USMLE Questions and Answers Latest Update –
Comprehensive High-Yield Review Guide and Practice
Questions
Introduction
This document contains a comprehensive collection of high-yield
USMLE practice questions and concise, verified answers covering
the core basic and clinical sciences tested on the USMLE. It includes
microbiology, pharmacology, pathology, physiology, anatomy,
biochemistry, immunology, neurology, pediatrics, internal medicine,
surgery, genetics, and diagnostic concepts presented in a rapid-
review question-and-answer format. The material is designed for
efficient memorization and board preparation, making it an
excellent resource for final revision before examinations.
Exam Questions and Answers
Which walls of the orbit are weakest and most prone to fracture
secondary to blunt trauma to the eye?--- correct precise answer ---
Medial (composed of ethmoid and lacrimal bones, opens into
ethmoid air cells) and inferior (opens into maxillary sinus)
,Where does Iron absorption occur?--- correct precise answer ---
Duodenum and proximal jejunum (gastrojejunostomies often
bypass this segment and result in IDA)
Gram positive cocci that is coagulase-negative, catalase-negative,
and pyrrolidonyl arylamidase (PYR) positive--- correct precise
answer ---Streptococcus pyogenes (would also be bacitracin
sensitive)
tetrahydrobiopterin--- correct precise answer ---(BH4) It serves as a
cofactor to hydroxylase enzymes used in the synthesis of tyrosine,
dopa, serotonin and nitric oxide
dihydrobiopterin reductase deficiency--- correct precise answer ---
Rare cause of PKU. Defective regeneration of BH4, a cofactor for
phenylalanine hydroxylase -> accumulation of phenylalanine and
deficiency of tyrosine (PKU)
What is the enzyme that converts 25-OH vit D to 1,25-diOH vit D?---
correct precise answer ---1-alpha hydroxylase
Why do patients with sarcoidosis get hypercalcemia?--- correct
precise answer ---Activated T-lymphocytes secrete IFN-gamma
which increases activity of 1-alpha hydroxylase in macrophages in
the granulomas. This results in increased formation of active vit D
and increased Ca absorption and increased bone resorption
,What is the difference between a gastric erosion and a gastric
ulcer?--- correct precise answer ---Gastric erosions do not extend
through the muscularis mucosa (they are limited to the mucosa).
Gastric ulcers penetrate through mucosal layers and into the
submucosa
Chlorpheniramine MOA--- correct precise answer ---1st generation
antihistamine (blocks both central and peripheral H1 receptors)
Bony swelling of the DIP joint associated with OA--- correct precise
answer ---Heberden's nodes
Bouchard's nodes--- correct precise answer ---bony swelling of the
PIP associated with OA
What bacteria can cause AV block?--- correct precise answer ---
Borrelia burgdorferi (Lyme disease)
Which a-adrenergic antagonists are used in the treatment of
pheochromocytoma?--- correct precise answer ---
phenoxybenzamine or phentolamine
What drug class ends with the suffix "-dronate"?--- correct precise
answer ---Bisphosphonates (alendronate, risendronate and
etidronate)
, teriparatide MOA--- correct precise answer ---recombinant PTH
analogue. When given in pulsatile fashion it stimulates osteoblasts
and can be used for osteoporosis
osteoclasts deficient in carbonic anhydrase II--- correct precise
answer ---cause of osteopetrosis (osteoclasts can't create an acidic
environment and can't resorb bone)
"my hats are getting too tight"--- correct precise answer ---Paget
disease of bone (may also cause some hearing loss with narrowing
of the auditory foramen)
what drug class ends with "-mustine"?--- correct precise answer ---
nitrosureas (alkylating agents used as cancer chemotherapy)
most commonly injured ligament in ankle sprain?--- correct precise
answer ---anterior talofibular ligament
What are the 4 muscles of the rotator cuff and what is their
action?--- correct precise answer ---supraspinatus - initial abduction
of arm (before the action of the deltoid)
infraspinatus - lateral rotation of arm
teres minor - lateral rotation and adduction
subscapularis - medial rotation and adduction
anatomical snuff box tenderness--- correct precise answer ---
scaphoid fracture
Comprehensive High-Yield Review Guide and Practice
Questions
Introduction
This document contains a comprehensive collection of high-yield
USMLE practice questions and concise, verified answers covering
the core basic and clinical sciences tested on the USMLE. It includes
microbiology, pharmacology, pathology, physiology, anatomy,
biochemistry, immunology, neurology, pediatrics, internal medicine,
surgery, genetics, and diagnostic concepts presented in a rapid-
review question-and-answer format. The material is designed for
efficient memorization and board preparation, making it an
excellent resource for final revision before examinations.
Exam Questions and Answers
Which walls of the orbit are weakest and most prone to fracture
secondary to blunt trauma to the eye?--- correct precise answer ---
Medial (composed of ethmoid and lacrimal bones, opens into
ethmoid air cells) and inferior (opens into maxillary sinus)
,Where does Iron absorption occur?--- correct precise answer ---
Duodenum and proximal jejunum (gastrojejunostomies often
bypass this segment and result in IDA)
Gram positive cocci that is coagulase-negative, catalase-negative,
and pyrrolidonyl arylamidase (PYR) positive--- correct precise
answer ---Streptococcus pyogenes (would also be bacitracin
sensitive)
tetrahydrobiopterin--- correct precise answer ---(BH4) It serves as a
cofactor to hydroxylase enzymes used in the synthesis of tyrosine,
dopa, serotonin and nitric oxide
dihydrobiopterin reductase deficiency--- correct precise answer ---
Rare cause of PKU. Defective regeneration of BH4, a cofactor for
phenylalanine hydroxylase -> accumulation of phenylalanine and
deficiency of tyrosine (PKU)
What is the enzyme that converts 25-OH vit D to 1,25-diOH vit D?---
correct precise answer ---1-alpha hydroxylase
Why do patients with sarcoidosis get hypercalcemia?--- correct
precise answer ---Activated T-lymphocytes secrete IFN-gamma
which increases activity of 1-alpha hydroxylase in macrophages in
the granulomas. This results in increased formation of active vit D
and increased Ca absorption and increased bone resorption
,What is the difference between a gastric erosion and a gastric
ulcer?--- correct precise answer ---Gastric erosions do not extend
through the muscularis mucosa (they are limited to the mucosa).
Gastric ulcers penetrate through mucosal layers and into the
submucosa
Chlorpheniramine MOA--- correct precise answer ---1st generation
antihistamine (blocks both central and peripheral H1 receptors)
Bony swelling of the DIP joint associated with OA--- correct precise
answer ---Heberden's nodes
Bouchard's nodes--- correct precise answer ---bony swelling of the
PIP associated with OA
What bacteria can cause AV block?--- correct precise answer ---
Borrelia burgdorferi (Lyme disease)
Which a-adrenergic antagonists are used in the treatment of
pheochromocytoma?--- correct precise answer ---
phenoxybenzamine or phentolamine
What drug class ends with the suffix "-dronate"?--- correct precise
answer ---Bisphosphonates (alendronate, risendronate and
etidronate)
, teriparatide MOA--- correct precise answer ---recombinant PTH
analogue. When given in pulsatile fashion it stimulates osteoblasts
and can be used for osteoporosis
osteoclasts deficient in carbonic anhydrase II--- correct precise
answer ---cause of osteopetrosis (osteoclasts can't create an acidic
environment and can't resorb bone)
"my hats are getting too tight"--- correct precise answer ---Paget
disease of bone (may also cause some hearing loss with narrowing
of the auditory foramen)
what drug class ends with "-mustine"?--- correct precise answer ---
nitrosureas (alkylating agents used as cancer chemotherapy)
most commonly injured ligament in ankle sprain?--- correct precise
answer ---anterior talofibular ligament
What are the 4 muscles of the rotator cuff and what is their
action?--- correct precise answer ---supraspinatus - initial abduction
of arm (before the action of the deltoid)
infraspinatus - lateral rotation of arm
teres minor - lateral rotation and adduction
subscapularis - medial rotation and adduction
anatomical snuff box tenderness--- correct precise answer ---
scaphoid fracture
