PHR 241 Exam 3 Histamines
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Antagonists of histamine's actions have important clinical uses.
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True
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False
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In the study of medicine, histamine is an organic nitrogenous compound which is involved in local immune responses. It also regulates physiological function in the gut and acts as a neurotransmitter for the brain, spinal cord and uterus.
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- 2.
First generation antihistamines possess anti-cholinergic activity.
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True
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False
Correct Answer
A. TrueExplanation
First generation antihistamines, such as diphenhydramine and chlorpheniramine, do possess anti-cholinergic activity. This means that they not only block the effects of histamine, but also block the effects of acetylcholine, a neurotransmitter involved in various bodily functions. This can result in side effects such as dry mouth, blurred vision, constipation, and urinary retention. Therefore, the statement that first generation antihistamines possess anti-cholinergic activity is true.Rate this question:
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- 3.
Which histamine receptor-has an effect on gastric parietiel cells, cardiac muscle, and some smooth muscle-is Gs coupled-causes an elevation in cAMP
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H1
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H2
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H3
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H4
Correct Answer
A. H2Explanation
The correct answer is H2. Histamine receptor H2 has an effect on gastric parietal cells, cardiac muscle, and some smooth muscle. It is Gs coupled, which means it activates the Gs protein and stimulates the production of cyclic adenosine monophosphate (cAMP), leading to various physiological responses.Rate this question:
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- 4.
Histamine receptors are what type of receptors?
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Ligand-gated ion channels
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GPCR
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Channel-linked receptors
Correct Answer
A. GPCRExplanation
Histamine receptors are classified as GPCRs (G-protein coupled receptors). GPCRs are a large family of cell surface receptors that are involved in signal transduction. They are characterized by their ability to activate intracellular signaling pathways through the interaction with G-proteins. Histamine receptors, when activated by histamine, initiate a cascade of cellular responses by activating G-proteins and modulating downstream signaling pathways. Therefore, histamine receptors are categorized as GPCRs.Rate this question:
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- 5.
2nd generation drugs have an extended duration of actoin
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True
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False
Correct Answer
A. TrueExplanation
Second-generation drugs are a newer class of medications that have been developed to improve upon the limitations of first-generation drugs. One of the key improvements is their extended duration of action. This means that these drugs remain active in the body for a longer period of time, allowing for less frequent dosing and potentially improving patient compliance. Therefore, the statement that second-generation drugs have an extended duration of action is true.Rate this question:
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- 6.
Antihistamines can have a paradoxical effect on children. (ie. insomnia, nervousness, tremors)
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True
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False
Correct Answer
A. TrueExplanation
Antihistamines, despite being commonly used to treat allergies and induce drowsiness, can have the opposite effect on children. This means that instead of causing sleepiness, they may experience insomnia, nervousness, and tremors. Therefore, the statement that antihistamines can have a paradoxical effect on children is true.Rate this question:
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- 7.
Antihistamines are an effective treatment in bronchial asthma
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True
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False
Correct Answer
A. FalseExplanation
Antihistamines are not considered an effective treatment for bronchial asthma. While antihistamines can help with allergies and symptoms such as sneezing and itching, they do not have a significant impact on the airway inflammation and constriction that occurs in asthma. The mainstay of asthma treatment includes bronchodilators (such as inhalers) and anti-inflammatory medications (such as corticosteroids). Therefore, the statement that antihistamines are an effective treatment in bronchial asthma is false.Rate this question:
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- 8.
Edema is mediated by which histamine receptor?
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H1
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H2
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H3
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H4
Correct Answer
A. H1Explanation
Edema is the accumulation of fluid in the tissues, and it is mediated by the H1 histamine receptor. Histamine is a chemical released by the body during an allergic reaction or inflammation. When histamine binds to the H1 receptor, it causes blood vessels to dilate and become more permeable, leading to fluid leakage into the surrounding tissues and resulting in edema. The H1 receptor is primarily responsible for the allergic response, including symptoms such as itching, redness, and swelling.Rate this question:
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- 9.
Which histamine receptor is the main receptor that causes a direct decrease in blood pressure?
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H1
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H2
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H3
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H4
Correct Answer
A. H1Explanation
Mainly H1... but some H2 dependencyRate this question:
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- 10.
2nd generation antihistamines blcok muscarinic receptors.
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True
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False
Correct Answer
A. FalseExplanation
first generation ones do... 2nd mostly do not...Rate this question:
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- 11.
Which of the following is/are not true regarding histamines?
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They are autocoids
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They are distantly acting hormones
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They mediate immediate allergic reactions
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They function as a neurotransmitter
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They regulate gastric acid secretions
Correct Answer
A. They are distantly acting hormonesExplanation
THey are LOcALLY acting hormones! :)Rate this question:
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- 12.
Histamine has clinical applications
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True
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False
Correct Answer
A. FalseExplanation
Histamine does have clinical applications, particularly in the field of medicine. It is involved in various physiological processes and is used in the diagnosis and treatment of certain medical conditions. Therefore, the statement that histamine has clinical applications is incorrect.Rate this question:
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- 13.
Histamine is a majore player in human asthmas.
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True
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False
Correct Answer
A. FalseExplanation
It does NOT play a role, however, asthmatic airways still respond greatly to histamine.Rate this question:
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- 14.
Physiological antagonists bind to the receptor.
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True
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False
Correct Answer
A. FalseExplanation
WIKI: Physiological agonism and antagonism is the mechanism of substances to induce the same ultimate effects in the body as other substances, as if they were receptor agonists or antagonists, but without binding to the same receptor.Rate this question:
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- 15.
H2 receptors mediate contraction of intestinal smooth muscle
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True
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False
Correct Answer
A. FalseExplanation
H1 receptors mediate contraction of intestinal smooth muscle
H2 receptors mediate parietal cell acid production in gastric mucosaRate this question:
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- 16.
Antihistamines are good decongestants
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True
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False
Correct Answer
A. FalseExplanation
The statement "antihistamines are good decongestants" is false. Antihistamines are medications that are primarily used to relieve allergy symptoms such as sneezing, itching, and runny nose. They work by blocking the effects of histamine, a substance released by the body during an allergic reaction. While antihistamines can help with some symptoms of congestion, they are not as effective as decongestants in relieving nasal congestion. Decongestants work by narrowing the blood vessels in the nasal passages, reducing swelling and congestion. So, while antihistamines can provide some relief for congestion, they are not considered to be good decongestants.Rate this question:
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- 17.
Which of the following is/are not true regarding H1 histamine receptors?
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They are found in smooth muscle
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They are Gs coupled
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They cause elevation in IP3, Ca2+, and diacylglycerol
Correct Answer
A. They are Gs coupledExplanation
They are Gq coupledRate this question:
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- 18.
Which histamine receptor regulates the release of neurotransmitters in the brain and myenteric plexus?
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H1
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H2
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H3
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H4
Correct Answer
A. H3Explanation
It is Gi coupled to N-type calcium channelsRate this question:
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- 19.
Antihistamines are physiological antagonists of histamine
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True
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False
Correct Answer
A. FalseExplanation
They are histamine receptor antagonists... competitive H1 receptor blockers.Rate this question:
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- 20.
The axon relfex is the direct action on ______ receptors on sensory nerve endings and/or depolariztion of efferent axons.
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H1
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H2
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H3
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H4
Correct Answer
A. H1Explanation
The correct answer is H1 because the axon reflex involves the direct action on H1 receptors on sensory nerve endings and/or depolarization of efferent axons. This suggests that H1 receptors play a role in initiating the axon reflex response.Rate this question:
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- 21.
2nd generation antihistamines are more effective than 1st generation ones.
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True
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False
Correct Answer
A. FalseExplanation
Equally effectiveRate this question:
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- 22.
Whcih of the following is/are not second generation antihistamines?
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Diphenhydramine
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Fexofenadine
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Loratidine
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Pyrilamine
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Cetirizine
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Promethazine
Correct Answer(s)
A. Diphenhydramine
A. Pyrilamine
A. PromethazineExplanation
Diphenhydramine, pyrilamine, and promethazine are not second-generation antihistamines because they are first-generation antihistamines. First-generation antihistamines are known to cause drowsiness and have a shorter duration of action compared to second-generation antihistamines. Fexofenadine, loratadine, and cetirizine, on the other hand, are second-generation antihistamines that have a longer duration of action and are less likely to cause drowsiness.Rate this question:
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- 23.
Which of the following is/are adverse effects of antihistamines?
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Sedation
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Dry mouth
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Blurred vision
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Urinary excretion
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Increased GI motility
Correct Answer(s)
A. Sedation
A. Dry mouth
A. Blurred visionExplanation
urinary RETENTION
DECREASED GI motilityRate this question:
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- 24.
Which of the following is/are true about physiological antagonists of histamine.
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They bind to the same receptor as histamine
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They are bronchoconstrictors
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They are vasodilators
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They are inhibitors of degranulation
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None of the above are true
Correct Answer
A. They are inhibitors of degranulationExplanation
they are vasoconstrictors
They are are bronchodilatorsRate this question:
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- 25.
Which of the followingcardiovascular effects of histamine is/are indicative of histamine release in the skin?
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Decrease in BP
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Headache
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Edema
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Heat, redness and local swelling
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Urticaria or hives
Correct Answer(s)
A. Heat, redness and local swelling
A. Urticaria or hivesExplanation
The cardiovascular effects of histamine that are indicative of histamine release in the skin are heat, redness, and local swelling. These symptoms are commonly associated with an allergic reaction and are caused by the dilation of blood vessels in the skin, leading to increased blood flow and the characteristic redness and swelling. Urticaria or hives, which are also listed as the correct answer, are another common skin manifestation of histamine release and are characterized by itchy, raised welts on the skin.Rate this question:
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- 26.
Which of the following are effective decongestants?
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Antihistamines
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Phenylephrine
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Pseudoephedrine
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Oxymetazoline
Correct Answer(s)
A. Phenylephrine
A. Pseudoephedrine
A. OxymetazolineExplanation
Phenylephrine, pseudoephedrine, and oxymetazoline are all effective decongestants. Decongestants work by constricting blood vessels in the nasal passages, reducing swelling and congestion. Phenylephrine is commonly found in over-the-counter nasal sprays and oral medications. Pseudoephedrine is also available over-the-counter and is often used in combination with other medications to treat congestion. Oxymetazoline is a nasal spray that provides fast relief from nasal congestion. These decongestants are effective in relieving symptoms of nasal congestion caused by allergies, colds, or sinus infections.Rate this question:
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- 27.
Histamine is found is which of the following location(s)?
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Vesicular granules of mast cells or basophils
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Neuronal tissue in the brain
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Enterochromaffin-like cells in teh fundus of the stomach
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Venoms
Correct Answer(s)
A. Vesicular granules of mast cells or basophils
A. Neuronal tissue in the brain
A. Enterochromaffin-like cells in teh fundus of the stomach
A. VenomsExplanation
Histamine is found in vesicular granules of mast cells or basophils, neuronal tissue in the brain, enterochromaffin-like cells in the fundus of the stomach, and venoms.Rate this question:
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- 28.
WHich of teh following cuases a release of histamine?
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Type II Allergic reactions
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Venoms
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Toxins
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Radiation
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Warm temperatures
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Some drugs
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Mechanical injury
Correct Answer(s)
A. Venoms
A. Toxins
A. Radiation
A. Some drugs
A. Mechanical injuryExplanation
TYPE I Immediate allergic reactions
COLD temperatures!Rate this question:
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- 29.
Which of the following are major pharmacological effects fo antihistamines?
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Sedation
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Increased and thickened secretions
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Increased heart rate
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Reversal of histamine-induced vasodilation
Correct Answer(s)
A. Sedation
A. Increased heart rate
A. Reversal of histamine-induced vasodilationExplanation
decreased and thickened secretionsRate this question:
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Mar 20, 2023Quiz Edited by
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Nov 08, 2010Quiz Created by
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