Integrated Metabolic Regulation — MCQs
Which of the following is not a substrate for gluconeogenesis?
Metabolic changes seen in starvation include all of the following except?
Insulin resistance down-regulates -
All of the following are increased in Acute stress except
All of these cause hyperglycemia except:
Which of the following is not seen in a hyperkinetic child?
What is the recommended daily calcium intake for adult non-pregnant females?
What is the body's first physiological response to hypoglycemia?
Integrated management of neonatal and childhood illness includes all except :
Which micronutrient supplement should be administered during an acute episode of diarrhoea?
Integrated Metabolic Regulation Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is not a substrate for gluconeogenesis?
- A. Leucine (Correct Answer)
- B. Lactate
- C. Propionate
- D. Glycerol
Explanation: ***Leucine*** - **Leucine** is an exclusively **ketogenic amino acid**, meaning its breakdown products can only be converted into **ketone bodies** or fatty acids, not glucose. - It does not have a carbon skeleton that can be directly converted into **pyruvate** or **oxaloacetate**, which are key intermediates in gluconeogenesis. *Lactate* - **Lactate** is a major substrate for gluconeogenesis, particularly during exercise or fasting. - It is converted to **pyruvate** by **lactate dehydrogenase**, and pyruvate can then enter the gluconeogenic pathway. *Propionate* - **Propionate** is a fatty acid with an odd number of carbon atoms, primarily derived from the catabolism of odd-chain fatty acids or from bacterial fermentation in the colon. - It can be converted into **succinyl CoA**, an intermediate of the citric acid cycle, which can then be used for gluconeogenesis. *Glycerol* - **Glycerol**, released during the breakdown of triglycerides, is an important substrate for gluconeogenesis. - It is phosphorylated to **glycerol-3-phosphate**, which is then oxidized to **dihydroxyacetone phosphate (DHAP)**, an intermediate in glycolysis and gluconeogenesis.
Question 2: Metabolic changes seen in starvation include all of the following except?
- A. Ketogenesis
- B. Protein degradation
- C. Increased gluconeogenesis
- D. Increased glycolysis (Correct Answer)
Explanation: ***Increased glycolysis*** - In starvation, the body's primary goal is to conserve **glucose** for essential organs like the brain, as glucose supply is limited. Therefore, glycolysis, the breakdown of glucose, is *decreased*, not increased. - The body shifts to using alternative fuels such as **fatty acids** and **ketone bodies** to spare glucose. *Increased gluconeogenesis* - **Gluconeogenesis**, the synthesis of glucose from non-carbohydrate precursors like amino acids and glycerol, is *increased* during starvation to maintain blood glucose levels. - This process is crucial for providing glucose to tissues that primarily rely on it, such as the brain and red blood cells. *Ketogenesis* - **Ketogenesis**, the production of ketone bodies from fatty acids, is significantly *increased* during prolonged starvation. - **Ketone bodies** become a major energy source for the brain and other tissues when glucose is scarce, helping to spare muscle protein. *Protein degradation* - **Protein degradation** (proteolysis) is *increased* during starvation, especially in the initial phases, to provide amino acids for gluconeogenesis. - Muscle protein is a primary source of these amino acids, contributing to muscle wasting observed in prolonged starvation.
Question 3: Insulin resistance down-regulates -
- A. GLUT-4 (Correct Answer)
- B. GLUT-2
- C. GLUT-1
- D. GLUT-3
Explanation: ***GLUT-4*** - **Insulin resistance** primarily affects cells that express **GLUT-4**, such as **adipocytes** and **skeletal muscle cells**. - In insulin-resistant states, the translocation of **GLUT-4 transporters** to the cell membrane in response to insulin is impaired, leading to **reduced glucose uptake**. *GLUT-2* - **GLUT-2** is primarily found in the **liver**, **pancreatic beta cells**, kidneys, and small intestine. - Its function is to transport glucose **bidirectionally** and is not regulated by insulin in the same manner as GLUT-4; thus, it is not directly down-regulated by insulin resistance. *GLUT-1* - **GLUT-1** is responsible for **basal glucose uptake** in most cells, including **erythrocytes** and cells of the blood-brain barrier. - Its expression is constitutive and largely **insulin-independent**, meaning it is not significantly down-regulated in insulin resistance. *GLUT-3* - **GLUT-3** is predominantly found in **neurons** and is crucial for **glucose transport into the brain**. - It has a high affinity for glucose and its expression is also largely **insulin-independent**, making it unaffected by insulin resistance in most contexts.
Question 4: All of the following are increased in Acute stress except
- A. Growth hormone
- B. Epinephrine
- C. Glucagon
- D. Insulin (Correct Answer)
Explanation: ***Insulin*** - During acute stress, **insulin secretion is actively suppressed** by catecholamines (epinephrine and norepinephrine) acting on **alpha-2 adrenergic receptors** on pancreatic beta cells. - This suppression is crucial for the stress response, as it allows **unopposed action of counter-regulatory hormones** to mobilize glucose and raise blood glucose levels. - The body prioritizes **immediate energy availability** (high blood glucose) over storage, making insulin the hormone that is **decreased, not increased**, during acute stress. *Growth hormone* - **Growth hormone** is a counter-regulatory hormone that **increases during acute stress** to mobilize energy stores, particularly by promoting lipolysis and gluconeogenesis. - Its actions contribute to the stress-induced elevation of **blood glucose levels**. *Epinephrine* - **Epinephrine** (adrenaline) is a primary catecholamine released during acute stress, leading to a rapid **fight or flight response**. - It significantly **increases heart rate**, blood pressure, and **glucose mobilization** through glycogenolysis and gluconeogenesis. *Glucagon* - **Glucagon** is a key hormone involved in **maintaining glucose homeostasis** and is significantly **increased during acute stress**. - It primarily acts on the liver to **stimulate glycogenolysis** and **gluconeogenesis**, thereby raising blood glucose levels to provide energy.
Question 5: All of these cause hyperglycemia except:
- A. Catecholamines
- B. Insulin (Correct Answer)
- C. Cortisol
- D. GH
Explanation: ***Insulin*** - Insulin's primary function is to **lower blood glucose levels** by facilitating glucose uptake into cells and promoting glycogen synthesis. - It counters the effects of hormones that elevate blood sugar, directly leading to a **decrease in hyperglycemia**. *Catecholamines* - **Catecholamines** (e.g., epinephrine, norepinephrine) increase blood glucose by promoting **glycogenolysis** and **gluconeogenesis**. - They also **inhibit insulin secretion**, further contributing to elevated blood sugar. *Cortisol* - **Cortisol** is a **glucocorticoid** that raises blood glucose by increasing **gluconeogenesis** and reducing peripheral **glucose utilization**. - It can also decrease insulin sensitivity, leading to **hyperglycemia**. *GH* - **Growth hormone (GH)** can induce **insulin resistance** in peripheral tissues, which leads to reduced glucose uptake. - It also promotes **gluconeogenesis**, both contributing to elevated blood glucose levels.
Question 6: Which of the following is not seen in a hyperkinetic child?
- A. Left-right disorientation (Correct Answer)
- B. Decreased attention span
- C. Aggressive outbursts
- D. Soft neurological signs
Explanation: ***Left to right disorientation*** - **Left-right disorientation** is a sign of **developmental coordination disorder** or other specific learning difficulties, not a core symptom of hyperkinesis (ADHD). - Hyperkinetic children primarily exhibit symptoms related to **inattention**, **hyperactivity**, and **impulsivity**. *Decreased attention span* - A **decreased attention span** is a cardinal feature of **Attention-Deficit/Hyperactivity Disorder (ADHD)**, which is synonymous with hyperkinesis in children. - Children with ADHD often struggle with sustaining focus on tasks, leading to difficulties in academic and social settings. *Aggressive outbursts* - **Aggressive outbursts** and **irritability** can be associated features of hyperkinetic disorder, particularly in children who also experience **oppositional defiant disorder** or **conduct disorder** as comorbidities. - Impulsivity and difficulty with emotional regulation can contribute to these behaviors. *Soft neurological signs* - **Soft neurological signs** (e.g., poor coordination, minor motor deficits, abnormal reflexes) are more frequently observed in children with **hyperkinetic disorder** compared to neurotypical children. - These signs indicate subtle neurological dysfunction that is not localized or severe enough to be classified as a distinct neurological disorder.
Question 7: What is the recommended daily calcium intake for adult non-pregnant females?
- A. 1000 mg (Correct Answer)
- B. 1200 mg
- C. 600 mg
- D. 800 mg
Explanation: ***1000 mg*** - The recommended daily calcium intake for adult non-pregnant females (ages 19-50) is **1000 mg** according to **WHO and international guidelines** (US RDA/NIH) to maintain bone health and prevent osteoporosis. - This is the **standard recommendation** used in most medical textbooks and international nutritional guidelines. - Adequate calcium intake supports various bodily functions, including **nerve transmission**, **muscle contraction**, and **hormone secretion**. *1200 mg* - While 1200 mg is the recommended intake for **older women (above 50-70 years)** or during **pregnancy/lactation** per some guidelines, it is generally higher than necessary for non-pregnant adult females aged 19-50. - While not harmful, this higher dose is not specifically indicated for the general non-pregnant adult female population. *600 mg* - This amount of calcium is **lower than the internationally recommended daily allowance** for adult women (though it aligns with some regional guidelines like ICMR for sedentary women). - For optimal bone health and prevention of osteoporosis, **1000 mg is the widely accepted standard** in medical education. *800 mg* - This value is **below the internationally recommended daily intake** for adult non-pregnant females, which could lead to long-term calcium deficiency. - Insufficient calcium intake can increase the risk of conditions like **osteopenia** and **osteoporosis**.
Question 8: What is the body's first physiological response to hypoglycemia?
- A. Decreased insulin (Correct Answer)
- B. Increased glucagon
- C. Increased cortisol
- D. Increased norepinephrine
Explanation: ***Decreased insulin*** - **Decreased insulin secretion** is the body's **first and earliest** physiological response to falling blood glucose levels, occurring at approximately **80-85 mg/dL**. - This represents the **primary defense mechanism** against hypoglycemia - by reducing insulin release from pancreatic beta cells, the body removes the most potent glucose-lowering stimulus. - This allows blood glucose to stabilize before it drops further, and occurs **before** any active counterregulatory hormones are released. - This is a critical **first-line defense** that prevents the need for more aggressive counterregulatory responses. *Increased glucagon* - **Glucagon** is the **second line of defense** against hypoglycemia, with secretion increasing at glucose levels around **65-70 mg/dL**. - While glucagon is the most important **active counterregulatory hormone** (stimulating glycogenolysis and gluconeogenesis), it is not the *first* response. - The temporal sequence is: insulin suppression occurs first, followed by glucagon release if glucose continues to fall. *Increased cortisol* - **Cortisol** is a late counterregulatory hormone, responding to more severe or prolonged hypoglycemia (glucose <65 mg/dL). - It promotes gluconeogenesis and reduces peripheral glucose utilization over hours, not minutes. - Along with growth hormone, cortisol provides sustained glucose elevation but is not an early response. *Increased norepinephrine* - **Norepinephrine** (and epinephrine) are part of the sympathetic/adrenomedullary response to hypoglycemia at approximately **65-70 mg/dL**. - These catecholamines provide important counterregulation but are activated after insulin suppression has already occurred. - They contribute to both glucose mobilization and the symptomatic (adrenergic) response to hypoglycemia.
Question 9: Integrated management of neonatal and childhood illness includes all except :
- A. Pneumonia
- B. Diarrhoea
- C. Tuberculosis (Correct Answer)
- D. Malaria
Explanation: ***Tuberculosis*** - While tuberculosis can significantly affect children, especially in endemic areas, it is typically managed under **separate, specialized programs** (such as the National TB Elimination Programme) due to its **chronic nature**, specific diagnostic requirements (including tuberculin skin testing, chest X-rays, and microbiological investigations), and prolonged treatment regimens (6-12 months with multiple drugs). - The **Integrated Management of Neonatal and Childhood Illness (IMNCI)** strategy focuses on acute, common childhood illnesses that require rapid assessment and standardized treatment protocols, which differ fundamentally from the comprehensive, long-term management approach required for TB. - TB screening may be part of child health programs, but the actual management follows dedicated TB control protocols rather than IMNCI guidelines. *Pneumonia* - **Pneumonia** is a core component of the IMNCI strategy because it is a leading cause of childhood mortality worldwide and requires standardized assessment for danger signs, fast breathing, and chest indrawing. - IMNCI provides clear protocols for classifying and managing **acute respiratory infections** with appropriate antibiotic therapy based on severity. *Diarrhoea* - **Diarrhoea** is a major focus of IMNCI as it causes significant dehydration and mortality in young children. - IMNCI includes protocols for assessing dehydration status, providing oral rehydration therapy (ORT), administering zinc supplementation, and managing persistent diarrhea and dysentery. *Malaria* - In malaria-endemic regions, **malaria** is integrated into IMNCI with guidelines for rapid diagnostic testing (RDTs) or clinical diagnosis based on fever patterns. - IMNCI helps healthcare workers quickly identify and treat uncomplicated malaria in children with appropriate antimalarials to reduce morbidity and mortality.
Question 10: Which micronutrient supplement should be administered during an acute episode of diarrhoea?
- A. Iron
- B. Copper
- C. Calcium
- D. Zinc (Correct Answer)
Explanation: ***Zinc*** - **Zinc supplementation** is recommended for acute diarrhea because it reduces the **duration** and **severity** of episodes. - Zinc helps in the **regeneration of the intestinal mucosa**, enhances immune function, and improves water and electrolyte absorption. *Iron* - Routine iron supplementation is **not recommended** during acute diarrhea, as excess iron can aggravate infections by providing nutrients for bacterial growth. - Iron can also cause **gastrointestinal upset**, which would worsen diarrhea symptoms. *Copper* - Copper is not indicated as a primary micronutrient supplement during acute diarrhea. - While essential, its role in mitigating acute diarrheal symptoms or recovery is **not established** like zinc. *Calcium* - Calcium supplementation is not a standard recommendation for the management of acute diarrhea. - While important for overall health, it does not directly impact the **duration** or **severity** of a diarrheal episode.
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