Stress and HPA Axis Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Stress and HPA Axis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Stress and HPA Axis Indian Medical PG Question 1: Which of the following neuroanatomical areas is/are considered to be involved in the etiology of depression?
- A. Striatum
- B. Amygdala
- C. Hippocampus
- D. All of the options (Correct Answer)
Stress and HPA Axis Explanation: ***All of the options***
- The **amygdala**, **hippocampus**, and **striatum** are all part of complex neural circuits that have been implicated in the pathophysiology of depression.
- Dysregulation in these areas can lead to emotional processing deficits, memory impairments, and anhedonia, which are core symptoms of depression.
*Amygdala*
- The **amygdala** is primarily involved in processing emotions, particularly fear and anxiety, and shows increased activity in depressed individuals, contributing to negative mood.
- While significant, it is just one component of a broader network involved in depression.
*Hippocampus*
- The **hippocampus** plays a crucial role in memory and mood regulation, and studies often show reduced volume and function in depressed patients, affecting learning and emotional context.
- Although it is significantly affected, depression involves multiple brain regions, not solely the hippocampus.
*Striatum*
- The **striatum**, particularly the **ventral striatum**, is vital for reward processing, motivation, and motor control, and its dysfunction can contribute to anhedonia and lack of motivation in depression.
- While critical for reward pathways, the striatum is part of a larger interconnected system implicated in this condition.
Stress and HPA Axis Indian Medical PG Question 2: Stress hyperglycemia occurs due to all except -
- A. Increased level of ACTH
- B. Decreased level of norepinephrine (Correct Answer)
- C. Insulin resistance
- D. Increased level of cortisol
Stress and HPA Axis Explanation: ***Decreased level of norepinephrine***
- **Norepinephrine** is a **catecholamine** that generally **increases blood glucose** by stimulating **glycogenolysis** and **gluconeogenesis**.
- Therefore, a *decrease* in norepinephrine would *reduce* stress-induced hyperglycemia, making this the exception.
*Increased level of ACTH*
- **ACTH (Adrenocorticotropic Hormone)** stimulates the adrenal glands to release **cortisol**, which contributes significantly to stress hyperglycemia.
- Increased ACTH levels therefore *promote* hyperglycemia in stress.
*Insulin resistance*
- **Insulin resistance** is a common feature during stress, where target cells become less responsive to insulin's effects.
- This reduced insulin sensitivity leads to higher circulating glucose levels, contributing to hyperglycemia.
*Increased level of cortisol*
- **Cortisol** is a key **stress hormone** that promotes **gluconeogenesis** (production of glucose from non-carbohydrate sources) and **glycogenolysis** (breakdown of glycogen to glucose).
- Elevated cortisol levels directly lead to an increase in blood glucose, causing hyperglycemia.
Stress and HPA Axis Indian Medical PG Question 3: Adrenal medulla secretes all EXCEPT:
- A. Epinephrine
- B. Norepinephrine
- C. Dopamine
- D. Cortisol (Correct Answer)
Stress and HPA Axis Explanation: ***Cortisol***
- **Cortisol** is a **glucocorticoid** hormone primarily secreted by the **adrenal cortex**, not the adrenal medulla.
- Its main functions include regulating metabolism, suppressing the immune system, and aiding in stress response.
*Epinephrine*
- **Epinephrine** (adrenaline) is the primary hormone secreted by the **adrenal medulla**, constituting about 80% of its output.
- It plays a crucial role in the **"fight-or-flight" response**, increasing heart rate, blood pressure, and glucose levels.
*Norepinephrine*
- **Norepinephrine** (noradrenaline) is also secreted by the **adrenal medulla**, making up about 20% of its secretion.
- It works alongside epinephrine in the **sympathetic nervous system** to constrict blood vessels and increase alertness.
- Norepinephrine also serves as a precursor in the biosynthesis of epinephrine.
*Dopamine*
- **Dopamine** is an important **neurotransmitter** that also serves as a precursor in the synthesis of norepinephrine and epinephrine.
- While dopamine itself is secreted in small amounts by the adrenal medulla, its primary role is generally considered in the central nervous system and as an intermediate in catecholamine synthesis.
Stress and HPA Axis Indian Medical PG Question 4: What would be the most probable diagnosis for a 50-year-old chronic smoker who presents with hemoptysis, truncal obesity, and hypertension, and has an elevated ACTH level that is not suppressible with high-dose dexamethasone?
- A. Ectopic ACTH producing lung cancer (Correct Answer)
- B. Adrenal adenoma
- C. Bilateral adrenal hyperplasia
- D. Pituitary tumor
Stress and HPA Axis Explanation: ***Ectopic ACTH producing lung cancer***
- The combination of **hemoptysis** in a **chronic smoker** points towards a pulmonary malignancy, which can produce **ectopic ACTH**, leading to Cushing's syndrome symptoms [2, 5].
- The **elevated ACTH** that is **not suppressible with high-dose dexamethasone** is characteristic of ectopic ACTH production, as the tumor cells do not respond to feedback inhibition [1].
*Adrenal adenoma*
- An **adrenal adenoma** causes **ACTH-independent Cushing's syndrome**, meaning ACTH levels would be low [1].
- While it can cause symptoms like truncal obesity and hypertension, it does not explain the hemoptysis or elevated ACTH.
*Bilateral adrenal hyperplasia*
- **Bilateral adrenal hyperplasia** can cause Cushing's syndrome, but it is typically **ACTH-dependent** and often responsive to high-dose dexamethasone if it's pituitary-driven [1].
- It does not account for the hemoptysis or the **non-suppressible ACTH** level in this particular presentation.
*Pituitary tumor*
- A **pituitary tumor** (Cushing's disease) produces ACTH, causing Cushing's syndrome, and typically shows **suppression with high-dose dexamethasone** (though not always fully).
- It would not explain the symptom of **hemoptysis** associated with a chronic smoker [2].
Stress and HPA Axis Indian Medical PG Question 5: All the following mediate their action using cAMP as second messenger except:
- A. Glucagon
- B. Dopamine
- C. Corticotropin
- D. Vasopressin (Correct Answer)
Stress and HPA Axis Explanation: ***Vasopressin (ADH)***
- Vasopressin has **dual signaling mechanisms** depending on receptor type:
- **V2 receptors** (kidney collecting duct): Use **Gs-protein → cAMP pathway** for water reabsorption via aquaporin-2 insertion
- **V1 receptors** (vascular smooth muscle): Use **Gq-protein → IP3/DAG pathway** for vasoconstriction
- In the context of this question, vasopressin is considered the exception because it has **significant non-cAMP mediated actions** through V1 receptors, unlike the other hormones listed which **predominantly or exclusively** use cAMP
- **Note**: This is a teaching point about receptor subtypes; vasopressin DOES use cAMP at V2 receptors
*Glucagon*
- **Exclusively uses cAMP pathway** in hepatocytes and adipocytes
- Binds to **glucagon receptor** (GPCR) → **Gs-protein** → adenylyl cyclase activation → **increased cAMP** → PKA activation
- Promotes glycogenolysis, gluconeogenesis, and lipolysis
*Dopamine*
- **D1 and D5 receptors** are **Gs-coupled** → **stimulate adenylyl cyclase** → **increase cAMP**
- Important for neurotransmission (motor control, reward) and renal vasodilation
- D2-family receptors (D2, D3, D4) inhibit cAMP but D1-family predominates in many physiological contexts
*Corticotropin (ACTH)*
- Binds to **melanocortin-2 receptor (MC2R)** on adrenal cortex
- **Gs-protein coupled** → adenylyl cyclase activation → **increased cAMP** → PKA activation
- Stimulates steroidogenesis and cortisol secretion
- **Exclusively cAMP-dependent mechanism**
Stress and HPA Axis Indian Medical PG Question 6: Nitric Oxide (NO) is a novel neurotransmitter which is considered to have an effect in the pathophysiology of which of the following psychiatric conditions?
- A. Schizophrenia
- B. Substance Misuse
- C. OCD
- D. Mood Disorders (Correct Answer)
Stress and HPA Axis Explanation: ***Mood Disorders***
- **Nitric oxide (NO)** has been implicated in the pathophysiology of **mood disorders**, such as major depressive disorder and bipolar disorder, due to its role in **neurotransmission** and **neuronal plasticity**.
- NO can modulate the activity of various neurotransmitter systems (e.g., serotonergic, dopaminergic) that are known to be dysregulated in mood disorders, influencing **affect** and **emotional regulation**.
*Schizophrenia*
- While **NO dysfunction** has been investigated in schizophrenia, its role is less clearly established as a primary effector compared to neurotransmitters like **dopamine** and **glutamate**.
- Research in schizophrenia often focuses on the **dopamine hypothesis** or **glutamate hypofunction**, with NO having a more modulatory role.
*Substance Misuse*
- NO is known to be involved in pathways related to **reward** and **addiction**, but it is generally considered a **modulator** of neurotransmission rather than a primary neurotransmitter in the development of substance misuse.
- The pathophysiology of substance misuse is highly complex, involving multiple neurotransmitter systems and circuits, including **dopamine** and the mesolimbic reward system.
*OCD*
- The primary neurotransmitter theories for **Obsessive-Compulsive Disorder (OCD)** largely focus on **serotonin dysregulation**, with treatments like SSRIs being highly effective.
- While NO may have some modulatory effects on brain circuits involved in OCD, it is not considered a central player in its pathophysiology compared to other conditions.
Stress and HPA Axis Indian Medical PG Question 7: Under which one of the following conditions, the HPA axis suppression is likely to result in crisis due to adrenal insufficiency following withdrawal of glucocorticoids?
- A. If glucocorticoids have been prescribed repeatedly within the previous year (Correct Answer)
- B. If the dose is less than equivalent of 5 mg prednisolone per day
- C. If glucocorticoids have been given by intravenous route for five days
- D. If glucocorticoids have been administered orally for one week
Stress and HPA Axis Explanation: ***Correct: If glucocorticoids have been prescribed repeatedly within the previous year***
- While a **single short course** of glucocorticoids typically does not cause significant HPA axis suppression, **repeated exposure over time** (multiple courses within a year) can lead to **cumulative suppression** of the hypothalamic-pituitary-adrenal axis
- This is particularly true if the courses are **frequent, prolonged, or at high doses** without adequate recovery periods between treatments
- **Chronic or repeated suppression** impairs the body's ability to produce sufficient endogenous cortisol when exogenous glucocorticoids are withdrawn, increasing the risk of **adrenal insufficiency crisis**
- Among the given options, this represents the **highest risk scenario** for HPA axis suppression requiring careful withdrawal management
*Incorrect: If the dose is less than equivalent of 5 mg prednisolone per day*
- Doses **< 5 mg prednisolone equivalent per day** are considered **physiologic replacement doses**
- Such low doses do **NOT suppress** the HPA axis significantly
- This represents a **low-risk scenario** for adrenal insufficiency
- Standard teaching: HPA suppression risk increases with doses **> 20 mg/day prednisolone equivalent**
*Incorrect: If glucocorticoids have been given by intravenous route for five days*
- **Short-course therapy (< 7-10 days)**, even at high doses and by IV route, typically does **NOT cause prolonged HPA axis suppression**
- The HPA axis usually **recovers rapidly** after brief exposure
- Abrupt discontinuation after 5 days **does not typically require tapering** and is unlikely to cause adrenal crisis
- The route of administration (IV vs oral) is less important than **duration and total dose**
*Incorrect: If glucocorticoids have been administered orally for one week*
- Similar to the IV scenario, **one week of oral therapy** is considered a **short course**
- Such brief duration typically does not cause significant HPA axis suppression requiring taper
- The adrenal glands usually maintain responsiveness after only **7 days** of treatment
- **Duration > 3 weeks** at supraphysiologic doses is the traditional threshold for concern about HPA suppression
Stress and HPA Axis Indian Medical PG Question 8: A 45-year-old male's blood test shows an increase in Homovanillic acid (HVA). Which of the following conditions is this finding most likely associated with?
- A. Phenylketonuria (PKU)
- B. Schizophrenia (Correct Answer)
- C. Depression
- D. Parkinson's disease
Stress and HPA Axis Explanation: **Explanation:**
The correct answer is **Schizophrenia**. This question tests your knowledge of neurotransmitter metabolites and their clinical significance in psychiatric disorders.
**1. Why Schizophrenia is correct:**
**Homovanillic acid (HVA)** is the primary metabolic byproduct of **Dopamine**. According to the **Dopamine Hypothesis of Schizophrenia**, the disorder is characterized by dopaminergic hyperactivity, particularly in the mesolimbic pathway. Increased turnover of dopamine leads to elevated levels of HVA in the blood, cerebrospinal fluid (CSF), and urine. Monitoring HVA levels is often used in research to gauge central dopamine activity.
**2. Why the other options are incorrect:**
* **Phenylketonuria (PKU):** This is a metabolic disorder caused by a deficiency of phenylalanine hydroxylase. It leads to an accumulation of Phenylalanine, not HVA.
* **Depression:** Depression is primarily associated with decreased levels of **5-HIAA** (5-Hydroxyindoleacetic acid), which is the metabolite of Serotonin. While dopamine can be involved, HVA is not a diagnostic marker for depression.
* **Parkinson’s Disease:** This condition involves the degeneration of dopaminergic neurons in the substantia nigra. Therefore, one would expect a **decrease** in HVA levels due to dopamine deficiency, rather than an increase.
**High-Yield Clinical Pearls for NEET-PG:**
* **Dopamine → HVA** (Homovanillic Acid)
* **Serotonin → 5-HIAA** (Decreased in suicide attempts and impulsive aggression)
* **Norepinephrine → VMA** (Vanillylmandelic Acid) and **MHPG** (3-methoxy-4-hydroxyphenylglycol).
* **VMA** is a crucial marker for diagnosing **Pheochromocytoma** and **Neuroblastoma**.
* In Schizophrenia, HVA levels often correlate with the severity of positive symptoms (hallucinations/delusions).
Stress and HPA Axis Indian Medical PG Question 9: Which of the following features is NOT commonly associated with 22q11.2 deletion syndrome?
- A. Mental retardation (Correct Answer)
- B. Schizophrenia
- C. ADHD
- D. Congenital heart defects
Stress and HPA Axis Explanation: **Explanation:**
**22q11.2 Deletion Syndrome** (also known as DiGeorge or Velocardiofacial Syndrome) is the most common microdeletion syndrome in humans. The correct answer is **Mental retardation (Option A)** because, while patients frequently exhibit borderline intellectual functioning or learning disabilities, global "mental retardation" (moderate to severe intellectual disability) is **not** a defining or universal feature of the syndrome. Most patients have an IQ in the 70–85 range.
**Analysis of Incorrect Options:**
* **Schizophrenia (Option B):** This is a hallmark psychiatric association. Approximately 25–30% of individuals with this deletion develop schizophrenia, making it one of the strongest known genetic risk factors for the disorder.
* **ADHD (Option C):** Neurodevelopmental disorders are highly prevalent; ADHD is the most common psychiatric diagnosis in children with 22q11.2 deletion, affecting roughly 30–40% of patients.
* **Congenital heart defects (Option D):** These are classic physical manifestations, particularly conotruncal defects (e.g., Tetralogy of Fallot, interrupted aortic arch), occurring in about 75% of cases.
**High-Yield Clinical Pearls for NEET-PG:**
* **Mnemonic (CATCH-22):** **C**ardiac defects, **A**bnormal facies, **T**hymic hypoplasia (T-cell deficiency), **C**left palate, **H**ypocalcemia (hypoparathyroidism), due to **22**q11 deletion.
* **Psychiatry Link:** It is often tested as the "genetic link to schizophrenia."
* **Diagnosis:** Confirmed via **FISH** (Fluorescence In Situ Hybridization) or chromosomal microarray.
* **Key Gene:** The **TBX1** gene is primarily responsible for the physical phenotypes.
Stress and HPA Axis Indian Medical PG Question 10: Which chromosome is associated with bipolar disease?
- A. Chromosome 16
- B. Chromosome 13 (Correct Answer)
- C. Chromosome 14
- D. Chromosome 11
Stress and HPA Axis Explanation: **Explanation:**
Bipolar Disorder (BD) is a highly heritable psychiatric condition with a complex polygenic inheritance pattern. Genetic linkage studies have consistently identified specific loci associated with an increased susceptibility to the disorder.
**1. Why Chromosome 13 is Correct:**
Chromosome **13q** (specifically the 13q32 locus) is one of the most strongly linked regions to Bipolar Disorder. This region contains the **G72 (DAOA)** gene, which is involved in glutamatergic neurotransmission. Mutations or polymorphisms in this area are associated with both Bipolar Disorder and Schizophrenia, suggesting a shared genetic vulnerability between psychotic and mood disorders.
**2. Analysis of Incorrect Options:**
* **Chromosome 16 (Option A):** While some studies suggest minor links to various psychiatric traits, it is not a primary or high-yield locus specifically associated with Bipolar Disorder in standard medical curricula.
* **Chromosome 14 (Option B):** This chromosome is most famously associated with **Early-onset Alzheimer’s Disease** (Presenilin-1 gene located at 14q24.3).
* **Chromosome 11 (Option D):** Chromosome 11 is significant in psychiatry for the **BDNF** (Brain-Derived Neurotrophic Factor) gene and the **DRD4** gene, but Chromosome 13 remains the more classic "textbook" answer for linkage studies in Bipolar Disorder.
**Clinical Pearls for NEET-PG:**
* **Other Linked Chromosomes:** Besides 13q, Chromosomes **18q, 21q, and 22q** are frequently cited in association with Bipolar Disorder.
* **Heritability:** Bipolar Disorder has the highest heritability among major psychiatric disorders (approx. 80-85%).
* **Twin Studies:** If one monozygotic twin has Bipolar I disorder, there is a **40-70%** chance the other twin will also be affected.
* **First-degree relatives:** They have a 5-10 times higher risk of developing the disorder compared to the general population.
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