Histology — MCQs
On this page
All of the following are features of hemolytic anemia except?
Articular cartilage at the ends of bones is composed of which of the following?
Which of the following is true about apocrine glands?
Transitional epithelium is seen in all of the following structures except?
Histologic examination of normal skin demonstrates small numbers of perivascular cells, with darkly stained ovoid nuclei and granular cytoplasm on hematoxylin and eosin staining. The cells demonstrate metachromasia of the cytoplasm when stained with Giemsa stain. Which of the following products would these cells be most likely to secrete?
Iron dextran preparations may be used for all the following conditions except?
Which of the following is NOT true regarding elastic cartilage?
What type of collagen is predominantly found in muscle tissue?
Which of the following is seen in eosinophil granules?
Oncocytes are found in all of the following locations except:
Histology Indian Medical PG Practice Questions and MCQs
Question 221: All of the following are features of hemolytic anemia except?
- A. Decreased RBC life span
- B. Altered erythroid and myeloid ratio
- C. Bilirubin in urine (Correct Answer)
- D. Decreased haptoglobin
Explanation: **Explanation:** The core concept in hemolytic anemia is the premature destruction of Red Blood Cells (RBCs), leading to an increase in **unconjugated bilirubin** (indirect bilirubin) [1]. 1. **Why "Bilirubin in urine" is the correct answer (The Exception):** In hemolytic anemia, the liver is overwhelmed by the excess production of unconjugated bilirubin. However, unconjugated bilirubin is **lipid-soluble** and bound to albumin; it cannot pass through the glomerular basement membrane [1]. Therefore, it does not appear in the urine (**acholuric jaundice**). Bilirubinuria only occurs when there is an increase in *conjugated* (water-soluble) bilirubin, typically seen in obstructive jaundice or hepatitis. 2. **Analysis of Incorrect Options:** * **Decreased RBC life span:** This is the definition of hemolysis. Normal RBCs live ~120 days; in hemolytic anemia, this is significantly reduced [1]. * **Altered Erythroid to Myeloid (E:M) ratio:** Normally, the E:M ratio is 1:3 or 1:4. In hemolysis, the bone marrow compensates for RBC loss by undergoing **erythroid hyperplasia**, which reverses or alters this ratio (e.g., 1:1 or higher). * **Decreased Haptoglobin:** Haptoglobin is a plasma protein that binds free hemoglobin released from lysed RBCs. During intravascular hemolysis, haptoglobin levels drop significantly as it is consumed while clearing free hemoglobin. **NEET-PG High-Yield Pearls:** * **Urine Findings:** In hemolysis, urine contains increased **Urobilinogen** but **NO Bilirubin** [1]. * **Markers of Hemolysis:** ↑ Reticulocyte count, ↑ LDH (Lactate Dehydrogenase), ↓ Haptoglobin, and ↑ Indirect Bilirubin [1]. * **Schistocytes:** Presence on a peripheral smear indicates microangiopathic hemolytic anemia (MAHA).
Question 222: Articular cartilage at the ends of bones is composed of which of the following?
- A. Fibrocartilage
- B. Hyaline cartilage (Correct Answer)
- C. Elastic cartilage
- D. Chondronectin
Explanation: ### **Explanation** **Correct Answer: B. Hyaline cartilage** **Why it is correct:** Articular cartilage is a specialized type of **hyaline cartilage** that covers the articulating surfaces of bones in synovial joints [1]. Its primary function is to provide a smooth, lubricated surface for low-friction articulation and to facilitate the transmission of loads to the underlying subchondral bone [1]. Structurally, it is unique because it **lacks a perichondrium**, allowing for a smooth gliding surface, though this also limits its regenerative capacity. **Why incorrect options are wrong:** * **A. Fibrocartilage:** This contains thick bundles of Type I collagen. It is found in areas requiring high tensile strength, such as the intervertebral discs, pubic symphysis, and TMJ. * **C. Elastic cartilage:** This contains abundant elastic fibers and is found in structures requiring flexibility and shape retention, such as the pinna of the ear, external auditory meatus, and epiglottis. * **D. Chondronectin:** This is not a type of cartilage but an adhesive glycoprotein found in the cartilage matrix that helps chondrocytes attach to Type II collagen. **NEET-PG High-Yield Pearls:** 1. **Collagen Type:** Hyaline cartilage is predominantly composed of **Type II collagen** ("Hyaline = Type Two") [1]. 2. **Nutrition:** Since articular cartilage is avascular, it receives nutrition via **diffusion from the synovial fluid** [1]. 3. **Calcification:** Hyaline cartilage is the only type of cartilage that undergoes calcification during endochondral ossification [2]. 4. **Growth:** It grows via both interstitial (from within) and appositional (from the perichondrium) mechanisms, except at articular surfaces where appositional growth is absent.
Question 223: Which of the following is true about apocrine glands?
- A. Modified sweat gland
- B. Modified sebaceous gland (Correct Answer)
- C. Present in the groin and axilla
- D. Infection is known as hydradenitis suppurativa
Explanation: ### Explanation The question focuses on the classification and characteristics of skin glands. The correct answer is **B (Modified sebaceous gland)**, though this requires a specific understanding of specialized glands. **1. Why Option B is Correct:** While most sweat glands are eccrine or apocrine, certain specialized glands in the body are **modified sebaceous glands**. The most classic examples include the **Meibomian glands** (tarsal glands) and **Zeis glands** in the eyelids, as well as **Montgomery tubercles** in the areola. These glands utilize a holocrine or apocrine-like secretion mechanism but are histologically derived from or related to the sebaceous unit. *Note: In many standard textbooks, "Apocrine sweat glands" are distinct from sebaceous glands. However, in the context of specific "modified" glands (like those in the eyelid), they are classified as modified sebaceous glands.* **2. Why Other Options are Incorrect:** * **Option A:** Apocrine glands are a type of sweat gland, but they are not "modified" sweat glands in the general sense; they are one of the two primary types of sweat glands (the other being eccrine). * **Option C:** While true for standard **apocrine sweat glands**, if the question identifies the gland as a "modified" gland, it refers to specific locations like the eyelids or areola, not the axilla [1]. * **Option D:** **Hidradenitis suppurativa** is a chronic inflammatory condition specifically affecting the **apocrine sweat glands** (axilla/groin), not modified sebaceous glands. **High-Yield Clinical Pearls for NEET-PG:** * **Holocrine Secretion:** The entire cell disintegrates (e.g., Sebaceous glands). * **Apocrine Secretion:** Only the apical part of the cell is pinched off (e.g., Mammary glands, Moll’s glands). * **Merocrine/Eccrine Secretion:** Exocytosis without cell loss (e.g., Most sweat glands, Pancreas). * **Ceruminous glands** (ear wax) and **Moll’s glands** (eyelid) are modified apocrine sweat glands.
Question 224: Transitional epithelium is seen in all of the following structures except?
- A. Collecting duct (Correct Answer)
- B. Calyces
- C. Ureter
- D. Bladder
Explanation: **Explanation:** The correct answer is **Collecting duct**. **1. Why Collecting Duct is the correct answer:** Transitional epithelium (also known as **Urothelium**) is a specialized stratified epithelium designed to stretch and withstand the toxicity of urine [1]. It lines the urinary tract from the renal pelvis down to the proximal part of the urethra. The **collecting ducts**, however, are part of the renal parenchyma (tubular system). They are lined by **simple cuboidal epithelium**, which transitions into **simple columnar epithelium** as the ducts increase in size (Ducts of Bellini) before opening into the renal papilla. **2. Why the other options are incorrect:** * **Calyces (Major and Minor):** These represent the beginning of the extra-renal excretory pathway. They are lined with transitional epithelium to accommodate volume changes. * **Ureter:** This muscular tube is lined with transitional epithelium (typically 3–5 layers thick) to allow for the passage of urine boluses via peristalsis. * **Bladder:** The bladder contains the thickest layer of transitional epithelium (up to 6 or more layers when empty) [1]. The superficial cells, known as **Umbrella cells**, are characteristic of this tissue and protect underlying layers from hypertonic urine. **High-Yield Clinical Pearls for NEET-PG:** * **Distribution:** Transitional epithelium is found in the Renal Pelvis, Calyces, Ureter, Urinary Bladder, and Prostatic Urethra [1]. * **Key Feature:** The presence of **"Umbrella Cells"** (large, dome-shaped surface cells) and **"Crust"** (thickened apical plasma membrane) which prevents water loss from tissues into the concentrated urine. * **Histology Tip:** If a question asks about the **distal urethra**, the lining changes to stratified squamous epithelium. * **Pathology Link:** Transitional Cell Carcinoma (TCC) is the most common primary malignancy of the urinary bladder.
Question 225: Histologic examination of normal skin demonstrates small numbers of perivascular cells, with darkly stained ovoid nuclei and granular cytoplasm on hematoxylin and eosin staining. The cells demonstrate metachromasia of the cytoplasm when stained with Giemsa stain. Which of the following products would these cells be most likely to secrete?
- A. Bradykinin
- B. Complement factor 3a
- C. Histamine (Correct Answer)
- D. Interleukin 2
Explanation: The clinical description provided—perivascular cells with ovoid nuclei, granular cytoplasm, and characteristic **metachromasia** (changing the color of the dye) with Giemsa or Toluidine blue stain—is classic for **Mast Cells**. [1] **Why Histamine is Correct:** Mast cells are the primary effectors of Type I hypersensitivity reactions. Their cytoplasm is packed with basophilic granules containing preformed mediators. Upon cross-linking of surface-bound IgE by an antigen, these cells degranulate, releasing **Histamine**, heparin, and eosinophil chemotactic factors. [1] Histamine causes vasodilation, increased vascular permeability, and smooth muscle contraction. **Analysis of Incorrect Options:** * **A. Bradykinin:** This is a potent vasodilator produced by the kinin-kallikrein system in the plasma, not stored in mast cell granules. * **B. Complement factor 3a (C3a):** This is an anaphylatoxin produced during the complement cascade in the serum. While C3a can *induce* mast cell degranulation, it is not secreted by the mast cell itself. * **D. Interleukin 2 (IL-2):** This is a cytokine primarily secreted by Th1 CD4+ T-cells to stimulate the proliferation of T and B lymphocytes. **High-Yield NEET-PG Pearls:** * **Metachromasia:** Occurs because the high concentration of acidic heparin in mast cell granules shifts the absorption spectrum of basic dyes (e.g., Toluidine blue turns purple/red). * **Mast Cells vs. Basophils:** While similar in function, mast cells reside in connective tissue (perivascular), whereas basophils circulate in the blood. [1] * **C-kit (CD117):** This is a specific surface marker for mast cells often tested in pathology. * **Systemic Mastocytosis:** Look for increased **Serum Tryptase** levels as a diagnostic marker for mast cell activation/proliferation.
Question 226: Iron dextran preparations may be used for all the following conditions except?
- A. Iron deficiency anemia not responding to oral iron therapy
- B. Persistent blood loss
- C. Malabsorption related macrocytic anemia (Correct Answer)
- D. Patients on erythropoietin therapy for chronic disease related anemia
Explanation: The core concept behind this question is the distinction between **Microcytic** (Iron deficiency) and **Macrocytic** (Vitamin B12/Folate deficiency) anemias. **Why Option C is the Correct Answer:** Iron dextran is a parenteral iron preparation used specifically to treat **Iron Deficiency Anemia (IDA)**. Macrocytic anemia, particularly when related to malabsorption (like Celiac disease or Pernicious anemia), is typically caused by a deficiency in **Vitamin B12 or Folic acid**, not iron [1]. Administering iron dextran in this scenario is inappropriate as it does not address the underlying nutritional deficiency and carries a risk of iron overload and anaphylaxis. **Analysis of Incorrect Options:** * **Option A:** Oral iron failure (due to intolerance or non-compliance) is a primary indication for parenteral iron. * **Option B:** In cases of persistent, rapid blood loss (e.g., GI bleeds or Menorrhagia), oral iron cannot be absorbed fast enough to keep pace with the loss, necessitating IV iron dextran [2]. * **Option D:** Patients on Erythropoietin (EPO) for chronic kidney disease have a massive demand for iron to produce new RBCs [3]. Oral iron is often insufficient to meet this "functional iron deficiency," making IV iron a standard adjunct. **High-Yield Clinical Pearls for NEET-PG:** * **Test Dose:** Iron dextran requires a mandatory test dose due to the high risk of **Type I Hypersensitivity (Anaphylaxis)**. * **Calculation:** The total dose of iron required is calculated using the **Ganzoni Formula**: *Total Iron Deficit (mg) = Body weight (kg) × (Target Hb - Actual Hb) × 2.4 + Iron stores (500mg).* * **Staining:** On histology, iron is visualized using the **Prussian Blue (Perl’s) stain**.
Question 227: Which of the following is NOT true regarding elastic cartilage?
- A. It is made up of yellow elastic fibers.
- B. It is more pliable than hyaline cartilage.
- C. It is highly vascular. (Correct Answer)
- D. It is found in the inlet of the larynx.
Explanation: The correct answer is **C (It is highly vascular)** because it is a fundamental principle of histology that **all cartilage is avascular** [1]. Cartilage (hyaline, elastic, and fibrocartilage) lacks blood vessels, lymphatics, and nerves [1]. Chondrocytes receive nutrients and oxygen via diffusion from the surrounding **perichondrium** or synovial fluid. Therefore, the statement that elastic cartilage is highly vascular is factually incorrect. **Analysis of other options:** * **Option A:** Elastic cartilage is characterized by a dense network of **yellow elastic fibers** (elastin) in its matrix, in addition to Type II collagen [2]. This gives it a distinct yellowish appearance macroscopically. * **Option B:** Due to the high density of elastic fibers, it is significantly **more pliable and flexible** than hyaline cartilage, allowing it to regain its shape after deformation. * **Option C:** As noted, it is avascular. * **Option D:** Elastic cartilage is found in structures requiring flexibility. In the larynx, it forms the **epiglottis** (which guards the inlet), the corniculate, and cuneiform cartilages, as well as the apex of the arytenoids. **NEET-PG High-Yield Pearls:** 1. **Locations of Elastic Cartilage (The "3 E’s"):** **E**piglottis, **E**xternal Ear (pinna/meatus), and **E**ustachian tube. 2. **Calcification:** Unlike hyaline cartilage, elastic cartilage **never calcifies** with age. 3. **Regeneration:** It has a perichondrium (like most hyaline cartilage), which aids in appositional growth, but its regenerative capacity is limited. 4. **Staining:** Elastic fibers are best visualized using special stains like **Orcein** or **Verhoeff-Van Gieson (VVG)**.
Question 228: What type of collagen is predominantly found in muscle tissue?
- A. Type I
- B. Type V
- C. Type VI (Correct Answer)
- D. Type IX
Explanation: **Explanation:** The correct answer is **Type VI Collagen**. While muscle tissue contains several collagen types (I, III, IV, and V) within its connective tissue layers, **Type VI collagen** is uniquely predominant and essential within the muscle interstitium and the basement membrane zone of myofibers. It forms a microfibrillar network that anchors the basement membrane to the surrounding extracellular matrix, providing structural integrity and mechanical support during muscle contraction. Mutations in the genes encoding Type VI collagen lead to significant muscle pathologies, such as Bethlem Myopathy and Ullrich Congenital Muscular Dystrophy. **Analysis of Incorrect Options:** * **Type I:** This is the most abundant collagen in the body, found in bone, skin, tendons, and ligaments [2]. While present in the epimysium of muscles, it is not the "predominant" functional collagen specific to the muscle fiber interface. * **Type V:** This type is typically found in the placenta and skin, often co-distributing with Type I collagen to regulate fibril diameter. * **Type IX:** This is a FACIT (Fibril-Associated Collagens with Interrupted Triple helices) collagen found primarily in **cartilage** and vitreous humor, where it associates with Type II collagen. **High-Yield Clinical Pearls for NEET-PG:** * **Type I:** Bone, Tendon, Sclera (Mnemonic: "B**one**") [2]. * **Type II:** Cartilage, Vitreous body (Mnemonic: "Car**two**lage"). * **Type III:** Reticular fibers, Blood vessels, Granulation tissue. * **Type IV:** Basement membrane (Mnemonic: "Under the **floor**") [1]. * **Alport Syndrome:** Mutation in Type IV collagen (leads to nephritis and deafness). * **Osteogenesis Imperfecta:** Mutation in Type I collagen [2].
Question 229: Which of the following is seen in eosinophil granules?
- A. Cathepsin
- B. Major basic protein (Correct Answer)
- C. Transferrin
- D. All of the above
Explanation: **Explanation:** Eosinophils are granulocytes characterized by large, acidophilic (eosinophilic) granules [1]. These granules are unique because they contain a crystalline core (internum) surrounded by a less dense matrix (externum). **Why Major Basic Protein (MBP) is correct:** The crystalline core of the eosinophil’s specific granules is composed primarily of **Major Basic Protein (MBP)**. MBP is highly arginine-rich, giving the granules their characteristic eosinophilia. Its primary function is to disrupt the membranes of parasites (helminths) and induce degranulation of mast cells and basophils. Other key components found in the matrix of these granules include Eosinophil Cationic Protein (ECP), Eosinophil Peroxidase (EPO), and Eosinophil-Derived Neurotoxin (EDN). **Why other options are incorrect:** * **Cathepsin:** These are proteases typically found in **lysosomes** of various cells (like macrophages and neutrophils) rather than the specific granules of eosinophils. * **Transferrin:** This is a plasma protein synthesized in the liver responsible for **iron transport** in the blood. It is not a constituent of eosinophil granules. **High-Yield Clinical Pearls for NEET-PG:** * **Charcot-Leyden Crystals:** These are hexagonal, bipyramidal crystals found in sputum (asthma) or stool (parasitic infections), formed from the breakdown of eosinophil membranes (specifically **Galectin-10**). * **Eosinophilia:** Classically seen in **NAACP**: **N**eoplasia, **A**llergy/Asthma, **A**ddison’s disease, **C**onnective tissue disorders, and **P**arasitic infections [1]. * **Histology Tip:** Under Electron Microscopy, the "internum" (crystalline core) containing MBP is the most pathognomonic feature of an eosinophil.
Question 230: Oncocytes are found in all of the following locations except:
- A. Thyroid
- B. Pancreas
- C. Pituitary
- D. Pineal gland (Correct Answer)
Explanation: Detailed Explanation: Oncocytes (also known as oxyphil cells) are large, polygonal epithelial cells characterized by an intensely eosinophilic, granular cytoplasm. This appearance is due to the presence of an abundant number of mitochondria [2], [3]. They are typically not present in healthy young tissue but appear with aging or in certain pathological states. 1. Why Pineal Gland is the Correct Answer: The pineal gland consists primarily of pinealocytes and glial-like interstitial cells [1]. It undergoes calcification with age (forming corpora arenacea or "brain sand"), but it does not contain oncocytes. Therefore, it is the exception. 2. Analysis of Other Options: * Thyroid: Oncocytes in the thyroid are known as Hürthle cells (Askanazy cells). They are commonly seen in Hashimoto’s thyroiditis and Hürthle cell tumors [3]. * Pancreas: Oncocytes can be found in the epithelial lining of the pancreatic ducts, especially in elderly individuals or in rare oncocytic neoplasms of the pancreas. * Pituitary: Oncocytic changes are frequently observed in the anterior pituitary gland, particularly in the adenohypophysis of aging individuals or within specific pituitary adenomas (oncocytomas). Clinical Pearls for NEET-PG: * Most Common Site: The most classic location for oncocytes is the Parotid gland (Warthin’s tumor and Oncocytoma). * Other Locations: They are also found in the Parathyroid (Oxyphil cells) [2], Lacrimal glands, and Kidney (Renal Oncocytoma). * Key Feature: The hallmark of an oncocyte is the massive accumulation of mitochondria, which can be confirmed via electron microscopy or immunohistochemistry (anti-mitochondrial antibody) [2].
Practice by Chapter
Basic Tissue Types
Practice Questions
Cell Biology and Organelles
Practice Questions
Epithelial Tissue
Practice Questions
Connective Tissue
Practice Questions
Muscular Tissue
Practice Questions
Nervous Tissue
Practice Questions
Cardiovascular System Histology
Practice Questions
Lymphoid Organs and Immune System
Practice Questions
Endocrine System Histology
Practice Questions
Respiratory System Histology
Practice Questions
Digestive System Histology
Practice Questions
Urinary and Reproductive System Histology
Practice Questions
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free