INI-CET 2026 Practice Questions

Q: Emotional tone and prosody of speech is primarily controlled by which brain region?

Cingulate gyrus. ***Cingulate gyrus*** - The **cingulate gyrus**, specifically the anterior portion, is deeply integrated into the **limbic system** and plays a crucial role in the processing of **emotional tone** and **affective prosody** during speech. - Damage to this region or the associated **medial frontal circuits** often results in **aprosodia** or difficulty in expressing or understanding the emotional content conveyed through vocal intonation and inflection. *Posterior superior temporal gyrus* - This region corresponds to **Wernicke's area**, which is primarily responsible for the **comprehension of language** and semantic processing rather than the emotional tone of speech. - Lesions here typically produce **receptive aphasia**, characterized by fluent but meaningless speech, rather than a deficit in affective prosody. *Posterior inferior parietal gyrus* - This area is typically associated with the **angular gyrus** and **supramarginal gyrus**, which are vital for **language processing**, reading, and integration of multisensory information. - It is not the primary center for modulating the emotional or prosodic inflection of speech. *Precentral gyrus* - The precentral gyrus serves as the **primary motor cortex**, responsible for the execution of voluntary motor movements, including the fine motor control of speech musculature (articulation). - While it allows for the physical production of words, it does not manage the underlying **emotional valence** or rhythm (prosody) of the communication.

Q: Reason for biphasic flow in right coronary artery?

Low pressure in right ventricle. ***Low pressure in right ventricle*** - The right coronary artery (RCA) supplies the right ventricle, which has a significantly lower wall pressure compared to the left ventricle, allowing for continuous myocardial perfusion throughout the cardiac cycle. - Because the **right ventricular (RV) systolic pressure** is low, mechanical compression of the coronary vessels is minimal during systole, resulting in a **biphasic flow pattern** with peaks in both systole and diastole. *Increased aortic pressure* - While higher aortic pressure generally increases coronary perfusion pressure across the entire heart, it does not specifically account for the unique **biphasic waveform** seen in the right coronary circulation. - The flow pattern is primarily determined by the **phasic intramyocardial pressure** variations rather than the absolute driving pressure provided by the aorta. *Increased right ventricular mass* - Hypertrophy of the right ventricle, such as in cases of **pulmonary hypertension**, would actually increase myocardial compressive forces and potentially attenuate or eliminate the systolic component of RCA flow. - Increased mass typically leads to higher localized resistance to flow, which would contradict the characteristic biphasic blood flow pattern observed in normal physiological states. *High pressure in right ventricle* - If the right ventricle were under high pressure, as seen in conditions like **pulmonary hypertension** or **pulmonary stenosis**, the RCA would experience profound systolic compression, often reducing or abolishing systolic flow. - High RV pressure would lead to a more **monophasic diastolic flow** pattern, similar to that observed in the left coronary artery, rather than the biphasic flow characteristic of low-pressure systems.

Q: Which adrenergic or muscarinic receptor subtype is coupled to the Gs protein?

Beta adrenergic receptor. ***Beta adrenergic receptor*** - The **beta-adrenergic receptors** (β1, β2, and β3) are classical G protein-coupled receptors that stimulate the enzyme **adenylyl cyclase** via the **Gs protein**. - Activation leads to an increase in intracellular **cyclic AMP (cAMP)**, resulting in physiological effects such as increased heart rate and bronchodilation. *M1 receptor* - This muscarinic receptor subtype is coupled to the **Gq protein**, which activates **phospholipase C**. - Its activation primarily leads to an increase in intracellular **calcium** and activation of **protein kinase C**. *M2 receptor* - The M2 muscarinic receptor is coupled to the **Gi protein**. - This leads to the **inhibition of adenylyl cyclase**, thereby decreasing levels of **cAMP** within the cell. *Alpha adrenergic receptor* - Alpha-1 receptors are coupled to the **Gq protein**, while alpha-2 receptors are coupled to the **Gi protein**. - Neither of these major alpha-receptor subtypes is linked to the **Gs protein** signaling pathway.

Q: Which sensory receptor generates a hyperpolarizing receptor potential upon stimulation?

Visual receptor (rods/cones). ***Visual receptor (rods/cones)*** - Unlike most sensory receptors that depolarize, light absorption by **photopigments** in photoreceptors activates a G-protein cascade (transducin) that closes **cGMP-gated sodium channels**. - This closure leads to a **reduction in cation influx** (sodium and calcium currents), resulting in **hyperpolarization** of the receptor membrane and a subsequent decrease in glutamate release. *Gustatory receptor* - Most taste receptors, such as those for **sweet, bitter, and umami**, utilize G-protein coupled receptors that trigger intracellular signaling cascades leading to **depolarization**. - Depolarization promotes the opening of voltage-gated calcium channels, triggering the release of neurotransmitters to sensory afferents. *Olfactory receptor* - Binding of odorants to G-protein coupled receptors (Golf) activates **adenylyl cyclase**, increasing cyclic AMP (cAMP) levels. - Increased cAMP opens cyclic-nucleotide-gated channels, allowing **influx of sodium and calcium**, which results in **depolarization** of the olfactory receptor neuron. *Auditory receptor* - Hair cells in the cochlea depolarize when stereocilia are bent toward the tallest stereocilium, causing **mechanically-gated ion channels** to open. - This cation influx (predominantly **potassium**) leads to **depolarization** of the hair cell membrane.

Q: Which cerebral lobe primarily governs hand-eye coordination?

Parietal. ### ***Parietal*** - The **parietal lobe** is the primary center for **visuospatial processing** and the integration of sensory information, commonly known as the **dorsal stream** or the 'where/how' pathway. - It processes inputs from the visual cortex and somatosensory cortex to guide **hand-eye coordination**, allowing for accurate reaching, grasping, and spatial manipulation of objects. *Frontal* - Primarily responsible for **executive functions**, planning, decision-making, and **voluntary motor control** processed via the motor cortex. - While it initiates movement, it relies on spatial-sensory data from the parietal cortex to refine the accuracy of movements like hand-eye coordination. *Occipital* - The **occipital lobe** is the primary visual processing center dedicated to **visual perception**, such as color, light, and orientation detection. - It merely identifies *what* is being seen, but it lacks the capacity to integrate this data with motor pathways for physical coordination. *Temporal* - Primarily involved in **auditory processing**, language comprehension, and long-term memory formation via the **ventral stream** or the 'what' pathway. - It is crucial for object recognition (e.g., naming an object) but does not play a significant role in guiding the spatial coordinates required for hand-eye coordination.

Q: Which structure in the nephron functions as the counter-current multiplier to help concentrate urine?

Thick ascending loop of Henle. ***Thick ascending loop of Henle*** - This segment actively reabsorbs **sodium, potassium, and chloride** via the **NKCC2 cotransporter** while being **impermeable to water**, which creates the high medullary interstitial osmolarity required for urine concentration. - The active transport of solutes in this segment provides the driving force for the **counter-current multiplier system**, allowing the kidney to produce urine that is hypertonic to plasma. *Thin ascending loop of Henle* - This segment is **passive** in its function, allowing for the diffusion of **sodium and chloride** along their concentration gradients due to the high osmolarity of the surrounding interstitium. - It does not actively transport solutes and therefore lacks the metabolic engine to

Q: Following a bolus administration of insulin, which of the following occurs?

Glucose uptake into muscle via GLUT 4. ***Glucose uptake into muscle via GLUT 4*** - Insulin stimulates the translocation of **GLUT 4** glucose transporters to the plasma membrane in **skeletal muscle** and adipose tissue cells. - This mechanism significantly increases cellular **glucose uptake** and utilization following a meal or an insulin bolus. *Glucose uptake into the liver via GLUT 4* - The liver does not express the **GLUT 4** transporter; it relies primarily on **GLUT 2** for glucose transport. - Hepatic glucose regulation is influenced by insulin but mediated through enzymatic pathways rather than transporter translocation. *Glucose uptake into muscle via GLUT 2* - **GLUT 2** is a high-capacity, insulin-independent transporter primarily found in the liver, pancreas, and intestine, not skeletal muscle. - Muscles utilize **GLUT 4**, which is the primary **insulin-sensitive** glucose transporter in these tissues. *Glucose uptake into the liver via GLUT 2* - While the liver does use **GLUT 2**, this transporter is **insulin-independent** and facilitates bidirectional glucose movement based on concentration gradients. - Although insulin affects hepatic glucose metabolism (e.g., via **glycogen synthase**), it does not control the *process of uptake* via GLUT 2 translocation.

Q: If a patient is on testosterone therapy, what changes can one see in LH and FSH levels?

Decreased LH, decreased FSH. ***Decreased LH, decreased FSH*** - Exogenous **testosterone** exerts strong **negative feedback** on the **hypothalamic-pituitary-gonadal (HPG) axis**. - This suppression leads to reduced secretion of **Gonadotropin-Releasing Hormone (GnRH)**, which subsequently lowers the release of both **Luteinizing Hormone (LH)** and **Follicle-Stimulating Hormone (FSH)** from the anterior pituitary. *Increased LH, decreased FSH* - **LH** levels would not increase because **testosterone** suppresses the pituitary's output of gonadotropins rather than stimulating it. - This pattern does not correspond to the physiological effect of testosterone administration on the feedback loop. *Decreased LH, increased FSH* - While **LH** would indeed decrease due to negative feedback, **FSH** would also be concurrently suppressed, not increased. - There is no mechanism in this context for isolated **FSH** increase while receiving androgen therapy. *Increased LH, increased FSH* - This pattern is characteristic of **primary hypogonadism**, where the testes fail to produce testosterone, thus removing the negative feedback on the pituitary. - With exogenous **testosterone** administration, the opposite effect occurs (suppression rather than elevation).

Q: During oral rehydration therapy in diarrhoea, which transporter is most active in promoting fluid absorption?

SGLT1. ***SGLT1*** - SGLT1 (Sodium-Glucose Linked Transporter 1) is a symporter that transports **glucose and sodium** across the apical membrane of the enterocyte, which creates an **osmotic gradient** driving massive water absorption. - This mechanism remains intact even during secretory diarrheas, forming the physiological basis for **Oral Rehydration Therapy (ORT)** effectiveness. *CFTR* - The CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) is a chloride channel responsible for **secreting chloride** ions into the intestinal lumen, which drives fluid secretion. - Its activity is often pathologically upregulated in diarrheal diseases like **cholera**, contributing to the loss of fluids and electrolytes rather than absorption. *NHE* - The NHE (Sodium-Hydrogen Exchanger) is a sodium transporter involved in neutral sodium absorption primarily in the **jejunum and ileum**. - While it contributes to normal sodium uptake, it is not the target mechanism exploited by ORT solutions containing glucose to maximally stimulate fluid uptake. *Na+-K+ ATPase* - Located on the **basolateral membrane**, this pump maintains the electrochemical gradient by pumping sodium out of the cell and potassium into it. - While essential for secondary active transport, it provides the low intracellular sodium concentration necessary for transporters to function but is not the apical gateway utilized for **glucose-coupled uptake**.

Question 1

Emotional tone and prosody of speech is primarily controlled by which brain region?

Accepted Answer

Cingulate gyrus

Answer

Posterior superior temporal gyrus

Answer

Posterior inferior parietal gyrus

Answer

Precentral gyrus

Question 2

Reason for biphasic flow in right coronary artery?

Accepted Answer

Low pressure in right ventricle

Answer

Increased aortic pressure

Answer

Increased right ventricular mass

Answer

High pressure in right ventricle

Question 3

Which adrenergic or muscarinic receptor subtype is coupled to the Gs protein?

Accepted Answer

Beta adrenergic receptor

Answer

Alpha adrenergic receptor

Answer

M1 receptor

Answer

M2 receptor

Question 4

In a graph of glomerular filterability vs. effective molecular radius, if X and Y are two molecules,
which statement is correct?

1. Y has more filterability than X
2. Y has more filterability than Z
3. X has less filterability than Y
4. X represents positively charged molecules

Accepted Answer

3 and 4

Answer

1 and 2

Answer

2 and 3

Answer

1 and 4

Question 5

Which sensory receptor generates a hyperpolarizing receptor potential upon stimulation?

Accepted Answer

Visual receptor (rods/cones)

Answer

Gustatory receptor

Answer

Olfactory receptor

Answer

Auditory receptor

Question 6

Which cerebral lobe primarily governs hand-eye coordination?

Accepted Answer

Parietal

Answer

Frontal

Answer

Occipital

Answer

Temporal

Question 7

Which structure in the nephron functions as the counter-current multiplier to help concentrate
urine?

Accepted Answer

Thick ascending loop of Henle

Answer

Thin ascending loop of Henle

Answer

Collecting duct

Answer

Vasa recta

Question 8

Following a bolus administration of insulin, which of the following occurs?

Accepted Answer

Glucose uptake into muscle via GLUT 4

Answer

Glucose uptake into the liver via GLUT 4

Answer

Glucose uptake into muscle via GLUT 2

Answer

Glucose uptake into the liver via GLUT 2

Question 9

If a patient is on testosterone therapy, what changes can one see in LH and FSH levels?

Accepted Answer

Decreased LH, decreased FSH

Answer

Increased LH, decreased FSH

Answer

Decreased LH, increased FSH

Answer

Increased LH, increased FSH

Question 10

During oral rehydration therapy in diarrhoea, which transporter is most active in promoting fluid
absorption?

Accepted Answer

SGLT1

Answer

CFTR

Answer

NHE

Answer

Na+-K+ ATPase

INI-CET 2026

Physiology