Anatomy
8 questionsSuperficial middle cerebral vein drains into -
Lips do not drain into which group of lymph nodes?
Which structure forms the lateral border of the ischiorectal fossa?
Common hepatic artery is a branch of:
Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
Which of the following structures does not pass through the superior thoracic aperture?
What is the primary lymphatic drainage pathway of the ovary?
Inversion and eversion of foot occurs at which joint
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 111: Superficial middle cerebral vein drains into -
- A. Internal cerebral vein
- B. Cavernous sinus (Correct Answer)
- C. Great cerebral vein of Galen
- D. Straight sinus
Explanation: **Cavernous sinus** - The **superficial middle cerebral vein** runs along the **lateral sulcus** and is a major drainage pathway, typically emptying into the **cavernous sinus**. - Its drainage into the **cavernous sinus** then allows blood to eventually reach the superior and inferior petrosal sinuses [1]. *Internal cerebral vein* - This vein is part of the **deep venous system** of the brain [1] and primarily drains structures like the **basal ganglia** and **thalamus**. - It does not receive direct drainage from the **superficial middle cerebral vein**. *Great cerebral vein of Galen* - The **great cerebral vein of Galen** is formed by the union of the **internal cerebral veins** and is a major collector of **deep venous blood**. - It drains into the **straight sinus** and is not the primary drainage site for the superficial middle cerebral vein. *Straight sinus* - The **straight sinus** is a large dural venous sinus that receives blood from the **great cerebral vein of Galen** and the **inferior sagittal sinus**. - It primarily drains deeper structures of the brain and does not directly receive the **superficial middle cerebral vein** [1].
Question 112: Lips do not drain into which group of lymph nodes?
- A. Submandibular nodes
- B. Preauricular parotid (Correct Answer)
- C. None of the options
- D. Submental nodes
Explanation: ***Preauricular parotid*** - Lymph from the lips primarily drains into the **submental**, **submandibular**, and **deep cervical lymph nodes** [1]. - **Preauricular parotid nodes** primarily drain the lateral surface of the auricle, external auditory canal, temporoparietal scalp, and lateral parts of the eyelids and cheek. - The lips do **NOT** drain into preauricular nodes. *Submandibular nodes* - The **lateral parts of the lower lip** and the **entire upper lip** drain into the submandibular lymph nodes [1]. - These nodes are a primary drainage pathway for the oral region. *Submental nodes* - The **central part of the lower lip** drains into the submental lymph nodes [1]. - These nodes lie between the anterior bellies of the digastric muscles beneath the chin. - They receive lymph from the central lower lip, floor of mouth, and tip of tongue. *None of the options* - This option is incorrect because there is a specific group of nodes listed that the lips do *not* drain into (preauricular parotid).
Question 113: Which structure forms the lateral border of the ischiorectal fossa?
- A. Perineal membrane
- B. Obturator internus muscle (Correct Answer)
- C. Gluteus maximus
- D. Sacrotuberous ligament
Explanation: ***Obturator internus muscle*** - The **ischiorectal fossa** (also known as the **ischioanal fossa**) is a wedge-shaped space in the perineum, and its lateral wall is formed by the **obturator internus muscle** and its covering fascia [1]. - This muscle originates from the inner surface of the **obturator membrane** and the surrounding bone, descending through the lesser sciatic foramen to insert on the greater trochanter of the femur. *Perineal membrane* - The **perineal membrane** is a dense fibrous sheet that forms the inferior boundary of the **deep perineal pouch**. - It does not form a lateral border of the ischiorectal fossa but rather contributes to the floor of the **urogenital triangle**, anterior to the fossa. *Gluteus maximus* - The **gluteus maximus** is a large muscle of the buttock, primarily involved in extension and lateral rotation of the hip. - It lies superficial to the structures of the perineum and therefore does not form a boundary of the **ischiorectal fossa**. *Sacrotuberous ligament* - The **sacrotuberous ligament** is a strong fibrous band connecting the sacrum to the ischial tuberosity. - While it helps to define the boundaries of the **perineum** posteriorly and contributes to the stability of the **sacroiliac joint**, it does not form the lateral wall of the **ischiorectal fossa**.
Question 114: Common hepatic artery is a branch of:
- A. Splenic artery
- B. Superior mesenteric artery
- C. Inferior mesenteric artery
- D. Coeliac trunk (Correct Answer)
Explanation: ***Coeliac trunk*** - The **common hepatic artery** is one of the three main branches arising from the **coeliac trunk**, which is the first major anterior branch of the abdominal aorta [1]. - It typically supplies the **liver**, gallbladder, pylorus of the stomach, and part of the duodenum through its various branches [1]. *Splenic artery* - The **splenic artery** is another major branch of the coeliac trunk, primarily supplying the **spleen**, and also gives off branches to the stomach and pancreas [1]. - It does not directly give rise to the common hepatic artery. *Superior mesenteric artery* - The **superior mesenteric artery (SMA)** originates just inferior to the coeliac trunk from the abdominal aorta and supplies structures of the **midgut**, including the small intestine, and parts of the large intestine. - It is not a direct source of the common hepatic artery. *Inferior mesenteric artery* - The **inferior mesenteric artery (IMA)** arises from the abdominal aorta further inferior to the SMA and supplies the **hindgut**, including the distal transverse colon to the superior part of the rectum. - It is anatomically distinct and separate from the arterial supply to the foregut-derived organs supplied by the common hepatic artery.
Question 115: Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
- A. Sciatic nerve (Correct Answer)
- B. Superior gluteal artery
- C. Inferior gluteal artery
- D. Piriformis muscle
Explanation: ***Sciatic nerve*** - The **sciatic nerve** is the largest nerve in the human body, formed from the sacral plexus, and it is indeed the largest structure that passes through the **greater sciatic foramen** as it descends into the posterior thigh. - It supplies motor and sensory innervation to the posterior thigh, lower leg, and foot. *Superior gluteal artery* - The superior gluteal artery exits the pelvis through the **greater sciatic foramen** above the piriformis muscle. - While significant, it is an artery and not a nerve, and it is not the largest structure passing through this foramen. *Inferior gluteal artery* - The inferior gluteal artery also exits the pelvis via the **greater sciatic foramen**, inferior to the piriformis muscle. - Like the superior gluteal artery, it is an arterial structure and not a nerve, and it is not the largest structure in the foramen. *Piriformis muscle* - The **piriformis muscle** originates inside the pelvis and passes through the **greater sciatic foramen** to insert on the greater trochanter of the femur. - Although it occupies a significant portion of the foramen, it is a muscle, not a nerve, and the sciatic nerve is the largest nerve exiting this aperture.
Question 116: 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 117: 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 118: Inversion and eversion of foot occurs at which joint
- A. Ankle
- B. Subtalar (Correct Answer)
- C. Tarso-metatarsal
- D. None of the options
Explanation: ***Subtalar*** - The **subtalar joint** (talocalcaneal joint) is primarily responsible for **inversion** and **eversion** movements of the foot. - **Inversion** involves tilting the sole of the foot medially (turning inward), while **eversion** involves tilting the sole laterally (turning outward). - This joint allows the foot to **adapt to uneven surfaces** and plays a crucial role in the biomechanics of walking and running. - The subtalar joint is essential for shock absorption and balance during gait. *Ankle* - The **ankle joint** (talocrural joint) is a hinge joint primarily responsible for **dorsiflexion** and **plantarflexion** of the foot. - It allows moving the foot up and down but has minimal contribution to inversion and eversion. *Tarso-metatarsal* - The **tarso-metatarsal joints** (Lisfranc joints) connect the tarsal bones to the metatarsal bones. - These joints contribute primarily to the **stability and arch integrity** of the foot, with minimal movement capacity. - They allow slight gliding movements but not significant inversion or eversion. *None of the options* - This option is incorrect because the **subtalar joint** is indeed the primary joint responsible for inversion and eversion of the foot. - Understanding foot joint biomechanics is essential for diagnosing gait abnormalities, ankle sprains, and foot pathologies.
Internal Medicine
1 questionsIn which portion of the esophagus do esophageal varices primarily occur?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 111: In which portion of the esophagus do esophageal varices primarily occur?
- A. All sites
- B. Upper
- C. Lower (Correct Answer)
- D. Middle
Explanation: **Lower** - Esophageal varices are most commonly found in the **distal (lower) third of the esophagus** [1] because this is where the portal venous system (short gastric and left gastric veins) anastomoses with the systemic venous system (white esophageal veins draining into the azygous system) [1]. - Increased portal pressure (e.g., in **portal hypertension** due to liver cirrhosis) causes blood to back up into these collateral vessels, leading to their dilation and formation of varices, particularly prominent in the lower esophagus [1]. *Upper* - While some collateral circulation exists throughout the esophagus, varices are not predominantly found in the upper portion as the primary portosystemic anastomoses responsible for variceal formation are more distal. - Varices in the upper esophagus are less common and typically less clinically significant in terms of bleeding risk. *Middle* - The middle portion of the esophagus has some venous drainage, but it is not the primary site for the significant portosystemic collaterals that lead to the formation of large, high-risk varices. - Varices can extend into the middle esophagus, but their origin and highest concentration are usually in the lower third. *All sites* - While varices can technically be found at various points along the esophagus, stating "all sites" is inaccurate because they have a **marked predilection for the lower third** due to specific anatomical venous connections [1]. - The risk of rupture and bleeding is also highest in the larger varices found in the lower esophagus [1].
Physiology
1 questionsLabour pain in uterus is carried by
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 111: Labour pain in uterus is carried by
- A. Sympathetic nerves (Correct Answer)
- B. Pudendal nerve
- C. Parasympathetic nerves
- D. Splanchnic nerve
Explanation: ***Sympathetic nerves*** - Pain signals from the **uterus** during the first stage of labor (cervical dilation and uterine contractions) are transmitted via **visceral afferent fibers that accompany the sympathetic nerves** through the **hypogastric plexus**. - These fibers synapse in the **thoracolumbar spinal cord** at **T10-L1 segments**, leading to referred pain in these dermatomes. - The pathway is: Uterus → Uterine plexus → Superior hypogastric plexus → Sympathetic chain → T10-L1 dorsal roots. *Splanchnic nerve* - While visceral afferents do travel with splanchnic nerves in the thoracoabdominal region, for **uterine pain** specifically, the standard medical terminology refers to **sympathetic nerves** and the **hypogastric plexus** as the primary pathway. - Splanchnic nerves typically refer to thoracic sympathetic contributions (T5-T12) to upper abdominal viscera. *Pudendal nerve* - The **pudendal nerve (S2-S4)** primarily innervates the perineum, external genitalia, and pelvic floor structures. - It transmits pain during the **second stage of labor**, particularly with stretching of the perineum and vaginal distension, but **not from the uterus itself**. *Parasympathetic nerves* - **Parasympathetic innervation (S2-S4 via pelvic splanchnic nerves)** to the uterus influences motor function but does **not transmit nociceptive (pain) signals** during labor. - These nerves are involved in visceral reflexes and efferent control, not the primary afferent pain pathway.