct Answer: C
Rationale: Rationale:
- Noradrenaline stimulates both α and β receptors, leading to increased heart rate and vasoconstriction.
- It does not decrease heart rate; it actually increases heart rate due to its actions on β receptors.
- Noradrenaline causes vasoconstriction by activating α receptors, leading to increased blood pressure.
- The incorrect statement is C, as noradrenaline actually increases blood pressure by causing vasoconstriction.
Ritodrine is a drug indicated for suppressing uterine contractions in premature labor. The drug also causes bronchodilation. It has no vasoconstrictor effects, nor any effects on the size of the pupil of the eye. Which of the following is the most likely classification of this drug?
- A. α-adrenergic agonist
- B. Antimuscarinic drug
- C. β-adrenergic agonist
- D. β-adrenergic blocker
Correct Answer: C
Rationale: The correct answer is C: β-adrenergic agonist. Ritodrine is indicated for suppressing uterine contractions, which is a typical effect of β-adrenergic agonists. Bronchodilation is also a known effect of β-adrenergic agonists. Since the drug has no vasoconstrictor effects and does not affect the size of the pupil of the eye, it is unlikely to be an α-adrenergic agonist or an antimuscarinic drug. Additionally, the fact that ritodrine causes bronchodilation further supports its classification as a β-adrenergic agonist.
Jan, an insulin-dependent diabetic, was admitted to the emergency room with hypoglycemia after playing tennis all afternoon. The probable cause of this reaction was
- A. increased exercise level
- B. insufficient insulin dosage
- C. increased food intake
- D. increased glucagon production
Correct Answer: A
Rationale: Increased exercise can cause hypoglycemia in insulin-dependent diabetics by using up glucose in the body more quickly than the insulin can manage.
The pituitary gland is related laterally to:
- A. The cavernous sinus
- B. Hypothalamus
- C. Diaphragma sellae
- D. Optic chiasma
Correct Answer: A
Rationale: Step 1: The pituitary gland is located in the sella turcica of the sphenoid bone.
Step 2: The cavernous sinus is a venous sinus located on each side of the sella turcica.
Step 3: The pituitary gland lies laterally to the cavernous sinus.
Step 4: Therefore, the correct answer is A: The cavernous sinus.
Summary: B is incorrect as the hypothalamus is superior to the pituitary gland. C is incorrect as the diaphragma sellae is a part of the dura mater covering the pituitary gland. D is incorrect as the optic chiasma is located superior to the pituitary gland.