NEET-PG 2012 - Anatomy Practice Questions

Q: The thoracic duct crosses from the right to the left at the level of

T4-T5 vertebra. ***T4-T5 vertebra*** - The **thoracic duct** crosses from the right to the left side of the vertebral column at the level of the **T4-T5 vertebrae**, specifically just above the root of the left lung. - This crossover is an important anatomical landmark as it signifies the duct's ascent towards the neck to drain into the left subclavian vein. *T12 vertebra* - The **thoracic duct** originates from the **cisterna chyli** at the level of the L1 or L2 vertebra and ascends into the thorax at or below the T12 vertebra, it does not cross over at this level. - This level primarily marks its entry into the thoracic cavity, not its main crossover point. *T6 vertebra* - While the **thoracic duct** is present in the thorax at this level, it does not undergo its characteristic crossover from right to left at the T6 vertebra. - The duct continues its ascent along the right side of the vertebral column before moving across. *T2 vertebra* - By the level of the T2 vertebra, the **thoracic duct** has already crossed to the left side of the vertebral column and is ascending towards its termination in the neck. - The crossover event occurs more inferiorly, at the T4-T5 level.

Q: Which structure is located immediately posterior to the head of the pancreas?

Portal vein. ***Portal vein*** - The **portal vein** is formed by the union of the **splenic vein** and the **superior mesenteric vein** (SMV) posterior to the **neck** of the pancreas [1]. - It then runs in a **groove on the posterior surface** of the head of the pancreas, lying anterior to the **inferior vena cava** (IVC). - Among the given options, the portal vein has the most direct posterior relationship to the head of the pancreas. *Splenic artery* - The **splenic artery** runs along the **superior border** of the pancreas, following its body and tail. - It does not lie posterior to the head of the pancreas. - It is a branch of the **celiac trunk** and supplies the spleen. *Inferior mesenteric vein* - The **inferior mesenteric vein** typically drains into the **splenic vein** or the junction of the splenic and superior mesenteric veins. - It ascends **anterior** to the left kidney and does not lie immediately posterior to the head of the pancreas. *Coeliac trunk* - The **celiac trunk** originates from the **abdominal aorta** at the level of T12-L1 vertebra. - It lies **superior and anterior** to the pancreas, giving off the splenic artery, common hepatic artery, and left gastric artery. - It is not located posterior to the head of the pancreas.

Q: The nutrient artery to the femur is?

Profunda femoris artery. ***Profunda femoris artery*** - The **profunda femoris artery** (deep femoral artery) is the main blood supply to the **femur's diaphysis** via its perforating branches. - Typically, the **second perforating branch** gives rise to the nutrient artery, which enters the bone through the **nutrient foramen** in the middle third of the femoral shaft. *Femoral artery* - The **femoral artery** is the main artery of the thigh and gives off several branches, including the profunda femoris artery. - While it is the source of blood for the entire lower limb, it does not directly give rise to the main **nutrient artery of the femur**. *Popliteal artery* - The **popliteal artery** is a continuation of the femoral artery in the popliteal fossa behind the knee. - It primarily supplies structures around the knee joint and the lower leg, not the direct **diaphyseal nutrient supply** to the femur. *Medial circumflex femoral artery* - The **medial circumflex femoral artery** primarily supplies the head and neck of the femur, crucial for its vascularity, especially in children. - It does not serve as the **main nutrient artery** for the femoral shaft (diaphysis).

Q: Rouviere nodes are situated in?

Retropharynx. ***Retropharynx*** - Rouviere nodes are a group of **retropharyngeal lymph nodes** located in the space behind the pharynx. - They are clinically significant as they are the **first station of lymphatic drainage** for the nasopharynx and can be involved in cancers of that region. *Nasopharyngeal region* - While Rouviere nodes drain the nasopharynx, they are **located *behind* the nasopharynx** in the retropharyngeal space, not within the nasopharyngeal region itself. - The nasopharynx is the superior part of the pharynx, above the soft palate. *Oral region* - The oral cavity drainage primarily involves **submandibular, submental, and deep cervical lymph nodes**. - Rouviere nodes are not typically involved in the initial lymphatic drainage of the oral region. *Supraclavicular region* - **Supraclavicular nodes** are located above the clavicle in the supraclavicular fossa and represent a distant drainage site. - Involvement of these nodes usually indicates more **advanced disease** or drainage from organs in the chest or abdomen.

Q: Pituicytes are seen in ?

Posterior lobe. ***Posterior lobe*** - **Pituicytes** are specialized glial cells found exclusively in the **posterior pituitary** (neurohypophysis). [1] - They provide structural support and regulation for the nerve terminals that release **antidiuretic hormone (ADH)** and **oxytocin**. [1] *Anterior lobe* - The anterior pituitary, or **adenohypophysis**, consists of glandular epithelial cells that synthesize and secrete various hormones. [2] - It does not contain pituicytes, which are glial cells. [2] *Intermediate lobe* - The intermediate lobe is a rudimentary part of the pituitary gland in humans, primarily producing **melanocyte-stimulating hormone (MSH)**. [1] - While it is part of the pituitary, it does not contain pituicytes. *All of the options* - Pituicytes are specific to the posterior pituitary, so they are not found in all parts of the gland. - Different lobes of the pituitary gland have distinct cellular compositions and functions.

Q: Podocytes are seen in -

Bowman's capsule. **Bowman's capsule** - **Podocytes** are specialized epithelial cells that form the **visceral layer** of Bowman's capsule. They have foot processes (pedicels) that interdigitate to form slit diaphragms, which are crucial for the **filtration barrier** of the glomerulus [1]. - These cells facilitate the selective passage of water and small solutes from the blood into Bowman's space, while preventing the filtration of large proteins and blood cells. *Proximal convoluted tubule* - The **proximal convoluted tubule** is primarily involved in the **reabsorption** of essential nutrients, ions, and water from the filtrate back into the bloodstream [1]. - Its cells are characterized by a **brush border** (microvilli) and numerous mitochondria, indicating high metabolic activity, and are not podocytes [1]. *Distal convoluted tubule* - The **distal convoluted tubule** plays a role in fine-tuning the reabsorption of ions and water, under the influence of hormones like **aldosterone** and **ADH**. - Its cells lack the specialized foot processes and filtration function characteristic of podocytes. *Collecting tubule of the kidney* - The **collecting tubule** (or collecting duct) is involved in regulating water reabsorption and acid-base balance, responding to **ADH** to concentrate urine. - Its epithelial cells are principal cells and intercalated cells, which are different in structure and function from podocytes.

Q: Anal valve is found in which part of anal canal?

Middle. ***Middle*** - The **anal valves** are crescentic folds located at the level of the **pectinate (dentate) line** in the middle portion of the anal canal. - They mark the inferior limit of the **anal columns** and form small recesses called **anal sinuses**. *Lower* - The lower part of the anal canal, below the pectinate line, is lined by **anoderm** and lacks anal valves. - This region is sensitive to pain due to somatic innervation. *At anus* - The anus refers to the external opening and perianal skin, which does not contain anal valves. - The anal canal transitions into the perianal skin at the anocutaneous line. *Upper* - The upper part of the anal canal, above the pectinate line, contains the **anal columns (columns of Morgagni)** but not the anal valves themselves, which are located at the base of these columns. - This region is lined by columnar epithelium and is relatively insensitive to pain.

Q: What is the outer layer of the blastocyst called?

Trophoblast. ***Trophoblast*** - The **trophoblast** is the outer layer of cells of the blastocyst, which goes on to form the **placenta** and other extraembryonic tissues [1]. - It plays a crucial role in the **implantation** of the blastocyst into the uterine wall and in producing hormones [1]. *Primitive streak* - The **primitive streak** is a structure that forms during **gastrulation**, much later than the initial blastocyst stage. - It establishes the **anterior-posterior axis** and initiates the formation of the three germ layers. *Yolk sac* - The **yolk sac** is an extraembryonic membrane that forms within the blastocyst cavity, but it is not the outermost layer of the entire structure. - It is involved in early **nutrient transfer** and **blood cell formation** before the placenta is fully functional. *Embryo proper* - The **embryo proper**, derived from the **inner cell mass (ICM)**, is the part of the blastocyst that will develop into the actual embryo [2]. - It is located *inside* the trophoblast layer, not forming the outer boundary of the blastocyst [2].

Q: Inferior parathyroid develops from which pharyngeal pouch?

3rd. The inferior parathyroid glands develop from the dorsal wing of the third pharyngeal pouch. Due to their origin, they often migrate further caudally than the superior parathyroid glands, sometimes even locating within the thymus which also develops from the third pouch. *1st* - The first pharyngeal pouch contributes to the formation of the eustachian tube, tympanic cavity, and mastoid air cells. - It has no role in the development of the parathyroid glands. *2nd* - The second pharyngeal pouch mainly gives rise to the palatine tonsils and their crypts. - It is not involved in the development of parathyroid tissue. *4th* - The fourth pharyngeal pouch gives rise to the superior parathyroid glands and the parafollicular cells (C cells) of the thyroid, which produce calcitonin. - While it forms parathyroid tissue, it is for the superior glands, not the inferior ones.

Q: After trauma, a person cannot move their eye outward beyond the midpoint. Which nerve is injured?

6th. ***6th*** - The **abducens nerve (CN VI)** innervates the **lateral rectus muscle**, which is responsible for moving the eye **outward (abduction)** [1]. - Injury to the abducens nerve would result in an inability to move the eye laterally, causing an **esotropia** (eye turned inward at rest) [1]. *2nd* - The **optic nerve (CN II)** is responsible for **vision**, not eye movement [2]. - Damage to this nerve would cause **visual field defects** or **blindness** [3]. *3rd* - The **oculomotor nerve (CN III)** controls most extraocular muscles, including the **medial, superior, and inferior rectus** and **inferior oblique muscles**, as well as the **levator palpebrae superioris** and **pupillary constriction** [2]. - Injury to CN III would lead to a **down and out deviation of the eye**, **ptosis**, and a **dilated pupil** [2]. *4th* - The **trochlear nerve (CN IV)** innervates the **superior oblique muscle**, which primarily causes **intorsion** (rotation downward and inward) [1]. - Damage to this nerve results in **vertical diplopia**, especially when looking down and in, and a characteristic **head tilt** to compensate [3].

Question 1

The thoracic duct crosses from the right to the left at the level of

Accepted Answer

T4-T5 vertebra

Answer

T12 vertebra

Answer

T2 vertebra

Answer

T6 vertebra

Question 2

Which structure is located immediately posterior to the head of the pancreas?

Accepted Answer

Portal vein

Answer

Splenic artery

Answer

Inferior mesenteric vein

Answer

Coeliac trunk

Question 3

The nutrient artery to the femur is?

Accepted Answer

Profunda femoris artery

Answer

Femoral artery

Answer

Popliteal artery

Answer

Medial circumflex femoral artery

Question 4

Rouviere nodes are situated in?

Accepted Answer

Retropharynx

Answer

Nasopharyngeal region

Answer

Oral region

Answer

Supraclavicular region

Question 5

Pituicytes are seen in ?

Accepted Answer

Posterior lobe

Answer

Anterior lobe

Answer

Intermediate lobe

Answer

All of the options

Question 6

Podocytes are seen in -

Accepted Answer

Bowman's capsule

Answer

Proximal convoluted tubule

Answer

Distal convoluted tubule

Answer

Collecting tubule of the kidney

Question 7

Anal valve is found in which part of anal canal?

Accepted Answer

Middle

Answer

Lower

Answer

At anus

Answer

Upper

Question 8

What is the outer layer of the blastocyst called?

Accepted Answer

Trophoblast

Answer

Embryo proper

Answer

Primitive streak

Answer

Yolk sac

Question 9

Inferior parathyroid develops from which pharyngeal pouch?

Accepted Answer

3rd

Answer

1st

Answer

2nd

Answer

4th

Question 10

After trauma, a person cannot move their eye outward beyond the midpoint. Which nerve is injured?

Accepted Answer

6th

Answer

3rd

Answer

4th

Answer

2nd

NEET-PG 2012 — Anatomy