Mixed Deck — All COMLEX-USA Topics Flashcards

Which condition causes an anion gap metabolic acidosis with a normal osmol gap?

Answer: Lactic acidosis

Lactic acidosis causes an elevated anion gap metabolic acidosis; isopropanol causes elevated osmol gap without anion gap; methanol and ethylene glycol cause both gaps.

A 19-year-old woman at 18 weeks gestation presents with painless cervical dilation to 4 cm and no uterine contractions. Membranes are intact. Which diagnosis is most likely?

Answer: Cervical insufficiency

Cervical insufficiency (incompetent cervix) presents with painless cervical dilation in the second trimester without uterine contractions.

The Galbreath technique is a mandibular drainage technique primarily used to treat dysfunction of which structure?

Answer: Eustachian tube / middle ear

The Galbreath technique uses rhythmic mandibular traction to open the Eustachian tube and facilitate middle ear drainage.

Which enzyme is deficient in Tay-Sachs disease, leading to accumulation of GM2 ganglioside?

Answer: Hexosaminidase A

Tay-Sachs disease results from deficiency of hexosaminidase A, causing GM2 ganglioside accumulation in lysosomes.

A patient appears with an absent triceps tendon reflex and weakness in the extensors of the hand, wrist, and elbow due to a neurological deficiency. Which nerve is the most likely to be affected?

Answer: Radial

Explanation: The radial nerve innervates the extensors of the upper extremity (elbow, triceps, wrist & hand). An absent triceps (C7) reflex & wrist drop will indicate radial nerve pathology

Okazaki fragments are synthesized on which strand during DNA replication?

Answer: Lagging strand

Okazaki fragments are short DNA segments synthesized discontinuously on the lagging strand, which runs antiparallel to the direction of replication fork movement.

A 45-year-old woman has heavy menstrual bleeding, urinary frequency, and a 14-week-size uterus on exam. Ultrasound confirms multiple intramural fibroids. She wishes to maintain fertility. What is the most appropriate surgical treatment?

Answer: Myomectomy

Myomectomy removes fibroids while preserving the uterus and is the preferred surgical option for women who desire future fertility.

Atropine reverses bradycardia caused by organophosphate poisoning by which mechanism?

Answer: Competitively blocking muscarinic receptors

Atropine competitively antagonizes muscarinic acetylcholine receptors, reversing the excess cholinergic (SLUDGE) effects of organophosphate poisoning.

Neck pain is reported by a patient. After a comprehensive examination, you discover that several muscles are in spasm. The most painful muscle arises from the cervical vertebra's TPs and attaches to rib 1. What kind of muscle is it?

Answer: Anterior Scalene

The question describes a muscle originating from the transverse processes of cervical vertebrae and attaching to the first rib. This anatomical description perfectly matches the anterior scalene muscle, which typically originates from the transverse processes of C3-C6 and inserts onto the first rib. The middle scalene also attaches to the first rib but usually originates from C2-C7, while the posterior scalene attaches to the second rib.

Which antidepressant class is associated with hypertensive crisis when combined with tyramine-rich foods?

Answer: MAOIs

MAOIs prevent tyramine breakdown in the gut; consuming tyramine-rich foods (aged cheese, cured meats) causes massive sympathetic activation and hypertensive crisis.

Leg edema affects a 25-year-old woman in her 36th week of pregnancy. What is the most effective first treatment

Answer: Thoracic inlet release

Explanation: The thoracic inlet should be released prior to lymphatic pumping procedures to remove any impedance entering the thoracic duct and, ultimately, the central circulation.

The bile salt-independent fraction of bile secretion is driven primarily by which mechanism?

Answer: Bicarbonate secretion by cholangiocytes

Cholangiocytes secrete bicarbonate via CFTR and AE2 exchangers, driving water flow and contributing to the bile salt-independent fraction of bile.

In acute cholecystitis, which physical exam finding is pain with palpation of the RUQ that increases with inspiration?

Answer: Murphy's sign

Murphy's sign is cessation of inspiration due to pain when the examiner presses the RUQ and the inflamed gallbladder descends to meet the fingers.

The Chapman reflex point for the heart is located anteriorly between which ribs?

Answer: 2nd and 3rd ribs on the left

The anterior Chapman point for the heart is found between the 2nd and 3rd ribs on the left side of the sternum.

A 50-year-old woman reports 9 months of hot flashes, night sweats, and vaginal dryness. FSH is 58 mIU/mL and estradiol is 12 pg/mL. She has had no menses for 13 months. What is the diagnosis?

Answer: Menopause

Menopause is defined as 12 consecutive months of amenorrhea with elevated FSH (>40 mIU/mL) and low estradiol in a woman typically over 45 years.

Which of the following statements about a patient with an anterior fibular head SD is correct?

Answer: The synovial articulation of the tibio-fibular joint resists posterior glide.

An anterior fibular head somatic dysfunction means the fibular head is displaced anteriorly relative to the tibia. In this position, the proximal tibiofibular joint, which is a synovial articulation, will be at its anterior limit of motion. Consequently, any attempt to move the fibular head posteriorly (a posterior glide) will be met with resistance, as it is already restricted in that direction.

A patient presents to the ED with anaphylaxis and urticaria after a bee sting. First-line treatment is:

Answer: Epinephrine 0.3–0.5 mg IM (thigh)

Epinephrine IM (anterolateral thigh) is the first and most critical treatment for anaphylaxis; antihistamines and steroids are adjuncts but do not replace epinephrine.

Which structure in the nephron is primarily responsible for concentrating urine through countercurrent multiplication?

Answer: Loop of Henle

The loop of Henle creates a hyperosmotic medullary gradient via countercurrent multiplication, enabling the collecting duct to concentrate urine.

Which surgical complication presents with fever, tachycardia, elevated WBC, and rigidity beginning 24–48 hours after bowel surgery?

Answer: Anastomotic leak

Anastomotic leak after bowel surgery presents with fever, tachycardia, leukocytosis, and peritoneal signs due to bowel contents leaking into the peritoneum.

Which muscle energy technique principle involves the patient contracting against the physician's unyielding resistance to mobilize a restricted segment?

Answer: Post-isometric relaxation

Post-isometric relaxation (PIR) uses the reflex relaxation that follows an isometric contraction to gain increased range of motion.