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Anatomy

Penetrating trauma to the anterior neck superior to the clavicle can cause bleeding of thesubclavian artery: the surgeon needs to isolate the artery, by removing the clavicle to gain access:

the anterior scalene muscle is attached to the top of the first rib, and behind it is the subclavian,

and behind that is the first rib Surgery can result in inadvertent damage of the phrenic nerveon CXR, the damaged side will

be raised since when a patient holds breath during CXR, the contracted/functioning diaphragm

will move downward, but the paralyzed diaphragm will move upward since the negative pressure

generated by the functioning side will pull the paralyzed diaphragm up

Biochemistry

Turners syndrome: chicks who will never have menstrual periods (amenorrhea) and have a foldof skin that runs from the neck to shoulder (webbed neckcystic hygroma), short stature, short

fourth metacarpal bone; associated conditions are coartation of the aorta, aortic dissection,

bicuspid aortic valve, hypertension, osteoporosis (from poor estrogen production), horseshoe

kidney, lymphedema in feet and hands

Downs syndrome is associated with ASD more than VSD. B1 deficiency: beriberi; wet beriberi causes dilated cardiomyopathy and edema; dry beriberi

causes polyneuritis (inflammation of multiple peripheral nerves) and muscle wasting; B2

deficiency causes cracking of the lops and corners of the mouth (stomatitiskind of like HSV-1)

and corneal vascularization; B3 defieicney causes diarrhea, dementia, and dermatitis, and glossitis

(thick tongue)

First degree hearblock (long PR intervals) and Mobitz type I second degree heart block arecaused by AV node abnormalities; Mobitz type II (random absence in QRS complex) is caused

by defect in the His-Purkinje system

Marfans cardiovascular problems: aortic aneurysms and mitral valve prolapse, and aorticdissection (due to hypertension and cystic medial necrosis); syphilis causes aortic aneurysms that

can lead to aortic regurg due to weakening of the wall by disruption of vasa vasorum (tertiary

syphilis is characterized by gummasskin lesions, aortitis, and neurosyphilissharp pain and

decreased proprioception); Marfans also presents with joint hyperflexibility, lens disloacation,

pneumothorax

B blockers decrease contractility and HR, and therefore permit greater filling time duringdiastole, so EDV increases, and so does ejection time

Dilated cardiomyopathy can be caused by viruses (T cell mediated damage against the virus-infected cells), sarcoidosis (granulomatous inflammation of the myocytes), drugs such as

doxorubicin, alcohol, or cocaine (hyperadrenergic state would be seen), ischemic, or familial with

antibodies against the myocytes.

Nitrates such as nitroglycerin do NOT cause production of de novo NO, but release NO fromtheir own structure; the NO mediates venodilation by binding to gunaylate cyclase and causing

production of cGMP which causes dilation

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Do NOT use ACE inhibitors with K sparing diuretics such as spironolactone, since it will causesevere hyperkalemia

Microbiology

Diagnose syphilis with VDRL and confirm with FTA-ABS Endotoxins are a characteristic of gram negative bacteria and Listeria Corynebacterium diptheriae causes pharyngitis, cough/sore throat with cervical

lymphadenopathy has an exotoxin endoced by a Beta-prophage; it grows on tellurite agar with

metachromatic (blue/red) granules; can use Elek test for toxin

pharyngitis (i.e. sore throat) with lymphadenopathy and fever can also be Strep, EBV, CMV(mono), and HIV

Strep viridians is the most common cause of bacterial endocarditis, and it is more common inpatients who have had prior damage, such as mitral valve prolapse

Salmonella typhi causes rose spots on abdomen, fever, headache, and diarrheabut not bloodydiarrhea unlike Shigella and Salmonella spp. (others) Giving antibiotics to women may encourage Candida to grow since low pH is maintained by

lactobacilli, and without them, pH increases; Candida will cause a vaginal itching with vaginal

discharge with cheese-like consistency

Adverse effects of metronidazole include GI discomfort and disulfiram-like effect whencombined with alcohol, headache, and metallic taste

Gardnerella vaginialis has a gray discharge, and Trichomonas vaginalis has yellow-green frothyvaginal discharge; both are given metronidazole

Macrolides such as azithromycin bind to 23S of the 50S subunit, and inhibit protein synthesis byblocking translocationgive mainly only forMycoplasma; clindamycin blocks peptide formation

at 50S subunit; tetracyclines block aa-tRNA from attaching to 30S; aminoglycosides cause

misreading of the mRNA and prevent formation of the initiation complex

Rash starting on palms and soles can ONLY be: rocky mountain spotted fever (which alsopresents with hepatosplenomegaly, headache, fever, and possibly thrombocytopenia due to DIC),

N. gonorrhea, secondary syphilis; although not rash, Coxsackie A can cause hand-foot painful

ulcertations

Tricuspid vegatations/endocarditis due to S. aureus due to IV drug abuse can seed septic embolifrom the right side of the heart to the lung, which presents with cough, pleuretic chest pain,

diffuse pulmonary infiltrates, and pyopneumothorax

Rabies pro-symptoms are fever, headache, sore throat, tenderness around bite site; they progressto encephalitis, foaming of the mouth due to inability to swallow, spasms, and seizures

Coccidioides immitis presents with symptoms similar to TB: night sweats, lung cavitations,weight loss, but with additional signs: erythema, arthralgias/artirhitis;Legionella would cause

many of the same symptoms, but would also have GI symptoms, and is due to a contaminated

water source; also causes hy[ponatremia which is unique to this pneumonia

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Any pathology with right sided valvessuspect IV drug use or carcinoid syndrome (pulmonicstenosis and tricuspid insufficiency); give octreotide for carcinoid syndrome

Cancer markers: alpha-fetoprotein: detects hepatocellular cancer; 5-Hydroxyindoleacetic acid(5HIAA) is metabolite of serotonincarcinoid tumor; Cancer antigen-125 (CA-125): monitor

treatment (not diagnose) ovarian cancer; carbohydrate antigen 19-9: monitors (not diagnoses)

pancreatic cancer; carcinoembryoic antigen (CEA) monitors (not diagnoses) mainly colorectaland pancreatic, but also some gastric and breast cancers

Mullers maneuver involves asking the patient to breath in against a closed mouth and nose; thiscan detect closed upper airways and is the opposite of the Valsalva maneuver

Direct acting symptahomimetics bind to postsynaptic adrenergic receptors without interactingwith presynaptic neurons; indirect acting sympathomimetics cause catecholamine release from

presynaptic terminals without interacting with receptors on postsynaptic neurons; disadvanteage

of indirect acting sympathomimetics such as ephedrine is their ability to enter the CNS and

produce undesirable stimulation; direct are more selective, and are generally shorter acting.

If cyanosis is occurring later in life (around age 5-10), then Eisenmengers syndrome hashappened and reversed the shunt from left to right (which does not cause cyanosis) to right to left(which does cause cyanosis); the causes of left to right shunt which eventually reverse are: ASD,

VSD (caused by incomplete fusion of the right bulbar ridge, left bulbar ridge and AV cushions),

and PDA. All other congenital abnormalities will present with cyanosis at birth such as tetralogy

of fallot (due to anterosuperior displacement of infundibular septum), transposition of great

vessels, tricuspid atresia, and truncus arteriosis which all have right to left shunt. VSD will

present with a holosystolic murmur , and should be given sildenafil to vasodilate the pulmonary

vasculature to reduce right to left shunting (after Eisenmengers syndrome has occurred) since

more blood can go into the vasculaturethis is only transient solution, since defect has to be

surgically repaired.

Acute renal failure can cause elevated BUN and creatinine, and the inability of the kidney tosecrete K, leading to hyperkalemiathat leads to peaked T waves and arrhythmias and even

cardiac arrest. In a patient with renal failure, EKG must be checked. Hypokalemia will cause U

waves and flattened T waves, and arrhythmias and paralysis

Differeing bp in the arms is concern for aortic dissection, since false lumen can occlude thesubclavian take off from the aorta on one side

Two high risk complications of coarctation of aorta are bacterial endocarditis and cerebralhemorrhage; it can also lead to hypertensive cardiomyopathy and ascending aortic dissection

Chronotropy=HR and increases rate of SA node firing by increasing Na and Ca current (does SAnode even have Na current?), dromotropy=rate of conduction by increasing AV node conduction

by increasing Ca current, lusotropy=rate of relaxation

Kawasaki disease: fever, conjunctivitis, vesicles/ulcers/cracked/swollen of lips and oral mucosa,rash/edematous hands and feet, desquamation of skin on fingertips

Perforated nasal septum is a complication associated with Wegners granulomatosis Statins and fibrates both cause myositis (inflammation of muscle) with release of creatine kinase

and hepatotoxicity; fibrates also cause cholesterol gallstones. Fibrates upregulate LPL which

increases TG clearance. Niacin causes flushing, hyperglycemia, and hyperuricemia, and works by

inhibiting lipolysis in adipose tissue and reduces hepatic triglyceride synthesis and hepatic VLDL

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secretion. Bile acid resins taste bad and cause GI problems with decrease fat soluble vitamin

absorptionthey also increase TG.

Coronary vasodilation is mediated by NO, O2, and adenosine; cerebral arteries are mediated byCO2, and skeletal muscle by lactate

Digoxin causes an increase in cardiac contractility and thus CO; increase in CO causes a decreasein symp activitiy and reduces vascular resistance; digoxin causes hyperkalemia, yellow halos, andGI upset. It binds to the K binding site on the Na/K ATPase, so if there is hypokalemia, there is a

lot of available spots on the ATPase for dig to bind, so it will have a greater effect

Libman Sacks endocarditis occurs on the mitral valve and results in mitral stenosis IV drug abuse leading to tricuspid endocarditis does not usually present with the typical Oslers

nodes, Roths spots, and Janeway lesions. The tricuspid vegetations by IV use can easily

embolize and cause a PE secondary to the endocarditis, similar to PE secondary to DVT (which

would present as pleuritic chest pain); note that Libman Sacks endocarditis cannot embolize

Class IB is best after MI; class IC is Contraindicated post-MI and in structural abnormalities NE will increase bp by vasoconstriction on alpha1 receptors, and therefore the HR will decrease;

isoproterenol does not act on alpha receptors, only betas, so it will cause vasodilation by B2, andHR will increase. Epi will also decrease bp and cause increase in HR

Tuberous sclerosis is an autosomal dominant condition which presents with a classic triad ofseizures, mental retardation and facial angiofibromas (acnelike papules on the face). TS is

characterized by nodular proliferation of astrocytes in the cerebral cortex. Half of patients

develop rhadomyomas, which are benign, but may compromise cardiac function, esp. AV valves.

They may also get angioliposmas of the kidney

Torsades de pointes can be caused by low K levels, long QT (congenital or acquired throughdrugs), K channel blockers such as sotalol, and class IA bc they also are K channel blockers, such

as quinidine. Note that quinidine also causes tinnitus and headaches; treat torsade with MgSO4

In hypertrophic cardiomyopathy, Ca channel blockers and beta blockers can be used to improvesymptoms but they do not decrease mortality, which only an ICD does

Mitral stenosis has high pitched opening snap in diastole with low-pitched harsh rumblingmurmur

Infants of diabetic mothers are at risk for hypoglycemia that causes seizures (since the mothershyperinsulinemia will cause low glucose), and pulmonary problems such as tachypnea, and

respiratory distress syndrome as well as and transposition of the great vessels, and VSD,

Carotid sinus baroreceptors synapse through cranial nerve IX to the nucleus tractus solitarius ofthe medulla

Class I antiarrythmics all have a greater affinity for cardiac tissue that is depolarizedwhether itis due to hypoxia or frequently depolarized due to tachycardia, which is why they selectively

target only these tissues Because abdomainal aneursyms are usually below the renal arteries, and the main artery that

comes off the abdominal aorta is the IMA, the descending and sigmoid colons can be damaged

during repairs of the abdominal aortic aneurysm

Digoxin blocks the Na/K ATPase, but also stimulates the vagus nerve IVC compression is common in women in the third trimester of pregnancy, and this can cause

hypotension when lying down due to decreased venous return to the heart

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Rheumatic fever histology: focal area of interstitial inflammation with fragmented collagen,mononuclear (Anitschkows) cells, and multinucleated giant (Aschoffs) cells

Hemostasis

Fat embolism will present with dyspnea and petechiae on chest, with possible neurologicabnormalities

PE will present with pleuritic chest pain, pleural effusion, dyspnea, hemoptysis DVT can present with Homans sign where dorsiflexion of the foot is difficult due to tender calf

muscle; it can also result in edema since there is less venous return due to obstruction, and that

would cause increase capillary hydrostatic pressure (similar to CHF which also causes edema due

to stasis and increased cap pressure)

Neuroscience

ACh is synthesized in the basal nucleus of Meynert NE is synthesized in the locus ceruleus Serotonin is synthesized in the raphe nucleus Dopamine is synthesized in the ventral tegmentum and substantia nigra

White Cell disorders

ALL therapy requires prophylaxis to the scrotum and CSF With CLL, there is a lot of white cells, some of which are smudged; CLL complications are

autoimmune hemolytic anemia, hypogammaglobulinemia, and if more mutations occur,progression to large diffuse B cell lymphoma, where there will be splenomegaly and LAD

Hairy cell leukemia is positive for tartrate acid phosphatase (TRAP); has splenomegaly (redpulpunusual), and no LAD

In mycoses fungoides, the Sezary syndrome hematogenous spread have cerebriform nuclei In myelofibrosis, the megakaryocytes produce PDGF, which results in marrow fibrosis (unlike

essential thrombocythemia, which does not result in marrow fibrosis, or hyperuricemia and gout,

and does not progress to acute leukemia as do the other myeloproliferative disorders)

Burkitt lymphoma has starry sky appearance: macrophages ingesting apoptotic tumor cellsscatted in a sheet of monotonous lymphoid cells

Hodgkin lymphoma: B cell called Reed-Sternberg cell has multilobed nuclei and prominentnuclei (owl eyed nuclei) with abundant pale cytoplasmpositive CD30 and 15

Gastrointestinal Pathology

Kruckeberg tumorA. Arise in the left colon:

a. Hyperplastic polyps (rectosigmoid)

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b. Ulcerative colitisc. Colonic diverticula (sigmoid colon most commonresults in left lower quadrant pain)d. Volvulus (sigmoid colon in adults)e. Hirschprung disease (sigmoid colon and rectum, because neural crest cells keep go from

north to south, and if they stop early, everything lower will not be innervated)

f. ischemic colitis (generally, splenic flexure gets hit worst since that is the part of the colonlast supplied by the SMA)

g. colorectal carcinoma by the adenoma-carcinoma pathwayB. Arise in the right colon or side:

a. Crohn disease (the terminal ileum and cecum which is why right lower quadrant pain)b. Angiodysplasiac. Volvulus (cecum in adults)d. Appenidicitis (right sided pain, but starts as periumbilical, then becomes right-sided)e. Colorectal carcinoma by the microsatellite instability (MSI) pathway

Exocrine Pancreas, Gall Bladder, and liver Pathology

Serum tumor marker for pancreatic cancer is CA 19-9 Serum tumor marker for colorectal cancer is CEA (for assessing treatment, not for screening) Whipple procedure for pancreatic cancer Uridine glucoronyl transferase (UGT) in hepatocytes conjugates bilirubin Porcelain gallbladder is a late complication of chronic cholecystitis with a shrunken, hard

gallbladder, that is calcified; it is a risk factor for gallbladder cancer

Hemochromatosis is due to mutations in the HFE gene; presents with triad of cirrhosis, diabetes,and bronze skin

Hepatic adenoma is associated with oral contraceptive use (also hypercoagulability is associatedwith contraceptives)

Disorders associated with down syndrome: Hirshprungs disease, duodenal atresia, ALL (>5years), acute megakaryoblastic leukemia (

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Endocrine Pathology

Hypothyroidism in children is cretinism: caused by dyshormogenetic goiter, maternalhypothyroidism, iodine deficiency

Sheehan syndrome during pregnancy