5/29 Mixed

Question 1

Intestinal malrotation

Answer 1

Results when the midgut undergoes incomplete embryological counterclockwise rotation
It can present as intestinal obstruction (due to compression by the adhesive bands) and midgut volvulus (intestinal ischemia due to twisting around the blood vessels)

Question 2

Fragile X syndrome

Answer 2

X-linked disorder that presents with a long narrow face, a prominent chin and forehead, large testes, developmental delay and neuropsychiatric findings that overlap with anxiety disorders, autism, and ADHD

Question 3

Aplastic anemia

Answer 3

Most commonly due to a toxic effect or autoimmune response causing apoptosis of pluripotent stem cells (pancytopenia)
Bone marrow biopsy reveals hypocellularity with an abundance of fat cells

Question 4

Regional airway resistance

Answer 4

Within the first 10 generations of bronchi contributes to most of the total airway resistance of the lower respiratory tract
Resistance is maximal in the 2nd to 5th generation airways, including the segmental bronchi
In contrast, airways

Question 5

Nonbacterial thrombotic endocarditis

Answer 5

A form of noninfectious endocarditis characterized by deposition of sterile platelet thrombi on cardiac valves
Commonly associated with advanced malignancy and can also occur with chronic inflammatory disorder (antiphospholipid syndrome, systemic lupus erythematosis), and sepsis

Question 6

Acute acalculous cholescystitis

Answer 6

An acute inflammation of the gallbladder in the absence of gallstones, typically occurs in critically ill patients (sepsis, severe burns, trauma, immunosuppression) due to gallbladder stasis and ischemia
Fever, RUQ pain, leukocytosis

Question 7

Chronic mesenteric ischemia

Answer 7

Atherosclerosis of the mesenteric arteries, resulting in diminished blood flow to the intestine after meals
Causes postprandial epigastric pain (“intestinal angina”) with associated food aversion/weight loss
Pathogenesis is similar to angina pectoris

Question 8

Anal fissures

Answer 8

Longitudinal tears in the mucosa
Usually due to passage of hard stool in patients with chronic constipation
Most occur at the POSTERIOR MIDLINE, likely due to decreased blood flow to this area

Question 9

Primary central nervous system lymphoma

Answer 9

2nd most common cause of ring-enhancing lesions with mass effect in HIV
Negative toxoplasma serologies, no response to ABX therapy
Large-cell non-Hodgkin lymphoma of B-cell origin (EBV)

Question 10

Postoperative urinary retention with incomplete bladder emtpying

Answer 10

Thought to involve decreased micturition reflex activity, decreased contractility of the bladder detrusor, and/or increased vesicle sphincter tone
Can be treated with a muscarinic agonist (BETHANECHOL) or an a1 blocking drug

Question 11

Ramelteon

Answer 11

Melatonin agonist

Safe and effective in reducing time to sleep onset in the elderly

Question 12

Hawthorne effect (observer effect)

Answer 12

Tendency of study subjects to change their behavior as a result of their awareness that they are being studied

Question 13

Disorders of impaired BH4 (tetrahydrobiopterin)

Answer 13

MC = dihydrobiopterin reductase deficiency
Accounts for 2% of phenylketonuria cases
BH4 is important cofactor for phenylalanine hydroxylase and tyrosine hydroxylase
Phenylalanine levels can be corrected with dietary restriction, downstream deficiencies of dopamine, NE, EPI, and serotonin lead to progressive neurologic deterioration

Question 14

NSAID associated chronic renal injury

Answer 14

Chronic interstitial nephritis and PAPILLARY NECROSIS

Question 15

Systemic mastocytosis

Answer 15

Abnormal proliferation of mast cells and increased histamine release
Histamine causes hypersecretion of gastric acid by parietal cells in the stomach as well as a variety of other symtpoms (Hypotension, flushing, pruritus)

Question 16

Pudendal nerve block

Answer 16

Performed by injecting an anesthetic intravaginally, medial to the ischial spine, through the sacrospinous ligament
This provide anethesia to most of the perineum

Question 17

Perineal body

Answer 17

Is a fibromuscular tissue between the urogenital and anal triangle
A midline episiotomy is a vertical incision from the posterior vaginal opening to the perineal body
It transects the vaginal submucosal tissue but not the external anal sphincter or the rectal mucosa

Question 18

Congenital toricollis

Answer 18

Typically noted by 2 to 4 weeks of age, after which the child prefers to hold the head tilted to one side
It is most commonly the result of malposition of the head in utero or birth trauma
Most cases resolve with conservative therapy and stretching exercises

Question 19

Ventricular Septal Defect

Answer 19

A significant increase in blood oxygen saturation between 2 right sided vessels or chambers indicated the present of a left-to-right shunt
If such an oxygen step-up occurs between the right atrium and right ventricle, a VSD is most likely responsible
VSD is the most common congenital heart disease, and a small VSD produces a holosytolic murmur that is loudest over the left-mid sternal border

Question 20

Sickle cell patients

Answer 20

Most common organism causing bacteremia in sickle cell patients is Streptococccus pneumonieae, followed by Hemophilus influenza