NEET-PG 2015 Practice Questions

Q: Which of the following statements about the adductors of the thigh is correct?

Adductor brevis is the shortest adductor muscle. ***Adductor brevis is the shortest adductor muscle*** - The **adductor brevis** is the shortest muscle among the adductor group in the thigh. - The three main adductors by size: **adductor magnus** (longest and largest) > **adductor longus** (intermediate) > **adductor brevis** (shortest). - Adductor brevis lies deep to pectineus and adductor longus, and plays a key role in **thigh adduction**. *The ischial head of adductor magnus is not an adductor muscle.* - The **ischial/hamstring part of adductor magnus** does contribute to adduction despite its primary action being hip extension like other hamstrings. - It also acts on the **hip joint** to extend the thigh, but its adductor action is functionally important. *The main blood supply to the adductors is from the profunda femoris artery.* - While the **profunda femoris artery (deep femoral artery)** supplies the posterior and lateral compartments of the thigh, the adductors primarily receive blood from the **obturator artery** and branches of the femoral artery. - The **obturator artery** is specifically known for supplying the adductor muscles of the medial compartment. *The adductor magnus is the largest muscle in the thigh.* - The **adductor magnus** is the largest muscle in the adductor group, but not the largest muscle in the entire thigh. - The **quadriceps femoris group** (vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) collectively forms the largest muscle mass in the thigh.

Q: Which of the following is a tributary of the coronary sinus?

Great cardiac vein. ***Great cardiac vein*** - The **great cardiac vein** is a major tributary that drains into the **coronary sinus**, carrying deoxygenated blood from the anterior and left ventricular walls [1]. - It travels alongside the **anterior interventricular artery** (LAD) and then wraps around the left side of the heart to join the coronary sinus [1]. *Anterior cardiac vein* - The **anterior cardiac veins** typically collect blood directly into the **right atrium**, bypassing the coronary sinus [1]. - They primarily drain the anterior wall of the right ventricle. *Thebesian vein* - **Thebesian veins** (or venae cordis minimae) are small veins that drain blood from the **myocardium directly into the heart chambers**, predominantly the atria [1]. - They represent a direct communication between the myocardial capillaries and the heart chambers, not tributaries of the coronary sinus. *Smallest cardiac vein* - The term "smallest cardiac vein" is often used synonymously with **Thebesian veins** [1]. - These veins empty directly into the **heart chambers**, serving as an ancillary drainage system, rather than converging into the coronary sinus.

Q: Which of the following structures is located within the cavernous sinus?

Internal carotid artery. ***Internal carotid artery*** - The **internal carotid artery** passes **through the lumen** of the cavernous sinus, which is a dural venous sinus located on either side of the sella turcica. - Along with the **abducens nerve (CN VI)**, the internal carotid artery is one of only two structures that passes directly through the cavernous sinus cavity itself. - This is the **most accurate answer** as it traverses the actual sinus space, not just the wall. *Maxillary division of V nerve* - The **maxillary division of the trigeminal nerve (V2)** runs within the **lateral wall** of the cavernous sinus, not through its lumen. - While technically "within" the sinus structure, it is embedded in the dural wall rather than passing through the blood-filled cavity. - This nerve exits the skull through the **foramen rotundum**. - Other nerves in the lateral wall include **CN III, CN IV, and V1**. *Mandibular division of V nerve* - The **mandibular division of the trigeminal nerve (V3)** does not pass through or near the cavernous sinus. - It exits the middle cranial fossa directly via the **foramen ovale**, positioned inferior and separate from the cavernous sinus. - V3 is the only division of the trigeminal nerve that does not have any relationship with the cavernous sinus. *Facial nerve* - The **facial nerve (CN VII)** has no anatomical relationship with the cavernous sinus. - It enters the temporal bone through the **internal acoustic meatus**, travels through the facial canal, and exits via the **stylomastoid foramen**. - Its course is entirely separate from the cavernous sinus region.

Q: Which structure(s) passes behind the inguinal ligament:

All of the options. ***Correct: All of the options*** All three structures pass deep to (behind) the inguinal ligament as they transition from the pelvis/abdomen into the thigh [1]. The inguinal ligament forms the superior border of the femoral triangle [1]. ***Femoral branch of genitofemoral nerve (Correct)*** - Pierces the **psoas major** muscle and descends along its anterior surface - Passes through the **lacuna musculorum** (lateral compartment) deep to the inguinal ligament - Lies **lateral to the femoral artery** - Provides sensory innervation to the skin over the femoral triangle ***Femoral vein (Correct)*** - Continuation of the popliteal vein from the lower limb - Passes through the **lacuna vasorum** (medial compartment/femoral canal) within the **femoral sheath** - Located **medial to the femoral artery** behind the inguinal ligament [1] - Carries deoxygenated blood back to the heart via the external iliac vein ***Psoas major (Correct)*** - Major hip flexor muscle originating from lumbar vertebrae (T12-L5) - Passes through the **lacuna musculorum** deep to the inguinal ligament - Located **lateral to the femoral vessels** - Combines with iliacus to form iliopsoas, inserting on the lesser trochanter of femur

Q: Which of the following enzymes is not part of the fatty acid synthase complex?

Acetyl-CoA carboxylase. ***Acetyl-CoA carboxylase*** - **Acetyl-CoA carboxylase (ACC)** is a crucial enzyme in fatty acid synthesis, catalyzing the committed and rate-limiting step of converting **acetyl-CoA to malonyl-CoA**. - While essential for providing the substrates for fatty acid synthase, ACC is a **separate, distinct enzyme** and not structurally part of the fatty acid synthase complex itself. *Ketoacyl reductase* - **Ketoacyl reductase** is an integral enzymatic domain of the fatty acid synthase complex. - It catalyzes the **first reduction step** in the fatty acid synthesis cycle, converting a $\beta$-ketoacyl group to a $\beta$-hydroxyacyl group using NADPH. *Enoyl reductase* - **Enoyl reductase** is an intrinsic enzymatic domain of the fatty acid synthase complex. - It catalyzes the **second reduction step**, converting a trans- $\alpha$, $\beta$-enoyl group to a saturated acyl group using NADPH. *Ketoacyl synthase* - **Ketoacyl synthase (or $\beta$-ketoacyl-ACP synthase)** is a core enzymatic domain within the fatty acid synthase complex. - It catalyzes the **condensation reaction** between the growing acyl chain and malonyl-ACP, forming a $\beta$-ketoacyl-ACP.

Q: Epulis arises from -

Gingiva. ***Gingiva*** - **Epulis** refers to a localized, tumor-like enlargement of the **gingiva** (gum tissue). - These lesions are typically inflammatory or reactive in nature, arising from the connective tissue of the gum. *Enamel* - **Enamel** is the hard, outermost protective layer of the tooth crown, which is of ectodermal origin. - Lesions originating from enamel itself are rare and typically involve developmental defects or structural damage, not soft tissue growths like epulis. *Root of teeth* - The **root of the teeth** is embedded in the alveolar bone and covered by cementum, with the surrounding structures including the periodontal ligament and alveolar bone. - While infections or cysts can arise from the root, epulis specifically describes a growth of the overlying **gingival tissue**. *Pulp* - The **pulp** is the soft tissue inside the tooth containing nerves, blood vessels, and connective tissue. - Pathologies originating from the pulp are typically infectious (pulpitis), degenerative, or involve growth of odontogenic tissues (e.g., pulp polyps within the tooth chamber), not surface gingival lesions.

Q: Phrynoderma is primarily associated with a deficiency of which of the following?

Vitamin A. ***Vitamin A*** - **Phrynoderma** (toad skin) has been **classically attributed to vitamin A deficiency** in traditional medical literature and was the accepted answer in historical examinations. - It presents as **follicular hyperkeratosis** with dry, scaly, rough skin having prominent hair follicles with a sandpaper-like texture. - However, **modern evidence** suggests phrynoderma is a **multifactorial condition** often involving **multiple nutritional deficiencies**, with vitamin A being one important contributor among others. *Essential fatty acid* - Deficiency of **essential fatty acids** (linoleic and alpha-linolenic acid) causes **skin dryness, flakiness, and follicular hyperkeratosis**. - **Recent studies** indicate EFA deficiency may play a **significant role** in phrynoderma, particularly in developing countries where multiple nutritional deficiencies coexist. - The clinical presentation can closely mimic vitamin A deficiency-related skin changes. *Vitamin D* - Deficiency of **vitamin D** primarily causes **rickets** in children and **osteomalacia** in adults with bone pain, muscle weakness, and skeletal deformities. - While vitamin D has roles in skin health, its deficiency does not directly cause the follicular hyperkeratosis characteristic of phrynoderma. *Niacin* - **Niacin (vitamin B3)** deficiency causes **pellagra** with the classic \"3 Ds\": **dermatitis, diarrhea, and dementia**. - Pellagra dermatitis is typically **symmetrical in sun-exposed areas** with redness, scaling, and hyperpigmentation—distinctly different from the follicular pattern of phrynoderma.

Q: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Granulomatous uveitis. ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms.

Q: Which of the following is not found in DiGeorge's syndrome?

Eczema. ***Eczema*** - **Eczema** is NOT a recognized feature of **DiGeorge syndrome** (22q11.2 deletion syndrome). - While individuals with immunodeficiencies may experience various skin conditions, eczema is specifically associated with conditions like **Hyper-IgE syndrome, Wiskott-Aldrich syndrome**, or atopic disorders, not DiGeorge's. - DiGeorge's follows the **CATCH-22 mnemonic**: Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, Hypocalcemia, 22q11 deletion. *Tetany* - **Tetany IS found** in DiGeorge's syndrome due to **hypocalcemia** from parathyroid gland hypoplasia or aplasia. - The lack of parathyroid hormone leads to **low serum calcium levels**, resulting in increased neuromuscular excitability and tetany. *T cell lymphopenia* - **T-cell lymphopenia IS found** in DiGeorge's syndrome due to **thymic hypoplasia or aplasia**. - The primary immunological defect is **T-cell deficiency**, leading to increased susceptibility to viral, fungal, and intracellular bacterial infections. - B-cell numbers are typically normal, though antibody responses may be impaired due to lack of T-cell help. *Mucocutaneous candidiasis* - **This IS found** in patients with DiGeorge's syndrome as an opportunistic infection due to **T-cell immunodeficiency**. - The impaired **cellular immunity** makes individuals highly susceptible to fungal infections like *Candida albicans* affecting mucous membranes and skin.

Q: Which dopamine receptor is known for its inhibitory action in the central nervous system?

Dopamine Receptor D2. ***Dopamine Receptor D2*** - The **D2 receptor** is a member of the D2-like family (D2, D3, D4), which are **G-protein coupled receptors** that inhibit adenylyl cyclase activity. - Its activation typically leads to a **decrease in neuronal excitability** and neurotransmitter release, providing an inhibitory effect in the CNS. *Dopamine Receptor D5* - The **D5 receptor** belongs to the D1-like family (D1, D5), which are **G-protein coupled receptors** that stimulate adenylyl cyclase activity. - Activation of D5 receptors typically leads to **excitatory effects** rather than inhibitory ones in the CNS. *No inhibitory dopamine receptor present* - This statement is incorrect as specific dopamine receptor subtypes, particularly the **D2-like family**, are well-established to exert inhibitory actions in the CNS. - These inhibitory effects are crucial for various physiological processes, including motor control and reward pathways. *Dopamine Receptor D1* - The **D1 receptor** is part of the D1-like family (D1, D5) and is known for its **excitatory effects** in the CNS. - Activation of D1 receptors leads to an **increase in intracellular cAMP** and generally enhances neuronal activity.

Question 1

Which of the following statements about the adductors of the thigh is correct?

Accepted Answer

Adductor brevis is the shortest adductor muscle

Answer

The main blood supply to the adductors is from the profunda femoris artery.

Answer

The ischial head of adductor magnus is not an adductor muscle.

Answer

The adductor magnus is the largest muscle in the thigh.

Question 2

Which of the following is a tributary of the coronary sinus?

Accepted Answer

Great cardiac vein

Answer

Anterior cardiac vein

Answer

Smallest cardiac vein

Answer

Thebesian vein

Question 3

Which of the following structures is located within the cavernous sinus?

Accepted Answer

Internal carotid artery

Answer

Maxillary division of V nerve

Answer

Mandibular division of V nerve

Answer

Facial nerve

Question 4

Which structure(s) passes behind the inguinal ligament:

Accepted Answer

All of the options

Answer

Femoral branch of genitofemoral nerve

Answer

Femoral vein

Answer

Psoas major

Question 5

Which of the following enzymes is not part of the fatty acid synthase complex?

Accepted Answer

Acetyl-CoA carboxylase

Answer

Enoyl reductase

Answer

Ketoacyl synthase

Answer

Ketoacyl reductase

Question 6

Epulis arises from -

Accepted Answer

Gingiva

Answer

Enamel

Answer

Root of teeth

Answer

Pulp

Question 7

Phrynoderma is primarily associated with a deficiency of which of the following?

Accepted Answer

Vitamin A

Answer

Essential fatty acid

Answer

Vitamin D

Answer

Niacin

Question 8

Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Accepted Answer

Granulomatous uveitis

Answer

Hemorrhagic uveitis

Answer

Old healed uveitis

Answer

Acute anterior uveitis

Question 9

Which of the following is not found in DiGeorge's syndrome?

Accepted Answer

Eczema

Answer

Tetany

Answer

T cell lymphopenia

Answer

Mucocutaneous candidiasis

Question 10

Which dopamine receptor is known for its inhibitory action in the central nervous system?

Accepted Answer

Dopamine Receptor D2

Answer

Dopamine Receptor D5

Answer

No inhibitory dopamine receptor present

Answer

Dopamine Receptor D1

NEET-PG 2015

Anatomy

Biochemistry

Dental

Dermatology

Ophthalmology

Pediatrics

Pharmacology