NEET-PG 2017 Practice Questions

Q: Which nerve marked as X innervates the Aortic Arch?

Aortic depressor nerve. ***Aortic depressor nerve*** - The nerve marked as X in the diagram directly innervates the **aortic baroreceptors** located in the aortic arch. - This nerve is also known as the **aortic depressor nerve**, a branch of the vagus nerve (CN X), which transmits sensory information about blood pressure from the aortic arch to the central nervous system. *Carotid sinus nerve* - The carotid sinus nerve (also known as Hering's nerve) innervates the **carotid sinus and carotid body**, which are located at the bifurcation of the common carotid artery. - This nerve transmits sensory information from the carotid baroreceptors and chemoreceptors, distinct from the aortic arch. *Inferior cervical cardiac nerve* - The inferior cervical cardiac nerve is a **sympathetic nerve** that originates from the inferior cervical ganglion and innervates the heart. - It does not primarily innervate the aortic arch baroreceptors; its function is related to cardiac rate and contractility. *Superior cervical cardiac nerve* - Similar to the inferior cervical cardiac nerve, the superior cervical cardiac nerve is a **sympathetic nerve** originating from the superior cervical ganglion. - It primarily contributes to the cardiac plexus and innervates the heart, not specifically the aortic arch baroreceptors.

Q: Which of the following is correct about the type of neuron shown below?

Pseudo-unipolar cell. ***Pseudo-unipolar cell*** - The image shows a neuron with a **single process** emerging from the cell body that then **divides into two branches** (one leading to dendrites and the other to the axon terminal), which is characteristic of a pseudo-unipolar neuron. - These neurons are typically found in **sensory ganglia**, such as the dorsal root ganglia, where they transmit sensory information. *Bipolar neuron* - A bipolar neuron has **two distinct processes** extending from the cell body: one axon and one dendrite. - Examples include neurons found in the **retina** and **olfactory epithelium**. *Unipolar cell* - A unipolar neuron has a **single process** extending from the cell body, which serves as both the dendrite and the axon. - These are typically found in **invertebrates**, though the term can sometimes be confusingly used for pseudo-unipolar neurons in some contexts. *All of the above* - This is incorrect because the neuron depicted specifically matches the morphology of a pseudo-unipolar cell, not all the listed types. - Each neuron type has distinct morphological features (number of poles/processes from the cell body).

Q: In the sarcomere diagram shown below, what do the marked areas X and Y represent?

X=H zone, Y=A band. ***X=H zone, Y=A band*** - **X** points to the central region of the A band, visible only in a relaxed sarcomere, which is called the **H zone**, containing only thick myosin filaments. - **Y** encompasses the entire length of the thick filaments, including the regions where they overlap with thin filaments, defining the **A band**. *X=A band, Y=H band* - This is incorrect because X specifically indicates the central, lighter region within the A band, which is the H zone. - Y points to the entire segment occupied by the thick filaments, which is the A band. *X=Z line, Y=M line* - The **Z line** marks the boundaries of a sarcomere, anchoring the thin (actin) filaments, and is not indicated by X. - The **M line** is the central line within the H zone that anchors the thick (myosin) filaments, and is not indicated by Y. *X=M line, Y=Z line* - As explained, X indicates the **H zone**, which is a broader region than the M line. - Y indicates the **A band**, and not the Z line; the Z line is located at the ends of the sarcomere.

Q: The following test is performed for evaluating the integrity of: (Recent NEET Pattern 2016-17)

Cerebellum. ***Cerebellum*** - The image depicts a person performing a **tandem gait** (walking heel-to-toe along a straight line), which is a common test for **cerebellar function**. - The cerebellum is critical for **coordination**, balance, and **fine motor control**, including the ability to maintain a straight path during walking. *Basal ganglia* - The basal ganglia are primarily involved in the **initiation and modulation of movement**, and their dysfunction leads to characteristic movement disorders such as **Parkinsonism (bradykinesia, rigidity, tremor)** or **Huntington's disease (chorea)**. - While gait can be affected in basal ganglia disorders (e.g., shuffling gait in Parkinson's), tandem gait specifically emphasizes balance and coordination more directly attributed to cerebellar function. *Corticospinal pathway* - The **corticospinal pathway** (pyramidal tract) is responsible for **voluntary, skilled movements**, particularly of the distal limbs. - Damage to this pathway typically results in **weakness (paresis)**, spasticity, and hyperreflexia, which would manifest as difficulty with initiating or executing movements rather than purely balance and coordination issues highlighted by tandem gait. *Spinothalamic pathway* - The spinothalamic pathway transmits **pain** and **temperature** sensations from the body to the brain. - Evaluating this pathway involves sensory testing (e.g., pinprick, hot/cold sensation), which is unrelated to the motor task of tandem walking.

Q: Which protein is responsible for the effect shown in RBC marked as $X$ ?

Band 3 protein. ***Band 3 protein*** - The image indicates that **X** facilitates the exchange of **bicarbonate (HCO₃⁻)** out of the red blood cell and **chloride (Cl⁻)** into the red blood cell, a process known as the **chloride shift** or **Hamburger phenomenon**. - This specific transporter is the **Band 3 anion exchanger 1 (AE1)**, also known as **Band 3 protein**, which is crucial for maintaining electrical neutrality during CO₂ transport. - **Band 3 protein** is the most abundant membrane protein in RBCs and accounts for approximately **25% of RBC membrane protein**. *Spectrin* - Spectrin is a **cytoskeletal protein** that forms a structural network on the inner surface of the RBC membrane. - It provides **mechanical stability and flexibility** to RBCs but does not participate in anion exchange. - Defects in spectrin cause hereditary spherocytosis and elliptocytosis. *Glycophorin* - Glycophorins are **surface glycoproteins** that carry many of the carbohydrate groups on the RBC surface. - They play roles in **membrane stability and blood group antigens** (MN blood group system). - They do not function as anion exchangers or transporters for bicarbonate/chloride. *Ankyrin* - Ankyrin is an **anchoring protein** that links the cytoskeletal protein spectrin to Band 3 protein. - It provides **structural support** and maintains membrane integrity but does not transport ions. - Ankyrin deficiency can cause hereditary spherocytosis.

Q: Identify the modality of intercellular communication shown below.

Paracrine. ***Paracrine*** - The image shows a **signaling cell** releasing **signaling molecules** (red dots) into the extracellular space, which then act on a nearby **target cell**. This local signaling is characteristic of paracrine communication. - In **paracrine signaling**, the molecules travel short distances through the interstitial fluid to influence neighboring cells, without entering the bloodstream. *Autocrine* - In **autocrine signaling**, a cell releases signaling molecules that then act on **receptors on the same cell** that produced them. The image clearly depicts communication between two different cells. - The signaling molecules are shown moving from one cell (signaling cell) to another distinct cell (target cell), rather than acting back on the originating cell. *Synaptic* - **Synaptic signaling** involves specialized structures called **synapses** where neurons transmit signals using **neurotransmitters** across a synaptic cleft to a target cell (another neuron, muscle cell, or gland cell). The image does not show a neuronal structure or a synapse. - This type of communication is highly specific to the nervous system and involves electrical impulses followed by chemical transmission, which is not represented here. *Gap junction* - **Gap junction communication** involves direct passage of signaling molecules between adjacent cells through specialized protein channels called **gap junctions**. - The image depicts signaling molecules being released into the extracellular space and binding to receptors on the target cell, rather than passing directly between the cytoplasms of two cells.

Q: Which of the following area of visual cortex is related to color vision?

V8. ***V8*** - **V8** is a specific area within the human **visual cortex** that has been implicated in **color perception**. - Damage to this area can lead to **cerebral achromatopsia**, a condition where individuals lose the ability to perceive colors. *V1* - **V1**, also known as the **primary visual cortex**, processes basic visual information such as orientation, spatial frequency, and color. - While it processes color information, it is not considered the primary or most specialized area for **color vision** compared to V8. *V2* - **V2** receives input from V1 and is involved in processing more complex visual features, including **form, depth, and color**. - It plays a role in color processing but is less specialized for this function than V8. *V3* - **V3** is primarily involved in processing **dynamic form** and motion, with some contribution to complex visual features. - It is not extensively associated with **color perception** as its main function.

Q: A head trauma patient is shown below. Diagnosis is?

Decerebrate rigidity. ***Decerebrate rigidity*** - The image shows **extension and internal rotation of the arms** with pronation, and **extension of the legs** with plantar flexion. This posture is characteristic of decerebrate rigidity. - This posturing indicates severe damage to the **brainstem**, specifically below the red nucleus, which is a more ominous sign than decorticate posturing. *Decorticate rigidity* - Decorticate rigidity would present with **flexion of the arms** at the elbows and wrists (to the core), adduction of the shoulders, and extension of the lower limbs. - This posturing is typically due to damage to the **corticospinal tracts above the red nucleus** (e.g., cerebral hemispheres, internal capsule, thalamus). *Acute dystonia* - Acute dystonia involves sustained or repetitive muscle contractions leading to **twisting and repetitive movements** or abnormal fixed postures. - It often affects specific muscle groups, such as the neck (torticollis), eyes (oculogyric crisis), or trunk, and is not typically a generalized rigidity pattern seen in head trauma as extensively as shown. *Catatonia* - Catatonia is a neuropsychiatric syndrome characterized by a variety of motor or behavioral abnormalities, including **immobility, mutism, stupor, waxy flexibility, and negativism**. - While it can involve abnormal posturing, it is a conscious state often associated with psychiatric conditions or general medical conditions, and doesn't manifest as the specific brainstem-related rigidity evident in the image.

Question 1

Which nerve marked as X innervates the Aortic Arch?

Accepted Answer

Aortic depressor nerve

Answer

Carotid sinus nerve

Answer

Inferior cervical cardiac nerve

Answer

Superior cervical cardiac nerve

Question 2

Which of the following is correct about the type of neuron shown below?

Accepted Answer

Pseudo-unipolar cell

Answer

Bipolar neuron

Answer

Unipolar cell

Answer

All of the above

Question 3

In the sarcomere diagram shown below, what do the marked areas X and Y represent?

Accepted Answer

X=H zone, Y=A band

Answer

X=A band, Y=H band

Answer

X=Z line, Y=M line

Answer

X=M line, Y=Z line

Question 4

Name the pathways marked as $X$ and $Y$.

Accepted Answer

$X=$ Ventral corticospinal pathway and $Y=$ Lateral corticospinal pathway

Answer

$X=$ Ventral corticospinal pathway and $Y=$ Lateral spinothalamic Pathway

Answer

$X=$ Ventral corticospinal pathway and $Y=$ Lateral spinocerebellar pathway

Answer

$X=$ Lateral corticospinal pathway and $Y=$ Ventral corticospinal pathway

Question 5

The following test is performed for evaluating the integrity of: (Recent NEET Pattern 2016-17)

Accepted Answer

Cerebellum

Answer

Basal ganglia

Answer

Corticospinal pathway

Answer

Spinothalamic pathway

Question 6

Which protein is responsible for the effect shown in RBC marked as $X$ ?

Accepted Answer

Band 3 protein

Answer

Spectrin

Answer

Glycophorin

Answer

Ankyrin

Question 7

Identify the modality of intercellular communication shown below.

Accepted Answer

Paracrine

Answer

Autocrine

Answer

Synaptic

Answer

Gap junction

Question 8

The following skeletal muscle recording shows presence of: (Recent NEET Pattern 2016-17)

Accepted Answer

A = Twitch, B = Summation, C = Incomplete tetanus, D = Complete tetanus

Answer

A = Summation, B = Twitch, C = Complete tetanus, D = Incomplete tetanus

Answer

A = Twitch, B = Incomplete tetanus, C = Summation, D = Complete tetanus

Answer

A = Incomplete tetanus, B = Complete tetanus, C = Twitch, D = Summation

Question 9

Which of the following area of visual cortex is related to color vision?

Accepted Answer

V8

Answer

V1

Answer

V2

Answer

V3

Question 10

A head trauma patient is shown below. Diagnosis is?

Accepted Answer

Decerebrate rigidity

Answer

Decorticate rigidity

Answer

Acute dystonia

Answer

Catatonia

NEET-PG 2017

Anatomy

Internal Medicine

Physiology

Surgery