COMAT FBS: KEY MEDICAL
CONCEPTS AND MECHANISMS EXAM
allergic rhinitis pathophysiology - Correct Answers -APCs (dendritics) at mucosal
surfaces present peptides from allergens to MHC-II = ligand for naive CD4 = Th2
activation and cytokine secretion / B cell isotype switching = IgE and eosino/mast/neutro
proliferation
allergic rhinitis early reaction - Correct Answers -w/in 30min, type I HS
allergic rhinitis late reaction - Correct Answers -w/in 6hr
anaphylaxis mechanism - Correct Answers -first exposure = IgE Abs
hypersensitivity types - Correct Answers -1. IgE-mediated (allergies, asthma,
anaphylaxis) 2. Cytotoxic ANTIBODY-mediated (IgM, IgG) (bullous pemphigoid,
autoimmune hemolytic anemia, good pasture) 3. Immune COMPLEX-mediated (Ag-Ab)
(SLE, arthus reaction, serums sickness) 4. Delayed-type T cell/MQ-mediated (allergic
contact dermatitis , TB, transplant rejection)
autoimmune RECEPTOR-mediated (IgM, IgG) - Correct Answers -anemia mechanism
via blood loss that causes iron deficiency, hemolysis, or reduced erythropoiesis
hypochromic microcytic anemia associated conditions - Correct Answers -iron
deficiency anemia, thalassemia MINOR (only abn is Hb electrophoresis), lead poisoning
(prominent basophilic stippling), chronic infection
iron deficiency anemia - Correct Answers -hypochromic microcytic, 'cigar cells'
high bilirubin w a high reticulocyte count relates to - Correct Answers -hemolytic anemia
thalassemia major - Correct Answers -associated w severe hemolytic anemia,
hyperplasia/expansion of bones via increased marrow space to accommodate = RBC
overproduction, chronic hypoxia
,anesthesia mechanism - Correct Answers -activate inhibitory CNS receptors (GABA[A])
and inactivate excitatory presynaptic voltage-gated sodium channels in glutamatergic
synapse
anesthesia - Correct Answers -activate GABA(A [a-1/BZ1 and a-2/BZ2) Cl- channels =
hyperpolarizes = inhibits CNS; associated receptors / agents (6): NMDA receptor
antagonist (ketamine), opioid receptor agonists (Mu, kappa, delta), two-pore potassium
channel (K[2P]s) activation = hyperpolarizes = inhibits CNS, alpha-2 adrenergic
receptor agonist (guanfacine, clonidine, tizanidine), dopamine receptor antagonists
(antipsychs)
four stages of anesthesia - Correct Answers -1: analgesia (motion / breathing reduced,
amnesia, euphoria), 2: excitement (delirium, combative behavior, still reactive to touch),
3: surgical anesthesia (unconsciousness, loss of equilibrium, decreasing eye
movement, NOT reactive to touch), 4: medullary depression / death (resp / cardiac
depression / arrest, NO eye movement)
what type of hypersensitivity is asthma - Correct Answers -type I: IgE-mediated
asthma pathophysiology - Correct Answers -Type I IgE-mediated;
allergens/viruses/exercise = REVERSIBLE and RECURRENT SMOOTH MM spasms at
SMALL bronchioles and increased mucus = airway restriction; chronicity = airway
remodeling (permanent structural changes in smooth mm/collagen)
bullous pemphigoid - Correct Answers -Type II cytotoxic antibody-mediated; IgG
autoAb's targeting DYSTONIN = anti-HEMIDESMOSOME Ab's = loss of
KERATINOCYTES to basement membrane adhesion
Candidiasis treatment - Correct Answers -Fluconazole
cellulitis pathophysiology - Correct Answers -via GAS, S aureus, MRSA; flora infects
breaks through skin; spread into fascial lining = necrotizing fasciitis; S aureus =
furuncles, carbuncles, abscesses
chlamydia trachomatis treatment - Correct Answers -Doxycycline (+ ceftriaxone for
gonorrhea coinfection); azithromycin (for trachoma)
contractions mechanism - Correct Answers -non-pregnant (menstrual cycle): at sub-
endometrial layer of estrogen/progesterone receptor-rich myometrium; frequency
increases toward ovulation, and decreases in luteal phase for possible implantation;
labor: via oxytocin positive feedback; prostaglandins / inflamm mediators = encourage
myometrial contractions and gap junction / connexin-43 expression
coronary vasospasm is caused by what agents (3) - Correct Answers -Cocaine,
sumatriptan, ergot alkaloids
, coronary vasospasm pathophysiology - Correct Answers -coronary aa is hyperreactive
to vasoconstrictor stimuli (via endothelial dysfunction, chronic inflammation, oxidative
stress, smooth mm hyper contractility / myosin light chain phosphorylation / Rho-kinase
activation) (and smoking = vasospastic angina) = ischemia
coronary vasospasm management - Correct Answers -calcium channel blockers
(verapamil, diltiazem), nitrates, statins (atorvastatin, [etc.]-statin)
cystic fibrosis pathophysiology - Correct Answers -auto recessive = CFTR chloride
channel gene mutation that anchors at (exocrine glands) lung, pancreas, sweat glands
= thick mucus = CFTR misfolding / degradation = mucus plugging, fibrosis, cysts
chronic cystic fibrosis infective spp - Correct Answers -S aureus, H influ, pseudomonas
( = 'mucoid pseudomonas' via interleukin 17), aspergillus / candida
cystitis spp - Correct Answers -(UTI) E coli, klebsiella, proteus
cystitis treatment - Correct Answers -trimethoprim-sulfamethexazole (or nitrofurantoin,
cephies, FQs)
delayed emergence - Correct Answers -failure to regain consciousness 30 - 60min after
general anesthesia = stroke, hypoxic-ischemic brain injury, status epilepticus,
emergence delirium, sepsis, multi-organ failure via excessive dosing, decreased
metabolism / clearance, inadequate drug reversal at end of surgery
agents used to treat delayed emergence - Correct Answers -naloxone for narcotics,
flumazenil for benzos, neostigmine for neuromuscular blocking agents
C diphtheria features / buzzwords - Correct Answers -GPR, small, curved rods 'chinese
letters'; exotoxin: via lyosgenic bacteriophage / beta-prophage = ADP-ribosylates EF-2
to inactive protein synth; loeffler's (metachormatic blue/red) or tinsdale / tellurite (black
colonies) = grey-white membrane, lymphadenopathy, myocarditis, CNS neuropathies,
renal disease
C diphtheria agar - Correct Answers -loeffler's agar ( = metachromatic blue/red
granules); tinsdale / tellurite ( = black colonies)
C diphtheria vaccines - Correct Answers -diphtheria toxoid (active), diphtheria antitoxin
(passive)
EPEC - Correct Answers -watery, no toxins ; intimin / Tir (adhesion / receptor) ; type III
secretion system = 'P'edestal attachment
ETEC - Correct Answers -watery, TOXINS ; heat stabile toxin (guanylate cyclase =
cGMP) ; heat labile toxin (AB toxins ; A subunit ADP-ribosylates G-protein = cAMP) =
ions / water move out of cells to intestinal lumen
CONCEPTS AND MECHANISMS EXAM
allergic rhinitis pathophysiology - Correct Answers -APCs (dendritics) at mucosal
surfaces present peptides from allergens to MHC-II = ligand for naive CD4 = Th2
activation and cytokine secretion / B cell isotype switching = IgE and eosino/mast/neutro
proliferation
allergic rhinitis early reaction - Correct Answers -w/in 30min, type I HS
allergic rhinitis late reaction - Correct Answers -w/in 6hr
anaphylaxis mechanism - Correct Answers -first exposure = IgE Abs
hypersensitivity types - Correct Answers -1. IgE-mediated (allergies, asthma,
anaphylaxis) 2. Cytotoxic ANTIBODY-mediated (IgM, IgG) (bullous pemphigoid,
autoimmune hemolytic anemia, good pasture) 3. Immune COMPLEX-mediated (Ag-Ab)
(SLE, arthus reaction, serums sickness) 4. Delayed-type T cell/MQ-mediated (allergic
contact dermatitis , TB, transplant rejection)
autoimmune RECEPTOR-mediated (IgM, IgG) - Correct Answers -anemia mechanism
via blood loss that causes iron deficiency, hemolysis, or reduced erythropoiesis
hypochromic microcytic anemia associated conditions - Correct Answers -iron
deficiency anemia, thalassemia MINOR (only abn is Hb electrophoresis), lead poisoning
(prominent basophilic stippling), chronic infection
iron deficiency anemia - Correct Answers -hypochromic microcytic, 'cigar cells'
high bilirubin w a high reticulocyte count relates to - Correct Answers -hemolytic anemia
thalassemia major - Correct Answers -associated w severe hemolytic anemia,
hyperplasia/expansion of bones via increased marrow space to accommodate = RBC
overproduction, chronic hypoxia
,anesthesia mechanism - Correct Answers -activate inhibitory CNS receptors (GABA[A])
and inactivate excitatory presynaptic voltage-gated sodium channels in glutamatergic
synapse
anesthesia - Correct Answers -activate GABA(A [a-1/BZ1 and a-2/BZ2) Cl- channels =
hyperpolarizes = inhibits CNS; associated receptors / agents (6): NMDA receptor
antagonist (ketamine), opioid receptor agonists (Mu, kappa, delta), two-pore potassium
channel (K[2P]s) activation = hyperpolarizes = inhibits CNS, alpha-2 adrenergic
receptor agonist (guanfacine, clonidine, tizanidine), dopamine receptor antagonists
(antipsychs)
four stages of anesthesia - Correct Answers -1: analgesia (motion / breathing reduced,
amnesia, euphoria), 2: excitement (delirium, combative behavior, still reactive to touch),
3: surgical anesthesia (unconsciousness, loss of equilibrium, decreasing eye
movement, NOT reactive to touch), 4: medullary depression / death (resp / cardiac
depression / arrest, NO eye movement)
what type of hypersensitivity is asthma - Correct Answers -type I: IgE-mediated
asthma pathophysiology - Correct Answers -Type I IgE-mediated;
allergens/viruses/exercise = REVERSIBLE and RECURRENT SMOOTH MM spasms at
SMALL bronchioles and increased mucus = airway restriction; chronicity = airway
remodeling (permanent structural changes in smooth mm/collagen)
bullous pemphigoid - Correct Answers -Type II cytotoxic antibody-mediated; IgG
autoAb's targeting DYSTONIN = anti-HEMIDESMOSOME Ab's = loss of
KERATINOCYTES to basement membrane adhesion
Candidiasis treatment - Correct Answers -Fluconazole
cellulitis pathophysiology - Correct Answers -via GAS, S aureus, MRSA; flora infects
breaks through skin; spread into fascial lining = necrotizing fasciitis; S aureus =
furuncles, carbuncles, abscesses
chlamydia trachomatis treatment - Correct Answers -Doxycycline (+ ceftriaxone for
gonorrhea coinfection); azithromycin (for trachoma)
contractions mechanism - Correct Answers -non-pregnant (menstrual cycle): at sub-
endometrial layer of estrogen/progesterone receptor-rich myometrium; frequency
increases toward ovulation, and decreases in luteal phase for possible implantation;
labor: via oxytocin positive feedback; prostaglandins / inflamm mediators = encourage
myometrial contractions and gap junction / connexin-43 expression
coronary vasospasm is caused by what agents (3) - Correct Answers -Cocaine,
sumatriptan, ergot alkaloids
, coronary vasospasm pathophysiology - Correct Answers -coronary aa is hyperreactive
to vasoconstrictor stimuli (via endothelial dysfunction, chronic inflammation, oxidative
stress, smooth mm hyper contractility / myosin light chain phosphorylation / Rho-kinase
activation) (and smoking = vasospastic angina) = ischemia
coronary vasospasm management - Correct Answers -calcium channel blockers
(verapamil, diltiazem), nitrates, statins (atorvastatin, [etc.]-statin)
cystic fibrosis pathophysiology - Correct Answers -auto recessive = CFTR chloride
channel gene mutation that anchors at (exocrine glands) lung, pancreas, sweat glands
= thick mucus = CFTR misfolding / degradation = mucus plugging, fibrosis, cysts
chronic cystic fibrosis infective spp - Correct Answers -S aureus, H influ, pseudomonas
( = 'mucoid pseudomonas' via interleukin 17), aspergillus / candida
cystitis spp - Correct Answers -(UTI) E coli, klebsiella, proteus
cystitis treatment - Correct Answers -trimethoprim-sulfamethexazole (or nitrofurantoin,
cephies, FQs)
delayed emergence - Correct Answers -failure to regain consciousness 30 - 60min after
general anesthesia = stroke, hypoxic-ischemic brain injury, status epilepticus,
emergence delirium, sepsis, multi-organ failure via excessive dosing, decreased
metabolism / clearance, inadequate drug reversal at end of surgery
agents used to treat delayed emergence - Correct Answers -naloxone for narcotics,
flumazenil for benzos, neostigmine for neuromuscular blocking agents
C diphtheria features / buzzwords - Correct Answers -GPR, small, curved rods 'chinese
letters'; exotoxin: via lyosgenic bacteriophage / beta-prophage = ADP-ribosylates EF-2
to inactive protein synth; loeffler's (metachormatic blue/red) or tinsdale / tellurite (black
colonies) = grey-white membrane, lymphadenopathy, myocarditis, CNS neuropathies,
renal disease
C diphtheria agar - Correct Answers -loeffler's agar ( = metachromatic blue/red
granules); tinsdale / tellurite ( = black colonies)
C diphtheria vaccines - Correct Answers -diphtheria toxoid (active), diphtheria antitoxin
(passive)
EPEC - Correct Answers -watery, no toxins ; intimin / Tir (adhesion / receptor) ; type III
secretion system = 'P'edestal attachment
ETEC - Correct Answers -watery, TOXINS ; heat stabile toxin (guanylate cyclase =
cGMP) ; heat labile toxin (AB toxins ; A subunit ADP-ribosylates G-protein = cAMP) =
ions / water move out of cells to intestinal lumen
