Anonymous
07-01-2004, 01:01 PM
Guys, as i'm doing my second review I found this funny and beneficial way to study by looking for important exceptions in medicine. So far I have found about 50 exceptions. You can join me if you have a time and desire.
EXCEPTIONS:
NEURO
1. Blood-brain barrier present everywhere in the brain EXCEPT hypothalamus, circumventricular organ
2. BZs are metabolized via oxidative pathways to active metabolites EXCEPT oxazepam, temazepam, and lorazepam (LOT) which conjugate with glucuronide producing inactive metabolites, and therefore may be safer in elderly.
3. All extracellular fluids have lower concentration of Cl- than intracellular EXCEPT CSF
4. All extracellular fluids have lower concentration of K+ EXCEPT endolymph (scala tympany, semicircular canals, utricle, saccule)
5. All receptor cells respond to stimuli with depolarization EXCEPT cones and rods which hyperpolarize
6. All neurons are unable to replace themselves EXCEPT olfactory receptor cells
7. Most CNS structures are of Neural tube origin EXCEPT adenohypophisis (Rathke¡¦s pouch), Pia and arachnoids (neural crest), Dura (mesoderm), microglia (mesoderm), vessels (mesoderm).
8. All NS receptors that directly coupled to ion channels have only letters in their names (GABAa, GABAb, Nn, etc.) EXCEPT 5HT3 Serotonin receptor.
9. All NS receptors that coupled to ion channels via second messengers have numbers in their names (M1, D2, etc.) EXCEPT opioid receptors which named mu, delta, kappa.
10. All receptors with numbers in their name are excitatory if numbered 1 (D1, M1, etc.); and inhibitory if 2 (D2, M2, etc.) EXCEPT serotonin receptors ( 1- inhibitory, 2 and 3 ¡V excitatory)
11. All abused substances¡¦ withdrawal syndrome is not life threatening EXCEPT of barbiturates.
12. Valproic acid can be used in all types of seizure states EXCEPT status epilepticus
13. There are three main anticonvulsants; carbamazepine, valproic a., phenytoin. They cause spina bifida if taken during pregnancy EXCEPT phenytoin which results in cleft palate.
14. Anticonvulsants induce P450 EXCEPT Valproic acid which inhibits P450.
15. Opioids act as cholinomimetics EXCEPT Meperidine which is M-blocker, therefore sphincters spasm and miosis are not side effects of meperidine.
16. All neuroleptics eventually result in tardive diskinesia (extrapyramidal s.), amenorrhea-galactorrhea EXCEPT Clozapine and Olanzapine due to blockage of 5HT2 rather than D2a.
CARDIO
17. In all excitable cells upstroke of action potential caused by inward Na current EXCEPT SA, AV nodes where upstroke is result of inward Ca2+ current.
18. In all excitable cells blockage of fast Na+ channels would block action potential EXCEPT heart fibers where action potential still will be generated due to slow Ca++ influx, meaning action potential will be prolonged, but still it will be generated. In other words, Ca++ will take over but doing it much slower. This is a ground for class 1 antiarrhitmics action.
19. In all excitable cells voltage-dependent Na channels are opened by depolarization (more positive charge) EXCEPT in SA, AV nodes, where Na channels opened by hyperpolarization (more negative charge).. This is why Phase 4 accounts for pacemaker activity and called ¡§funny current¡¨
20. Preload and contractility always move in opposite directions (preload decreases---contract increases, etc.) EXCEPT in heavy exercise, when both preload and contractility increase
21. Under normal conditions arterioles of all tissues respond to sympathetic stimulation EXCEPT cerebral, coronorary, renal circulation.
22. Under emergency conditions arterioles of all tissues respond to sympathetic stimulation EXCEPT cerebra, coronary (renal arterioles might constrict compromisinf renal circulation)
23. All arterioles respond to hypoxia by vasodilation EXCEPT pulmonary, which constrict.
24. Arterioles of all tissues are filled with blood during systole EXCEPT coronary which fiiled with blood during diastole
25. In exercise all major hemodinamic indices increase EXCEPT TPR which decreases
26. Aorta has vasa vasorum in all segments EXCEPT abdominal part below renal arteries. That¡¦s why this part most susceptible for development of atherosclerotic aneurism
27. Spider angiomas are abnormal findings EXCEPT in pregnancy where they considered normal
28. ESR is not indicative for diagnostic screening any longer EXCEPT in Temporal arteritis
29. In all rickettsial diseases rush starts on trunk and spreads to extremities EXCEPT Rocky Mountain spotted fever, in which rush starts on extremeties and spreads on trunk.
30. Fungi commonly do not invade vessels EXCEPT Mucor, Candida, Aspergillus which therefore cause hemorrhagic lung infarction
31. Corticosteroids are commonly indicated in vasculitis EXCEPT Kawasaki disease where they increase incidence of coronary artery aneurism and therefore contraindicated
32. PAN commonly does not involve lungs and lower airways EXCEPT in patients with asthma, then it¡¦s called Churg-Strauss syndrome
33. Immune vasculitises usually require medications EXCEPT Henoh-Schoilen purpura which is in mild cases self-limiting in 1-6 weeks
34. In muscles Ca++ opens more Ca++ channels EXCEPT in smooth muscles where Na+ opens more Ca+ channels. ?????????????????????
35. In cyanosis PaO2 and SaO2 usually decreased (SaO2<80%) EXCEPT in RHF.
36. DVT often causes embolization of pulmonary artery EXCEPT in cases of ASD, when systemic emboli can bee seen. This is called paradoxical emboli.
37. In the brain all vesssels have typical histology EXCEPT at the junction of communicating arteries and main vessels, where there is no internal elastic lamina and smooth muscles layers. This predisposes to Berry aneurisms if BP is high.
38. Most common complication of all aneurisms is rupture EXCEPT cardiac aneurism, which lined with scar tissue and therefore hard to rupture.
39. Pulse (and BP) usually increase on inspiration EXCEPT in pericarditis, where pulse decreases on inspiration and called pulsus paradoxus
40. All ¡§-olols¡¨ are beta-blockers EXCEPT for labetalol & carvedilol which have combined beta- and alpha-blocking activity.
41. All ANS receptors are coupled to second messengers EXCEPT Nn receptors which are directly coupled to ion channels
42. All ANS receptors which are coupled to second messengers are acting via cAMP system EXCEPT M3 Ach receptors which act via cGMP (activated by NO). M3 receptors located in blood vessels and therefore dennervated.
43. All lipid-lowering agents tend to decrease VLDL, TG EXCEPT bile sequestrants (cholestiramine) which increase VLDL, TG.
RESPIRATORY
44. All rickettsias transmitted by vector EXCEPT Coxiella burnetii (Q fever) which is transmitted by inhalation without vector.
45. Yeasts are not usually phagocytosed EXCEPT Histoplasma capsulatum yeasts.
HEMATOLOGY
46. Virtually all cells possess either MHC I, or II, or both EXCEPT RBCs that have none of these Ag. However, they do have ABO, Rh, Kell Ag, Duffy (Fy) Ag, I (i) Ag system, ***** Ag.
47. All Hemoglobins are denaturated by acid EXCEPT HbF. This is the basis for Kleihauer-Batke test for identifying fetal RBCs in maternal circulation after delivery.
48. Pathology at the same site is usually worsening the clinical picture EXCEPT hereditary hemoglobinopathies. Combination of ƒÑ- and ƒÒ ¡V Thalassemias are better than either one alone; SCD is better when combined with either of Thalassemias.
49. Heavy metals cannot deposit in bones EXCEPT Lead, which deposits in epiphyses resulting in growth retardation.
50. In Nature most of things grow bigger as they mature EXCEPT cell nucleus which is getting smaller as DNA matures. This is why in B12/Folate deficiency all nucleated cells are bigger; for the same reason, cancer cells which are immature by definition generally have huge nuclei.
51. Dementia is irreversible condition EXCEPT dementias resulted from B12 deficiency and Hypothyroidism, which reversible.
EXCEPTIONS:
NEURO
1. Blood-brain barrier present everywhere in the brain EXCEPT hypothalamus, circumventricular organ
2. BZs are metabolized via oxidative pathways to active metabolites EXCEPT oxazepam, temazepam, and lorazepam (LOT) which conjugate with glucuronide producing inactive metabolites, and therefore may be safer in elderly.
3. All extracellular fluids have lower concentration of Cl- than intracellular EXCEPT CSF
4. All extracellular fluids have lower concentration of K+ EXCEPT endolymph (scala tympany, semicircular canals, utricle, saccule)
5. All receptor cells respond to stimuli with depolarization EXCEPT cones and rods which hyperpolarize
6. All neurons are unable to replace themselves EXCEPT olfactory receptor cells
7. Most CNS structures are of Neural tube origin EXCEPT adenohypophisis (Rathke¡¦s pouch), Pia and arachnoids (neural crest), Dura (mesoderm), microglia (mesoderm), vessels (mesoderm).
8. All NS receptors that directly coupled to ion channels have only letters in their names (GABAa, GABAb, Nn, etc.) EXCEPT 5HT3 Serotonin receptor.
9. All NS receptors that coupled to ion channels via second messengers have numbers in their names (M1, D2, etc.) EXCEPT opioid receptors which named mu, delta, kappa.
10. All receptors with numbers in their name are excitatory if numbered 1 (D1, M1, etc.); and inhibitory if 2 (D2, M2, etc.) EXCEPT serotonin receptors ( 1- inhibitory, 2 and 3 ¡V excitatory)
11. All abused substances¡¦ withdrawal syndrome is not life threatening EXCEPT of barbiturates.
12. Valproic acid can be used in all types of seizure states EXCEPT status epilepticus
13. There are three main anticonvulsants; carbamazepine, valproic a., phenytoin. They cause spina bifida if taken during pregnancy EXCEPT phenytoin which results in cleft palate.
14. Anticonvulsants induce P450 EXCEPT Valproic acid which inhibits P450.
15. Opioids act as cholinomimetics EXCEPT Meperidine which is M-blocker, therefore sphincters spasm and miosis are not side effects of meperidine.
16. All neuroleptics eventually result in tardive diskinesia (extrapyramidal s.), amenorrhea-galactorrhea EXCEPT Clozapine and Olanzapine due to blockage of 5HT2 rather than D2a.
CARDIO
17. In all excitable cells upstroke of action potential caused by inward Na current EXCEPT SA, AV nodes where upstroke is result of inward Ca2+ current.
18. In all excitable cells blockage of fast Na+ channels would block action potential EXCEPT heart fibers where action potential still will be generated due to slow Ca++ influx, meaning action potential will be prolonged, but still it will be generated. In other words, Ca++ will take over but doing it much slower. This is a ground for class 1 antiarrhitmics action.
19. In all excitable cells voltage-dependent Na channels are opened by depolarization (more positive charge) EXCEPT in SA, AV nodes, where Na channels opened by hyperpolarization (more negative charge).. This is why Phase 4 accounts for pacemaker activity and called ¡§funny current¡¨
20. Preload and contractility always move in opposite directions (preload decreases---contract increases, etc.) EXCEPT in heavy exercise, when both preload and contractility increase
21. Under normal conditions arterioles of all tissues respond to sympathetic stimulation EXCEPT cerebral, coronorary, renal circulation.
22. Under emergency conditions arterioles of all tissues respond to sympathetic stimulation EXCEPT cerebra, coronary (renal arterioles might constrict compromisinf renal circulation)
23. All arterioles respond to hypoxia by vasodilation EXCEPT pulmonary, which constrict.
24. Arterioles of all tissues are filled with blood during systole EXCEPT coronary which fiiled with blood during diastole
25. In exercise all major hemodinamic indices increase EXCEPT TPR which decreases
26. Aorta has vasa vasorum in all segments EXCEPT abdominal part below renal arteries. That¡¦s why this part most susceptible for development of atherosclerotic aneurism
27. Spider angiomas are abnormal findings EXCEPT in pregnancy where they considered normal
28. ESR is not indicative for diagnostic screening any longer EXCEPT in Temporal arteritis
29. In all rickettsial diseases rush starts on trunk and spreads to extremities EXCEPT Rocky Mountain spotted fever, in which rush starts on extremeties and spreads on trunk.
30. Fungi commonly do not invade vessels EXCEPT Mucor, Candida, Aspergillus which therefore cause hemorrhagic lung infarction
31. Corticosteroids are commonly indicated in vasculitis EXCEPT Kawasaki disease where they increase incidence of coronary artery aneurism and therefore contraindicated
32. PAN commonly does not involve lungs and lower airways EXCEPT in patients with asthma, then it¡¦s called Churg-Strauss syndrome
33. Immune vasculitises usually require medications EXCEPT Henoh-Schoilen purpura which is in mild cases self-limiting in 1-6 weeks
34. In muscles Ca++ opens more Ca++ channels EXCEPT in smooth muscles where Na+ opens more Ca+ channels. ?????????????????????
35. In cyanosis PaO2 and SaO2 usually decreased (SaO2<80%) EXCEPT in RHF.
36. DVT often causes embolization of pulmonary artery EXCEPT in cases of ASD, when systemic emboli can bee seen. This is called paradoxical emboli.
37. In the brain all vesssels have typical histology EXCEPT at the junction of communicating arteries and main vessels, where there is no internal elastic lamina and smooth muscles layers. This predisposes to Berry aneurisms if BP is high.
38. Most common complication of all aneurisms is rupture EXCEPT cardiac aneurism, which lined with scar tissue and therefore hard to rupture.
39. Pulse (and BP) usually increase on inspiration EXCEPT in pericarditis, where pulse decreases on inspiration and called pulsus paradoxus
40. All ¡§-olols¡¨ are beta-blockers EXCEPT for labetalol & carvedilol which have combined beta- and alpha-blocking activity.
41. All ANS receptors are coupled to second messengers EXCEPT Nn receptors which are directly coupled to ion channels
42. All ANS receptors which are coupled to second messengers are acting via cAMP system EXCEPT M3 Ach receptors which act via cGMP (activated by NO). M3 receptors located in blood vessels and therefore dennervated.
43. All lipid-lowering agents tend to decrease VLDL, TG EXCEPT bile sequestrants (cholestiramine) which increase VLDL, TG.
RESPIRATORY
44. All rickettsias transmitted by vector EXCEPT Coxiella burnetii (Q fever) which is transmitted by inhalation without vector.
45. Yeasts are not usually phagocytosed EXCEPT Histoplasma capsulatum yeasts.
HEMATOLOGY
46. Virtually all cells possess either MHC I, or II, or both EXCEPT RBCs that have none of these Ag. However, they do have ABO, Rh, Kell Ag, Duffy (Fy) Ag, I (i) Ag system, ***** Ag.
47. All Hemoglobins are denaturated by acid EXCEPT HbF. This is the basis for Kleihauer-Batke test for identifying fetal RBCs in maternal circulation after delivery.
48. Pathology at the same site is usually worsening the clinical picture EXCEPT hereditary hemoglobinopathies. Combination of ƒÑ- and ƒÒ ¡V Thalassemias are better than either one alone; SCD is better when combined with either of Thalassemias.
49. Heavy metals cannot deposit in bones EXCEPT Lead, which deposits in epiphyses resulting in growth retardation.
50. In Nature most of things grow bigger as they mature EXCEPT cell nucleus which is getting smaller as DNA matures. This is why in B12/Folate deficiency all nucleated cells are bigger; for the same reason, cancer cells which are immature by definition generally have huge nuclei.
51. Dementia is irreversible condition EXCEPT dementias resulted from B12 deficiency and Hypothyroidism, which reversible.