Anatomy
9 questionsSuperficial inguinal ring is a defect in the:
Which of the following is NOT a component of the spermatic cord?
Which of the following muscles is contained in the superficial perineal space?
Gastrosplenic ligament contains ?
Which of the following is a derivative of ventral mesogastrium ?
What is the correct sequence of uterine blood flow?
Nerve supply of stapedius is:
The sternocleidomastoid muscle is examined by
Floor of Petit triangle is formed by?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 91: Superficial inguinal ring is a defect in the:
- A. Internal oblique muscle
- B. Transverse abdominis aponeurosis
- C. External oblique aponeurosis (Correct Answer)
- D. Internal oblique aponeurosis
Explanation: ***External oblique aponeurosis*** - The **superficial inguinal ring** is a triangular opening in the **aponeurosis of the external oblique muscle** [1]. - It allows passage of the **spermatic cord** in males and the **round ligament of the uterus** in females. *Transverse abdominis aponeurosis* - The **transverse abdominis aponeurosis** contributes to the posterior wall of the **inguinal canal**, but not the superficial inguinal ring itself [2]. - The deepest abdominal muscle, its aponeurosis forms the **conjoint tendon** with the internal oblique aponeurosis. *Internal oblique muscle* - The **internal oblique muscle** forms the arching roof and part of the anterior wall of the **inguinal canal** [2]. - Its aponeurosis contributes to the **conjoint tendon** and the falx inguinalis. *Internal oblique aponeurosis* - The **internal oblique aponeurosis** is part of the anterior wall and forms the conjoint tendon with the transverse abdominis aponeurosis [2]. - This aponeurosis does not form the superficial inguinal ring; instead, it is found deeper to the external oblique aponeurosis.
Question 92: Which of the following is NOT a component of the spermatic cord?
- A. Poupart's ligament (Correct Answer)
- B. Genito-femoral nerve
- C. Vas deferens
- D. Pampiniform plexus
Explanation: ***Poupart's ligament*** - **Poupart's ligament**, also known as the **inguinal ligament**, is a fibrous band extending from the anterior superior iliac spine to the pubic tubercle and forms the **inferior boundary of the inguinal canal**. - It is a boundary structure of the inguinal canal but is **not contained within the spermatic cord** itself [1]. *Genito-femoral nerve* - The **genital branch of the genitofemoral nerve** passes through the inguinal canal and supplies the **cremaster muscle** and scrotal skin [1]. - While it accompanies the spermatic cord through the canal, it is **not traditionally listed as a component of the spermatic cord** in standard anatomical classification, though some sources may include it [1]. *Vas deferens* - The **vas deferens** (ductus deferens) is a thick muscular tube that transports sperm from the epididymis to the ejaculatory duct. - It is a **primary structural component of the spermatic cord** and is the most prominent palpable structure within it. *Pampiniform plexus* - The **pampiniform plexus** is a network of 8-12 veins that surrounds the testicular artery within the spermatic cord. - This venous plexus provides a **countercurrent heat exchange mechanism** for thermoregulation of the testes and is a major component of the spermatic cord.
Question 93: Which of the following muscles is contained in the superficial perineal space?
- A. Sphincter urethrae muscle
- B. Deep transverse perinei muscle
- C. Bulbourethral gland
- D. Ischiocavernosus muscle (Correct Answer)
Explanation: ***Ischiocavernosus muscle*** - This muscle is located in the **superficial perineal space** and is the correct answer - Arises from the **ischial tuberosity** and surrounds the crus of the corpus cavernosum - Functions in maintaining **penile/clitoral erection** by compressing the crus and impeding venous return - Other muscles in the superficial perineal space include **bulbospongiosus** and **superficial transverse perinei** *Sphincter urethrae muscle* - Located in the **deep perineal space**, not superficial - Part of the urogenital diaphragm - Provides **voluntary control of urination** - Innervated by the pudendal nerve (S2-S4) *Deep transverse perinei muscle* - Also located in the **deep perineal space** - Forms part of the urogenital diaphragm along with sphincter urethrae - Contributes to pelvic floor support and **urinary continence** *Bulbourethral gland* - This is a **gland, not a muscle**, making it an incorrect choice on two counts - Located in the **deep perineal space** in males (Cowper's glands) - Secretes pre-ejaculate fluid that lubricates the urethra - This option tests both anatomical knowledge and ability to distinguish structure types
Question 94: Gastrosplenic ligament contains ?
- A. Splenic vessels
- B. Tail of pancreas
- C. Short gastric artery (Correct Answer)
- D. Portal vein
Explanation: ***Short gastric artery*** - The **short gastric arteries** are branches of the **splenic artery** and supply the **fundus** and upper part of the **greater curvature** of the stomach. - These vessels travel within the **gastrosplenic ligament** (or gastrosplenic omentum), connecting the greater curvature of the stomach to the hilum of the spleen [1]. *Splenic vessels* - The **splenic artery** and **vein** primarily travel within the **splenorenal ligament** (or lienorenal ligament), connecting the spleen to the posterior abdominal wall. - These major vessels supply and drain the spleen itself, not typically running within the gastrosplenic ligament [1]. *Tail of pancreas* - The **tail of the pancreas** is typically located within the **splenorenal ligament**, closely associated with the **hilum of the spleen** [1]. - It does not extend into the gastrosplenic ligament, which connects the stomach to the spleen. *Portal vein* - The **portal vein** is a major vessel formed by the confluence of the **splenic vein** and **superior mesenteric vein**, and it is located in the **hepatoduodenal ligament** (part of the lesser omentum) along with the hepatic artery and common bile duct. - This vessel is far removed from the gastrosplenic ligament, which is situated between the stomach and spleen.
Question 95: Which of the following is a derivative of ventral mesogastrium ?
- A. Lesser omentum (Correct Answer)
- B. Splenorenal ligament
- C. Greater omentum
- D. Gastrosplenic ligament
Explanation: ***Lesser omentum*** - The **lesser omentum** is formed from the **ventral mesogastrium**, which connects the developing stomach to the anterior abdominal wall [1]. - It specifically derives from the part of the ventral mesogastrium that encloses the developing liver and extends to the lesser curvature of the stomach and the duodenum [1]. *Greater omentum* - The **greater omentum** develops from the **dorsal mesogastrium**, which means it is a derivative of the dorsal rather than the ventral mesentery [1]. - It arises from a rapid growth and fusion of the **dorsal mesogastrium**, hanging from the greater curvature of the stomach. *Splenorenal ligament* - The **splenorenal ligament** develops from the **dorsal mesogastrium**, specifically from the portion that connects the spleen to the posterior abdominal wall (near the kidney). - Its formation is a consequence of the rotation of the stomach and the development of the spleen within the dorsal mesentery. *Gastrosplenic ligament* - The **gastrosplenic ligament** is also derived from the **dorsal mesogastrium**, connecting the greater curvature of the stomach to the hilum of the spleen. - As the stomach rotates, the dorsal mesogastrium expands, eventually forming both the gastrosplenic and splenorenal ligaments.
Question 96: What is the correct sequence of uterine blood flow?
- A. Uterine A → Radial A → Arcuate A → Spiral A
- B. Uterine A → Spiral A → Radial A → Arcuate A
- C. Uterine A → Arcuate A → Spiral A → Radial A
- D. Uterine A → Arcuate A → Radial A → Spiral A (Correct Answer)
Explanation: ***Uterine A → Arcuate A → Radial A → Spiral A*** - The **uterine artery** is the primary blood supply, branching into several arteries within the myometrium. - **Arcuate arteries** encircle the uterus, giving off perpendicular branches called **radial arteries**, which then give rise to the **spiral arteries** that supply the endometrium [1]. *Uterine A → Radial A → Arcuate A → Spiral A* - This sequence is incorrect because **radial arteries** arise from **arcuate arteries**, not the other way around. - **Arcuate arteries** are larger circumferential vessels that branch into the smaller radial arteries. *Uterine A → Spiral A → Radial A → Arcuate A* - This sequence is highly incorrect as **spiral arteries** are the most distal branches supplying the endometrium, not preceding radial or arcuate arteries [1]. - The flow is from larger to smaller vessels, with **spiral arteries** being the smallest and most terminal. *Uterine A → Arcuate A → Spiral A → Radial A* - This sequence incorrectly places **spiral arteries** before **radial arteries**. - **Radial arteries** are the immediate precursors to **spiral arteries**, providing direct branches to them.
Question 97: Nerve supply of stapedius is:
- A. Facial nerve (7th nerve) (Correct Answer)
- B. Oculomotor nerve (3rd nerve)
- C. Trigeminal nerve (5th nerve)
- D. Glossopharyngeal nerve (9th nerve)
Explanation: ***Facial nerve (7th nerve)*** - The **facial nerve** is responsible for innervating the **stapedius muscle**, which helps to dampen loud sounds by pulling the stapes away from the oval window. - A lesion in the facial nerve can lead to **hyperacusis** due to the paralysis of the stapedius muscle. *Oculomotor nerve (3rd nerve)* - The **oculomotor nerve** primarily controls **eye movements** and **pupil constriction**. - It does not have any direct involvement in the innervation of middle ear muscles. *Trigeminal nerve (5th nerve)* - The **trigeminal nerve** is responsible for **sensation of the face** and innervates the **muscles of mastication**. - It provides motor supply to the **tensor tympani muscle**, not the stapedius. *Glossopharyngeal nerve (9th nerve)* - The **glossopharyngeal nerve** is primarily involved in **taste sensation** from the posterior tongue, **swallowing**, and mediating the **gag reflex**. - It does not innervate any muscles of the middle ear.
Question 98: The sternocleidomastoid muscle is examined by
- A. Shrugging of shoulder
- B. Overhead abduction
- C. Turning the head towards the same side to assess the muscle on that side
- D. Turning the head towards the opposite side to assess the muscle on that side (Correct Answer)
Explanation: ***Turning the head towards the opposite side to assess the muscle on that side*** - The **sternocleidomastoid muscle** unilaterally acts to rotate the head to the **contralateral side**. - To palpate or visually inspect the right sternocleidomastoid, the patient would turn their head to the left, making the right muscle prominent. *Turning the head towards the same side to assess the muscle on that side* - Turning the head towards the same side primarily engages the **ipsilateral deep neck flexors** and **splenius capitis**, not the sternocleidomastoid. - This action would relax the sternocleidomastoid on the side towards which the head is turned, making it difficult to assess. *Shrugging of shoulder* - Shrugging the shoulder is primarily an action of the **trapezius** and **levator scapulae muscles**. - The sternocleidomastoid does not contribute significantly to shoulder elevation. *Overhead abduction* - Overhead abduction of the arm is primarily performed by the **deltoid muscle** and assisted by the **supraspinatus**. - This movement is entirely unrelated to the function of the sternocleidomastoid muscle.
Question 99: Floor of Petit triangle is formed by?
- A. Internal oblique muscle (Correct Answer)
- B. Sacrospinalis muscle
- C. Rectus abdominis muscle
- D. Fascia Transversalis layer
Explanation: ***Internal oblique muscle*** - The **Petit triangle** (lumbar triangle) is a landmark defined by the **latissimus dorsi posteriorly**, the **external oblique anteriorly**, and the **iliac crest inferiorly**. - Its **floor** is consistently formed by the **internal oblique muscle**, which lies deep to the external oblique [1]. *Sacrospinalis muscle* - The **sacrospinalis muscle** (erector spinae) is part of the deep back muscles, located medial to the Petit triangle. - It forms part of the **vertebral column's musculature** and is not directly associated with the floor of the Petit triangle. *Rectus abdominis muscle* - The **rectus abdominis muscle** is located medially in the anterior abdominal wall [1]. - It is distinct from the lateral abdominal wall muscles that form the boundaries and floor of the Petit triangle. *Fascia Transversalis layer* - The **fascia transversalis** is a deeper fascial layer lining the abdominal wall. - While it's deep to the internal oblique, the **muscle itself** forms the immediate anatomical floor of the Petit triangle.
Physiology
1 questionsStapedius pulls stapes in which direction?
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 91: Stapedius pulls stapes in which direction?
- A. Anterior
- B. Superior
- C. Inferior
- D. Posterior (Correct Answer)
Explanation: ***Posterior*** - The **stapedius muscle** attaches to the **posterior surface of the stapes neck**. - Contraction of the stapedius muscle pulls the stapes **posteriorly and laterally** (posterolaterally), tilting the footplate away from the oval window and reducing sound transmission. - This action dampens excessive vibrations and protects the inner ear from loud sounds as part of the **acoustic reflex**. *Anterior* - Pulling the stapes anteriorly would push the footplate further into the **oval window**, which would increase sound transmission rather than dampen it. - No muscle pulls the stapes anteriorly in the context of the **acoustic reflex**. *Superior* - The stapedius muscle's action is primarily along the **posterolateral axis**, not superiorly. - Pulling superiorly would not effectively dampen sound vibrations or protect the inner ear from acoustic trauma. *Inferior* - The anatomy and function of the stapedius muscle do not support an inferior pulling action. - The stapedius acts to stabilize and retract the stapes **posterolaterally**, not inferiorly.