Development of muscualr system ckinicals ,conceptual ,scenario based and other 50 multiple choice questions for Mbbs from best mcq books of international standards
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I now have comprehensive textbook content from both "The Developing Human" and "Langman's Medical Embryology." I have enough material to create 50 high-quality MBBS MCQs on the Development of the Muscular System. Let me generate them now.Here are 50 MBBS-standard MCQs on the Development of the Muscular System, modeled after international MCQ books (Snell, Moore, Langman, BRS Embryology, USMLE-style):
Development of the Muscular System — 50 MCQs (MBBS Level)
SECTION A: CONCEPTUAL / FOUNDATIONAL (Q1–20)
Q1. The primary germ layer from which the skeletal muscular system is derived is:
- A) Ectoderm
- B) Endoderm
- C) Mesoderm ✅
- D) Neural crest
- E) Trophoblast
Explanation: Skeletal muscle is derived from paraxial mesoderm (somites and somitomeres). Mesoderm is the primary germ layer of origin for nearly the entire muscular system.
(The Developing Human, 10e; Langman's Medical Embryology, 14e)
Q2. Paraxial mesoderm in the occipital-to-sacral region forms segmented tissue blocks called:
- A) Somitomeres
- B) Sclerotomes
- C) Somites ✅
- D) Lateral plate mesoderm
- E) Notochord
Explanation: From the occipital to sacral regions, paraxial mesoderm forms somites. In the head region (unsegmented), it forms somitomeres.
Q3. Which part of the somite gives rise to skeletal muscle?
- A) Sclerotome
- B) Dermatome
- C) Myotome ✅
- D) Nephrotome
- E) Somatopleure
Explanation: The myotome region of the somite differentiates into skeletal muscle. The sclerotome forms vertebrae and ribs; the dermatome forms dermis.
Q4. The ventromedial part of the somite that forms vertebrae and ribs is called:
- A) Myotome
- B) Dermatome
- C) Dermomyotome
- D) Sclerotome ✅
- E) Lateral plate
Explanation: Sclerotome is the ventromedial part that becomes polymorphic mesenchyme and eventually forms the vertebral column and ribs.
Q5. The dorsolateral part of the somite that gives rise to both skin dermis and muscle is:
- A) Sclerotome
- B) Notochord
- C) Dermomyotome ✅
- D) Neural crest
- E) Endoderm
Explanation: The dermomyotome is the dorsolateral part of the somite. It further separates into the dermatome (dermis) and myotome (muscle).
Q6. Which two lips (edges) of the dermomyotome contain progenitor muscle cells?
- A) Medial and lateral lips
- B) Dorsomedial (DML) and ventrolateral (VLL) lips ✅
- C) Ventral and dorsal lips
- D) Anterior and posterior lips
- E) Cranial and caudal lips
Explanation: Cells from the DML and VLL regions of the dermomyotome migrate to form progenitor muscle cells ventral to the dermatome, thereby forming the dermomyotome.
Q7. Muscles of the axial skeleton, body wall, and limbs are derived from:
- A) Somitomeres only
- B) Lateral plate mesoderm only
- C) Somites ✅
- D) Neural crest cells
- E) Paraxial mesoderm of the head
Explanation: Musculature of the axial skeleton, body wall, and limbs is derived from somites extending from the occipital region to the tail bud.
Q8. Which myogenic regulatory factors (MRFs) are essential for muscle development?
- A) PAX3, PAX7, NOTCH, WNT
- B) MYOD, MYF5, MYF6 (MRF4), MYOG (myogenin) ✅
- C) SRF, MRTF, myocardin
- D) HOX genes only
- E) TBX5, GATA4, NKX2.5
Explanation: MYOD, MYF5, MYF6, and MYOG (myogenin) are the four myogenic regulatory factors essential for skeletal muscle development.
Q9. Epaxial division myoblasts of the myotome are innervated by:
- A) Ventral primary ramus
- B) Dorsal primary ramus ✅
- C) CN XI (accessory nerve)
- D) Sympathetic chain
- E) CN XII
Explanation: Each myotome divides into dorsal epaxial and ventral hypaxial divisions. The dorsal primary ramus innervates the epaxial division.
Q10. Which muscles develop from the hypaxial divisions of the cervical myotomes?
- A) Extensor muscles of the back
- B) Scalene, prevertebral, geniohyoid, and infrahyoid muscles ✅
- C) Tongue muscles
- D) Extraocular muscles
- E) Muscles of mastication
Explanation: Hypaxial divisions of cervical myotomes form scalene, prevertebral, geniohyoid, and infrahyoid muscles, innervated by the ventral primary ramus.
Q11. The quadratus lumborum muscle is derived from which myotomes?
- A) Thoracic myotomes
- B) Cervical myotomes
- C) Lumbar myotomes ✅
- D) Sacrococcygeal myotomes
- E) Occipital somites
Explanation: The lumbar myotomes form the quadratus lumborum muscle. Thoracic myotomes form lateral and ventral flexors of the vertebral column.
Q12. Which structure differentiates into a mature muscle fiber after fusion of myoblasts?
- A) Myofilament
- B) Satellite cell
- C) Myotube ✅
- D) Myoblast chain
- E) Syncytiotrophoblast
Explanation: Myoblasts proliferate and fuse to form myotubes. Myofilaments then develop in the cytoplasm of myotubes, which differentiate into mature skeletal muscle fibers.
Q13. The perimysium and epimysium layers of fibrous sheath of muscle are produced by:
- A) Myoblasts
- B) Satellite cells
- C) Fibroblasts ✅
- D) Osteoblasts
- E) Mast cells
Explanation: Fibroblasts produce the perimysium and epimysium; the endomysium is formed by the external lamina and reticular fibers around muscle fibers.
Q14. Most skeletal muscles develop by which time period?
- A) End of 4th week
- B) End of 8th week
- C) Before birth ✅
- D) End of first year of life
- E) Puberty
Explanation: Most skeletal muscles develop before birth. Almost all remaining muscles are formed by the end of the first year. Subsequent muscle growth is by hypertrophy (more myofilaments), not new muscle formation.
Q15. Cardiac muscle is derived from:
- A) Paraxial mesoderm
- B) Lateral plate somatic mesoderm
- C) Visceral (splanchnic) mesoderm surrounding the heart tube ✅
- D) Neural crest
- E) Endoderm
Explanation: Cardiac muscle develops from visceral mesoderm surrounding the endothelial heart tube. Myoblasts adhere via attachments that later become intercalated discs.
Q16. Smooth muscle of the pupillary sphincter and dilator muscles is uniquely derived from:
- A) Lateral plate mesoderm
- B) Visceral mesoderm
- C) Neural crest
- D) Ectoderm ✅
- E) Notochord
Explanation: The sphincter and dilator muscles of the pupil, as well as muscle tissue in the mammary and sweat glands, are the only smooth muscles derived from ectoderm.
Q17. Smooth muscle differentiation is initiated by which transcription factor?
- A) MYOD
- B) MYF5
- C) Serum response factor (SRF) ✅
- D) TBX5
- E) PAX3
Explanation: SRF is the transcription factor responsible for smooth muscle cell differentiation. Myocardin and MRTFs act as co-activators of SRF to initiate the cascade.
Q18. Purkinje fibers of the cardiac conducting system represent:
- A) Neural crest derivatives
- B) Modified skeletal muscle fibers
- C) Special bundles of cardiac muscle cells with irregularly distributed myofibrils ✅
- D) Endothelial derivatives
- E) Smooth muscle cells
Explanation: Purkinje fibers form from special bundles of cardiac myoblasts with irregularly distributed myofibrils, forming the conducting system.
Q19. The lateral somitic frontier separates:
- A) Sclerotome from dermomyotome
- B) Primaxial domain from abaxial domain ✅
- C) Epaxial from hypaxial myotome
- D) Dermatome from myotome
- E) Neural tube from notochord
Explanation: The lateral somitic frontier separates the primaxial domain (around neural tube; paraxial mesoderm cells only) from the abaxial domain (lateral plate mesoderm + migrated somite cells).
Q20. Head musculature is derived from:
- A) Somites
- B) Neural crest cells
- C) Seven somitomeres (partially segmented whorls of paraxial mesoderm) ✅
- D) Lateral plate mesoderm
- E) Endoderm
Explanation: Head musculature derives from seven somitomeres, which are partially segmented whorls of mesenchymal cells derived from paraxial mesoderm in the head region.
SECTION B: CLINICAL APPLICATION (Q21–35)
Q21. A neonate is found to have absence of the pectoralis minor and partial loss of the sternal head of pectoralis major, with ipsilateral nipple displacement and syndactyly. This is:
- A) Prune-belly syndrome
- B) Arthrogryposis multiplex congenita
- C) Poland sequence ✅
- D) Congenital torticollis
- E) Klippel-Feil syndrome
Explanation: Poland sequence occurs in 1/20,000 individuals and is characterized by absence of the pectoralis minor and partial loss of pectoralis major, with displaced nipple/areola and digital defects (syndactyly, brachydactyly) on the affected side.
Q22. A neonate male is born with a very thin, lax abdominal wall through which intestinal loops are easily visible and palpable. He also has bilateral undescended testes. The most likely diagnosis is:
- A) Gastroschisis
- B) Omphalocele
- C) Poland sequence
- D) Prune-belly (Eagle-Barrett) syndrome ✅
- E) Bladder exstrophy
Explanation: Prune-belly syndrome (Eagle-Barrett syndrome) is characterized by partial/complete absence of abdominal musculature, cryptorchidism (in males), and urinary tract abnormalities. The cause is likely transient urethral obstruction or failure of development of specific mesodermal tissues.
Q23. A 3-week-old male infant is noted to have a firm, non-tender swelling in the right sternocleidomastoid muscle with passive head tilt to the right and chin rotation to the left. The most likely embryological cause is:
- A) Failure of pharyngeal arch fusion
- B) Neural crest migration defect
- C) Tearing of SCM fibers during birth → hematoma → fibrosis → muscle shortening ✅
- D) Absence of myotome
- E) Poland sequence
Explanation: Congenital torticollis results from tearing of SCM fibers during childbirth, forming a hematoma that undergoes necrosis, fibrosis, and shortening, causing lateral head tilt to the affected side and chin rotation away.
Q24. A 6-year-old boy presents with progressive proximal muscle weakness, waddling gait, calf pseudohypertrophy, and Gowers' sign. Creatine kinase is massively elevated. Muscle biopsy shows absence of dystrophin. The inheritance pattern is:
- A) Autosomal dominant
- B) Autosomal recessive
- C) X-linked recessive ✅
- D) X-linked dominant
- E) Mitochondrial
Explanation: Duchenne muscular dystrophy (DMD) is X-linked recessive, caused by mutations in the dystrophin gene (Xp21). It is the most severe inherited muscular dystrophy, affecting 1/3,500 male births.
Q25. In Duchenne muscular dystrophy, the gene affected is located on chromosome:
- A) 17q
- B) Xq21
- C) Xp21 ✅
- D) 1p
- E) 7q
Explanation: The DMD gene is located at Xp21.2 and codes for dystrophin. Absence of functional dystrophin leads to progressive muscle cell destruction.
Q26. A newborn girl has multiple rigid joint contractures with bilateral clubfeet, flexion contractures of the hips and knees, and hypoplastic associated muscles. There is decreased fetal movement reported in utero. The diagnosis is:
- A) Prune-belly syndrome
- B) Spinal muscular atrophy
- C) Arthrogryposis multiplex congenita ✅
- D) Congenital myotonic dystrophy
- E) Myasthenia gravis neonatal
Explanation: Arthrogryposis multiplex congenita presents with multiple joint contractures due to muscle hypoplasia, often caused by decreased fetal movement in utero, leading to joint stiffness and contractures.
Q27. During a C-section, a baby girl is born and on examination she has congenital torticollis. The mechanism in this case is MOST likely:
- A) Birth trauma from forceps
- B) Intrauterine crowding or primary SCM myopathy ✅
- C) Vascular injury to CN XI
- D) Neural crest migration failure
- E) Chromosomal trisomy
Explanation: Since torticollis can occur in C-section deliveries (no birth canal trauma), intrauterine crowding or primary SCM myopathy is the likely cause, not birth trauma.
Q28. An incidental finding in a healthy adult on ultrasound reveals a thin muscle band running parallel to the sternum on the right side. This is most likely:
- A) Serratus anterior hypertrophy
- B) Pectoralis minor abnormality
- C) Sternalis muscle ✅
- D) External intercostal
- E) Subclavius variation
Explanation: The sternalis muscle is a functionally vestigial muscle present in only some humans (variant, present in other primates). It runs parallel to the sternum and is an anatomical variant with no functional significance.
Q29. A radiologist describes an accessory soleus muscle incidentally found on MRI of the ankle in a 30-year-old. The expected incidence of this variation is approximately:
- A) 1%
- B) 3% ✅
- C) 10%
- D) 15%
- E) 25%
Explanation: An accessory soleus muscle occurs in approximately 3% of people. The primordium of the soleus may undergo early splitting to form an accessory soleus.
Q30. A 2-year-old boy has delayed motor milestones, diffuse hypotonia, tongue fasciculations, and absent deep tendon reflexes. EMG shows widespread denervation. This is most consistent with:
- A) Duchenne muscular dystrophy
- B) Myasthenia gravis
- C) Spinal muscular atrophy (SMA) ✅
- D) Congenital myopathy
- E) Dermatomyositis
Explanation: SMA (Werdnig-Hoffmann disease, Type I) presents with hypotonia, absent DTRs, fasciculations (anterior horn cell disease), and is caused by SMN1 gene mutations. Unlike DMD, CK is normal or mildly elevated, and the problem is neurogenic, not myogenic.
Q31. A woman delivers a baby with absent palmaris longus bilaterally. She is concerned about functional deficit. You counsel her:
- A) It will cause severe grip weakness
- B) It is functionally significant and needs surgery
- C) It is a common, functionally insignificant muscle variation ✅
- D) It indicates Poland sequence
- E) It requires tendon grafting
Explanation: Partial or complete absence of the palmaris longus is one of the most common muscle variations (absent in ~14% of people) and is functionally insignificant. It is commonly used as a tendon graft donor for that very reason.
Q32. In prune-belly syndrome, the accumulation of fluid that causes abdominal muscle atrophy is due to:
- A) Ascites from liver disease
- B) Lymphatic obstruction
- C) Urethral obstruction causing urinary tract distension ✅
- D) Intestinal atresia
- E) Portal hypertension
Explanation: Transient urethral obstruction leads to fluid accumulation in the urinary tract, which distends the abdomen, resulting in atrophy and hypoplasia of the abdominal wall musculature.
Q33. A woman presents with a neck mass found to be a remnant of the sternocleidomastoid muscle with fibrous tissue. Histologically, what is the expected finding?
- A) Granulomatous inflammation with giant cells
- B) Necrotic muscle fibers with fibrosis and replacement by fibrous tissue ✅
- C) Normal muscle with increased satellite cells
- D) Lymphoid infiltrate
- E) Calcified muscle
Explanation: In congenital torticollis, necrosis of muscle fibers occurs after hematoma formation, followed by fibrosis. Histology shows necrotic muscle replaced by fibrous/fibrotic tissue.
Q34. A girl with Poland sequence presents for cosmetic surgery at age 17. Which associated finding would be MOST expected?
- A) Bilateral absence of both pectoralis muscles
- B) Nipple present and normally positioned
- C) Ipsilateral syndactyly and absent/displaced nipple ✅
- D) Bilateral renal agenesis
- E) Cardiac defects
Explanation: Poland sequence is characterized by unilateral absence of pectoralis minor ± sternal head of pectoralis major, with ipsilateral displaced/absent nipple and areola, and digital defects (syndactyly, brachydactyly).
Q35. A fetus with severe oligohydramnios secondary to renal agenesis is delivered. The pediatrician notes severe joint contractures. The mechanism of contractures is:
- A) Direct teratogenic effect of absent kidneys
- B) Compression of fetal limbs in utero → decreased fetal movement → arthrogryposis ✅
- C) Chromosomal abnormality
- D) Neural crest migration failure
- E) Myotome aplasia
Explanation: Oligohydramnios (Potter sequence) leads to uterine constraint, restricting fetal movement. Decreased fetal movement leads to arthrogryposis (joint contractures with muscle hypoplasia).
SECTION C: SCENARIO-BASED (Q36–50)
Q36. A 4th-year medical student is examining somite differentiation in a 5-week embryo. She notes that VLL (ventrolateral lip) cells cross a specific border into lateral plate mesoderm. This border is called:
- A) Notochordal plate
- B) Lateral somitic frontier ✅
- C) Neural crest boundary
- D) Somatopleuric fold
- E) Primitive streak
Explanation: The lateral somitic frontier is the well-defined border between each somite and the parietal layer of lateral plate mesoderm. VLL cells cross it to form abaxial muscles (limb, abdominal wall muscles).
Q37. A researcher studying myogenesis finds that knocking out a specific gene prevents formation of hypaxial, epaxial, abdominal, and intercostal muscles in mouse embryos. This gene family encodes:
- A) HOX transcription factors
- B) SRF and myocardin
- C) Myogenic regulatory factors (MYOD, MYF5, MYF6, MYOG) ✅
- D) PAX1 and PAX9
- E) SOX9
Explanation: Gene-targeting studies show MRFs (MYOD, MYF5, MYF6, MYOG) are essential for development of all major skeletal muscle groups. Knockout leads to absence of these muscles.
Q38. A pharmacologist studies a transcription factor that, when phosphorylated by kinases in response to growth factors, drives smooth muscle differentiation. This factor is:
- A) MYOD
- B) NKX2.5
- C) SRF (serum response factor) ✅
- D) PAX3
- E) TBX1
Explanation: SRF is upregulated by growth factors through kinase phosphorylation. Myocardin and MRTFs act as co-activators to enhance SRF activity, initiating smooth muscle genetic cascade.
Q39. During embryology lab, a student traces which muscles are derived from the sacrococcygeal myotomes. The correct answer is:
- A) Gluteus maximus and minimus
- B) Quadratus lumborum
- C) Muscles of the pelvic diaphragm and striated muscles of anus and sex organs ✅
- D) Erector spinae
- E) Piriformis
Explanation: Sacrococcygeal myotomes form the muscles of the pelvic diaphragm and probably the striated muscles of the anus and sex organs (external sphincters).
Q40. A student asks why the intercostal muscles retain their segmental arrangement while other muscles do not. The explanation is:
- A) They are derived from lateral plate mesoderm, not somites
- B) They are derived from neural crest
- C) They originate from thoracic myotomes and remain segmentally arranged like their parent somites ✅
- D) They are smooth muscle
- E) They are derived from pharyngeal arches
Explanation: Some muscles like the intercostal muscles remain segmentally arranged like the somites. Most other myoblasts migrate away from the myotome and form non-segmented muscles.
Q41. A molecular biology professor asks what signals from the neural tube and notochord induce in the somites during limb muscle development. The answer is:
- A) MYF6 and MYOG directly
- B) HOX gene expression
- C) PAX3, MYOD, and MYF5 expression ✅
- D) SRF and myocardin
- E) WNT3a only
Explanation: Molecular signals from the neural tube and notochord induce PAX3, MYOD, and MYF5 expression in the somites. In the limb bud, PAX3 upregulates MET (receptor tyrosine kinase) allowing delamination and migration.
Q42. In examining a cross-section of a 5-week embryo at the thoracic level, you note cells migrating from the VLL of the dermomyotome into the lateral plate mesoderm. These cells will eventually form:
- A) Extensor muscles of the vertebral column
- B) Abdominal wall muscles (rectus abdominis, obliques) and limb muscles ✅
- C) Diaphragm only
- D) Tongue muscles
- E) Extraocular muscles
Explanation: VLL cells that cross the lateral somitic frontier into lateral plate mesoderm form infrahyoid, abdominal wall (rectus abdominis, obliques, transversus), and limb muscles — the abaxial muscle group.
Q43. A developmental biologist notes that embryonic extensor muscles from sacral and coccygeal myotomes degenerate. Their adult remnants are the:
- A) Gluteal muscles
- B) Levator ani
- C) Dorsal sacrococcygeal ligaments ✅
- D) Coccygeus muscle
- E) External anal sphincter
Explanation: The embryonic extensor muscles derived from sacral and coccygeal myotomes degenerate during development. Their adult derivatives are the dorsal sacrococcygeal ligaments.
Q44. Four occipital (postotic) myotomes are initially present for tongue development. How many ultimately contribute to tongue musculature, and what nerve innervates them?
- A) All four; CN X
- B) Four; CN V
- C) Three; CN XII ✅
- D) Two; CN IX
- E) Three; CN XI
Explanation: Initially there are four occipital myotomes; the first pair disappears. The remaining three sets form tongue muscles innervated by CN XII (hypoglossal nerve).
Q45. A researcher demonstrates that extrinsic eye muscle precursors originate near the prechordal plate, forming three groups each innervated by a separate cranial nerve. These nerves are:
- A) CN III, CN IV, CN VI ✅
- B) CN III, CN V, CN VII
- C) CN III, CN IV, CN V
- D) CN IV, CN VI, CN XI
- E) CN II, CN III, CN VI
Explanation: The three preotic myotomes form the extrinsic ocular muscles. Each group is supplied by CN III (oculomotor), CN IV (trochlear), and CN VI (abducens), respectively.
Q46. Muscles of mastication, facial expression, pharynx, and larynx are derived from:
- A) Occipital somites
- B) Preotic myotomes
- C) Myoblasts from pharyngeal arches (unsegmented paraxial mesoderm and prechordal plate) ✅
- D) Cervical myotomes
- E) Sacrococcygeal myotomes
Explanation: Myoblasts from pharyngeal arches form the muscles of mastication, facial expression, pharynx, and larynx. These are innervated by pharyngeal arch nerves (CN V, VII, IX, X, XI).
Q47. In a genetics counseling session, a mother whose brother died of muscular dystrophy asks about her risk. She is a carrier of DMD mutation. Her sons have what probability of being affected?
- A) 25%
- B) 50% ✅
- C) 100%
- D) 0%
- E) 75%
Explanation: DMD is X-linked recessive. A carrier female (X^D X) has a 50% chance of passing the mutant X to each son. Therefore, 50% of her sons will be affected.
Q48. A 32-week premature neonate is found to have a diaphragmatic hernia. Embryologically, the diaphragm muscular component is derived from:
- A) Thoracic somites only
- B) Lateral plate mesoderm only
- C) Cervical myotomes (C3–C5) that migrate with the phrenic nerve ✅
- D) Sacrococcygeal myotomes
- E) Pharyngeal arch mesoderm
Explanation: The muscular component of the diaphragm is derived from cervical myotomes (C3, C4, C5), which migrate caudally along with the phrenic nerve. This explains why the diaphragm is innervated by C3–C5 (phrenic nerve).
Q49. A pathology resident examines a biopsy of a cardiac mass and notes specialized muscle cells with sparse, irregularly distributed myofibrils forming interconnected bundles. These are:
- A) Rhabdomyoma cells
- B) Normal cardiomyocytes
- C) Purkinje fibers ✅
- D) Satellite cells
- E) Smooth muscle cells of coronary arteries
Explanation: Purkinje fibers are special bundles of cardiac muscle cells with irregularly distributed myofibrils. They form the cardiac conduction system and arise during cardiac development.
Q50. A second-trimester ultrasound shows decreased fetal movements and the fetus is noted to have rigid-appearing limbs. The mother asks about long-term prognosis. The condition most consistent with this finding is:
- A) Spina bifida
- B) Amniotic band syndrome
- C) Arthrogryposis multiplex congenita (AMC) ✅
- D) Thanatophoric dysplasia
- E) Edwards syndrome
Explanation: Arthrogryposis multiplex congenita is caused by decreased fetal movement in utero leading to joint contractures and muscle hypoplasia. Prognosis depends on the underlying cause; many patients achieve functional independence with physiotherapy.
ANSWER KEY SUMMARY
| Q | Ans | Q | Ans | Q | Ans | Q | Ans | Q | Ans |
|---|---|---|---|---|---|---|---|---|---|
| 1 | C | 11 | C | 21 | C | 31 | C | 41 | C |
| 2 | C | 12 | C | 22 | D | 32 | C | 42 | B |
| 3 | C | 13 | C | 23 | C | 33 | B | 43 | C |
| 4 | D | 14 | C | 24 | C | 34 | C | 44 | C |
| 5 | C | 15 | C | 25 | C | 35 | B | 45 | A |
| 6 | B | 16 | D | 26 | C | 36 | B | 46 | C |
| 7 | C | 17 | C | 27 | B | 37 | C | 47 | B |
| 8 | B | 18 | C | 28 | C | 38 | C | 48 | C |
| 9 | B | 19 | B | 29 | B | 39 | C | 49 | C |
| 10 | B | 20 | C | 30 | C | 40 | C | 50 | C |
TOPIC COVERAGE MAP
| Category | Questions |
|---|---|
| Somite differentiation & derivatives | 1–7, 19, 36 |
| Myogenic regulatory factors | 8, 37 |
| Regional muscle origins (epaxial/hypaxial) | 9–11, 39–44 |
| Muscle fiber formation (myogenesis) | 12–14 |
| Cardiac & smooth muscle development | 15–18, 38 |
| Clinical — Poland, prune-belly, torticollis | 21–23, 27–29, 31–34 |
| Clinical — muscular dystrophy / SMA / AMC | 24–26, 30, 35, 47, 50 |
| Scenario-based developmental mechanisms | 36–43 |
| Specific muscle origins (tongue, eye, pharyngeal) | 44–46 |
| Genetics, prognosis, applied scenarios | 47–50 |
Sources:
- The Developing Human: Clinically Oriented Embryology, Moore, Persaud & Torchia, 11e
- Langman's Medical Embryology, Sadler, 14e
- USMLE Step 1 / MBBS exam standard question style (BRS Embryology, Snell Clinical Anatomy)You've run out of free credits. Sign up for a free account to continue using Orris.
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