NEET-PG 2015 Practice Questions

Q: Which tract is responsible for the ventral tegmental decussation in the cerebral peduncle?

Rubrospinal tract. The rubrospinal tract originates in the red nucleus and decussates in the ventral tegmental decussation at the level of the midbrain, before descending to the spinal cord. This decussation is the characteristic feature that distinguishes it from other descending tracts. It primarily modulates flexor muscle tone and fine motor control of distal limb muscles. The tectospinal tract originates in the superior colliculus and decussates immediately as the dorsal tegmental decussation, involved in coordinating head and eye movements in response to stimuli. The vestibulospinal tract originates in the vestibular nuclei and descends ipsilaterally and contralaterally [1], but it does not form a distinct ventral tegmental decussation in the cerebral peduncle. It is crucial for maintaining posture and balance by influencing extensor muscles [1]. The tectobulbar tract arises from the superior colliculus and projects to cranial nerve nuclei, but it does not undergo the specific ventral tegmental decussation.

Q: Fossa ovalis is a remnant of -

Septum primum. ***Septum primum*** - The **fossa ovalis** is a depression in the right atrium that represents the sealed-off foramen ovale [2]. - It is formed from the **septum primum**, which becomes the floor of the fossa ovalis. *Septum secundum* - The **septum secundum** forms the limbus or rim of the fossa ovalis, not the fossa itself. - This structure develops later than the septum primum and partially covers the foramen ovale during fetal development [2]. *Septum spurium* - The **septum spurium** is an embryonic ridge in the right atrium that typically regresses during development and does not contribute to the fossa ovalis. - It is a transient structure formed by the confluence of the right and left venous valves. *AV cushion* - The **atrioventricular (AV) cushions** contribute to the formation of the AV valves and the atrial and ventricular septa, but not directly to the fossa ovalis [1]. - They are crucial for separating the atria from the ventricles and forming the mitral and tricuspid valves.

Q: Which of the following statements about fallopian tubes is incorrect?

Lined by cuboidal epithelium. ***Lined by cuboidal epithelium*** - The Fallopian tubes are lined by a **ciliated columnar epithelium**, not cuboidal epithelium, which aids in ovum transport. - This ciliated epithelium is critical for moving the ovum towards the uterus and for sperm transport. *Tubal ostium is the point where the tubal canal meets the peritoneal cavity* - The **tubal ostium** specifically refers to the opening of the **infundibulum** of the Fallopian tube into the **peritoneal cavity**, where it receives the ovum after ovulation. - This opening is surrounded by **fimbriae**, which are finger-like projections that help capture the ovum. *Müllerian ducts develop in females into the Fallopian tubes* - In females, the **Müllerian ducts (paramesonephric ducts)** differentiate to form the **Fallopian tubes**, uterus, cervix, and the upper two-thirds of the vagina. - This development is crucial for the formation of the female reproductive tract in the absence of Anti-Müllerian Hormone (AMH). *Isthmus is the narrower part of the tube that links to the uterus* - The **isthmus** is indeed the **narrower, muscular segment** of the Fallopian tube that connects directly to the **uterus**. - This region is characterized by its thick muscular wall and smaller lumen.

Q: Lining epithelium of vagina is

Squamous epithelium. Squamous epithelium * The vagina is lined by stratified squamous non-keratinized epithelium [1], providing a protective barrier against friction and pathogens. * This type of epithelium is well-suited for areas subject to significant mechanical stress, such as during intercourse and childbirth. Columnar epithelium * Columnar epithelium [2] is typically found in areas specialized for secretion and absorption, such as the gastrointestinal tract and glandular linings. * It would not offer the necessary protective qualities for the vaginal environment. Transitional epithelium * Transitional epithelium is a specialized stratified epithelium found in the urinary tract, capable of stretching and distending. * It is not found in the vagina, which requires a more robust, friction-resistant lining. Secretory epithelium * While the cervix has secretory glands, the lining of the vagina itself is not primarily secretory. * The primary role of the vaginal lining is protection, not secretion, and its cells do not typically produce a large amount of substances.

Q: Oxyntic cells are present in -

Body. ***Body*** - **Oxyntic cells**, also known as **parietal cells**, are predominantly located in the **fundus and body** of the stomach [1], [2]. - These cells are responsible for secreting **hydrochloric acid (HCl)** and **intrinsic factor**, which are crucial for digestion and vitamin B12 absorption [1]. - The gastric glands in the body contain the highest concentration of parietal cells [2]. *Pylorus* - The pylorus is the distal part of the stomach that connects to the duodenum. - It primarily contains **G cells**, which secrete **gastrin**, a hormone that stimulates HCl secretion from parietal cells [3]. - Pyloric glands contain mainly mucus-secreting cells, with few or no parietal cells [2]. *Cardia* - The cardia is the region near the gastroesophageal junction (entrance of the stomach). - This area primarily contains **cardiac glands** with mucus-secreting cells that protect the esophageal lining from gastric acid reflux. - Parietal cells are sparse or absent in the cardia [2]. *None of the options* - This option is incorrect because the **body of the stomach** is the correct location for oxyntic cells.

Q: Which is the first bone to start ossifying?

Clavicle. ***Clavicle*** - The **clavicle** is the **first bone to begin ossification** in the human body, starting around the **5th-6th week of gestation**. - It ossifies via **intramembranous ossification**, making it unique among long bones [1]. - This early ossification is a key landmark in fetal skeletal development and is consistently taught across medical curricula. *Mandible* - The **mandible** begins ossification around the **6th week of gestation**, shortly after the clavicle [1]. - While it is one of the earliest bones to ossify, it is **not the first**. - It also undergoes intramembranous ossification [1]. *Femur* - The **femur**, a long bone, begins ossification around the **7th-8th week of gestation** [1]. - It ossifies via **endochondral ossification**, which typically occurs later than intramembranous ossification [1]. *Tibia* - The **tibia** also begins ossification around the **7th-8th week of gestation**. - Like the femur, it follows the endochondral ossification pathway.

Q: Uvula vesicae seen in bladder is formed from the following structure?

Median lobe of the prostate. ***Median lobe of the prostate*** - The **uvula vesicae** is a slight median elevation on the internal surface of the **bladder base**, immediately behind the **internal urethral orifice**. - This elevation is formed by the underlying **median (middle) lobe of the prostate** projecting upward beneath the bladder mucosa. - In **benign prostatic hyperplasia (BPH)**, enlargement of the median lobe accentuates this prominence and can cause significant urinary obstruction. *Lateral lobe of the prostate* - Enlargement of the **lateral lobes** causes lateral compression of the prostatic urethra, not a median elevation at the bladder neck. - While they are the most common site of **BPH**, they do not form the uvula vesicae. *Anterior lobe of the prostate* - The **anterior lobe** (or anterior fibromuscular stroma) is located in front of the urethra and is non-glandular. - It does not contribute to the formation of the uvula vesicae or cause significant urinary symptoms. *Posterior lobe of the prostate* - The **posterior lobe** is located behind the urethra and is the most common site for **prostate cancer**. - It does not project into the bladder base and therefore does not form the uvula vesicae.

Q: Sensory nerve supply of gall bladder is through -

Vagus nerve (Cranial Nerve X). ***Vagus nerve (Cranial Nerve X)*** - The **vagus nerve** provides the primary **sensory (visceral afferent) innervation** to the gallbladder, carrying information about distension, contraction, and physiological state. - These **parasympathetic sensory fibers** travel through the vagus nerve to medullary centers, monitoring gallbladder function and participating in reflex arcs. - The vagus nerve is the main pathway for **general sensory innervation** of the gallbladder as per standard anatomical texts. *Celiac plexus (sympathetic fibers)* - The **celiac plexus** contains **sympathetic afferent fibers** that primarily transmit **pain sensation** from the gallbladder, especially during inflammation or biliary colic [1]. - These pain fibers travel via sympathetic pathways to spinal segments **T8-T9**, mediating referred pain to the epigastric region and right upper quadrant [1]. - While important for pain transmission, the celiac plexus is not classified as the primary sensory nerve supply in anatomical nomenclature. *Trigeminal nerve (Cranial Nerve V)* - The **trigeminal nerve** provides **sensory innervation to the face** and motor innervation to muscles of mastication. - It has no role in innervation of abdominal viscera, including the gallbladder. *Facial nerve (Cranial Nerve VII)* - The **facial nerve** controls **facial expression muscles**, provides taste sensation to the anterior two-thirds of the tongue, and supplies parasympathetic fibers to lacrimal and salivary glands. - It does not innervate any abdominal organs.

Q: Which structure forms the lateral border of the ischiorectal fossa?

Obturator internus muscle. ***Obturator internus muscle*** - The **ischiorectal fossa** (also known as the **ischioanal fossa**) is a wedge-shaped space in the perineum, and its lateral wall is formed by the **obturator internus muscle** and its covering fascia [1]. - This muscle originates from the inner surface of the **obturator membrane** and the surrounding bone, descending through the lesser sciatic foramen to insert on the greater trochanter of the femur. *Perineal membrane* - The **perineal membrane** is a dense fibrous sheet that forms the inferior boundary of the **deep perineal pouch**. - It does not form a lateral border of the ischiorectal fossa but rather contributes to the floor of the **urogenital triangle**, anterior to the fossa. *Gluteus maximus* - The **gluteus maximus** is a large muscle of the buttock, primarily involved in extension and lateral rotation of the hip. - It lies superficial to the structures of the perineum and therefore does not form a boundary of the **ischiorectal fossa**. *Sacrotuberous ligament* - The **sacrotuberous ligament** is a strong fibrous band connecting the sacrum to the ischial tuberosity. - While it helps to define the boundaries of the **perineum** posteriorly and contributes to the stability of the **sacroiliac joint**, it does not form the lateral wall of the **ischiorectal fossa**.

Q: Which of the following statements about the first part of the duodenum is false?

Supplied by the superior mesenteric artery. ***Supplied by the superior mesenteric artery*** - The first part of the duodenum, derived from the **foregut**, receives its blood supply from the **gastroduodenal artery**, a branch of the celiac artery [1], [2]. - The **superior mesenteric artery** primarily supplies the **midgut** derivatives, which include the distal half of the duodenum and onward [2]. *5 cm long* - The first part of the duodenum is indeed the **shortest** and widest section, typically measuring about **5 cm (2 inches)** in length. - This length allows it to course from the pylorus to the inferior border of the L1 vertebra. *Is superior part* - This statement is correct as the first part courses **superiorly** and then posteriorly, crossing the right crus of the diaphragm. - It lies at the level of the **L1 vertebra**. *Develops from foregut* - The first part of the duodenum, along with the other upper gastrointestinal structures (stomach, liver, pancreas), indeed develops from the **embryonic foregut** [1]. - The transition from foregut to midgut occurs at the level of the **major duodenal papilla**.

Question 1

Which tract is responsible for the ventral tegmental decussation in the cerebral peduncle?

Accepted Answer

Rubrospinal tract

Answer

Tectospinal tract

Answer

Vestibulospinal tract

Answer

Tectobulbar tract

Question 2

Fossa ovalis is a remnant of -

Accepted Answer

Septum primum

Answer

Septum secundum

Answer

Septum spurium

Answer

AV cushion

Question 3

Which of the following statements about fallopian tubes is incorrect?

Accepted Answer

Lined by cuboidal epithelium

Answer

Tubal ostium is the point where the tubal canal meets the peritoneal cavity

Answer

Müllerian ducts develop in females into the Fallopian tubes

Answer

Isthmus is the narrower part of the tube that links to the uterus

Question 4

Lining epithelium of vagina is

Accepted Answer

Squamous epithelium

Answer

Columnar epithelium

Answer

Transitional epithelium

Answer

Secretory epithelium

Question 5

Oxyntic cells are present in -

Accepted Answer

Body

Answer

Pylorus

Answer

Cardia

Answer

None of the options

Question 6

Which is the first bone to start ossifying?

Accepted Answer

Clavicle

Answer

Femur

Answer

Tibia

Answer

Mandible

Question 7

Uvula vesicae seen in bladder is formed from the following structure?

Accepted Answer

Median lobe of the prostate

Answer

Lateral lobe of the prostate

Answer

Anterior lobe of the prostate

Answer

Posterior lobe of the prostate

Question 8

Sensory nerve supply of gall bladder is through -

Accepted Answer

Vagus nerve (Cranial Nerve X)

Answer

Celiac plexus (sympathetic fibers)

Answer

Trigeminal nerve (Cranial Nerve V)

Answer

Facial nerve (Cranial Nerve VII)

Question 9

Which structure forms the lateral border of the ischiorectal fossa?

Accepted Answer

Obturator internus muscle

Answer

Perineal membrane

Answer

Gluteus maximus

Answer

Sacrotuberous ligament

Question 10

Which of the following statements about the first part of the duodenum is false?

Accepted Answer

Supplied by the superior mesenteric artery

Answer

5 cm long

Answer

Is superior part

Answer

Develops from foregut

NEET-PG 2015

Anatomy