Histology (Epithelium, Connective Tissue, Bone, Muscle, Nerve) MCQs

Anatomy · 52 free questions with answers & explanations.

1. Which type of epithelium lines the urinary bladder and is capable of stretching when the bladder fills?
2. In a cross-section of a peripheral nerve, which layer of connective tissue directly invests each individual nerve fiber?
3. On electron microscopy of a skeletal muscle fibre the A-band is measured and found to be unchanged after passive stretching of the muscle. This is because the A-band represents:
4. A bone biopsy from a patient with Paget's disease shows large, irregularly shaped osteoclasts with many nuclei (up to 100) and a chaotic 'mosaic' pattern of cement lines on histology. The cement lines in normal lamellar bone are composed primarily of:
5. On electron microscopy of a peripheral nerve, the Schmidt-Lanterman incisures (clefts) are oblique channels in the compact myelin sheath. What is their functional significance?
6. A biopsy of bone shows prominent cement lines, irregular woven bone replacing lamellar bone, and mosaic pattern on H&E. Which histological finding is characteristic of Paget's disease of bone?
7. Transitional epithelium (urothelium) is unique in having 'umbrella cells' (facet cells) on its luminal surface. What is the structural basis for the ability of the bladder to distend without leakage?
8. In cardiac muscle histology, intercalated discs are found at the Z-line level. Which specific junctional complexes within the intercalated disc transmit mechanical force and synchronise electrical excitation respectively?
9. In peripheral nerve regeneration following Wallerian degeneration, Schwann cells form Büngner bands. At what rate does axonal regeneration typically proceed, and which factor sets the clinical rule of thumb?
10. On electron microscopy of a nerve biopsy, the myelin sheath appears as alternating electron-dense and electron-lucent lines. The major dense line (MDL) is formed by apposition of which surface of Schwann cell membranes?
11. In compact bone histology, the Haversian system (osteon) consists of concentric lamellae around a central canal. The transverse/oblique canals connecting adjacent Haversian canals to the periosteum and to each other are called:
12. In skeletal muscle histology, which histochemical staining technique is used to differentiate Type I (slow-twitch, oxidative) from Type II (fast-twitch, glycolytic) fibres?
13. On electron microscopy of compact bone, which structure runs longitudinally and contains collagen fibrils and mineral hydroxyapatite crystals, forming concentric lamellae around the Haversian canal?
14. A peripheral nerve biopsy shows concentric layers of myelin forming multiple lamellae around an axon ('onion bulb' appearance) on light microscopy. This histological finding is characteristic of which condition?
15. The histological type of epithelium lining the trachea is pseudostratified columnar ciliated epithelium. This type is called respiratory epithelium or 'epithelium of Reissner' in which location?
16. On light microscopy of a cross-section of skeletal muscle, the I band, A band, H zone, and M line are visible. The I band contains which specific filament protein and represents which part of the sarcomere?
17. A 25-year-old medical student is examining a section of the trachea. He identifies pseudo-stratified ciliated columnar epithelium with goblet cells. The cilia beat in which direction and what is their primary function?
18. A histological section of peripheral nerve stained with osmium tetroxide shows a dark ring around each myelinated axon with a central pale region. The dark ring represents which structure?
19. In endochondral ossification, which zone of the epiphyseal plate (growth plate) contains hypertrophied chondrocytes undergoing calcification and is the zone targeted by the metaphyseal blood supply?
20. In skeletal muscle, the 'A band' appears dark on electron microscopy. What accounts for its dark appearance and what change occurs in the A band during muscle contraction?
21. A renal biopsy specimen stained with PAS stain shows thickening and splitting of the glomerular basement membrane (GBM) with a characteristic 'tram-track' appearance on electron microscopy. Which ultrastructural finding in the GBM is described by this appearance?
22. In routine H&E staining of peripheral nerve, a cross-section shows individual axons surrounded by myelin (clear halos) and then a thin endoneurial sheath. Which cell is responsible for myelination in the peripheral nervous system and what is the ratio of myelinating cells to axons?
23. In a bone biopsy taken from a patient with Paget's disease, the histological hallmark is disorganized bone with irregular cement lines creating a 'mosaic' or 'jigsaw puzzle' pattern. This pattern indicates repeated cycles of which two processes?
24. The epithelial lining of the gallbladder is a distinctive simple columnar epithelium. Which specialized structural feature of these cells facilitates bile concentration?
25. On electron microscopy of a peripheral nerve biopsy from a patient with Charcot-Marie-Tooth disease type 1, onion bulb formations are seen. What do these onion bulbs represent histologically?
26. A biopsy of a tendon shows parallel bundles of type I collagen with fibroblasts arranged in rows between the collagen bundles. These specialized fibroblasts are called:
27. On histology, the 'Z line' in a skeletal muscle sarcomere represents attachment of which protein, and its absence in a neonate with nemaline myopathy would be associated with defects in which structural component?
28. The histological difference between compact (cortical) and cancellous (trabecular) bone is best described by which feature?
29. On electron microscopy of a motor nerve terminal at the neuromuscular junction, which ultrastructural feature is responsible for storing acetylcholine and aligning it precisely over the postsynaptic junctional folds?
30. Articular (hyaline) cartilage covering the ends of bones in synovial joints lacks which two critical features, making it dependent on synovial fluid for nutrition and unable to fully repair after injury?
31. In the histological classification of nerve fibers, which characteristic determines whether a peripheral nerve axon is classified as myelinated or unmyelinated?
32. The zona pellucida is a glycoprotein coat surrounding the secondary oocyte. Which glycoprotein component of the zona pellucida binds specifically to the sperm acrosomal receptors and initiates the acrosome reaction?
33. On light microscopy of a cross-section of compact bone, which structure represents the functional unit (osteon) and where are the osteocytes located?
34. On electron microscopy of a nerve biopsy, which specific ultrastructural feature distinguishes a myelinated from an unmyelinated peripheral nerve fiber, and which cells produce the myelin sheath in the peripheral nervous system?
35. In a bone biopsy, osteoid seams that are wider than normal (> 15 micrometers) and unmineralized represent which pathological process, and what is the minimum number of calcification fronts expected to be active in normal bone?
36. The Z-disc (Z-line) of a sarcomere serves as the anchor for which protein filaments, and what proteins compose the Z-disc itself?
37. Type II pneumocytes (alveolar epithelial cells) are the progenitor cells of the alveolar epithelium. Which specific histological feature on electron microscopy identifies Type II pneumocytes?
38. On electron microscopy, the neuromuscular junction shows vesicles of acetylcholine (ACh) in the presynaptic terminal. The postsynaptic membrane (motor end plate) contains ACh receptors concentrated in junctional folds. Which type of acetylcholine receptor is found at the neuromuscular junction?
39. In Wallerian degeneration following peripheral nerve injury, the distal axon and its myelin sheath undergo degeneration. Which cells phagocytose the myelin debris and are essential for subsequent nerve regeneration?
40. Type II pneumocytes in the lung alveoli are surfactant-producing cells. They also serve as progenitor cells for alveolar repair. They are histologically identified by which feature?
41. In nerve histology, Wallerian degeneration after axon injury is characterised by which sequence of events distal to the injury site?
42. In a longitudinal section of peripheral nerve, the endoneurium, perineurium, and epineurium are concentric sheaths. Which layer is formed by cells joined by tight junctions that create the blood-nerve barrier?
43. In bone histology, the Haversian system (osteon) of compact bone consists of a central Haversian canal surrounded by concentric lamellae and osteocytes in lacunae. Canaliculi serve which function?
44. Type I collagen (fibrillar collagen) is synthesised intracellularly as procollagen and undergoes extracellular processing. Which enzyme cleaves the C- and N-terminal propeptides of procollagen to yield tropocollagen, and deficiency of which cofactor leads to inadequate hydroxylation of proline and lysine residues?
45. The neuromuscular junction (motor end plate) is a specialised cholinergic synapse. Which feature is UNIQUE to the motor end plate compared to a central cholinergic synapse?
46. On electron microscopy, a nerve fiber shows a thick myelin sheath with visible Schmidt-Lanterman clefts and a single Schwann cell wrapping one internodal segment. This appearance indicates which type of nerve fiber?
47. On electron microscopy, the neuromuscular junction shows synaptic vesicles containing acetylcholine in the motor nerve terminal. The active zones of ACh release align precisely with which postsynaptic structure that contains ACh receptors?
48. In endochondral ossification, the zone of the epiphyseal plate where chondrocytes die and their lacunae become calcified to serve as scaffolding for bone deposition is called:
49. On electron microscopy of a peripheral nerve, a single Schwann cell is found to envelop multiple unmyelinated axons. This arrangement is seen in which type of fiber?
50. Osteoclasts are derived from which cell lineage and are characterized by which ultrastructural feature?
51. Type I collagen is the most abundant protein in the human body. Which feature distinguishes it ultrastructurally from Type II collagen on electron microscopy?
52. The unmyelinated peripheral nerve fiber (C fiber) transmits impulse by which mechanism, and how does its conduction velocity compare to the smallest myelinated fibers?