Anatomy
9 questionsWhat anatomical structure does the pineal gland form part of?
Which organ is primarily supplied by the portal vein?
What is the typical length of the anal canal in adults?
Which chamber of the heart is located anterior to the sternum?
Which chamber of the heart forms the posterior surface?
Which of the following statements is false about the right bronchus?
Sacral promontory is the landmark for
Which testis is typically positioned higher?
Which part of the heart is located in the anterosuperior sternal region?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 81: What anatomical structure does the pineal gland form part of?
- A. Part of the anterior wall of the third ventricle
- B. Part of the roof of the third ventricle (Correct Answer)
- C. Part of the floor of the third ventricle
- D. Part of the posterior wall of the third ventricle
Explanation: **_Part of the roof of the third ventricle_** - The **pineal gland** is a small, pinecone-shaped endocrine gland that forms part of the **roof of the third ventricle** [1]. - It is attached to the roof by the **pineal stalk** and projects posteriorly from the **epithalamus**. - The roof of the third ventricle consists of the **tela choroidea**, the **pineal gland**, and the **choroid plexus** [1]. - The pineal gland regulates circadian rhythms through **melatonin** secretion. *Part of the posterior wall of the third ventricle* - The **posterior wall** of the third ventricle is formed by the **posterior commissure**, the **pineal recess**, and the **habenular commissure**. - While the pineal gland is located posteriorly, it is anatomically classified as part of the roof, not the posterior wall itself. *Part of the anterior wall of the third ventricle* - The **anterior wall** is formed by the **lamina terminalis**, **anterior commissure**, and columns of the fornix. - This is located at the opposite end of the third ventricle from the pineal gland. *Part of the floor of the third ventricle* - The **floor** is formed by structures of the **hypothalamus**, including the **optic chiasm**, **tuber cinereum**, **infundibulum**, and **mammillary bodies**. - The pineal gland is situated dorsally (superiorly), not in the floor.
Question 82: Which organ is primarily supplied by the portal vein?
- A. Spleen
- B. Liver (Correct Answer)
- C. Pancreas
- D. Colon
Explanation: ***Liver*** - The **portal vein** is unique in that it carries **nutrient-rich, deoxygenated blood** from the gastrointestinal tract and spleen directly to the liver [1], [2]. - This specialized circulation allows the liver to **process absorbed nutrients** and detoxify harmful substances before they enter the systemic circulation [1], [3]. *Spleen* - The spleen is supplied by the **splenic artery**, a branch of the **celiac trunk**, which carries oxygenated arterial blood to the organ. - While the splenic vein drains into the portal vein, the portal vein itself does not primarily supply the spleen [2]. *Pancreas* - The pancreas receives its blood supply from branches of the **celiac artery** and the **superior mesenteric artery**, specifically the splenic, gastroduodenal, and superior mesenteric arteries [1]. - While pancreatic veins drain into the portal system, the portal vein is not the primary arterial supply to the pancreas [1]. *Colon* - The colon is supplied by the **superior mesenteric artery** and the **inferior mesenteric artery**, which provide oxygenated arterial blood to different segments of the large intestine. - The venous drainage from the colon primarily collects into the superior and inferior mesenteric veins, which then merge to form part of the portal venous system, but the portal vein does not primarily supply the colon with blood [2].
Question 83: What is the typical length of the anal canal in adults?
- A. 10 - 15 mm
- B. 15 - 20 mm
- C. 25 - 30 mm
- D. 35 - 40 mm (Correct Answer)
Explanation: ***35 - 40 mm*** - The **anal canal** in adults typically measures between **3.5 to 4.0 cm** (35 to 40 mm) in length. - This length is measured from the **anorectal ring** to the **anal verge**. *10 - 15 mm* - This length is too short for the **adult anal canal**; it's approximately one-third of the actual length. - Such a short measurement would be anatomically incorrect and clinically significant for various colorectal conditions. *15 - 20 mm* - This measurement is still significantly shorter than the average length of the **adult anal canal**. - A canal this short would likely be pathological or developmental in origin. *25 - 30 mm* - While closer, this range is still generally below the accepted average length of the **adult anal canal**. - Precise anatomical measurements are crucial for diagnostic and surgical procedures in proctology.
Question 84: Which chamber of the heart is located anterior to the sternum?
- A. Left ventricle
- B. Right atrium
- C. Right ventricle (Correct Answer)
- D. Left atrium
Explanation: ***Right ventricle*** - The **right ventricle** forms the majority of the **anterior surface of the heart** and is the chamber closest to the sternum [2]. - This anatomical position is important clinically, for instance, in cases of **pericardial effusion** or **chest trauma**. *Left atrium* - The **left atrium** is located most **posteriorly** in the heart, adjacent to the esophagus [1], [2]. - Due to its posterior position, an enlarged left atrium can compress the esophagus, causing **dysphagia**. *Left ventricle* - The **left ventricle** forms the **apex of the heart** and is located more on the left and posterior aspect compared to the right ventricle [2]. - While it contributes to the anterior surface, the **right ventricle** is more directly anterior to the sternum [2]. *Right atrium* - The **right atrium** is positioned to the right and slightly posterior to the right ventricle. - It receives venous blood from the body and forms the **right border of the heart**.
Question 85: Which chamber of the heart forms the posterior surface?
- A. Right Atrium (RA)
- B. Left Atrium (LA) (Correct Answer)
- C. Left Ventricle (LV)
- D. Right Ventricle (RV)
Explanation: ***Left Atrium (LA)*** - The **left atrium** forms the posterior surface of the heart, lying in front of the esophagus and thoracic aorta [1]. - Its posterior position makes it susceptible to enlargement, which can compress the **esophagus** and cause dysphagia [1]. *Right Atrium (RA)* - The **right atrium** primarily forms the right border of the heart and receives deoxygenated blood from the systemic circulation. - It lies anteriorly and to the right, behind the sternum and costal cartilages. *Left Ventricle (LV)* - The **left ventricle** forms the apex of the heart and part of the left border. - It is positioned *inferiorly* and *anteriorly*, contributing significantly to the *diaphragmatic surface* of the heart. *Right Ventricle (RV)* - The **right ventricle** forms the majority of the anterior surface of the heart, directly behind the sternum. - It also contributes to the *inferior surface* of the heart, resting on the diaphragm.
Question 86: Which of the following statements is false about the right bronchus?
- A. Shorter
- B. More horizontal (Correct Answer)
- C. In the line of trachea
- D. Wider
Explanation: ***More horizontal*** - The right bronchus is traditionally described as **more vertical** or **more directly in line with the trachea** compared to the left bronchus. - This anatomical orientation makes it more susceptible to the aspiration of foreign bodies. *Shorter* - The **right main bronchus** is indeed shorter than the left main bronchus. - Its length is typically 2-3 cm, while the left main bronchus is about 5 cm long. *Wider* - The **right main bronchus** has a larger diameter than the left main bronchus. - This wider lumen contributes to the ease with which foreign bodies can enter it. *In the line of trachea* - The right main bronchus diverges from the trachea at a **less acute angle** (approximately 25 degrees) compared to the left (approximately 45 degrees). - This makes it appear more as a **direct continuation of the trachea**, facilitating aspiration into the right lung.
Question 87: Sacral promontory is the landmark for
- A. Termination of presacral nerve (Correct Answer)
- B. None of the options
- C. Origin of inferior mesenteric artery
- D. Origin of superior mesenteric artery
Explanation: ***Termination of presacral nerve*** - The **sacral promontory** is the key anatomical landmark where the **superior hypogastric plexus** (presacral nerve) **bifurcates** into the right and left hypogastric nerves. - This bifurcation typically occurs at the level of the **sacral promontory**, making it a crucial landmark for **presacral neurectomy** procedures. - The superior hypogastric plexus is formed by the fusion of sympathetic fibers and lies anterior to the L5 vertebra and sacral promontory. - Clinically important for **pelvic surgery** and **pain management** procedures. *Origin of superior mesenteric artery* - The **superior mesenteric artery (SMA)** originates from the **anterior aspect of the abdominal aorta** at the level of the **L1 vertebra**. - This is far superior to the sacral promontory, which is at the lumbosacral junction (L5-S1). - The SMA supplies the midgut derivatives. *Origin of inferior mesenteric artery* - The **inferior mesenteric artery (IMA)** originates from the **anterior aspect of the abdominal aorta** at the level of the **L3 vertebra**. - This is also well above the sacral promontory. - The IMA supplies the hindgut derivatives. *None of the options* - This is incorrect as the sacral promontory is indeed a recognized landmark for the **bifurcation/termination of the presacral nerve** (superior hypogastric plexus).
Question 88: Which testis is typically positioned higher?
- A. It varies between individuals
- B. Left testis
- C. Right testis (Correct Answer)
- D. Both are at the same level
Explanation: ***Right testis*** - The **right testis** is commonly positioned slightly higher than the left testis in most males [1]. - This anatomical variation is due to the **left spermatic cord** being inherently longer, which allows the left testis to hang lower. *Left testis* - The **left testis** is typically positioned lower than the right testis. - Its lower position is attributed to the generally **longer left spermatic cord**. *It varies between individuals* - While minor individual variations exist, a consistent pattern of the **right testis** being higher is observed in the majority of males. - The differences in cord length lead to a general trend, not complete randomness in height. *Both are at the same level* - It is uncommon for both testes to be at precisely the **same level**. - The **asymmetrical length** of the spermatic cords makes equal positioning rare.
Question 89: Which part of the heart is located in the anterosuperior sternal region?
- A. Right atrium and auricle.
- B. Left atrium.
- C. Left ventricle.
- D. Right ventricle. (Correct Answer)
Explanation: ***Right ventricle*** - The **right ventricle** forms the **most anterior part of the heart**, located directly behind the sternum and costal cartilages [1]. - Its position explains why **sternal precordial leads** (e.g., V1, V2) on an ECG primarily reflect right ventricular activity [1]. *Right atrium and auricle* - While part of the right atrium is anterior, the **right ventricle is significantly more anterior** and occupies the majority of the anterosuperior sternal region [1]. - The **right auricle** is a small, anterior appendage, but the broader chamber occupying this region is the ventricle [1]. *Left atrium* - The **left atrium** is the **most posterior chamber of the heart**, forming the base [1]. - It lies near the esophagus, making it susceptible to compression by an enlarged left atrium. *Left ventricle* - The **left ventricle** forms the **apex of the heart** and is located primarily on the **left and inferior** aspects. - It is not the most anterior structure; the right ventricle is positioned anteriorly to it [1].
Obstetrics and Gynecology
1 questionsWhat is a cochleate uterus?
NEET-PG 2013 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 81: What is a cochleate uterus?
- A. Large uterus
- B. Acute anteflexion (Correct Answer)
- C. Acute retroflexion
- D. Large cervix
Explanation: ***Acute anteflexion*** - A **cochleate uterus** describes a uterus with an **acute anteflexion**, meaning it is sharply bent forward at the junction of the cervix and the body of the uterus. - This anatomical variation can sometimes be associated with **dysmenorrhea** or difficulty with **intrauterine device (IUD) insertion**. *Large uterus* - A large uterus, also known as **uteromegaly**, is a general descriptive term for an enlarged uterus, which can be due to various causes such as **fibroids** or **adenomyosis**, and is not specific to an acute anteflexion. - It does not directly describe the acute angulation that defines a cochleate uterus. *Acute retroflexion* - **Acute retroflexion** refers to a uterus that is sharply bent backward at the level of the cervix. - This is the opposite of **anteflexion**, which describes a forward bend, and therefore is not a cochleate uterus. *Large cervix* - A **large cervix** describes an enlarged uterine cervix, which is the lower, narrow part of the uterus. - This typically relates to conditions like **cervical hypertrophy** or **nabothian cysts** and is distinct from the overall angulation of the uterine body in relation to the cervix.