Histology Practice Questions

Q: Which stain is used to stain the X chromosome?

Acriflavin Schiff reagent. **Explanation:** The correct answer is **Acriflavin Schiff reagent**. This stain is a fluorescent variant of the traditional Feulgen reaction used to detect DNA. In the context of cytogenetics and histology, Acriflavin Schiff is specifically utilized to visualize the **X-chromatin (Barr body)** in interphase nuclei, such as those found in buccal smears or hair root cells. The reagent binds to the deoxyribonucleic acid of the condensed X chromosome [1], allowing it to be identified under a fluorescence microscope. [1] **Analysis of Options:** * **A. Quinacrine:** This is a fluorescent stain primarily used for **Q-banding** of chromosomes [1]. It has a high affinity for the **Y-chromosome** (specifically the long arm), making it the gold standard for identifying the "Y-body" rather than the X-body. * **C. Methylene blue:** This is a basic dye used for general morphology to highlight nuclei and acidic components (like RNA). While it stains the nucleus, it is not specific for identifying the X chromosome or Barr bodies. * **D. Fluorescent green:** This is a general description of a signal (like FITC) rather than a specific histological stain used for sex chromatin identification. **High-Yield Clinical Pearls for NEET-PG:** * **Barr Body:** It represents the inactivated X chromosome (Lyon’s hypothesis) found in females. The number of Barr bodies = (Total number of X chromosomes – 1). * **Drumstick Appearance:** In neutrophils, the inactivated X chromosome appears as a "drumstick" appendage on the nucleus. * **Y-Body:** Identified using **Quinacrine Mustard**; it appears as a bright fluorescent dot in the interphase nucleus of males. * **Feulgen Stain:** The parent reaction for Acriflavin Schiff, specific for DNA (stains it magenta/red).

Q: Which of the following statements regarding the endometrium is true?

Spiral arteries extend directly from radial arteries.. ### Explanation The blood supply to the uterus follows a specific hierarchical branching pattern that is crucial for understanding the menstrual cycle and endometrial shedding. **1. Why Option A is Correct:** The uterine artery gives rise to **arcuate arteries** (located in the myometrium), which branch into **radial arteries**. As the radial arteries cross the myometrium-endometrium junction, they divide into two types of vessels: * **Basal arteries:** Supply the *stratum basalis* (permanent layer). * **Spiral arteries:** Extend directly from the radial arteries to supply the *stratum functionalis* (deciduous layer). **2. Why the Other Options are Incorrect:** * **Option B & C:** Both basal and spiral arteries arise from the **radial arteries**, not directly from the arcuate arteries. Arcuate arteries are located deeper within the myometrium and must first branch into radial arteries to reach the endometrium. * **Option D:** While spiral arteries are located in the **functionalis layer**, radial arteries are located within the **myometrium**. The functionalis layer contains only the spiral arteries and the capillary plexus. ### High-Yield NEET-PG Pearls: * **Hormonal Sensitivity:** Spiral arteries are highly sensitive to progesterone. Their constriction (due to progesterone withdrawal) leads to ischemia and the shedding of the *stratum functionalis* during menstruation. * **Regeneration:** The *stratum basalis* (supplied by basal arteries) does not shed during menses; it serves as the reservoir for regenerating the endometrium during the proliferative phase. * **Sequence Summary:** Uterine artery → Arcuate artery → Radial artery → Spiral/Basal artery.

Q: What is the epithelial lining of the glottis/ true vocal cords?

Stratified squamous non-keratinized. **Explanation:** The respiratory tract is predominantly lined by **pseudostratified ciliated columnar epithelium** (respiratory epithelium). However, areas subjected to significant mechanical stress or friction undergo a protective adaptation to **stratified squamous non-keratinized epithelium**. **1. Why Option A is correct:** The **true vocal cords (glottis)** are responsible for phonation. During speech and coughing, the vocal folds undergo high-frequency vibration and rapid contact (mechanical stress). To withstand this constant friction without damage, the epithelium transitions from respiratory type to stratified squamous non-keratinized epithelium. This provides a durable, multi-layered protective barrier. **2. Why other options are incorrect:** * **Option B (Keratinized):** Keratinization is a feature of the skin (epidermis) to prevent desiccation. Mucosal surfaces like the vocal cords remain moist and do not require a keratin layer. * **Options C & D (Columnar):** While ciliated columnar epithelium lines most of the larynx (supraglottis and subglottis), it is too fragile for the high-impact zone of the true vocal cords. **Clinical Pearls for NEET-PG:** * **The "Transition Zone":** The vocal cords are one of the few sites in the upper respiratory tract where this epithelial change occurs. Another high-yield site is the **epiglottis** (lingual surface and upper part of the laryngeal surface). * **Pathology Link:** Because the true vocal cords are lined by squamous epithelium, the most common malignancy of the larynx is **Squamous Cell Carcinoma (SCC)**. * **Reinke’s Space:** This is the potential space between the epithelium and the vocal ligament. Accumulation of fluid here leads to **Reinke’s edema**, commonly seen in smokers.

Q: Goblet cells are seen in which of the following ocular structures?

Conjunctiva. The **conjunctiva** is a thin, translucent mucous membrane that lines the inner surface of the eyelids and the anterior portion of the sclera [1]. Histologically, it consists of a non-keratinized stratified columnar (or squamous) epithelium containing interspersed **Goblet cells** [4]. These unicellular glands are responsible for secreting **mucin**, which forms the innermost layer of the precorneal tear film, ensuring the ocular surface remains lubricated and protected [3]. **Analysis of Options:** * **A. Cornea:** The corneal epithelium is a highly organized, non-keratinized stratified squamous epithelium [2]. It is devoid of goblet cells and blood vessels to maintain optical transparency. * **C. Retina:** The retina is a complex neurosensory tissue composed of ten layers of neurons and glial cells (e.g., photoreceptors, bipolar cells, ganglion cells) [5]. It does not contain glandular or epithelial goblet cells. * **D. All the above:** Incorrect, as goblet cells are specific to the conjunctival lining in the eye. **High-Yield Clinical Pearls for NEET-PG:** * **Bitot’s Spots:** In Vitamin A deficiency, the conjunctiva undergoes squamous metaplasia, leading to a loss of goblet cells and the formation of foamy keratinized patches (Bitot’s spots). * **Tear Film Layers:** Remember the mnemonic **M-A-L**: **M**ucin (Goblet cells), **A**queous (Lacrimal glands), and **L**ipid (Meibomian glands). * **Density:** Goblet cells are most densely concentrated in the **inferonasal quadrant** and the fornices of the conjunctiva.

Q: The splenic vein originates from which of the following structures?

Trabecular veins. **Explanation:** The splenic circulation follows a specific hierarchical flow. The **splenic vein** is formed by the union of several **trabecular veins**, which emerge from the splenic parenchyma. The venous drainage of the spleen begins at the **splenic sinusoids** (in the red pulp). These sinusoids drain into the **pulp veins**, which then coalesce to form **trabecular veins**. These veins travel within the connective tissue trabeculae and eventually exit the splenic hilum to form the splenic vein. The splenic vein then joins the superior mesenteric vein behind the neck of the pancreas to form the portal vein [2]. **Analysis of Incorrect Options:** * **A & B (Central and White Pulp Arteries):** These are part of the **arterial** supply. The splenic artery branches into trabecular arteries, which become central arteries as they are surrounded by the Periarteriolar Lymphoid Sheath (PALS) in the white pulp. * **C (Penicillar Arterioles):** These are the terminal branches of the central arteries located in the red pulp. They represent the arterial side of the circulation just before the blood enters the sinusoids (closed circulation) or the splenic cords (open circulation). **High-Yield Facts for NEET-PG:** * **Splenic Vein Landmarks:** It runs posterior to the body and tail of the pancreas [1]. Thrombosis of this vein can lead to **isolated gastric varices**. * **Open vs. Closed Circulation:** Humans primarily have "open circulation" where blood from penicillar arterioles empties into the splenic cords before entering sinusoids. * **Nutcracker Syndrome:** Compression of the left renal vein between the SMA and Aorta; however, the splenic vein is a key landmark located superior to this site.

Q: What type of epithelium lines the Schneiderian membrane?

Pseudostratified ciliated columnar epithelium.. ### Explanation The **Schneiderian membrane** is the anatomical term for the **nasal mucosa** (specifically the ectodermally derived schneiderian mucosa) that lines the nasal cavity and the paranasal sinuses. **1. Why the Correct Answer is Right:** The nasal cavity and paranasal sinuses are part of the upper respiratory tract. The characteristic lining of the respiratory tract is **Pseudostratified ciliated columnar epithelium** (often called "Respiratory Epithelium") [1]. This specialized tissue contains goblet cells that secrete mucus to trap particulate matter, while the cilia move the mucus toward the nasopharynx for clearance (mucociliary clearance) [1]. **2. Analysis of Incorrect Options:** * **A. Stratified squamous epithelium:** This is found in areas subject to mechanical stress or friction, such as the skin, oral cavity, and the **nasal vestibule** (the very entrance of the nose). * **C. Stratified columnar epithelium:** This is a rare type of epithelium found only in specific locations like the large ducts of salivary glands or parts of the male urethra. * **D. Stratified ciliated columnar epithelium:** This is not a standard histological classification in the human body; ciliated columnar cells are typically organized in a pseudostratified or simple arrangement. **3. Clinical Pearls for NEET-PG:** * **Schneiderian Papilloma:** A benign but locally aggressive tumor arising from this membrane, often associated with HPV [2]. * **Sinus Lift Procedure:** In dentistry/maxillofacial surgery, the Schneiderian membrane is elevated to add bone to the maxillary sinus for dental implants. * **Olfactory Epithelium:** While most of the nasal cavity is lined by respiratory epithelium, the roof (superior concha) is lined by **Olfactory Epithelium**, which contains bipolar sensory neurons [3].

Question 1

Which stain is used to stain the X chromosome?

Accepted Answer

Acriflavin Schiff reagent

Answer

Quinacrine

Answer

Methylene blue

Answer

Fluorescent green

Question 2

Which of the following statements regarding the endometrium is true?

Accepted Answer

Spiral arteries extend directly from radial arteries.

Answer

Basal arteries arise directly from arcuate arteries.

Answer

Spiral arteries arise directly from arcuate arteries.

Answer

Spiral arteries and radial arteries are located in the functionalis layer of the endometrium.

Question 3

In the central nervous system (CNS), oligodendrocytes share a similar function with which of the following cell types?

Accepted Answer

Schwann cells

Answer

Gemistocytes

Answer

Astrocytes

Answer

Microglial cells

Question 4

What best defines vasa vasorum?

Accepted Answer

Small blood vessels supplying the walls of large blood vessels

Answer

Small blood vessels supplying nerves

Answer

Vessels accompanying arteries

Answer

Vessels accompanying nerves

Question 5

What is the epithelial lining of the glottis/ true vocal cords?

Accepted Answer

Stratified squamous non-keratinized

Answer

Stratified squamous keratinized

Answer

Ciliated columnar

Answer

Non-ciliated columnar

Question 6

Goblet cells are seen in which of the following ocular structures?

Accepted Answer

Conjunctiva

Answer

Cornea

Answer

Retina

Answer

All the above

Question 7

Which of the following is not a hyaline cartilage?

Accepted Answer

Meniscus

Answer

Auricular cartilage

Answer

Thyroid cartilage

Answer

Nasal septum

Question 8

The splenic vein originates from which of the following structures?

Accepted Answer

Trabecular veins

Answer

Central arteries

Answer

White pulp arteries

Answer

Penicillar arterioles

Question 9

All are true about liver histology except?

Accepted Answer

Hepatic lobule is the anatomical unit.

Answer

Portal space contains bile duct, portal vein, and hepatic artery.

Answer

Zone I is well oxygenated.

Answer

Central vein drains the lobule.

Question 10

What type of epithelium lines the Schneiderian membrane?

Accepted Answer

Pseudostratified ciliated columnar epithelium.

Answer

Stratified squamous epithelium.

Answer

Stratified columnar epithelium.

Answer

Stratified ciliated columnar epithelium.

Histology — MCQs

Histology — MCQs

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