Anatomy
9 questionsWhat is the nerve supply of the larynx above the level of the vocal cords?
A surgeon removes a part of the liver located to the left of the falciform ligament. Which segments of the liver are removed?
Which muscle plays a role in winking?
What is the approximate ratio of connective tissue to smooth muscle in the cervix?
Which testis is typically positioned higher?
Helicine arteries are branches of which artery?
What is Galen's anastomosis?
Which chamber of the heart forms the posterior surface?
Line from midinguinal point to adductor tubercle represents?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 131: What is the nerve supply of the larynx above the level of the vocal cords?
- A. Superior laryngeal (Correct Answer)
- B. Recurrent laryngeal
- C. Glossopharyngeal
- D. External laryngeal nerve
Explanation: ***Superior laryngeal*** - The **superior laryngeal nerve** branches into the internal and external laryngeal nerves. The **internal laryngeal nerve** (a branch of the superior laryngeal nerve) provides all sensory innervation to the larynx **above the vocal cords**. - It also carries **parasympathetic fibers** to the laryngeal glands in this region. *Recurrent laryngeal* - The **recurrent laryngeal nerve** provides sensory innervation to the larynx **below the vocal cords** [1]. - It also innervates all of the intrinsic muscles of the larynx except for the cricothyroid muscle [1]. *Glossopharyngeal* - The **glossopharyngeal nerve (CN IX)** primarily provides sensory innervation to the **posterior one-third of the tongue**, tonsils, pharynx, and middle ear. - It does not directly provide sensory innervation to the larynx. *External laryngeal nerve* - The **external laryngeal nerve**, a branch of the superior laryngeal nerve, is primarily **motor** and innervates the **cricothyroid muscle**. - It provides **no sensory innervation** to any part of the larynx.
Question 132: A surgeon removes a part of the liver located to the left of the falciform ligament. Which segments of the liver are removed?
- A. Segments I & IV
- B. Segments V & VI
- C. Segments VII & VIII
- D. Segments II & III (Correct Answer)
Explanation: ***Segments II & III*** - The liver segments are defined by their **vascular supply** originating from the **portal vein** and **hepatic artery**, and their **biliary drainage** [1]. - The **falciform ligament** separates the **left lobe** of the liver into **medial** and **lateral** sections. The portion to its left corresponds to the lateral left lobe, which includes **segments II and III** [1, 2]. *Segments I & IV* - **Segment I** (`caudate lobe`) is located **posteriorly**, independent of the falciform ligament, and is supplied by both the left and right portal and hepatic arterial systems [1]. - **Segment IV** (`quadrate lobe`) is part of the **medial left lobe** and is situated to the **right of the falciform ligament** [1]. *Segments V & VI* - These segments are located in the **right lobe** of the liver, which is to the **right of the main portal fissure**, and are not associated with the falciform ligament's immediate left. - **Segment V** is **anterior** and **inferior**, and **Segment VI** is **posterior** and **inferior** within the right lobe. *Segments VII & VIII* - These segments are also located in the **right lobe** of the liver, specifically in the **superior** aspects [1]. - **Segment VII** is **posterior** and **superior**, while **Segment VIII** is **anterior** and **superior** in the right lobe, far from the falciform ligament.
Question 133: Which muscle plays a role in winking?
- A. Levator labii superioris
- B. Orbicularis oculi (Correct Answer)
- C. Levator palpebrae
- D. Corrugator supercilii
Explanation: ***Orbicularis oculi*** - This muscle is responsible for **closing the eyelid** and is essential for actions like blinking, squinting, and winking. - Its fibers encircle the eye and facilitate the **controlled closure** required for winking. *Levator labii superioris* - This muscle primarily functions to **elevate the upper lip**, playing a role in facial expressions such as sneering or smiling. - It has no direct involvement in the movement of the eyelids or the act of winking. *Corrugator supercilii* - This muscle is located in the eyebrow region and is responsible for **drawing the eyebrows medially and inferiorly**, creating vertical wrinkles between the eyebrows. - It is associated with expressions of frowning or concern, not eyelid closure. *Levator palpebrae* - This muscle is responsible for **opening the upper eyelid**, thus counteracting the action of the orbicularis oculi. - While essential for eye movement, it is not involved in the closing action required for winking.
Question 134: What is the approximate ratio of connective tissue to smooth muscle in the cervix?
- A. 2:1
- B. 5:1
- C. 15:1
- D. Approximately 8:1 (Correct Answer)
Explanation: ***Approximately 8:1*** - The **cervix** is predominantly composed of **fibrous connective tissue**, which provides its structural integrity and rigidity [1]. - This high ratio of **collagenous connective tissue** to smooth muscle is crucial for maintaining pregnancy and undergoing significant remodeling during parturition [1]. - The approximate ratio is **8:1 to 10:1**, with connective tissue forming about 85-90% of cervical tissue [1]. *2:1* - This ratio would imply a significantly higher proportion of **smooth muscle** (33%), making the cervix much more muscular and less fibrous than it actually is. - Such a composition would compromise the cervical function of maintaining a **closed uterine orifice** during pregnancy. *5:1* - While higher than 2:1, this ratio still underestimates the true dominance of **connective tissue** in the cervical structure. - The **cervix's mechanical properties**, including its ability to resist stretching, are primarily due to its abundant collagen content. *15:1* - This ratio overestimates the proportion of connective tissue, suggesting less than 7% smooth muscle. - While the cervix is indeed fibrous, it does contain a modest amount of **smooth muscle** (10-15%) particularly in the internal os region, making this ratio too extreme [1].
Question 135: 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 136: Helicine arteries are branches of which artery?
- A. None of the options
- B. Femoral artery
- C. External pudendal artery
- D. Internal pudendal artery (Correct Answer)
Explanation: ***Internal pudendal artery*** - The **internal pudendal artery** is the primary arterial supply to the external genitalia, and its branches, including the **helicine arteries**, are crucial for erectile function. - In males, these arteries supply the **corpus cavernosa** of the penis, and in females, they supply the **clitoris**, playing a key role in sexual arousal. *Femoral artery* - The **femoral artery** is a large artery in the thigh that supplies blood to the lower limb, but it does not directly branch into the helicine arteries of the genitalia. - Its main branches include the **deep femoral artery** and the **superficial femoral artery**, which are involved in blood supply to the muscles and skin of the thigh. *External pudendal artery* - The **external pudendal artery** branches off the femoral artery and supplies the skin of the external genitalia and the perineum, but not the deeper erectile tissues via helicine arteries. - It primarily provides superficial blood supply, such as to the **scrotum** or **labia majora**, and is distinct from the internal pudendal artery's deeper distribution. *None of the options* - This option is incorrect because the **internal pudendal artery** is indeed the origin of the helicine arteries. - The other options provided are incorrect as they do not directly give rise to the helicine arteries.
Question 137: What is Galen's anastomosis?
- A. Recurrent laryngeal nerve and external laryngeal nerve
- B. Internal laryngeal nerve and recurrent laryngeal nerve (Correct Answer)
- C. None of the options
- D. Recurrent laryngeal nerve and sympathetic trunk
Explanation: ***Internal laryngeal nerve and recurrent laryngeal nerve*** - **Galen's anastomosis** (also known as **ansa Galeni**) is the connection between the **internal laryngeal nerve** (a sensory branch of the superior laryngeal nerve) and the **recurrent laryngeal nerve** (motor branch of the vagus nerve). - This anastomosis occurs in the **laryngeal mucosa** and allows for communication between these two important nerves. - The **internal laryngeal nerve** provides **sensory innervation** to the larynx above the vocal cords, while the **recurrent laryngeal nerve** provides **motor innervation** to most intrinsic laryngeal muscles (except cricothyroid). - This anastomosis is clinically significant in understanding the complex innervation patterns of the larynx. *Recurrent laryngeal nerve and external laryngeal nerve* - While both nerves are branches of the vagus nerve and innervate laryngeal structures, this connection does not constitute **Galen's anastomosis**. - The recurrent laryngeal nerve innervates intrinsic laryngeal muscles (except cricothyroid), while the external laryngeal nerve innervates the **cricothyroid muscle** and is motor in nature. *None of the options* - This option is incorrect because the correct definition of **Galen's anastomosis** is provided in the first option. *Recurrent laryngeal nerve and sympathetic trunk* - While there may be sympathetic contributions to laryngeal innervation, this does not represent **Galen's anastomosis**. - The sympathetic trunk provides autonomic innervation but the specific named anastomosis refers to the connection between the internal laryngeal and recurrent laryngeal nerves.
Question 138: 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 139: Line from midinguinal point to adductor tubercle represents?
- A. Inferior epigastric artery
- B. Femoral artery (Correct Answer)
- C. Superior epigastric artery
- D. None of the options
Explanation: The line from the **midinguinal point** to the **adductor tubercle** accurately maps the anatomical course of the **femoral artery** in the thigh. This anatomical landmark is crucial for palpating the **femoral pulse** and locating the artery for clinical procedures like catheter insertion. *Inferior epigastric artery* - The **inferior epigastric artery** originates from the external iliac artery and ascends superiorly in the anterior abdominal wall [1]. - Its course is significantly more medial and superior, far from the line described. *Superior epigastric artery* - The **superior epigastric artery** is a terminal branch of the internal thoracic artery, descending into the rectus sheath in the upper abdomen [1]. - Its location is entirely within the anterior abdominal wall, high above the inguinal region. *None of the options* - This option is incorrect because the line from the midinguinal point to the adductor tubercle clearly represents the anatomical course of the femoral artery. - The other arteries listed are not found along this specific anatomical path.
Physiology
1 questionsDeoxygenated blood is not seen in which of the following?
NEET-PG 2013 - Physiology NEET-PG Practice Questions and MCQs
Question 131: Deoxygenated blood is not seen in which of the following?
- A. Pulmonary artery
- B. Umbilical artery
- C. Pulmonary vein (Correct Answer)
- D. Right atrium
Explanation: ***Pulmonary vein*** - The pulmonary veins carry **oxygenated blood** from the lungs back to the left atrium of the heart. - Their primary function is to transport blood that has undergone **gas exchange** in the lungs, making it rich in oxygen. *Pulmonary artery* - The pulmonary artery carries **deoxygenated blood** from the right ventricle of the heart to the lungs. - This is an exception to the general rule that arteries carry oxygenated blood, as its purpose is to deliver blood for **oxygenation**. *Right atrium* - The right atrium receives **deoxygenated blood** from the systemic circulation via the superior and inferior vena cava. - It acts as a collecting chamber for blood that has supplied oxygen to the body's tissues before it is pumped to the lungs. *Umbilical artery* - The umbilical arteries carry **deoxygenated blood** and waste products from the fetus to the placenta. - In fetal circulation, these arteries are responsible for removing metabolic wastes and carbon dioxide from the fetal circulation.