Free Questions and Answers for All Medical Students all over the World
12 USMLE Anatomy, Neuroanatomy and Physiology Quick Review Questions with Answers (Set 1)
These 12 quick USMLE review questions test high-yield facts that show up again and again on the exam: brachial plexus, surfactant, the frontal lobe, the cerebellum, hip ligaments, myelin, tracheal bifurcation, the nuclear lamina, steroid synthesis, spinal tracts and the eye. Each question includes the correct answer.
Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.
D- Ulnar nerve- A lower brachial plexus injury (C8–T1), also known as Klumpke palsy, most commonly affects the ulnar nerve. This results in weakness of intrinsic hand muscles and sensory loss in the medial hand. The axillary, musculocutaneous, and most radial nerve functions come from higher roots.
The correct answer is D
Question 2. Which statement is true regarding action of lung surfactant?
A- It affects large alveoli more than small alveoli
B- It elevates surface tension forces and decreases compliance
C- It lowers surface tension and decreases compliance
D- It lowers surface tension and increases compliance
D- It lowers surface tension and increases compliance- Lung surfactant reduces surface tension in the alveoli, which prevents alveolar collapse and makes the lungs easier to expand. This increases lung compliance, especially in smaller alveoli.
The correct answer is D
Question 3. Emotions, judgments, and motor aspects of speech are controlled by which one of the following lobes of the brain?
A- Frontal
B- Occipital
C- Parietal
D- Temporal
A- Frontal- The frontal lobe controls higher functions such as emotions, judgment, personality, decision-making, and the motor aspects of speech (via Broca’s area). The other lobes have roles in vision (occipital), sensory processing (parietal), and hearing/memory (temporal).
The correct answer is A
Question 4. A middle-aged woman is evaluated for gait problems. On examination, her ability to touch her nose while her eyes closed fails and so, touching the heel of one toe to the toe of the other. Which of the following locations is the most likely affected?
A-Cerebellum- It is the only location on the list that is responsible for control of gait and coordination of movements which are tested by those neurological tests and observing the patient’s gait.
The correct answer is A
Question 5. Which of the following ligaments is most likely torn in a case of posterior dislocation of the hip?
B- Ischiofemoral ligament- The ischiofemoral ligament is located posteriorly and is the ligament most likely torn during a posterior hip dislocation, the most common type of hip dislocation. Iliofemoral and sacrotuberous ligaments are not typically torn in this injury pattern.
The correct answer is B
Question 6. Which one of the following types of cells myelinates the axons of neurons of the CNS?
C- Oligodendroglia- Oligodendroglia (oligodendrocytes) produce myelin in the central nervous system. Schwann cells myelinate peripheral nerves. Astrocytes and microglia serve different supportive and immune functions.
The correct answer is C
Question 7. At which of these vertebral levels does the trachea bifurcate?
C- Fourth thoracic- The trachea bifurcates at the T4–T5 level, also known as the sternal angle (Angle of Louis). This is the classic anatomical landmark for the carina.
The correct answer is C
Question 8. Which one of the following proteins surrounds the nuclear envelope?
A- Lamin
B- Enkephalin
C- Tropomyosin
D- Vimentin
A- Lamin- Lamins are intermediate filaments that form the nuclear lamina, a meshwork lining the inner surface of the nuclear envelope. Vimentin is the intermediate filament of mesenchymal cells (fibroblasts, endothelium), tropomyosin regulates muscle contraction, and enkephalin is a neuropeptide.
The correct answer is A
Question 9. Which one of the following parts of the cell is the site of steroid synthesis?
D- Smooth endoplasmic reticulum- Steroid hormones are synthesized in the smooth endoplasmic reticulum, which contains the enzymes necessary for cholesterol and steroid metabolism.
The correct answer is D
Question 10. Which of the following types of sensations is carried to the thalamus by the anterolateral tracts after crossing the spinal cord?
A- Crude touch
B- Fine touch
C- Position
D- Vibrations
A- Crude touch- The anterolateral (spinothalamic) tracts carry pain, temperature, and crude touch after crossing to the opposite side of the spinal cord. Fine touch, vibration, and position sense travel in the dorsal columns, not the anterolateral system.
The correct answer is A
Question 11. Which of the following is a major complication of central retinal vein occlusion?
B- Glaucoma- Central retinal vein occlusion can lead to retinal ischemia, which stimulates neovascularization of the iris and angle. This can obstruct aqueous outflow and result in neovascular glaucoma, a major and serious complication.
The correct answer is B
Question 12. Which of the following is the leading cause of blindness in the elderly in the USA?
D- Macular degeneration- Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population in the United States. Cataracts and glaucoma are also common but do not surpass AMD as the top cause in this age group.
The correct answer is D
High-yield points from this set
Lower brachial plexus (C8–T1) injury affects the ulnar nerve.