Neuroanatomy Practice Questions

Q: Which of the following murmurs increases with the Valsalva maneuver?

Hypertrophic obstructive cardiomyopathy (HOCM). ### Explanation The **Valsalva maneuver** (specifically the strain phase) increases intrathoracic pressure, which decreases venous return to the heart. This leads to a **reduction in Left Ventricular (LV) end-diastolic volume** (preload). **Why HOCM is the correct answer:** In Hypertrophic Obstructive Cardiomyopathy, the pathology involves an asymmetrical septal hypertrophy that obstructs the LV outflow tract (LVOT). When the LV volume decreases (as during Valsalva), the ventricular walls and the anterior leaflet of the mitral valve move closer together. This **worsens the outflow obstruction**, thereby increasing the intensity of the systolic murmur. **Why the other options are incorrect:** * **Mitral Stenosis (A):** Decreased venous return reduces the flow across the stenotic mitral valve, thereby **decreasing** the intensity of the diastolic rumble [1]. * **Mitral Regurgitation (C) & Aortic Stenosis (D):** Both are "flow-dependent" systolic murmurs [1]. A decrease in preload leads to a lower stroke volume and less blood being ejected through the valves, resulting in a **decreased** murmur intensity [2]. **High-Yield Clinical Pearls for NEET-PG:** * **The "Rule of Two":** Most murmurs *decrease* in intensity during the Valsalva maneuver and standing. The only two exceptions (which **increase**) are **HOCM** and **Mitral Valve Prolapse (MVP)**. * **Handgrip Exercise:** This increases afterload. It **decreases** the murmur of HOCM and AS but **increases** the murmur of MR, AR, and VSD. * **Squatting:** Increases both preload and afterload; it **decreases** the HOCM murmur (opposite of Valsalva). [1, 2, 3, 4, 5]

Q: Which is the commonest type of cartilage to ossify?

Hyaline. **Explanation:** **1. Why Hyaline Cartilage is the Correct Answer:** Hyaline cartilage is the most abundant type of cartilage in the human body and serves as the primary precursor for the skeletal system [1]. The majority of the skeleton is formed through **endochondral ossification**, a process where a hyaline cartilage model is gradually replaced by bone [2]. Furthermore, hyaline cartilage has a natural tendency to calcify and ossify with age, particularly in the costal cartilages and the laryngeal skeleton (except the epiglottis). Its matrix is rich in Type II collagen and lacks the dense elastic or thick fibrous bundles that inhibit mineralization in other types [1]. **2. Why the Other Options are Incorrect:** * **Elastic Cartilage:** Contains a dense network of elastic fibers. It is specifically designed for flexibility and resilience. It **never ossifies or calcifies**, even with advancing age (e.g., pinna of the ear, epiglottis). * **Fibrous Cartilage (Fibrocartilage):** Contains thick bundles of Type I collagen. It acts as a shock absorber in high-stress areas (e.g., intervertebral discs, pubic symphysis). While it may occasionally undergo pathological calcification, it does not routinely ossify as a physiological process. * **Fibroelastic:** This is a hybrid description and not a primary classification of cartilage in this context. **3. Clinical Pearls & High-Yield Facts:** * **Articular Cartilage:** A type of hyaline cartilage that covers joint surfaces; it is unique because it **does not have a perichondrium** and does not normally ossify (to maintain joint mobility) [1]. * **Laryngeal Cartilages:** The thyroid, cricoid, and arytenoid cartilages are hyaline and often appear radiopaque on X-rays in older adults due to ossification. * **Growth Plate:** The epiphyseal plate is composed of hyaline cartilage; its ossification marks the end of longitudinal bone growth [2].

Q: Pathological gambling is included in DSM 5 under which category?

Substance use disorder. **Explanation:** The classification of **Pathological Gambling** underwent a significant shift in the transition from DSM-IV to **DSM-5**. It is now officially categorized under **Substance-Related and Addictive Disorders** (specifically as a "Non-Substance Addictive Disorder"). **Why Substance Use Disorder is correct:** Neurobiological research has shown that pathological gambling activates the brain's **reward system** (mesolimbic dopaminergic pathway) in a manner remarkably similar to drugs of abuse. Patients exhibit clinical features synonymous with substance addiction, such as **tolerance** (needing to gamble with increasing amounts of money), **withdrawal** (restlessness/irritability when attempting to stop), and repeated unsuccessful efforts to quit despite negative consequences. **Why other options are incorrect:** * **Impulse Control Disorder:** In DSM-IV, gambling was classified here (alongside kleptomania and pyromania). However, DSM-5 moved it because its clinical course and genetic markers align more closely with addictions than with other impulse control disorders. * **Obsessive Compulsive Disorder (OCD):** While both involve repetitive behaviors, OCD is driven by anxiety-reduction (neutralizing obsessions), whereas gambling is driven by the pursuit of reward/pleasure (arousal). * **Shared Psychotic Disorder (Folie à deux):** This is a psychotic syndrome where a symptom is transmitted from one individual to another; it has no clinical relation to gambling. **High-Yield Clinical Pearls for NEET-PG:** * **Neurotransmitter:** Dopamine is the primary neurotransmitter involved in the "reward" aspect of gambling. * **Brain Region:** The **Ventromedial Prefrontal Cortex** and **Nucleus Accumbens** are key areas involved in the pathology. * **Pharmacotherapy:** Opioid antagonists like **Naltrexone** have shown efficacy in reducing the urge to gamble by modulating the reward pathway.

Q: What is true about the corpus callosum?

Unites the far areas of the two sides of the brain.. The **Corpus Callosum** is the largest commissural fiber bundle in the brain, consisting of approximately 200 million axons. Its primary function is to facilitate interhemispheric communication. ### **Explanation of Options** * **Correct Answer (A):** The corpus callosum primarily connects **homologous (mirror-image) areas** of the two cerebral hemispheres. However, its specific functional role is to integrate information between "far" or distant cortical regions across the midline, allowing the two sides of the brain to function as a single unit. * **Option B:** While it does connect the frontal lobes (via the *Genu* and *Rostrum*), it also connects the parietal, temporal, and occipital lobes. Restricting its function to only the frontal lobes is incomplete. * **Option C:** While it "connects" the hemispheres, the term "unites" in neuroanatomical nomenclature often refers to the functional integration of distant cortical points, making Option A a more precise description of its physiological role. * **Option D:** The **Indusium griseum** (a thin layer of primitive gray matter) and the medial/lateral longitudinal striae are located **superior** to the corpus callosum. Therefore, the corpus callosum is *inferiorly* related to the Indusium griseum, not superiorly. ### **High-Yield Clinical Pearls for NEET-PG** 1. **Parts (Anterior to Posterior):** Rostrum $\rightarrow$ Genu $\rightarrow$ Body (Trunk) $\rightarrow$ Splenium. 2. **Forceps Minor:** Fibers of the **Genu** connecting the frontal lobes. 3. **Forceps Major:** Fibers of the **Splenium** connecting the occipital lobes. 4. **Tapetum:** Fibers of the trunk and splenium that form the roof and lateral wall of the posterior and inferior horns of the lateral ventricle. 5. **Clinical Correlation:** Surgical sectioning (Callosotomy) is used to treat intractable epilepsy to prevent the spread of seizure activity (Split-brain syndrome).

Q: All of the following arise from neuroepithelial cells except:

Microglial cells. The development of the central nervous system (CNS) begins with the formation of the **neural tube**. The wall of the neural tube is composed of **neuroepithelial cells**, which serve as the multipotent stem cells for almost all CNS structures. **1. Why Microglial cells is the correct answer:** Unlike other CNS cells, **microglial cells** do not originate from the neuroepithelium [1]. They are derived from **mesenchymal cells** (specifically from yolk sac macrophages) that migrate into the developing brain during the fetal period [1]. Functionally, they are the resident macrophages of the CNS and are part of the mononuclear phagocyte system [1], [2]. **2. Why the other options are incorrect:** The neuroepithelium differentiates into two primary lineages: * **Neuroblasts:** These give rise to **Neurons (Option A)** [4]. Once neuroblasts form, they lose their ability to divide. * **Glioblasts:** These give rise to macroglial cells [1], including: * **Oligodendrocytes (Option B):** Responsible for myelination in the CNS [2], [3]. * **Astrocytes:** Provide structural and metabolic support [1], [4]. * **Ependymal cells (Option D):** When the neuroepithelium ceases production of neuroblasts and glioblasts, the remaining cells differentiate into ependymal cells, which line the ventricles of the brain and the central canal of the spinal cord [4]. **High-Yield Clinical Pearls for NEET-PG:** * **Origin Summary:** All CNS cells are **ectodermal** (neuroectoderm) except Microglia, which are **mesodermal** [1]. * **PNS Exception:** Schwann cells and satellite cells are derived from **Neural Crest Cells**, not the neural tube neuroepithelium. * **Tumor Marker:** Glial Fibrillary Acidic Protein (GFAP) is a marker for cells of glial origin (Astrocytes, Ependymal cells), but *not* for Microglia.

Q: Which bones ossify at the lower end?

Lower end of femur. The correct answer is **Lower end of femur**. This question tests the knowledge of the **"Growing End"** of long bones and the specific timing of ossification centers, which is a high-yield topic for NEET-PG. **1. Why the Lower End of Femur is Correct:** The secondary ossification center for the lower end of the femur is unique because it appears just before birth (at approximately **9 months of intrauterine life**). In forensic medicine and pediatrics, the presence of this ossification center on an X-ray is a medico-legal indicator that a fetus has reached full-term maturity. **2. Analysis of Incorrect Options:** * **Upper end of humerus (Option A):** The growing end of the humerus is the upper end, but its ossification center typically appears shortly *after* birth (around 0–3 months). * **Lower end of humerus (Option B):** This is the non-growing end of the humerus. The ossification centers here (capitulum) appear around 1 year of age. * **Lower end of tibia (Option D):** The ossification center for the lower end of the tibia appears at approximately 6 months to 1 year of age. **3. NEET-PG Clinical Pearls & High-Yield Facts:** * **The Rule of Growing Ends:** "To the elbow I go, from the knee I flee." This means the growing ends are the upper end of the humerus, the lower ends of the radius/ulna, the upper end of the tibia/fibula, and the **lower end of the femur**. * **First Bone to Ossify:** Clavicle (5th–6th week of IU life; via intramembranous ossification) [1]. * **Last Bone to Ossify:** Pisiform (around 10–12 years). * **Medico-legal Importance:** The lower end of the femur and the upper end of the tibia are the only secondary centers present at birth, used to confirm neonatal maturity.

Q: Dystrophic calcification is seen in which of the following conditions?

Atheroma. Pathologic calcification is divided into two types: **Dystrophic** and **Metastatic**. **1. Why Atheroma is Correct:** Dystrophic calcification occurs in **dead, dying, or degenerated tissues** despite normal serum calcium levels. In an **atheroma** (advanced atherosclerosis), the necrotic core of the lipid plaque undergoes dystrophic calcification. This is a localized process where calcium salts deposit in damaged vessel walls, often leading to hardened arteries. **2. Why the Other Options are Incorrect:** Options B, C, and D are examples of **Metastatic Calcification**. This occurs in **normal tissues** due to a systemic derangement in calcium metabolism (**Hypercalcemia**). * **Paget’s Disease:** Involves excessive bone remodeling which can lead to elevated serum calcium [2]. * **Renal Osteodystrophy:** Chronic kidney disease leads to secondary hyperparathyroidism and hyperphosphatemia, causing calcium to deposit in healthy tissues (like blood vessels and lungs) [1]. * **Milk-Alkali Syndrome:** Caused by excessive ingestion of calcium and absorbable antacids, leading to hypercalcemia. **High-Yield NEET-PG Pearls:** * **Dystrophic Calcification:** Normal serum calcium; occurs in necrotic tissue (e.g., Caseous necrosis in TB, Psammoma bodies in papillary thyroid cancer, old infarcts, and damaged heart valves). * **Metastatic Calcification:** High serum calcium; occurs in healthy tissues, especially those with an internal alkaline environment (e.g., Gastric mucosa, Kidneys, Lungs, and Systemic arteries). * **Mnemonic for Metastatic sites:** "**K**idney, **L**ungs, **G**astric mucosa" (The **KLG** sites are prone due to acid excretion, making the tissue alkaline).

Q: Parasympathetic fibers of the vagus nerve supply which of the following structures?

Heart. **Explanation:** The **Vagus nerve (CN X)** is the longest cranial nerve and provides extensive parasympathetic (craniosacral) innervation to thoracic and abdominal viscera [1]. Its preganglionic parasympathetic fibers originate in the **Dorsal Nucleus of Vagus** and the **Nucleus Ambiguus** [1]. 1. **Why Heart is Correct:** The vagus nerve provides parasympathetic supply to the heart via cardiac branches [1]. These fibers synapse in ganglia located within the cardiac plexus and the atrial walls [2]. Stimulation results in a decreased heart rate (negative chronotropy) and decreased conduction velocity through the AV node [3]. 2. **Why other options are incorrect:** * **Parotid Gland:** Supplied by the **Glossopharyngeal nerve (CN IX)**. Fibers originate in the inferior salivatory nucleus and synapse in the **otic ganglion** [2]. * **Submandibular Gland:** Supplied by the **Facial nerve (CN VII)** via the chorda tympani branch. Fibers originate in the superior salivatory nucleus and synapse in the **submandibular ganglion** [2]. * **Ciliary Muscles:** Supplied by the **Oculomotor nerve (CN III)**. Fibers originate in the Edinger-Westphal nucleus and synapse in the **ciliary ganglion** [2]. **High-Yield NEET-PG Pearls:** * **The "Rule of 2/3rds":** The vagus nerve supplies the midgut up to the junction of the proximal 2/3rds and distal 1/3rd of the transverse colon. Beyond this point (hindgut), parasympathetic supply is taken over by the **Pelvic Splanchnic Nerves (S2-S4)**. * **Nucleus Ambiguus:** This nucleus provides the special visceral efferent (SVE) fibers to the muscles of the larynx and pharynx, but also contains the cell bodies for preganglionic parasympathetic cardiac inhibitory fibers [1]. * **Vagal Maneuvers:** Clinical techniques (like carotid sinus massage) increase vagal tone to terminate Supraventricular Tachycardia (SVT).

Question 1

Which of the following murmurs increases with the Valsalva maneuver?

Accepted Answer

Hypertrophic obstructive cardiomyopathy (HOCM)

Answer

Mitral stenosis

Answer

Mitral regurgitation

Answer

Aortic stenosis

Question 2

Which neuroanatomical part of the brain is involved in sexual drive?

Accepted Answer

Limbic system

Answer

Temporal lobe

Answer

Hypothalamus

Answer

Frontal lobe

Question 3

Which is the commonest type of cartilage to ossify?

Accepted Answer

Hyaline

Answer

Elastic

Answer

Fibrous

Answer

Fibroelastic

Question 4

Pathological gambling is included in DSM 5 under which category?

Accepted Answer

Substance use disorder

Answer

Impulse control disorder

Answer

Obsessive compulsive disorder

Answer

Shared psychotic disorder

Question 5

What is true about the corpus callosum?

Accepted Answer

Unites the far areas of the two sides of the brain.

Answer

Connects the two frontal lobes.

Answer

Unites the two hemispheres.

Answer

Is superiorly related to the Indusium griseum.

Question 6

All of the following arise from neuroepithelial cells except:

Accepted Answer

Microglial cells

Answer

Neuron

Answer

Oligodendrocyte

Answer

Ependymal cells

Question 7

Which bones ossify at the lower end?

Accepted Answer

Lower end of femur

Answer

Upper end of humerus

Answer

Lower end of humerus

Answer

Lower end of tibia

Question 8

Dystrophic calcification is seen in which of the following conditions?

Accepted Answer

Atheroma

Answer

Paget's disease

Answer

Renal osteodystrophy

Answer

Milk alkali syndrome

Question 9

Parasympathetic fibers of the vagus nerve supply which of the following structures?

Accepted Answer

Heart

Answer

Parotid gland

Answer

Submandibular gland

Answer

Ciliary muscles

Question 10

A 55-year-old right-handed veteran received a small shrapnel wound in the head. Within 1 year of receiving his wound, the man complained of seizures and was treated with seizure medication. The medication was not effective, and a section of the anterior corpus callosum was performed. Which of the following neurologic deficits is most likely?

Accepted Answer

The inability, with closed eyes, to identify verbally an object held in the left hand

Answer

Alexia

Answer

Gait ataxia

Answer

Loss of binocular vision

Neuroanatomy — MCQs

Neuroanatomy — MCQs

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