Anatomy
10 questionsWhich of the following does not directly drain into right atrium?
Which nerve roots are primarily involved in Erb's palsy?
Which are the segments of the upper lobe of the right lung?
What is the uppermost structure in left lung hilum?
What is the primary lymphatic drainage pathway of the ovary?
Which of the following structures does not pass through the superior thoracic aperture?
What is the embryological origin of the ligamentum arteriosum?
Base of the heart is formed by?
Right border of heart is formed by?
Which of the following statements about the anatomy of the right ventricle is correct?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 71: Which of the following does not directly drain into right atrium?
- A. Inferior vena cava
- B. Great cardiac vein (Correct Answer)
- C. Anterior cardiac vein
- D. Venae cordis minimi
Explanation: ***Great cardiac vein*** - The **great cardiac vein** drains into the **coronary sinus**, which then empties into the right atrium [1]. - It does not drain directly into the right atrium, distinguishing it from the other options. *Inferior vena cava* - The **inferior vena cava** is one of the major vessels that drains directly into the **right atrium**. - It carries deoxygenated blood from the lower body to the right atrium. *Anterior cardiac vein* - The **anterior cardiac veins** drain directly into the **right atrium**. - They tend to drain the anterior surface of the right ventricle. *Venae cordis minimi* - Also known as **Thebesian veins**, these are small veins that drain directly into the cardiac chambers, including the **right atrium**. - They represent a direct communication between the myocardial capillaries and the cardiac chambers.
Question 72: Which nerve roots are primarily involved in Erb's palsy?
- A. C5, C6 (Correct Answer)
- B. C4, C5
- C. C5, C7
- D. C6, C8
Explanation: C5, C6 - **Erb's palsy** primarily involves injury to the **upper trunk of the brachial plexus**, which is formed by the ventral rami of **C5 and C6** spinal nerves. - This lesion results in a characteristic "waiter's tip" posture due to paralysis of muscles supplied by these nerve roots, including the **deltoid**, **biceps**, and **brachialis**. *C4, C5* - While C5 is involved, **C4** is typically associated with the **phrenic nerve** and diaphragm function, and its primary involvement is not characteristic of Erb's palsy. - Injury to C4 and C5 alone would not produce the comprehensive motor deficits seen in Erb's palsy involving shoulder and elbow flexion. *C5, C7* - This option includes C5 but also **C7**, which is more commonly associated with the **middle trunk** of the brachial plexus. - While C7 can be involved in extended brachial plexus injuries, its primary involvement alone is not the classic presentation of Erb's palsy. *C6, C8* - This combination includes C6 but introduces **C8**, which is part of the **lower trunk** of the brachial plexus. - Injuries involving C8 and T1 are characteristic of **Klumpke's palsy**, affecting intrinsic hand muscles and causing a "claw hand" deformity, which is distinct from Erb's palsy.
Question 73: Which are the segments of the upper lobe of the right lung?
- A. Lateral, medial, superior
- B. Apical, anterior, posterior (Correct Answer)
- C. Basal, medial, lateral
- D. Anterior, posterior, medial
Explanation: ***Apical, anterior, posterior*** - The **right upper lobe** is consistently divided into three bronchopulmonary segments: **apical**, **anterior**, and **posterior** [1]. - These segments are named according to their anatomical position and the branching of the **tertiary bronchi** that supply them [1]. *Anterior, posterior, medial* - While **anterior** and **posterior** segments exist, the "medial" segment is not a standard division of the right upper lobe. - The term "medial" is typically associated with the **middle lobe** of the right lung (medial and lateral segments) [1]. *Lateral, medial, superior* - The segments **lateral** and **medial** are characteristic of the **right middle lobe** [1]. - "Superior" is a general directional term and not a specific segment name within the upper lobe in this context, although the apical segment is superiorly located. *Basal, medial, lateral* - **Basal** segments are found in the **lower lobes** of the lungs (e.g., anterior basal, medial basal, posterior basal, lateral basal). - **Medial** and **lateral** segments are typical of the **right middle lobe**, not the upper lobe [1].
Question 74: What is the uppermost structure in left lung hilum?
- A. Pulmonary artery (Correct Answer)
- B. Pulmonary vein
- C. Bronchial artery
- D. Left mainstem bronchus
Explanation: ***Pulmonary artery*** - In the **left lung hilum**, the **pulmonary artery** typically lies superior to the bronchus. - This anatomical position helps differentiate it from the relations in the right lung hilum, where the pulmonary artery is anterior to the bronchus. *Pulmonary vein* - The **pulmonary veins** are usually located anterior and inferior to the bronchus in both lung hila. - They tend to be the most anterior and inferior structures carrying oxygenated blood from the lungs. *Bronchial artery* - **Bronchial arteries** are smaller vessels that typically run on the posterior surface of the bronchi. - They are not considered the uppermost main structure in the hilum. *Left mainstem bronchus* - The **left mainstem bronchus** is usually found inferior to the pulmonary artery and posterior to the pulmonary veins in the left hilum. - It is a prominent structure but not the most superior.
Question 75: What is the primary lymphatic drainage pathway of the ovary?
- A. Deep inguinal
- B. Superficial inguinal
- C. Obturator
- D. Paraaortic (Correct Answer)
Explanation: ***Paraaortic*** - The **ovaries** develop embryologically in the abdominal cavity near the kidneys, and their lymphatic drainage follows the **ovarian vessels** (which arise from the aorta). - Lymph drains primarily to the **paraaortic (lumbar) lymph nodes** located along the **aorta** in the retroperitoneum at the level of L1-L2. - This is clinically important in ovarian cancer staging and treatment planning. *Deep inguinal* - The **deep inguinal lymph nodes** primarily drain the deep structures of the lower limb, perineum, and external genitalia. - They do not receive lymphatic drainage directly from the ovaries. *Superficial inguinal* - The **superficial inguinal lymph nodes** drain the skin of the lower abdomen, buttocks, perineum, external genitalia, and the superficial lower limb. - The ovaries are internal intra-abdominal organs and do not drain into these nodes. *Obturator* - The **obturator lymph nodes** are pelvic lymph nodes that primarily drain pelvic structures such as the bladder, uterine body, cervix, and upper vagina. - While adjacent to pelvic organs, they are not the primary drainage site for the ovaries, which drain superiorly along the ovarian vessels to the paraaortic nodes.
Question 76: Which of the following structures does not pass through the superior thoracic aperture?
- A. Right vagus
- B. Right brachiocephalic artery
- C. Thoracic duct
- D. Right recurrent laryngeal nerve (Correct Answer)
Explanation: ***Right recurrent laryngeal nerve*** - The **right recurrent laryngeal nerve** loops around the **right subclavian artery** in the neck [1] and ascends into the neck to innervate the larynx. - It does not descend into the thorax before recurring, thus it does not pass through the superior thoracic aperture [1]. *Right vagus* - The **right vagus nerve** passes through the superior thoracic aperture anterior to the right subclavian artery and enters the thorax. - It then descends posterior to the right brachiocephalic vein and superior vena cava before supplying thoracic and abdominal viscera. *Right brachiocephalic artery* - The **right brachiocephalic artery** (also known as the brachiocephalic trunk) is the first branch of the aortic arch and passes superiorly through the superior thoracic aperture. - It gives rise to the right common carotid artery and right subclavian artery in the neck. *Thoracic duct* - The **thoracic duct** ascends from the abdomen through the posterior mediastinum, passes through the superior thoracic aperture to enter the neck [2]. - In the neck, it arches laterally and empties into the left subclavian vein, or the junction of the left internal jugular and subclavian veins.
Question 77: What is the embryological origin of the ligamentum arteriosum?
- A. Remnant of the ductus arteriosus (Correct Answer)
- B. Remnant of the ductus venosus
- C. Remnant of the ductus utriculosaccularis
- D. Remnant of the ductus reuniens
Explanation: ***Remnant of the ductus arteriosus*** - The **ductus arteriosus** is a fetal blood vessel connecting the **pulmonary artery** to the **aorta**, bypassing the non-functional lungs [1]. - After birth, due to increased oxygen tension and decreased prostaglandins, it typically constricts and obliterates, forming the **ligamentum arteriosum** [2]. *Remnant of the ductus venosus* - The **ductus venosus** is a fetal shunt connecting the **umbilical vein** to the **inferior vena cava**, bypassing the liver's circulatory bed [2]. - After birth, it closes and becomes the **ligamentum venosum**, not the ligamentum arteriosum [2]. *Remnant of the ductus utriculosaccularis* - This is an **inner ear structure** connecting the utricle and saccule in the membranous labyrinth. - It is **not a cardiovascular structure** and has no relation to the ligamentum arteriosum. *Remnant of the ductus reuniens* - The **ductus reuniens** (also called ductus utriculosaccularis) is an **inner ear structure**, not a fetal cardiovascular shunt. - It has **no remnant** related to the ligamentum arteriosum or cardiovascular system.
Question 78: Base of the heart is formed by?
- A. Right atrium
- B. Right ventricle
- C. Left atrium (Correct Answer)
- D. Left ventricle
Explanation: ***Left atrium*** - The **left atrium** forms the major part of the **base of the heart**, receiving the four pulmonary veins. [1] - It lies in the posterior-superior aspect of the heart and is separated from the thoracic vertebrae by the **pericardium** and the **esophagus**. *Right atrium* - The **right atrium** forms the right border of the heart and receives deoxygenated blood from the **superior and inferior vena cava**. - It primarily forms part of the **anterior surface** of the heart, not the base. *Right ventricle* - The **right ventricle** forms a large part of the **anterior surface** and inferior border of the heart. - It is responsible for pumping blood to the **pulmonary circulation** but does not form the base. *Left ventricle* - The **left ventricle** forms the **apex** of the heart and much of its **left border** and **diaphragmatic surface**. - Its primary role is to pump oxygenated blood into the **systemic circulation**.
Question 79: Right border of heart is formed by?
- A. Right ventricle
- B. Right atrium (Correct Answer)
- C. SVC
- D. IVC
Explanation: ***Right atrium*** - The **right atrium** forms the major part of the **right border of the heart** as viewed in a posteroanterior (PA) chest X-ray. - Its position is along the right sternal margin, extending from the level of the third costal cartilage superiorly to the sixth costal cartilage inferiorly. *Right ventricle* - The **right ventricle** primarily forms the **anterior surface** and part of the inferior border of the heart. - It contributes minimally, if at all, to the visible right border in a standard PA view. *SVC* - The **superior vena cava (SVC)** drains into the right atrium and is located superior to it. - While it's adjacent to the right border, it does **not form the actual right border of the heart itself**. *IVC* - The **inferior vena cava (IVC)** drains into the right atrium from below. - It is positioned inferiorly and posteriorly, and therefore **does not form the right border** of the heart in a PA view.
Question 80: Which of the following statements about the anatomy of the right ventricle is correct?
- A. TV & PV Share fibrous continuity
- B. More prominent trabeculation
- C. The crista supraventricularis separates the tricuspid and pulmonary valves, and the apex is trabeculated (Correct Answer)
- D. All of the options
Explanation: The crista supraventricularis separates the tricuspid and pulmonary valves, and the apex is trabeculated - The **crista supraventricularis** (also known as the supraventricular crest) is a prominent muscular ridge that separates the **inflow tract** (tricuspid valve region) from the **outflow tract** (pulmonary valve region) in the right ventricle. - The **apex and trabecular portion** of the right ventricle contains prominent **trabeculae carneae**, which are irregular muscular ridges and columns. - This option is correct as it describes two key anatomical features: the structural separator between valves and the trabeculated apex. *TV & PV Share fibrous continuity* - This statement is **anatomically incorrect** for the right ventricle. - The **tricuspid valve** and **pulmonary valve** do NOT share fibrous continuity; they are separated by the **crista supraventricularis** (muscular ridge). - **Fibrous continuity** (mitral-aortic continuity) is a characteristic feature of the **left heart**, where the anterior mitral leaflet is continuous with the aortic valve, but this does NOT occur in the right ventricle. *More prominent trabeculation* - While this statement is **anatomically true** (the right ventricle has more prominent trabeculation than the left ventricle, which has a smoother wall), this option is **incomplete** when compared to the correct answer. - The question asks for the correct statement about right ventricle anatomy, and option 3 provides a **more comprehensive description** that includes both a unique structural landmark (crista supraventricularis) and the trabeculation feature. - In single-best-answer format, the most complete and specific option is preferred. *All of the options* - This option is incorrect because the statement "TV & PV Share fibrous continuity" is anatomically false. - Since not all options are correct, this cannot be the answer.