NEET-PG 2015 Practice Questions

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: What structures are derived from the neural crest?

All of the options. ***All of the options*** - The **neural crest** is a multipotent, migratory cell population that contributes to the formation of many diverse tissues and organs during vertebrate development. - Neural crest cells give rise to a wide array of derivatives, including components of the nervous system, pigment cells, skeletal and connective tissues of the head and face, and endocrine glands [1]. *Melanocytes* - **Melanocytes**, the pigment-producing cells found in the skin, hair, eyes, and other tissues, are derived from the **neural crest** [2]. - These cells migrate extensively during development from the neural crest to their final destinations throughout the body. - Neural crest-derived melanocytes produce melanin, which provides pigmentation and protection against UV radiation [2]. *Dental papillae* - The **dental papilla** is crucial for tooth development and is formed from **ectomesenchymal cells** that are derived from the cranial neural crest. - These cells differentiate into the odontoblasts that produce dentin and also contribute to the pulp of the tooth. *Adrenal medulla* - The cells of the **adrenal medulla**, which produce catecholamines like epinephrine and norepinephrine, are specialized **postganglionic sympathetic neurons** derived from the neural crest. - They develop from neuroectodermal cells that migrate to the developing adrenal gland.

Q: Shortest part of male urethra is :

Membranous. ***Membranous*** - The **membranous urethra** is the shortest and narrowest part of the male urethra, passing through the **deep perineal pouch**. - Its short length makes it particularly vulnerable to injury during trauma to the pelvis [1]. *Prostatic* - The **prostatic urethra** is approximately 3-4 cm long and runs through the prostate gland. - It is one of the longer segments of the male urethra and drains the ejaculatory ducts. *Bulbar* - The **bulbar urethra** is a segment of the spongy (penile) urethra, located within the bulb of the penis [1]. - It is generally longer than the membranous part and wider distally. *Penile* - The **penile urethra**, also known as the spongy urethra, is the longest part of the male urethra, extending through the corpus spongiosum of the penis. - It measures around 15 cm and expands at its distal end to form the navicular fossa.

Q: Which is the largest nerve that exits the pelvis through the greater sciatic foramen?

Sciatic nerve. ***Sciatic nerve*** - The **sciatic nerve** is the largest nerve in the human body, formed from the sacral plexus, and it is indeed the largest structure that passes through the **greater sciatic foramen** as it descends into the posterior thigh. - It supplies motor and sensory innervation to the posterior thigh, lower leg, and foot. *Superior gluteal artery* - The superior gluteal artery exits the pelvis through the **greater sciatic foramen** above the piriformis muscle. - While significant, it is an artery and not a nerve, and it is not the largest structure passing through this foramen. *Inferior gluteal artery* - The inferior gluteal artery also exits the pelvis via the **greater sciatic foramen**, inferior to the piriformis muscle. - Like the superior gluteal artery, it is an arterial structure and not a nerve, and it is not the largest structure in the foramen. *Piriformis muscle* - The **piriformis muscle** originates inside the pelvis and passes through the **greater sciatic foramen** to insert on the greater trochanter of the femur. - Although it occupies a significant portion of the foramen, it is a muscle, not a nerve, and the sciatic nerve is the largest nerve exiting this aperture.

Q: Fibrous stroma of liver is derived from -

Mesoderm from the septum transversum. ***Mesoderm from the septum transversum*** - The **fibrous stroma of the liver**, which provides its structural framework, develops from the **mesoderm** of the **septum transversum** [1]. - The septum transversum is a thick mass of mesoderm that contributes to the formation of the **diaphragm** and the connective tissue elements of the liver [1]. *Endoderm from the foregut* - While the **parenchymal cells (hepatocytes)** of the liver are derived from the **endoderm of the foregut**, this tissue forms the functional units, not the fibrous supporting stroma. - The endoderm forms the glandular tissue, while the mesoderm forms the connective tissue [1]. *Endoderm from the midgut* - The midgut endoderm gives rise to structures like the **small intestine**, cecum, appendix, ascending colon, and part of the transverse colon, but not the liver's stroma [2]. - Its primary role is in forming the epithelial lining of these digestive organs. *Endoderm from the hindgut* - The hindgut endoderm develops into the distal third of the transverse colon, descending colon, sigmoid colon, rectum, and superior part of the anal canal, - It plays no role in the development of the liver's fibrous stroma.

Q: Inferior pancreaticoduodenal artery is a branch of which of the following arteries?

Superior mesenteric artery. ***Superior mesenteric artery*** - The **inferior pancreaticoduodenal artery** is a direct branch of the **superior mesenteric artery (SMA)**. - It supplies the **head of the pancreas** and the **duodenum**, anastomosing with branches from the gastroduodenal artery. *Splenic artery* - The splenic artery is a branch of the **celiac trunk** and primarily supplies the **spleen**, stomach, and pancreas (via pancreatic branches). - It does not give rise to the inferior pancreaticoduodenal artery. *Left gastric artery* - The left gastric artery is a branch of the **celiac trunk** and supplies the **lesser curvature of the stomach** and distal esophagus. - It has no direct connection to the inferior pancreaticoduodenal artery. *Gastroduodenal artery* - The gastroduodenal artery is a branch of the **common hepatic artery** (from the celiac trunk) and gives off the **anterior and posterior superior pancreaticoduodenal arteries**. - While it supplies the head of the pancreas and duodenum, it is not the origin of the inferior pancreaticoduodenal artery, which arises from the SMA.

Q: Nephron is derived from ?

Metanephros. ***Metanephros*** - The **metanephric mesenchyme**, also known as the **metanephros**, gives rise to the excretory units of the kidney, which are the nephrons. - This mesenchymal tissue differentiates to form the **glomerulus**, Bowman's capsule, proximal and distal convoluted tubules, and the loop of Henle. *Ureteric bud* - The **ureteric bud** originates from the mesonephric duct and forms the collecting system of the kidney, including the ureter, renal pelvis, calyces, and collecting ducts. - It induces the differentiation of the metanephric mesenchyme but does not directly form the nephron itself. *Mesonephric duct* - The **mesonephric duct** (Wolffian duct) is a primitive embryonic structure that gives rise to the ureteric bud and parts of the male reproductive system. - It does not directly form any part of the nephron. *Mesonephros* - The **mesonephros** is a transient embryonic kidney that functions briefly during fetal development. - It degenerates and does not contribute to the formation of the definitive nephrons in the mature kidney.

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 is true about branchial cysts?

They mostly arise from the second branchial cleft.. ***They mostly arise from the second branchial cleft.*** - **Second branchial cleft cysts** are the most common type, accounting for approximately **95%** of all branchial anomalies. - They typically present as a smooth, fluctuant mass along the **anterior border of the sternocleidomastoid muscle** at the junction of the upper and middle third of the neck. - These cysts result from **incomplete obliteration** of the second branchial cleft during embryonic development. *Branchial cysts are more common in males than females.* - Branchial cysts have **no significant sex predilection**, affecting males and females with roughly equal frequency. - The overall incidence is relatively rare, with most cases presenting in late childhood or early adulthood. *Surgical intervention is not always necessary.* - **Complete surgical excision** is the **definitive treatment** and is strongly recommended for all branchial cysts. - Indications for surgery include: prevention of **recurrent infections**, risk of **abscess formation**, elimination of cosmetic concerns, and removal due to potential (though rare) **malignant transformation**. - While very small asymptomatic cysts may occasionally be observed, this carries significant risk of future complications, making surgery the standard of care in clinical practice. *They can cause dysphagia and hoarseness if infected.* - While an **infected branchial cyst** causes local inflammatory signs (pain, swelling, warmth, erythema), it **rarely causes dysphagia or hoarseness** unless exceptionally large. - These symptoms would require the cyst to compress the **pharynx** (dysphagia) or involve the **recurrent laryngeal nerve** (hoarseness), which is uncommon even with infection. - The primary presentation of infected cysts includes **tender neck mass** with overlying skin changes and possible **abscess formation**.

Question 1

Oxyntic cells are present in -

Accepted Answer

Body

Answer

Pylorus

Answer

Cardia

Answer

None of the options

Question 2

Which is the first bone to start ossifying?

Accepted Answer

Clavicle

Answer

Femur

Answer

Tibia

Answer

Mandible

Question 3

What structures are derived from the neural crest?

Accepted Answer

All of the options

Answer

Melanocytes

Answer

Dental papillae

Answer

Adrenal medulla

Question 4

Shortest part of male urethra is :

Accepted Answer

Membranous

Answer

Prostatic

Answer

Bulbar

Answer

Penile

Question 5

Which is the largest nerve that exits the pelvis through the greater sciatic foramen?

Accepted Answer

Sciatic nerve

Answer

Superior gluteal artery

Answer

Inferior gluteal artery

Answer

Piriformis muscle

Question 6

Fibrous stroma of liver is derived from -

Accepted Answer

Mesoderm from the septum transversum

Answer

Endoderm from the foregut

Answer

Endoderm from the midgut

Answer

Endoderm from the hindgut

Question 7

Inferior pancreaticoduodenal artery is a branch of which of the following arteries?

Accepted Answer

Superior mesenteric artery

Answer

Splenic artery

Answer

Left gastric artery

Answer

Gastroduodenal artery

Question 8

Nephron is derived from ?

Accepted Answer

Metanephros

Answer

Ureteric bud

Answer

Mesonephric duct

Answer

Mesonephros

Question 9

Fossa ovalis is a remnant of -

Accepted Answer

Septum primum

Answer

Septum secundum

Answer

Septum spurium

Answer

AV cushion

Question 10

Which of the following statements is true about branchial cysts?

Accepted Answer

They mostly arise from the second branchial cleft.

Answer

Branchial cysts are more common in males than females.

Answer

Surgical intervention is not always necessary.

Answer

They can cause dysphagia and hoarseness if infected.

NEET-PG 2015

Anatomy

Surgery