c1. BASIC SCIence C (155-226) Flashcards Preview

Nagelhout Anesthesia Review > c1. BASIC SCIence C (155-226) > Flashcards

Flashcards in c1. BASIC SCIence C (155-226) Deck (72):

155. surfactant is produced by:
a. type II pneumocytes
b. type I and II pneumocytes
c. type I pneumocytes
d. all pneumocytes are capable of producing surfactant

a. type II pneumocytes
lecithin/sphingomyelin (L/S) ratio is an assessment of surfactant in the lungs. Type II pneumocytes produce surfactant with an L/S ratio less than 1 at 32 weeks; 2 by 35 weeks and 4-6 at term (38 weeks)


156. decreased levels of surfactant in the preterm infant lead to all of the following except:
a. decreased compliance
b. decreased work of breathing
c. collapse of alveoli
d. impaired gas exchange

b. decreased work of breathing
premature infants with inadequate surfactant production suffer from respiratory distress syndrome (RDS). Therefore, you would expect an increase in work of breathing, hypoxemia, and acidosis


157. All are true of a caudal block except:
a. the injection is made in the epidural space
b. the chateter is advanced cephaad at a 45 degree angle to the skin
c. a triangle is drawn using the sacral hiatus and the posterior superior iliac spine
d. the bevel of the needle faces posteriorly

d. the bevel of the needle faces posteriorly
The bevel of the needle should face ANTERIORLY. The drug is injected in the epidural space with a volume of 1 to 2 ml per spinal segment anesthetized. 12-15 ml is required to fill the sacral canal.


158. The preferred anticholinergic for pediatrics is:
a. glycopyrrolate
b. atropine
c. scopolamine
d. hydroxyzine

b. atropine
atropine is the preferred anticholinergic agent in children. It is more effective in blocking the cardiac vagus and causes less drying of secretions than the others.


159. all of the following are components of tetrology of fallot except:
a. atrial septal defect
b. right ventricular hypertrophy
c. overriding aorta
d. pulmonary stenosis

a. ASD
Tetrology of fallot classically includes: right ventricular hypertrophy, overriding aorta, pulmonary stenosis and right ventricular obstruction


160. concurrent use of what eye drops can result in prolongation of succinylcholine or mivacurium
a. pilocarpine
b. timolol
c. cyclopentolate
d. echothiophate iodide

d. echothiphate iodide
also known as phospholine iodide is a long acting cholinesterase inhibitor. Therefore, with systemic absorption, patients may be at risk for low levels of cholinesterase.


161. Anesthetic management for the infant who presents for pyloric stenosis repair includes all of the following except:
a. rehydration
b. rapid sequence induction with cricoid pressure
c. avoid nitrous oxide
d. insertion of nasogastric tube before induction

c. avoid nitrous oxide
there is no reason to avoid nitrous oxide in children with pyloric stenosis and no proof of increased gastric pressure when nitrous oxide is delivered. Because these children are at such a high risk of aspiration, a rapid sequence induction, insertion of orogastric tube and rehydration to replace fluids are all necessary.


162. The most common reason a child needs to be admitted after a planned same day surgery is:
a. sore throat
b. vomiting
c. sleep apnea
d. excessive lethargy

b. vomiting
nausea and vomiting are very common in children. They occur after numerous operations; especially eye surgery, ENT procedures and abdominal operations. Efforts similar to those in adults to reduce the incidence of nausea and vomiting are equally important.


163. all of the following are known triggers of malignant hypertension except:
a. sevoflurane
b. sucinylcholine
c. halothane
d. vecuronium

d. vecuronium
most nondepolarizing muscle relaxants including vecuronium are known to be safe in patients withh malignant hyperthermia. The muscle relaxant to avoid is succinlycholine as well as ALL inhalation anesthetics EXCEPT nitrous oxide.


164. The majority of blood flow to the liver is derived from the
a. portal vein
b. hepatic artery
c. vena cava
d. mesenteric artery

a. portal vein
normal hepatic blood flow is about 1500 ml/min in adults. Twenty five to thirty percent is from the hepatic artery and 70-75% is from the portal vein.


165. all of the following are true of the oculocardiac reflex except:
a. the afferent pathway is CN III
b. the efferent pathway is CN X
c. it fatigues easily
d. it can be prevented by prophylactic use of atropine

a. the afferent pathway is CN III
the afferent pathway is via the TRIGEMINAL nerve (CN V), with the efferent pathway via the VAGUS nerve (CN X)


166. maintaining normal body temp is more difficult in infants than in adults because of all of the following except:
a. larger surface to volume ratio
b. increased total body water
c. increased metabolic rate
d. lack of sufficient body fat

b. increased total body water
to maintain normal body temperature, infants and children create heat by metabolizing brown fat, crying and moving vigorously, but, unlike adults, rarely by shivering


167. all of the following are true of the kidneys at birth except:
a. decreased concentrating ability
b. decreased GFR
c. decreased sodium excretion
d. increased renal blood flow

d. increased renal blood flow
the kidneys at birth are characterized by a decreased GFR, decreased sodium excretion and decreased concentrating ability. The GFR increases 2 to 3fold by 3 months. Adult renal function is reached at about 2 yrs of age. At 12 mos old, they have normal concentrating ability.


168. the primary reason increased doses of muscle relaxants are necessary for infants is:
a. immature hepatic system
b. decreased extracellular fluid volume
c. increased volume of distribution
d. increased GFR

c. increased volume of distribution
infants and neonates are more sensitive to muscle relaxants. However, higher doses are required because of higher volume of distribution resulting from high extracellular volume


169. all of the following are characteristic symptoms of laryngo-tracheo-bronchitis except:
a. high fever
b. airway obstruction
c. slow onset
d. barking cough

a. high fever
laryngotracheobronchitis is differentiated from epiglottitis in that it usually occurs in children 2 years or younger and is not accompanied by high fever. Its cause is viral and it develops gradually over 1-3 days.


170. laryngotracheobronchitis most often affects:
a. toddlers
b. children younger than 6 yrs
c. there is no age significance
d. children younger than 2 years

d. children younger than 2 years
laryngobronchitis usually occurs in children younger than 2 yrs old. In contrast, epiglottitis is most frequent in children ages 2-6 years old.


171. all are true of epiglottitis except:
a. it is accompanied by drooling
b. its cause is viral
c. it is less common than croup
d. affected children insist on sitting up

b. its cause is viral
epiglottitis is bacterial not viral, therefore antibiotics are indicated


172. the maximum dose of dantrolene is:
a. 5 mg/kg
b. 2.5 mg/kg
c. 10 mg/kg
d. 1 mg/kg

c. 10 mg/kg
the maximum dose of dantrolene is 10 mg/kg. starting dose is 2.5 mg/kg repeated as necessary up to 10 mg/kg. Dantrolene should be supplemented every 4-6 hours


173. an infant born with a scaphoid abdomen, profound arterial hypoxemia and a shift of the mediastinum is most likely has:

a. congenital diaphragmatic hernia
diaphragmatic hernia results from the incomplete closure of the diaphragm such that intestinal contents occupy the chest. manifestations at birth include scaphoid abdomen, profound arterial hypoxemia, pulmonary hypertension and congenital heart disease


174. The infant with pyloric stenosis manifests all of the following except:
a. hypochloremia
b. hypokalemia
c. dehydration
d. acidosis

d. acidosis
infants with pyloric stenosis generally present at 2 to 5 weeks of age with a loss of hydrogen ions from vomiting. Alkalosis, hypokalemia (and hypochloremia) and dehydration result


176. the half life of an empty "E" cylinder of N20 has a psi of:
a. 750
b. 500
c. 1100
d. 325

a. 750
the pressure in the tank will remain unchanged at 750 to 760 psi as long as there is any liquid left in the tank. The rest of the tank fills with vapor, thus maintaining the pressure.


177. cardiac output is altered in infants by:
a. systemic vasoconstriction
b. increasing stroke volume
c. increased heart rate
d. right to left shunt

c. increased heart rate
infants are much more dependent on changes in heart rate in response to environmental factors than in changes in stroke volume. As infants grow, their cardiovascular system becomes less dependent on rate and more in line functionally with that of adults. An immature baroreceptor reflex contributes to this phenomenon.


178. all of the following are true of the pediatric pulmonary system except:
a. smaller airways
b. increased airway resistance
c. higher closing volumes
d. larger alveoli

d. larger alveoli
the pediatric pulmonary system is characterized by smaller alveoli. There is a 13-fold growth in the number of alveoli between birth and 6 years of age and a 3-fold growth between age 6 years to adulthood


175. infants are at increased risk for retinopathy of prematurity up to:
a. 36 weeks
b. 44 weeks
c. 48 weeks
d. 50 weeks

b. 44 weeks
retinopathy of prematurity is most common in infants younger than 44 weeks after conception. Other factors may include multiple blood transfusions, apnea requiring mechanical ventilation, parenteral nutrition and hypoxemia


180. catecholamines are found in:
a. organs of Zuckerkandi
b. chromaffin cells
c. preganglionic fibers of the sympathetic nervous system
d. adrenal cortex

b. chromaffin cells
catecholamines are synthesized in the chromaffin cells which originate embreyonically from the neural crest
-organ of zuckerandi secretes catecholamines as a fetus (but is a potential sight of pheochromocytoma)
-postganglionic fibers in sympathetic nervous system (not pre),
-adrenal medulla has catecholamines (not cortex)


181. the most common symptom associated with pheochromocytoma is:
a. palpitations
b. excessive sweating
c. elevated basal metabolic rate
d. hypertension

d. hypertension
headache is actually the most common symptom; after that are hypertension and tachycardia are the most common symptoms of pheochromocytoma which accounts for 0.1% of all cases of HTN (HHTPD (headache, hypertension, tachycardia, palpitations, diaphoresis))
-palpitations, excessive sweating, and weight loss d/t elevated BMR are symptoms but less common;
-other symptoms include pallor, anxiety, elevated glucose


182 a. select the statement regarding muscle relaxation in patients with myasthenia gravis:
a. resistance to succinylcholine is common
b. patients have an increased number of acetylcholine receptors postjunctionally
c. nondepolarizing muscle relaxants should not be used
d. recovery from succinylcholine is shortened
182 b. what is the treatment for MG?

a. resistance to succinylcholine is common
Myasthenia gravis is when antibodies block ACH receptors at NMJ, therefore resistance to sux is common. A higher dose is usually needed (2 mg/kg). Still a prolonged effect of sux should be anticipated since MG is treated with anticholinesterase drugs (pyridostigmine, neostigmine, physostigmine) in order to increase muscle strength.
182 b. anticholinesterase drugs (pyridostigmine, neostigmine, physostigmine); definitive treatment for MG is thymectomy.


183. A diastolic murmur is characteristic of:
a. floppy valve syndrome
b. aortic stenosis
c. aortic insufficiency
d. mitral stenosis

c. aortic insufficiency
the common diastolic murmurs are associated with:
-aortic regurg/ insufficiency
-pulmonic regurg
-mitral stenosis
-tricuspid regurg
systolic murmurs (i.e. aortic and pulmonic stenosis; tricuspid stenosis, mitral prolapse or insufficiency).


184. All of the following produce systolic murmurs except:
a. aortic insufficiency
b. mitral insufficiency
c. aortic stenosis
d. tricuspid stenosis

a. aortic insufficiency
systolic murmurs are produced by pulmonary, aortic or tricuspid stenosis; hypertrophic cardiomyopathy, mitral valve regurg or prolapse & VSD


185. The main blood supply to the lumbar area of the spinal cord is by means of the:
a. posterior radicular artery
b. artery of Adamkiewicz
c. epidural veins
d. neuromedullary arteries

b. artery of Adamkiewicz
A singel segmental branch of the aorta is called the artery of Adamkiewicz. It supplies nearly all of the flow to the lower thoracic and lumbar segment. Injury to this artery renders the entire segment of spinal cord at risk for ischemia.


186. normal cerebral blood flow is:
a. 30 ml/100 g per imnute
b. 40 ml/ 100 g per minute
c. 70 ml/100 g per minute
d. 50 ml/100 g per minute

d. 50 ml/100 g (of brain)/min
Average cerebral blood flow is 50 ml/100 grams per minute; however flow in grey matter is about 80 ml, whereas in white matter it is about 20 ml. Thus, the 50 mL average. Total cerebral blood flow is about 750 ml/min which is about 15-20% of total cardiac output.


179. all of the following are secreted by the adrenal medulla except:
a. cortisol
b. dopamine
c. epinephrine
d. norepinephrine

a. cortisol
the adrenal gland is divided into 2 parts. The adrenal cortex secretes androgens and mineralcorticoids (aldosterone and glucocorticoids such as cortisone). The medulla secretes catecholamines (epinephrine, norepinephrine and dopamine).


187. Blood flow that is in excess of metabolic need is:
a. luxury perfusion
b. intracerebral steal
c. inverse steal
d. reverse perfusion

a. luxury perfusion
The combination of a reduceion in neuronal metabolic demand with an increase in cerebral blood flow has been termed luxury perfusion. This occurs most commonly with the inhalation anesthetic agents.


188. what kind of elecrtocautery practice or use is safest for patients with pacemakers?
a. electrocautery used in short bursts no more frequently than every 10 seconds
b. electrocautery current as low as possible
c. electrocautery ground plate be placed as far as possible from the pulse generator
d. all of the above

d. all of the above
despite improved shielding from the artificial cardiac pacemaker, all the steps are still recommended when caring for a patient with a pacer. Nerve stimulators are safe, but should be used on the opposite arm if possible.


189. The vapor pressure of a liquid is most dependent on the:
a. atmospheric pressure
b. specific heat of the container
c. temperature
d. concuctivity of the container

c. temperature
the vapor pressure of a liquid is mostly dependent on the evironmental temperature in which it exists. It is independent of atmospheric pressure.


190. Identify four characteristics of the circle system:
a. conservaton of gases, heat, and moisture and minimal operating room pollution and control of anesthetic depth
b. conservation of gases, heat, and moisture and minimal exhaustion of CO2 absorber
c. maximum humidification efficiency of gas usage, minimal operationg room polution and economy
d. all of the above

a. conservation of gasses, heat and moisture; minimal operating room pollution and control of anesthetic depth
The circle system characteristics include rebreathing of exhaled gasses, conservation of heat and humidity and scavenging of gasses and control of anesthetic depth.


191. Where does the fresh gas flow enter the breathing circuit in the circle system?
a. between the absorber and inspiratory valve
b. between the absorber and expiratory valve
c. between the reservoir bag and the absorber
d. between the reservoir bag and inspiratory valve

a. between the absorber and inspiratory valve
The fresh gas inlet is placed between the absorber and inspiratory valve to allow for mixing of some fresh gas with rebreathed gas. This also avoids absorption and release by soda lime before inspiration


192. What two blood products increase factor VIII?
a. fresh frozen plama and platelets
b. cryoprecipitate and fresh frozen plasma
c. packed red blood cells and platelets
d. packed red blood cells and fresh frozen plasma

-b. FFP and cryo
The most common inherited defect is homeostasis factor VIII (aka hemophelia A). FFP is considered to have 1 unit of factor VIII activity per mL. Cryo has 5 to 10 units per mL. Factor VIII concentrate has 40 units/mL. Factor VIII levels greater than 50% are optimal before surgery.


193. What cellular structure is responsible for metabolizing anesthetic gasses?
a. reductive metabolism
b. hepatic microsomes
c. oxidative metabolism
d. alveolar diffusion

b. hepatic microsomes
The smooth endoplasmic reticulum of hepatic cells contains the oxidative cytochrome enzymes responsible for most drug metabolism in the body. These sites are sometimes referred to as MICROSOMES.


194. Anesthetic partial pressure in the brain depends on:
a. solubility of the agent
b. minimal alveolar concentration of the agent
c. second gas effect
d. anesthetic partial pressure in the alveoli

-d. anesthetic partial pressure in the alveoli
The partial pressure of an anesthetic in the brain is always equivalent to the partial pressure in the alveoli. The alveolar membrane and the blood brain barrier do not represent obstacles to diffusion. The amount in the brain will always approximate the amount in the lungs.


195. What nerve is a part of the afferent pathway in the oculocardiac reflex?
a. trigeminal
b. vagus
c. gasserian
d. trochlear

-a. trigeminal
The oculocardiac reflex is trigeminovagal. The afferent pathway is by way of the ciliary ganglion to the opthalmic division to the opthalmic dividion of the trigeminal nerve and through the gasserian ganglion to the main sensory nucleus of the fourth ventricle. The EFFERENT pathway is the vagus nerve.


196. The apneustic center is located in the:
a. hypothalamus
b. pons
c. medulla
d. spinal cord

b. pons
the apneustic center is located in the lower part of the pons. The function of the apneustic center is not understood, but is presumed to operate in association with the pneumotaxic center to control depth of inspiration.


197. Dorsal root nerves are:
a. cholinergic
b. adrenergic
c. motor
d. sensory

-d. sensory
The spinal dorsal horn and root nerves and its analogous area in the medulla are complex sensory processing areas.


198. Approximately 90% of the blood supply to the brain is supplied by the:
a. external carotid artery
b. internal carotid artery
c. vertebral artery
d. middle cerebral artery

-b. internal carotid artery
The cerebral circulation comes from the internal carotid artery, the anterior and posterior communicating arteries


199. The adrenal medulla secretes approximately ____% of the epinephrine and _____% of the norepinephrine:
a. 40;60
b. 80;20
c. 60;40
d. 20;80

b. 80;20
As a specializd part of the sympathetic nervous system, the adrenal medulla synthesizes and secretes the catecholamines epinephrine (80%) and norepinephrine (20%).


200. The relationship vetween ventricular contraction strength and myocardial muscle fiber length is known as:
a. Henry's law
b. law of laplace
c. law of synergistic function
d. starling's law

-d. Frank Starling's law
Starling's law is based on the observation that if the cardiac muscle is stretched, it develops greater contractile tension. The atria as well as ventricular muscle obeys this law.


201. The phrenic nerve innervation to the diaphragm comes from the:
a. lumbar spinal cord
b. medulla
c. cervical spinal cord
d. pons

-c. cervical spinal cord
The phrenic nerve arises from the nerve roots of C3,C4 & C5 at the lateral border of the anterior scalene muscle.


202. Aortic stenosis is recognized by its characteristic:
a. diastolic murmur at second right intercostal space
b. systolic murmur at second right intercostal space
c. diastolic murmur at left fourth intercostal space
d. systolic murmur at the left fourth intercostal space

-b. aortic stenosis results in a systolic murmur. It is increased by leg elevation and amyl nitrate and decreased by squatting or valsalva manuver


203. Addison's disease and aldosterone deficiency results in:
a. renal Na+ loss and acidosis
b. renal Cl- loss and alkalosis
c. renal H+ loss and acidosis
d. renal K+ loss and alkalosis

-a. renal Na+ loss and acidosis
Lock of aldosterone secretion reduces sodium reabsorption and allows sodium chloride and water to be lost in great amounts. Acidosis develops because of a failure of potassium and hydrogen ions to be secreted in exchange for sodium reabsorption


204. Acetylcholine is a neurotransmitter for all the following except:
a. preganglionic sympathetic neurons
b. preganglionic parasympathetic neurons
c. postganglionic sympathetic receptors on the heart
d. postganglionic parasympathetic receptors on the heart

-c. postganglionic sympathetic receptors on the heart
The postganglionic sympathetic nerves in the heart secrete the catecholamine norepinephrine


205. The rate limiting step in the biosynthesis of endogenous catecholamines is:
a. metabolism of tyrosine to dopa
b. metabolism of dopa to dopamine
c. metabolism of phenylalanine
d. metabolism of norepinephrine to epinephrine

-a. metabolism of tyrosine to dopa
The enzyme tyrosine hydroxylase is the rate limiting enzyme in catecholamine synthesis. It catalyzes the step from tyrosine to dopa.


206. The adrenal cortex secretes hormones of what chemical class?
a. peptide
b. glycoprotein
c. amine
d. steroid

-d. steroid
The adrenal cortex secretes primarily cortisone, which has multiple metabolic functions for controlling proteins, carbohydrates and fats. It also secretes aldosterone.


207. The patient with myxedema would likely exhibit which of the following signs or symptoms?
a. heat intolerance
b. hypocholesterolemia
c. hyperactivity
d. slow mentation and puffy face

-d. slow mentation and puffy face
the patient with myxedema exhibits almost total lack of thyroid function and develops bagginess under the eyes and facial swelling. For unknown reasons, an increase in fluid in the interstitial space causes puffiness of the face. The edema is of the non-pitting type.


208. The structural unit of the thyroid gland is the:
a. chief cell
b. follicle
c. colloid
d. parafollicular cell

-b. follicle
The thyroid gland is composed of larged numbers of closed follicles filled with a secretory substance called colloid. The major constituent of colloid is thyroglobulin, which contains thyroid hormone within the molecule.


209. The structural unit layer of the arteries that allows dilation and construction is:
a. tunica intima
b. tunica media
c. tunica adventitia
d. vasa vasourm

-b. tunica media
The tunica media exhibits muscle strength and is innovated by sympathetic and parasympathetic nerves allowing for not only local control but also neuronal control of vascular tone


210. Which two veins form the portal vein?
a. hepatic and splenic
b. pancreatic and superior mesenteric
c. superior and inferior mesenteric
d. superior mesentiric and splenic

-d. superior mesenteric and splenic
The portal vein, which carries nutrients from the gut to the liver, arises from the superior mesenteric and splenic veins with some input from the renal veins before it enters the liver.


211. The first branches of the ascending aorta are:
a. inominate arteries
b. carotid arteries
c. vertebral arteries
d. coronary arteries

-d. coronary arteries
The right and left coronary arteries originate from the sinuses of Valsalva in the aortic valve


212. What is resopnsible for the majority of venous drainage of the myocardium?
a. anterior cardiac veins
b. thebesian veins
c. coronary sinus
d. posterior cardiac vein

-c. coronary sinus
The great and middle cardiac veins and the posterior left ventricular vein drain into the coronary sinus located posterior to the right atria


213. When does maximal left coronary artery filling occur?
a. early systole
b. early diastole
c. late systole
d. late diastole

-d.late diastole
Cardiac muscle relaxes during diastole allowing free flow through the coronary circulation. Coronary artery blood flow is greatest in early diastole and least during late diastole, (i guess thats what she is saying is that by the end of late diastole the maximal blood flow is in the LAD).
The subendocardium (especially of the left ventricle, develops much greater pressures than the epicardium. This reduces blood flow to these areas in comparison to the outer areas of the heart.


214. Which area of the myocardium is most succeptible to ischemic injury during episodes of reduced oxygen supply?
a. subendocardium
b. inferior endocardium
c. anterior wall tissue
d. posterior endocardium

-a. subendocardium
The subendocardium of the left ventricle is most succeptible to ischemia because metabolic requirements are greater due to systolic shortening (muscle contraction) and blood flow is restricted during systole.


215. cyanosis is a regular feature of:
a. coarctation of the aorta
b. patent ductus arteriosis
c. tetrology of fallot
d. sinple interventricular septal defect

-c. tetrology of fallot
in general cyanosis is due to hypoxia which is apparent by 6 months of age in a patient with tetrology of fallot. This cyanosis is due to right-to-left endocardiac shunt with decreased pulmonary blood flow and arterial hypoxia.


216. The relative humidity in the operating room providing enough conductivity in open surfaces to carry away static changes is:
a. 50-60%
b. 60-70%
c. 70-80%
d. 80-90%

b. 60-70%
Relative humidity is a percent expression of the actual water vapor content of a gas compared with its capacity to carry water at a given temperature. At room temperature, optimal humidity is 60-70%


217. A line isolation monitor (LIM) is a device that continuously monitors:
a. macro shock potentials
b. circuit breaker in the operating room
c. integrity of isolated power systems
d. contact and grounding of patients

-c. integrity of isolated power systems
A line isolationmonitor is a device that continuously monitors the integrity of an isolation power system. The device will sound an alarm if a faulty piece of equipment is connected to an isolated system changing it back to a conventional grounded system.


218. The increased need for intraoperative narcotics to maintain anesthesia depth in patients taking phenobarbitol may be an example of:
a. zero order kinetics
b. enzyme inhibition
c. enzyme induction
d.mercapturic acid synthesis

-c. enzyme induction
Phenobarbitol is one of the most potent enzyme inducing agents. Patients who take phenobarbitol have an increased ability to metabolize other hepatic eliminated drugs.


219. The maximum amount of air that can be inhaled from the resting end-expiratory level is:
a. tidal volume
b. vital capacity
c. inspiratory capacity
d. inspiratory reserve volume

-c. inspiratory capacity
The inspiratory capacity equals the tidal volume plus the inspiratory reserve volume. This equals about 3500 mL in a healthy adult.


220. Stimulation of the _______ receptors inhibits further norepinephrine release from presynaptic storage sites.
a. alpha 1
b. beta 1
c. alpha 2
d. beta 2

-c. alpha 2
Presynaptic receptors are referred to as autorecepteors because they autoregulate local control for the release of neurotransmitters from that particular neuron. they are designated with the number 2; thus alpha 2 receptors control the norepinephrine release.


221. an anesthetic agent with a low blood/gas partition coefficient would result in:
a. slow induction, rapid emergence
b. slow induction, slow emergence
c. rapid induction, slow emergence
d. rapid induction, rapid emergence

-d. rapid induction, rapid emergence
The blood/gas partition coefficient of an anesthetic agent indicates the speed of induction and emergence. A low blood/gas coefficient would yield a rapid uptake and elimination of the inhalation drug.


222. which is not a sign or symptom of atropine poisoning?
a. continuous flush
b. mydriasis
c. hyperreflexia
d. sedation

-d. sedation
the classic mnemonic regarding atropine poisoning states:
Red as a Beet, Hot as a Hare, Dry as the Sand and Mad as a Hatter. Therefore, atropine overdose causes CNS excitation not depression.


223.The boiling point of a liquid is defined as the temperature at which the vapor pressure of the liquid equals:
a. atmospheric pressure
b. its critical temperature
c. its critical pressure
d. its specific heat

-a. atmospheric pressure
The molecules bombard the wall of a container and create a pressure known as the saturated vapor pressure. Vapor pressure is independent of atmospheric pressure and depends on the physical characteristics of the liquid and the temperature. The boiling point is the temperature at which the vapor pressure equals atmospheric pressure.


224. Under normal conditions, 70% to 85% of the circulating blood volume lies within the:
a. arteries
b. arterioles
c. capillaries
d. veins

-d. veins
venous capitance exceeds other vascular beds. Eighty-four percent of the blood volume located in blood vessels, with the greatest majority being in the veins.


225. Blood is supplied to the anterior portion of the left ventricle by the:
a. circumflex artery
b. right coronary artery
c. left coronary artery
d. anterior descending artery

-d. anterior descending artery
aka. left descending artery; courses downward over the anterior of the left wall and supplies this arew aith contributions from the circumflex.


226. The ratio between blood concentration and concentration in the gaseous phase of an agent is:
a. diffusion ratio
b. partition coefficient
c. Avagadro's constant
d. exchange ratio

-b. partition coefficient
A partition coefficient is the ratio that indicates to what degree a substance separates itself when in different compartments