Local anesthetics: A. Inhibit transmission of nerve impulses by increasing sodium membrane permeability and the displacement of ionized calcium. B. Are classified as amides or esters. C. Produce peripheral vasodilation. D. Are weak acids.

Local anesthetics: A.  Inhibit transmission of nerve impulses by increasing sodium membrane permeability and the displacement of ionized calcium. B.  Are classified as amides or esters. C.  Produce peripheral vasodilation. D.  Are weak acids.
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Answer: BC  DISCUSSION: Local anesthetics act within the nerve membrane, where they inhibit transmission of nerve impulses by reducing sodium membrane permeability and the displacement of ionized calcium. All local anesthetics consist of a hydrophilic region and a hydrophobic region separated by an alkyl chain. The bond of the alkyl chain is either an ester or an amide, and these drugs are classified based on this bond. All local anesthetics except cocaine produce vasodilatation and are weak bases
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Description : Which of the following adrenergic inhibitors acts directly on the blood vessels, producing vasodilation? a) Prazosin hydrochloride (Minipress) Minipress is a peripheral vasodilator acting ... through centrally mediated alpha-adrenergic stimulation in the brain, producing blood pressure reduction.

Last Answer : a) Prazosin hydrochloride (Minipress) Minipress is a peripheral vasodilator acting directly on the blood vessel. It is not used in angina and coronary artery disease, however, because it induces tachycardia if not preceded by administration of propranolol and a diuretic.

The following is not true of local anaesthetics: A. The local anaesthetic is required in the unionized form for penetrating the neuronal membrane B. The local anaesthetic approaches its receptor only from the intraneuronal face of the Na+ channel C. The local anaesthetic binds to its receptor mainly when the Na+ channel is in the resting state D. The local anaesthetic combines with its receptor in the ionized cationic form

Description : The following is not true of local anaesthetics: A. The local anaesthetic is required in the unionized form for penetrating the neuronal membrane B. The local anaesthetic approaches its receptor ... the resting state D. The local anaesthetic combines with its receptor in the ionized cationic form

Last Answer : C. The local anaesthetic binds to its receptor mainly when the Na+ channel is in the resting state

Which element is essentials for the transmission of impulses in the nerve fibre?

Description : Which element is essentials for the transmission of impulses in the nerve fibre?

Last Answer : Calcium

Which is an example of negative feedback? A) Nursing action stimulates the hypothalamus to release oxytocin that triggers mammary gland milk production. B) When the blood becomes dilute, ADH is no longer released from the hypothalamus. C) Uterine stretching sends nerve impulses to the hypothalamus that releases oxytocin that triggers uterine contraction. D) FSH and LH stimulate the gonads to produce sperm or eggs. E) TRH stimulates the anterior pituitary to release thyroid-stimulating hormone.

Description : Which is an example of negative feedback? A) Nursing action stimulates the hypothalamus to release oxytocin that triggers mammary gland milk production. B) When the blood becomes dilute, ADH ... produce sperm or eggs. E) TRH stimulates the anterior pituitary to release thyroid-stimulating hormone.

Last Answer : B) When the blood becomes dilute, ADH is no longer released from the hypothalamus

Carbimazole differs from propylthiouracil in that: A. It is dose to dose less potent B. It has a shorter plasma half life C. It does not produce an active metabolite D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

Description : Carbimazole differs from propylthiouracil in that: A. It is dose to dose less potent B. It has a shorter plasma half life C. It does not produce an active metabolite D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

Last Answer : D. It does not inhibit peripheral conversion of thyroxine to triiodothyronine

Which of the following statement(s) is/are true concerning the neuroendocrine responses to shock? a. Sympathetic nerve endings release epinephrine which is responsible for greater than 80% of systemic vascular resistance b. Endogenous epinephrine is the primary contributor to systemic vascular resistance c. Increased pancreatic secretion of glucagon contributes to glucose intolerance associated with injury and sepsis d. The renin-angiotensin axis further augments the sympathetic-mediated vasoconstriction

Description : Which of the following statement(s) is/are true concerning the neuroendocrine responses to shock? a. Sympathetic nerve endings release epinephrine which is responsible for greater than 80% ... injury and sepsis d. The renin-angiotensin axis further augments the sympathetic-mediated vasoconstriction

Last Answer : Answer: c, d The neuroendocrine response to shock attempts to achieve restoration of effective blood volume, mobilization of metabolic substrates, and maintenance of central ... . Angiotensin II is an extremely effective vasoconstrictor that further augments sympathetic-mediated vasoconstriction

Chemically, fats are esters of long carbon-chain acids and which of the following: w) ethanol x) glycerol y) ethylene glycol z) sodium hydroxide

Description : Chemically, fats are esters of long carbon-chain acids and which of the following: w) ethanol x) glycerol y) ethylene glycol z) sodium hydroxide

Last Answer : ANSWER: X -- GLYCEROL

What are the side effects of local anesthetics?

Description : What are the side effects of local anesthetics?

Last Answer : It really is dependant on which local anaesthetic is used and how the person metabolizes it. Novacaine and cocaine for instance are both fairly common dental anaesthetics in the US, but each has a different effect on the user.

Wounds are classified according to the likelihood of bacterial contamination. Which of the following statement(s) is/are true concerning wound classifications? a. A clean-contaminated wound would be that associated with an elective colon resection with adequate mechanical and antibiotic bowel preparation b. A contaminated wound would include a resection of obstructed bowel with gross spillage of intestinal contents c. In a clean wound, no viscus is entered d. Antibiotic prophylaxis should be administered for all clean-contaminated and contaminated wounds and selectively in patients involving a clean wound

Description : Wounds are classified according to the likelihood of bacterial contamination. Which of the following statement(s) is/are true concerning wound classifications? a. A clean-contaminated wound would ... all clean-contaminated and contaminated wounds and selectively in patients involving a clean wound

Last Answer : Answer: a, b, c, d Wounds are classified under three classes according to the likelihood of bacterial contamination: 1) clean (no viscus is entered; e.g., herniorrhaphy); 2) clean- ... tenet involves cases in which a prosthetic material may be used (artificial joint, heart valve, tissue patch)

Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and chemical barriers at the mucus membrane level c. Most of the microorganisms found in the oropharynx eventually pass into the intestine d. In the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Description : Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and ... the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Last Answer : Answer: b, d The composition of the gut microflora is established in neonates after ingestion of microbes that are acquired during contamination from the birth canal and during initial feeding, and ... small number of aerobes are present, these microbes being outnumbered 100-300 to 1 by anaerobes

Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of reactions which lead to a variety of cellular injuries. Oxidants are derived from several sources, notably phagocytes. Among the effects of oxygen free radicals are membrane lipid peroxidation, DNA strand breaks, cytoskeletal disassembly and inhibition of glucose metabolism leading to decreased cellular ATP concentrations. (Figure 6-16) 187 Which of the following acute-phase protein levels are increased in human plasma following acute inflammation? a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin

Description : Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of ... a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin

Last Answer : Answer: a, b, c, d The acute-phase response is a series of homeostatic responses of the organism to tissue injury in infection and inflammation. After an inflammatory stimulus occurs, a number ... 30% to 50% of the level before injury. The reason for the decrease in production is poorly understood

Platelet activating factor is: a. Generated by the action of phospholipase A2 on membrane phospholipids b. Antiinflammatory in most of its actions c. Synthesized by endothelial and other cells d. Exerts a variety of biologic effects which are platelet-independent

Description : Platelet activating factor is: a. Generated by the action of phospholipase A2 on membrane phospholipids b. Antiinflammatory in most of its actions c. Synthesized by endothelial and other cells d. Exerts a variety of biologic effects which are platelet-independent

Last Answer : Answer: a, c, d Like the eicosanoids, platelet-activating factor (PAF) is not stored in cells but is rapidly produced during inflammation. PAF exerts a variety of biologic effects ... and LTB4. There is considerable overlap and redundancy in the effects produced by PAF and eicosanoids

Which of the following statements regarding the complement system are true? a. Complement activation yields products which are directly cytotoxic as well as products which act indirectly via activated leukocytes b. Complement products referred to as anaphylatoxins include C1, C3a, C4a, and C5a c. The principal role of C5a is in bacterial opsonization d. The alternative and classical pathways converge proximal to generating the membrane attack complex (C5b-9)

Description : Which of the following statements regarding the complement system are true? a. Complement activation yields products which are directly cytotoxic as well as products which act indirectly via activated ... and classical pathways converge proximal to generating the membrane attack complex (C5b-9)

Last Answer : Answer: a, d The complement system is composed of two different but linked sequences, the classic and alternative pathways. The pathways involve serum proteins that act to amplify the inflammatory-immune ... the C5 level proximal to generating the membrane attack complex (C5b-9) (Figure 6-3)

Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of the following statement(s) is/are true concerning intracellular receptors? a. The messengers or hormones must by lipophilic b. These intracellular receptors generally regulate protein synthesis c. The intracellular receptors are located entirely in the nucleus of the cell d. A heat-shock protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein