5/16 Mixed

Question 1

Valproic acid

Answer 1

Used in patients with tonic-clonic seizures and absence seizures

Question 2

HbS aggregates (sickling) occurs under conditions:

Answer 2

Associated with anoxia:
Low pH
High levels of 2,3 BPG
Low blood volume (dehydration)
Oxygen unloading (organs with high metabolic demands promote sickling by extracting more oxygen from the blood

*HbS aggregates in a deoxygenated state

Question 3

Two allele loci are said to be in linkage disequilibrium when…

Answer 3

A pair of alleles are inherited together in the same gamete (haplotype) more or less often than would be expected given random chance.

Question 4

Bacillus anthracis

Answer 4

Humans become infected most commonly by exposure through contact with infected animals or animal products (occupational- those who handle livestock)

Question 5

Preventable adverse event

Answer 5

An injury to a patient due to failure to follow evidence-based best practice guidelines

Question 6

Major virulence factor of H. influenza type B

Answer 6

Polysaccharide capsule-compose of polymer polyribosylribitol phosphate (PRP)
Protects the bacterium against phagocytosis and complement-mediated lysis by binding factor H (a complement control protein)

Question 7

Relationship between GFR and serum creatinine

Answer 7

When GFR is normal, relatively large decreases in GFR result in only small increases in serum creatinine
Conversely, when the GFR is significantly decreased, the small decrements in GFR produce relatively large changes in serum creatinine
Every time GFR halves, serum creatinine doubles

Question 8

MOA of opioids causing upper abdominal pain

Answer 8

Cause contraction of smooth muscle cells in the sphincter of Oddi, leading to spasm and an increase in common bile duct pressures (can cause biliary colic)

Question 9

Colitis associated carcinoma vs sporadic colorectal carcinoma

Answer 9

Colitis associated carcinoma is more likely to:

1. affect younger patients
2. progress from flat and non-polypoid dysplasia
3. histologically appear mucinous and have signet ring morphology
4. develop early p53 mutations and late APC mutations, opposite that of sporadic disease
5. Be distributed within the proximal colon
6. Be multifocal in nature

Question 10

Lymph drainage of the testis/scrotum

Answer 10

Lymphatic drainage of the testis is to the para-aortic lymph node (due to its intra-abdominal origin), while lymph drainage from the scrotum goes into the superficial inguinal lymph nodes

Question 11

Absolute risk reduction

Answer 11

= event rate in the control group - event rate in the treatment group
ERtreatment= # of events in the treatment arm/ number of subjects int he treatment arm

Question 12

Rb (retinoblastoma) tumor suppressor gene

Answer 12

Encodes a nuclear phosphoprotein that regulates G1 to S checkpoint
Active= hypophosphorylated
Inactive= hyperphosphorylated

Question 13

Hereditary spherocytosis

Answer 13

AD, Northern european descent
Hemolytic anemia, jaundice, splenomegaly
Increased MCHC, spherocytes on peripheral smear, negative coombs test, increased osmotic fragility on acidifited glycerol lysis test
Complications: pigmented gallstones, aplastic crises from parvovirus B19
Cytoskeleton abnormalities (spectrin and ankyrin)

Question 14

Which blood vessel has the lowest oxygen content

Answer 14

Coronary sinus- myocardial O2 extraction is very high, cardiac venous blood is the most deoxygenated

Question 15

Kinesin

Answer 15

Microtubule-associated ATP powered motor protein

Facilitate anterograde transport of neurotransmitter containing secretory vesicles down axons to synaptic terminals`

Question 16

Communicating hydroceles and indirect inguinal hernias

Answer 16

Caused by incomplete obliteration of the processus vaginalis
Resultant connection between the scrotum and abdominal cavity can allow for fluid leakage (hydrocele) or the passage of abdominal contents (indirect inguinal hernia)

Question 17

Candidal antigen skin test

Answer 17

Used to determine the presence of cellular or T cell mediated immunity through detection of delayed-type hypersensitivity reaction (IV)
Key cells involved are macrophages, CD4 helper T cells and CD8 cytotoxic T cells
Anergy, or failure to respond to candida antigen testing is typical in patients with SCID

Question 18

Carotid sinus hypersensitivity

Answer 18

Triggered by pressure on the carotid sinus by a tight shirt collar
The carotid sinus reflex has an afferent limb that arised from the baroreceptors in the carotid sinus and travels to the vagal nucleus and medullary centers via the glossopharyngeal nerve (CN IX); the efferent limb carries parasympathetic impulses via the vagus nerve (CNX)

Question 19

Optimal site for femoral nerve block

Answer 19

Inguinal crease at the lateral border of the femoral artery

Will anesthetize the skin and muscles of the anterior thigh (eg quadriceps, femur, knee)

Question 20

Acute intermittent porphyria (AIP)

Answer 20

AD disorder of heme synthesis pathway
Porphobilinogen (PBG) deaminase defiency
Gastrointestinal and neurologic symptoms (abd pain, vomiting, peripheral neuropathy, neuropsych derangements)
Reddish urine that darkens on exposure
Rx: inhibiting ALA synthase (administration of heme and glucose)

Question 21

Cystic Fibrosis

Answer 21

Produce eccrine sweat with higher than normal concentrations of sodium and chloride
Exposure to high temperature or exercise can lead to hyponatremia due to excessive sodium loss through sweat
Salt supplementation is recommended

Question 22

Cromolyn and Nedocromil

Answer 22

Mast cell-stabilizing agents
Inhibit mast cell degranulation independent of the triggering stimuli
Less effective than inhaled glucocorticoids and are considered second line for the treatment of allergic rhinitis and bronchial asthma

Question 23

Topical prostaglandins (Latanoprost)

Answer 23

Increase outflow of aqeous humor via the uveoscleral pathway and are the preferred treatment for open angle glaucoma

Question 24

Supercondylar humeral fractures

Answer 24

Common pediatric elbow fractures
Often occur after hyperflexion or hyperextension injuries
AnteroLATERAL displacement of the proximal fracture fragment typically cause radial nerve injury > wrist drop and sensory loss over the posterior forearm/dorsolateral hand
AnteroMEDIAL Displacement cause median nerve and brachial artery injury

Question 25

endometriosis (ectopic endometrium)

Answer 25

Presence of endometrial tissue outside the uterus

Dysmenorrhea, pelvic pain, dyspareunia, infertility

Question 26

Familial chylomicronemia syndrome

Answer 26

Protein defect: lipoprotein lipase, ApoC-II
Elevated lipoproteins: chylomicrons
Major manifestations: Acute pancreatitis, lipemia retinalis, reuptive skin xanthomas, hepatosplenomegaly

Question 27

Acute Myelogenous Leukemia (AML)

Answer 27

Very large nucleated cells with scant cytoplasm = blast cells (=ACUTE leukemia)
Linear, purple red inclusions = Auer rods
Pancytopenia

Question 28

Multifactorial inheritance

Answer 28

Complex process by which numerous genetic and environmental factors interact to determine phenotypic expression
The closer a relative is to the affected person, the more likely the relative is to develop the train
Ex. Spina bifida, cleft lip and palate, diabetes mellitus, coronary artery disease, hypertension

Question 29

Common peroneal nerve

Answer 29

Most commonly injured leg nerve
Blunt trauma to the lateral aspect of the leg, fibular neck fractures, and external pressure due to prolonged immobility can injure the nerve
“Foot drop” a`nd “steppage gait”

Question 30

Muscarine

Answer 30

A toxin found in certain mushrooms
Acts as a muscarinic agonist, resulting in increase in parasympathetic nervous system activity
Peripheral vasodilation due to synthesis of NO in endothelial cells, leads to vascular smooth muscle relaxation