Histology Practice Questions

Q: G-cells are primarily located in which region of the stomach?

Pyloric antrum. The stomach is histologically divided into regions based on the predominant cell types and glandular structure. **G-cells** are specialized neuroendocrine cells responsible for secreting **gastrin**, a hormone that stimulates gastric acid secretion. [1] **1. Why Pyloric Antrum is Correct:** G-cells are primarily located within the **pyloric antrum** (and to a lesser extent, the duodenum) [1][2]. These cells are found in the gastric pits of the antral mucosa. They respond to mechanical distension, presence of amino acids/peptides, and vagal stimulation (via Gastrin-Releasing Peptide) to release gastrin into the bloodstream, which then acts on parietal cells in the body of the stomach [3]. **2. Why Other Options are Incorrect:** * **Fundus and Body:** These regions contain **oxyntic (gastric) glands**. These glands are rich in **Parietal cells** (secreting HCl and Intrinsic Factor) and **Chief cells** (secreting Pepsinogen) [2]. They do not contain G-cells. * **Cardia:** This region primarily contains mucus-secreting glands to protect the esophagus from reflux; it lacks a significant population of G-cells or parietal cells [2]. **3. High-Yield Clinical Pearls for NEET-PG:** * **D-cells:** Located in the antrum (and body), they secrete **Somatostatin**, which inhibits gastrin release (paracrine inhibition) [3]. * **Zollinger-Ellison Syndrome:** Caused by a gastrinoma (usually in the "Gastrinoma Triangle"), leading to hypergastrinemia and refractory peptic ulcers [4]. * **Pernicious Anemia:** Associated with atrophy of the fundus/body (loss of parietal cells), leading to secondary G-cell hyperplasia in the antrum due to loss of negative feedback from gastric acid [4]. * **H. pylori:** Often colonizes the antrum first, potentially leading to increased gastrin secretion and duodenal ulcers.

Q: What is true about the fallopian tube?

It is lined by ciliated epithelium.. The fallopian tube (uterine tube) is a muscular tube approximately 10 cm long that facilitates the transport of ova and sperm. [1] ### **Explanation of Options** * **Correct Answer (C):** The fallopian tube is lined by **simple columnar ciliated epithelium**. These cilia beat toward the uterus, creating a current that helps transport the ovum and zygote. [2] Interspersed among these are non-ciliated **Peg cells**, which provide nutrition to the gametes. * **Option A:** The fallopian tube **lacks a submucosa**. The mucosa (endometrium-like but thinner) sits directly on the muscularis layer. * **Option B:** The tube is highly **hormone-dependent**. Estrogen increases the height of the epithelium and the number of cilia, while progesterone increases the number of secretory Peg cells. * **Option D:** The fallopian tube lies in the **upper free margin of the broad ligament** (specifically the **mesosalpinx**), not the round ligament. [1] ### **High-Yield NEET-PG Clinical Pearls** 1. **Narrowest Part:** The **Interstitial (Intramural) part** is the narrowest segment (1 mm diameter). 2. **Widest Part:** The **Ampulla** is the widest and longest part; it is the most common site for **fertilization** and **ectopic pregnancy**. [2] 3. **Blood Supply:** It has a dual supply from both the **Uterine artery** (medial 2/3) and the **Ovarian artery** (lateral 1/3). [1] 4. **Lymphatic Drainage:** Lymph drains primarily into the **Para-aortic (Pre-aortic) nodes**, following the ovarian vessels. 5. **Kartagener Syndrome:** Patients with primary ciliary dyskinesia may face subfertility due to impaired tubal ciliary movement.

Q: What is the most abundant fibrillary collagen found in the basement membrane?

Type 4. The correct answer is **Type 4 Collagen**. The basement membrane is a specialized form of extracellular matrix that underlies all epithelia and surrounds muscle cells and peripheral nerves [1]. Unlike fibrillar collagens that form long, rope-like structures, **Type 4 Collagen** is a **network-forming (non-fibrillar) collagen**. It forms a multi-layered, scaffold-like meshwork that provides structural support and acts as a selective filtration barrier. It is the primary structural component of the *lamina densa* within the basal lamina. **Analysis of Incorrect Options:** * **Type 1:** The most abundant collagen in the human body [2]. It forms thick fibers and is found in high-tension areas like **bone, skin, tendons, and late scars**. * **Type 2:** Primarily found in **cartilage** (hyaline and elastic) and the vitreous humor. It provides resistance to pressure. * **Type 3 (Reticulin):** Forms thin, branching fibers that create a supportive framework for highly cellular organs like the **liver, spleen, and lymph nodes**. It is also prominent in early wound healing (granulation tissue). **High-Yield Clinical Pearls for NEET-PG:** * **Goodpasture Syndrome:** Autoantibodies are directed against the alpha-3 chain of Type 4 Collagen, leading to glomerulonephritis and pulmonary hemorrhage. * **Alport Syndrome:** A genetic defect in Type 4 Collagen synthesis resulting in hereditary nephritis, sensorineural deafness, and ocular defects ("Can't see, can't pee, can't hear high C"). * **Mnemonic for Collagen Types:** * Type **1**: **B**one (and Skin) * Type **2**: **C**artilage * Type **3**: **R**eticular fibers * Type **4**: **F**loor (Basement membrane)

Q: Hyaline cartilage is located at all sites except?

Menisci of Knee joint. ### Explanation The correct answer is **B. Menisci of Knee joint**. **1. Why Menisci of Knee joint is correct:** The menisci of the knee joint are composed of **Fibrocartilage**, not hyaline cartilage. Fibrocartilage is characterized by dense bundles of Type I collagen fibers, providing high tensile strength and shock absorption. It lacks a perichondrium and is found in areas subject to heavy pressure and stretch, such as the intervertebral discs, pubic symphysis, and intra-articular discs (menisci). **2. Why the other options are incorrect:** * **Costal cartilage (A):** These connect the ribs to the sternum and are classic examples of hyaline cartilage. * **Articular cartilage (C):** The smooth, glass-like surface covering the ends of bones in synovial joints is hyaline cartilage [1]. Note: It is unique because it lacks a perichondrium. * **Epiphyseal plate (D):** Also known as the growth plate, it consists of hyaline cartilage and is responsible for the longitudinal growth of long bones via endochondral ossification [2]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Hyaline Cartilage:** Most common type; contains **Type II collagen** [1]. Locations include the nose, larynx (thyroid, cricoid), trachea, bronchi, and fetal skeleton [2]. * **Elastic Cartilage:** Contains Type II collagen + Elastic fibers. Locations (The "E"s): **E**xternal ear, **E**ustachian tube, and **E**piglottis. * **Fibrocartilage:** Contains **Type I collagen**. It is the strongest type of cartilage. * **Regeneration:** Cartilage has limited repair capacity because it is **avascular** (receives nutrients via diffusion) [1].

Q: Tight junctions are seen in all except?

Cardiac muscle. **Explanation:** **Tight Junctions (Zonula Occludens)** are specialized intercellular connection sites that seal the space between adjacent epithelial cells, creating a selective barrier that regulates the paracellular transport of water and solutes. **Why Cardiac Muscle is the Correct Answer:** Cardiac muscle cells are connected by **Intercalated Discs**, which contain three types of junctions: **Gap junctions** (for electrical coupling/ionic flow), **Desmosomes** (Macula adherens), and **Fascia adherens** (anchoring sites for actin). Tight junctions are notably **absent** in cardiac muscle because these cells do not function as a barrier to fluid transport; instead, they require low-resistance electrical communication provided by gap junctions to function as a functional syncytium. **Analysis of Incorrect Options:** * **Renal Tubules:** Tight junctions are essential here to maintain the osmotic gradient and regulate the reabsorption of electrolytes (e.g., in the Proximal Convoluted Tubule and Collecting Ducts). * **Intestine:** The intestinal epithelium uses tight junctions to form the "mucosal barrier," preventing the uncontrolled passage of digestive enzymes and bacteria into the bloodstream. * **Choroid Plexus:** Tight junctions between the epithelial cells of the choroid plexus form the **Blood-CSF barrier**, strictly regulating the composition of cerebrospinal fluid. **High-Yield NEET-PG Pearls:** * **Gap Junctions (Nexus):** Found in the heart and smooth muscle; composed of proteins called **Connexins**. * **Blood-Brain Barrier:** Formed by tight junctions between **endothelial cells** of cerebral capillaries. * **Clinical Correlation:** Defects in tight junction proteins (like Claudins) are linked to conditions like **Hereditary Hypomagnesemia** and **Celiac Disease**.

Q: What cells are present in the medulla of the ovary, which is homologous to interstitial cells of the testes?

Hilus cells. **Explanation:** The correct answer is **Hilus cells** (Option B). **Why Hilus cells are correct:** Hilus cells are located in the ovarian medulla and the hilum, adjacent to the vascular supply. They are considered the female homologue of **Leydig (interstitial) cells** of the testes [2]. Like Leydig cells, they are derived from the embryonic mesenchyme of the urogenital ridge, contain **Reinke crystals** in their cytoplasm, and are capable of secreting androgens [2]. **Analysis of Incorrect Options:** * **A. Stromal cells:** These are found in the ovarian cortex and provide structural support. While they can differentiate into theca cells (which also produce androgens), they are not the direct homologue of Leydig cells [1]. * **C. Germinal epithelium:** This is a misnomer for the simple cuboidal/squamous epithelium (mesothelium) covering the surface of the ovary. It does not have endocrine functions. * **D. Tunica albuginea:** This is a dense connective tissue layer located between the germinal epithelium and the cortex. It is a structural barrier, not a cellular secretory unit. **High-Yield NEET-PG Pearls:** 1. **Reinke Crystals:** These are pathognomonic for both Leydig cells and Hilus cells [2]. 2. **Hilus Cell Tumors:** These are rare ovarian tumors that typically present with **virilization** (masculinization) due to excessive testosterone production, often occurring in postmenopausal women [2]. 3. **Embryological Remnants:** While Hilus cells are homologous to Leydig cells, the **Gartner’s duct** in females is the remnant of the Wolffian duct (homologous to the Vas deferens).

Q: Elastic cartilage is absent in which of the following structures?

Trachea. The correct answer is **B. Trachea**. ### **Explanation** The classification of cartilage depends on the composition of its extracellular matrix. There are three main types: Hyaline, Elastic, and Fibrocartilage. 1. **Trachea (Correct Answer):** The trachea is composed of **Hyaline cartilage** [1]. It forms C-shaped rings that provide structural rigidity to keep the airway patent while allowing for slight flexibility. Hyaline cartilage is characterized by a glassy matrix and Type II collagen, but it lacks the dense network of elastic fibers found in elastic cartilage [1]. 2. **Epiglottis (Option A):** This is a classic example of **Elastic cartilage**. It requires high flexibility to bend and cover the laryngeal inlet during swallowing and must snap back to its original shape immediately afterward. 3. **External Auditory Canal & Auricle (Options C & D):** Both the pinna (auricle) and the lateral portion of the external acoustic meatus are made of **Elastic cartilage**. This provides the ear with its characteristic shape and the ability to withstand repeated bending without deformation. ### **NEET-PG High-Yield Pearls** * **Mnemonic for Elastic Cartilage:** Remember the **"7 Es"**: **E**piglottis, **E**xternal ear (Auricle), **E**xternal auditory canal, **E**ustachian tube (cartilaginous part), and the small laryngeal cartilages: **E**xtreme tips of arytenoids, **E**mblematic Cuneiform, and **E**mblematic Corniculate. * **Calcification:** Unlike Hyaline cartilage, **Elastic cartilage does not calcify** with age. * **Staining:** Elastic fibers are best visualized using special stains like **Orcein** or **Verhoeff-Van Gieson (VVG)**, appearing as dark, branching fibers. * **Fibrocartilage:** Found in the intervertebral discs, pubic symphysis, and TMJ; it is the only type that lacks a perichondrium.

Q: What is the middle piece of the sperm tail primarily composed of?

Mitochondria. **Explanation:** The sperm is divided into four distinct regions: the head, neck, middle piece, and tail (principal and end pieces). [1] **1. Why Mitochondria is Correct:** The **middle piece** of the sperm tail is characterized by a dense, spiral sheath of mitochondria known as the **mitochondrial sheath (nebenkern)**. These mitochondria are arranged circumferentially around the axoneme (the central core of microtubules). Their primary function is to provide the **ATP (energy)** required for flagellar movement and sperm motility, which is essential for the sperm to reach and fertilize the oocyte. [2], [3] **2. Why Other Options are Incorrect:** * **Golgi apparatus:** This organelle is involved in the formation of the **acrosomal cap** (found in the head of the sperm), which contains enzymes necessary for penetrating the ovum's zona pellucida. [1] * **Centriole:** The neck of the sperm contains two centrioles. The proximal centriole enters the egg during fertilization, while the distal centriole gives rise to the **axoneme** of the tail. * **Lysosome:** While the acrosome is often considered a specialized lysosome due to its hydrolytic enzymes (e.g., hyaluronidase), lysosomes are not the structural hallmark of the middle piece. **Clinical Pearls & High-Yield Facts:** * **Kartagener Syndrome:** A type of Primary Ciliary Dyskinesia where a defect in the dynein arms of the axoneme leads to immotile sperm and male infertility. [2] * **Mitochondrial Inheritance:** All mitochondria in the zygote are derived from the **ovum**. The sperm’s mitochondria in the middle piece are typically tagged with ubiquitin and degraded after fertilization. [3] * **Manchette:** A transient microtubular structure involved in shaping the sperm head during spermiogenesis.

Q: A tendon or ligament is attached to a bone through:

Sharpey's fibers. **Explanation:** **Sharpey’s fibers** (also known as bone fibers or perforating fibers) are the correct answer. These are a matrix of connective tissue consisting of bundles of strong, predominantly **Type I collagen fibers** that connect periosteum to bone [1]. They extend from the periosteum into the outer circumferential and interstitial lamellae of the bone tissue. Their primary function is to provide a secure anchorage for tendons and ligaments by becoming mineralized within the bone matrix, effectively "nailing" the soft tissue to the bone. **Analysis of Incorrect Options:** * **Tomes fibers:** These are cytoplasmic extensions of **odontoblasts** located within dentinal tubules. They are involved in dentin formation, not bone attachment. * **Interstitial fibers:** This is a general term for fibers within the interstitial space of various tissues. In bone, interstitial lamellae represent the remnants of old osteons but do not serve as the primary attachment mechanism for tendons. * **Haversian fibers:** This is a distractor term. **Haversian canals** are the central channels in osteons containing blood vessels and nerves; they do not function as attachment fibers. **High-Yield Clinical Pearls for NEET-PG:** * **Location:** Sharpey’s fibers are also found in the **Periodontal Ligament (PDL)**, where they anchor the tooth root into the alveolar bone. * **Composition:** They are primarily Type I collagen [2]. * **Function:** They are most numerous in areas of heavy physical stress, ensuring the stability of musculoskeletal attachments. * **Histology:** On decalcified sections, they appear as thick, wavy fibers penetrating the bone at right angles or obliquely.

Q: The articular cartilage is characterized by all of the following features except?

It has a rich nerve supply. Articular cartilage is a specialized type of **hyaline cartilage** that covers the weight-bearing surfaces of synovial joints [1]. Its primary function is to provide a smooth, low-friction surface and to distribute mechanical loads. **Why Option B is the correct answer:** Articular cartilage is unique because it is **aneural** (lacks a nerve supply), **avascular** (lacks blood vessels), and **alymphatic** [1]. Because it lacks nerves, the cartilage itself cannot perceive pain; pain in joint diseases (like osteoarthritis) typically arises from the underlying subchondral bone, the synovial membrane, or the joint capsule. **Analysis of incorrect options:** * **Option A (Devoid of perichondrium):** Unlike most hyaline cartilage, articular cartilage lacks a perichondrium. This allows for a perfectly smooth surface for joint movement. * **Option C (Avascular):** It is indeed avascular [1]. It receives its nutrition via **diffusion** from the synovial fluid and the underlying subchondral bone [1]. * **Option D (Lacks capacity to regenerate):** Due to the absence of a perichondrium (which contains progenitor cells) and a direct blood supply, articular cartilage has a very limited capacity for repair. Once damaged, it is often replaced by fibrocartilage, which is biomechanically inferior. **High-Yield NEET-PG Pearls:** * **Composition:** Primarily Type II Collagen and Proteoglycans (Aggrecan) [1]. * **Arrangement:** Chondrocytes are arranged in four distinct zones: Superficial (Tangential), Intermediate (Transitional), Deep (Radial), and Calcified. * **Tidemark:** A basophilic line that separates the deep zone from the calcified cartilage. * **Clinical Link:** In Osteoarthritis, the loss of articular cartilage leads to "bone-on-bone" contact, causing the characteristic pain and stiffness.

Question 1

G-cells are primarily located in which region of the stomach?

Accepted Answer

Pyloric antrum

Answer

Fundus

Answer

Cardia

Answer

Body

Question 2

What is true about the fallopian tube?

Accepted Answer

It is lined by ciliated epithelium.

Answer

It has a glandular submucosa.

Answer

It is independent of hormonal influence.

Answer

It lies in the round ligament.

Question 3

What is the most abundant fibrillary collagen found in the basement membrane?

Accepted Answer

Type 4

Answer

Type 1

Answer

Type 2

Answer

Type 3

Question 4

Hyaline cartilage is located at all sites except?

Accepted Answer

Menisci of Knee joint

Answer

Costal cartilage

Answer

Articular cartilage

Answer

Epiphyseal plate

Question 5

Tight junctions are seen in all except?

Accepted Answer

Cardiac muscle

Answer

Renal tubules

Answer

Intestine

Answer

Choroid plexus

Question 6

What cells are present in the medulla of the ovary, which is homologous to interstitial cells of the testes?

Accepted Answer

Hilus cells

Answer

Stromal cells

Answer

Germinal epithelium

Answer

Tunica albuginea

Question 7

Elastic cartilage is absent in which of the following structures?

Accepted Answer

Trachea

Answer

Epiglottis

Answer

External auditory canal

Answer

Auricle of the ear

Question 8

What is the middle piece of the sperm tail primarily composed of?

Accepted Answer

Mitochondria

Answer

Golgi apparatus

Answer

Centriole

Answer

Lysosome

Question 9

A tendon or ligament is attached to a bone through:

Accepted Answer

Sharpey's fibers

Answer

Tomes fibers

Answer

Interstitial fibers

Answer

Haversian fibers

Question 10

The articular cartilage is characterized by all of the following features except?

Accepted Answer

It has a rich nerve supply

Answer

It is devoid of perichondrium

Answer

It is avascular

Answer

It lacks the capacity to regenerate

Histology — MCQs

Histology — MCQs

On this page

Practice by Chapter

Want unlimited practice?