2015.04.10

Question 1

Serratus Anterior Muscle

Answer 1

Fixes the scapula against the posterior chest wall and rotate the scapula to allow abduction of the arm over the head.

Long thoracic nerve injury paralyzes this muscle and results in winging of the scapula.

Question 2

Latissimus Dorsi Muscle

Answer 2

Adduct and extend the humerus.

Thoracodorsal Nerve

Question 3

Deltoid Muscle

Answer 3

Three segments that act to flex, extend, and abduct the arm.

Axillary nerve innervation

Question 4

Rhomboid major

Answer 4

Draw the scapula medially at its medial border

Dorsal Scapular Nerve

Question 5

Teres Major

Answer 5

Adduct and medially rotate the arm.

Subscapular Nerve.

Question 6

Urachus

Answer 6

Remnant of the allantois (protrudes from yolk sac that extends into the area of the urogenital sinus during the 3rd week of gestation).

Connects the bladders with the yolk sac.

Question 7

Failure of Urachus to obliterate before birth

Answer 7

1. Patent urachus - connects umbilicus and the bladder.
2. Vesicourachal diverticulum - failure to close part of urachus adjacent to the bladder. Outpouching of apex of bladder.
3. Urachal sinus - failure to close distal part of urachus (adjacent to the umbilicus). Periumbilicial tenderness and purulent discharge from umbilicus.
4. Urachal cyst - failure of central portion to obliterate. Fluid-filled structure located between the two obliterated ends of the urachus.

Question 8

Meckel Diverticulum

Answer 8

Incomplete obliteration of the vitelline duct (persistent yolk stalk that connects small intestine with the skin at the umbilicus)

Meconium discharge from the umbilicus.

Question 9

Omphalocele

Answer 9

Incomplete closure of anterior abdominal wall during development.

Ventral opening at the umbilicus with protruding viscera COVERED by peritoneum.

Question 10

Gastroschisis

Answer 10

Inadequate enlargement of peritoneal cavity.

Viscera protrude through a defect in the anterior abdominal wall adjacent to the umbilicus and are NOT covered by peritoneum.

Question 11

Crossover Study

Answer 11

Subjects randomly allocated to a sequence of 2 or more treatments given consecutively.

A washout (no treatment) period is often added between treatment intervals to limit the confounding effects of prior treatment.

Question 12

Diagnostic confirmation of Menopause

Answer 12

Elevated serum FSH levels. (Loss of estrogen production since ovaries are less active leads to loss of inhibition)

LH levels also elevated (but later and less prominent phenomenon).

Question 13

Phosphodiesterase Inhibitors

Answer 13

Increases cardiac contractility via increased intracellular cAMP concentration (promotes increased intracellular calcium in myocytes).

In vascular SM, increases in cAMP cause vasodilation.

Question 14

Neonatal Intraventricular Hemorrage

Answer 14

Complication of prematurity (decreasing age and birth weight) that leads to long-term neurodevelopmental impairment.

Germinal matrix, highly cellular and vascularized layer in subventricular zone, from which neurons and glial cells migrate out lack glial fibers that support other blood vessels throught out the brain. (Becomes less prominent and vascular by 24-32 weeks of gestation, decreasing risk of IVH).

Question 15

Haloperidol

Answer 15

Treatment of agitation

Most commonly associated with neurleptic malignant syndrome (NMS) due to anti-dopaminergic activity of antipsychotic medications (D2 receptor).

Central dopaminergic systems are involved in thermoregulation, muscle tone and movement.

Results in: hyperthermia, generalized rigidity, autonomic instability, altered mental status.

Use Dopamine agonists (bromocriptine) and/or muscle relaxants (dantrolene)

Question 16

Difference between Serotonin Syndrome and Neuroleptic Malignant Syndrome

Answer 16

NMS has absence of myoclonus and presence of rigidity.

Question 17

Vitamin K

Answer 17

Assistance of glutamate residue carboxylation that is essential for production of clotting factors VII, IX, and X

Question 18

Increased 2,3-Biphosphoglycerate (BPG)

Answer 18

Achieved within erythrocytes to enable increased oxygen delivery in peripheral tissues in the presence of lower blood oxygen concentration (2,3-BPG decreases affinity of hemoglobin for oxygen).

2,3-BPG is produced from 1,3-BPG by Biphosphoglycerate Mutase. (Bypass step that forms ATP)

Question 19

Caldribine

Answer 19

Purine analog that is drug of choice for hairy cell leukemia.

Resistant to degradation by adenosine deaminase (purine disposal pathway). Allows it to reach high intracellular concentrations where is is incorporated into DNA and causes DNA strand breaks - antineoplastic.

Question 20

Superantigens

Answer 20

Enterotoxins, Exfoliative Toxins, Toxic Shock Syndrome Toxin (TSST-1)

MHC on APCs with variable region of T lymphocyte receptor to cause nonspecific “widespread” activation of T-cells resulting in release of IL-2 from T-cells and IL-1 and TNF from macrophages.

Question 21

Polyarteritis Nodosa (PAN)

Answer 21

Segmental, transmural, necrotizing inflamation of medium to small sized arteries in any organ.

Kidneys, heart, liver, and GI tract are most common.

Typically spares pulmonary and bronchial arteries.

Cutaneous manifestions in 1/3 of patients - palpable purpura.

Question 22

Androgens and acne

Answer 22

Androgens stimulate follicular epidermal hyperproliferation and excessive sebum production, thereby promoting acne development.

Anabolic steroid misuse, esp in competitive athletes is a known cause of acne.

Question 23

Risperidone

Answer 23

Anti-psychotic drug used for schizophrenia.

Antidopaminergic effects lead to hyperprolactinemia, which causes ameorrhea, galactorrhea, and breast soreness.

Hyperprolactinemia causes hypogonadism by inhibiting the release of gonadotrophin-releasing hormone from the hypothalamus.

Question 24

Tamoxifen and Raloxifene

Answer 24

Selective estrogen receptor modulators (SERMs) - tissue selective estrogen agonist and antagonist properties.

In Breast tissue, they are anti-estrogenic.

In Endometrial tissue and bone, they are stimulatory and cause endometrial hyperplasia/polyps/cancer and treat osteoporosis.

Question 25

Bilateral acoustic neuromas

Answer 25

Neurofibromatosis type 2 - autosomal dominant due to mutation of NF-2 gene on chromosome 22.

Causes tinnitus, vertigo, and hearing loss.

Question 26

Neurofibromatosis Type 1 (NF1), aka von Recklinghausen disease

Answer 26

NF1 tumor suppressor gene mutation that codes the protein neurofibromin.

Causes Café-au-lait spots, multiple neurofibromas, and Lisch nodules

Question 27

Colon Adenocarcinoma

Answer 27

Most common GI malignancy.

Frequently located in the rectosigmoid colon.

Obstructing symptoms (altered bowel habits, constipation, abdominal distention, NV)

2nd most common site is ascending colon (right sided colon cancers tend to grow as large, bulky masses that protrude into the colonic lumen and are more likely to bleed, causing iron-deficiency anemia. detected by positive fecal occult blood test)

Question 28

Sotalol

Answer 28

Beta-adrenergic blocking properties and class 3 antiarrhytmic (K+ channel blocking properties) like amiodarone, ibutilide, and dofetilide.

Prolongs PR interval and QT interval.

Question 29

Lesion in the optic tract

Answer 29

Contralateral homonymous hemianopia and relative afferent pupillary defect (Marcus Gunn pupil) in contralateral eye (since some obtic tract fibers project to pretectal nucleus in the midbrain - mostly from nasal portion of retina).

Question 30

Tuberculoid vs. Lepromatous Leprosy

Answer 30

Tuberculoid - strong Th1 mediated response (IL-2, IFN-r, IL-12), leading to activation of macrophages that kill M leprae organisms and limit disease extent. Localized inflammation that damages the skin and cutaneous nerves.

Lepromatous - inability to recognize and mount cellular immune response against atigens. Accumulation of acid fast bacilli within marcophages and Th2 cytokine profile.

Lepromin skin test is + in tuberculoid (Causes indurated nodule) and is - in lepromatous (weak Th1 cell-mediated immune response)