NEET-PG 2012 Practice Questions

Q: Which of the following is NOT a branch of 1st part of maxillary artery?

Greater palatine artery. ***Greater palatine artery*** - This artery is a branch of the **third part** of the maxillary artery, which supplies the palate. - The third part of the maxillary artery (also known as the pterygopalatine part) gives off branches that pass through the pterygopalatine fossa. *Middle meningeal artery* - This is a significant branch of the **first part** of the maxillary artery, entering the cranial cavity via the **foramen spinosum** to supply the dura mater. - It is often injured in head trauma, leading to an **epidural hematoma**. *Accessory meningeal artery* - This artery also arises from the **first part** of the maxillary artery and enters the skull through the **foramen ovale** to supply the dura mater. - It is a smaller branch compared to the middle meningeal artery. *Inferior alveolar artery* - It is a branch of the **first part** of the maxillary artery, descending to enter the mandible via the **mandibular foramen** to supply the teeth and bone of the mandible. - It gives off the **mylohyoid branch** before entering the mandibular foramen.

Q: What does Chamberlain's line refer to in anatomical terms?

Palate to foramen magnum. ***Palate to foramen magnum*** - **Chamberlain's line** is a measurement used in radiology to assess for **basilar invagination** or impression. - It extends from the **posterior margin of the hard palate** to the **posterior lip of the foramen magnum**. *Palate to occiput* - This description is too general and does not precisely define Chamberlain's line, which specifically uses the **posterior lip of the foramen magnum** as its posterior anchor point. - While the foramen magnum is within the occipital bone, "occiput" can refer to a broader area. *Palate to temporal* - The **temporal bone** is not part of the anatomical landmarks used for Chamberlain's line. - This line is focused on structures in the midline skull base. *Palate to parietal* - The **parietal bone** is located superiorly and laterally to the structures involved in Chamberlain's line. - It is not used as a landmark for this specific measurement.

Q: The nutrient artery to the femur is?

Profunda femoris artery. ***Profunda femoris artery*** - The **profunda femoris artery** (deep femoral artery) is the main blood supply to the **femur's diaphysis** via its perforating branches. - Typically, the **second perforating branch** gives rise to the nutrient artery, which enters the bone through the **nutrient foramen** in the middle third of the femoral shaft. *Femoral artery* - The **femoral artery** is the main artery of the thigh and gives off several branches, including the profunda femoris artery. - While it is the source of blood for the entire lower limb, it does not directly give rise to the main **nutrient artery of the femur**. *Popliteal artery* - The **popliteal artery** is a continuation of the femoral artery in the popliteal fossa behind the knee. - It primarily supplies structures around the knee joint and the lower leg, not the direct **diaphyseal nutrient supply** to the femur. *Medial circumflex femoral artery* - The **medial circumflex femoral artery** primarily supplies the head and neck of the femur, crucial for its vascularity, especially in children. - It does not serve as the **main nutrient artery** for the femoral shaft (diaphysis).

Q: What is the consequence of tibial nerve injury/palsy?

Loss of plantar flexion. **Loss of plantar flexion** - The **tibial nerve** innervates the muscles of the **posterior compartment of the leg**, which are primarily responsible for **plantar flexion** of the foot. - Injury to this nerve directly impairs the function of muscles like the gastrocnemius, soleus, and tibialis posterior, leading to a significant loss of the ability to point the foot downwards. *Dorsiflexion of foot at ankle joint* - **Dorsiflexion** is primarily mediated by muscles in the **anterior compartment of the leg**, such as the tibialis anterior, which are innervated by the **deep fibular nerve**. - Tibial nerve injury would not directly affect these muscles or their function; rather, it leads to issues with the opposing action. *Loss of sensation of dorsum of foot* - Sensation to the **dorsum of the foot** is primarily supplied by the **superficial fibular nerve** (for most of the dorsum) and the **deep fibular nerve** (for the first web space). - While the tibial nerve provides sensation to the sole of the foot, it does not typically innervate the dorsum. *Paralysis of muscles of anterior compartment of leg* - The muscles of the **anterior compartment of the leg** (e.g., tibialis anterior, extensor digitorum longus, extensor hallucis longus) are innervated by the **deep fibular nerve**. - A tibial nerve injury would paralyze muscles in the posterior compartment, not the anterior compartment.

Q: All of the following arteries are branches of the coeliac trunk, EXCEPT which one?

Right gastric artery. ***Right gastric artery*** - The **right gastric artery** typically originates from the **proper hepatic artery**, which is a branch of the common hepatic artery. - Therefore, it is not a direct branch of the coeliac trunk itself. *Left gastric artery* - The **left gastric artery** is one of the three main direct branches of the **coeliac trunk**. - It supplies the lesser curvature of the stomach and the abdominal esophagus. *Splenic artery* - The **splenic artery** is another major direct branch of the **coeliac trunk**. - It supplies the spleen, pancreas, and parts of the stomach via various branches. *Common hepatic artery* - The **common hepatic artery** is the third main direct branch of the **coeliac trunk**. - It gives rise to the proper hepatic artery and the gastroduodenal artery, supplying the liver, gallbladder, pylorus, and duodenum.

Q: Coronary sinus develops from?

Sinus venosus. Sinus venosus - The sinus venosus is a primordial cardiac chamber that receives venous blood from the body and placenta in the early embryonic heart. - The left horn of the sinus venosus loses its connection with the systemic venous circulation and becomes the coronary sinus, which drains most of the cardiac veins into the right atrium [1, 4]. Truncus arteriosus - The truncus arteriosus is the embryonic precursor to the ascending aorta and pulmonary trunk. - It does not contribute to the development of the coronary sinus. Conus - The conus (or conus cordis) is the outflow portion of the primitive ventricle and differentiates into the outflow tracts of the right (infundibulum) and left (aortic vestibule) ventricles. - It is not involved in the formation of the coronary sinus. AV canal - The atrioventricular (AV) canal connects the primitive atrium and ventricle and is crucial for the formation of the AV valves and septation of the heart chambers. - It does not directly develop into the coronary sinus.

Q: The anticodon region is an important part of which type of RNA?

t-RNA. **t-RNA** - The **anticodon region** is a critical component of **transfer RNA (tRNA)**, responsible for recognizing and binding to the complementary codon on mRNA during protein synthesis. - This interaction ensures that the correct **amino acid** is delivered to the growing polypeptide chain according to the genetic code. *r-RNA* - **Ribosomal RNA (rRNA)** is a structural and enzymatic component of **ribosomes**, which are the cellular machinery for protein synthesis. - While rRNA plays a crucial role in forming **peptide bonds** and facilitating translation, it does not possess an anticodon region. *m-RNA* - **Messenger RNA (mRNA)** carries the **genetic code** from DNA to the ribosomes in the form of codons, which specify the sequence of amino acids for protein synthesis. - mRNA molecules have codons, but they do not have an **anticodon region**; instead, they are read by the anticodons of tRNA. *hn-RNA* - **Heterogeneous nuclear RNA (hnRNA)** is a precursor to mRNA in eukaryotic cells, containing both exons and introns. - It undergoes extensive processing, including **splicing**, to become mature mRNA, but it does not have an **anticodon region**.

Q: What is Little's area, also known as Kiesselbach's plexus?

Anteroinferior nasal septum. ***Anteroinferior nasal septum*** - **Little's area**, or **Kiesselbach's plexus**, is a well-vascularized region located on the **anteroinferior portion of the nasal septum**. - This area is a common site for **anterior epistaxis** (nosebleeds) due to its superficial position and rich anastomotic blood supply from several arteries. *Anteroinferior lateral wall* - While the lateral nasal wall also contributes to the nasal blood supply, the specific region of **Little's area** is on the **septum**, not the lateral wall. - The **lateral wall** contains structures like the turbinates and their associated vascular networks, which are distinct from Kiesselbach's plexus. *Posteroinferior lateral wall* - The **posterior and inferior aspects** of the nasal cavity are not where Kiesselbach's plexus is predominantly located. - Bleeding from this posterior region often indicates **posterior epistaxis**, which can be more severe and difficult to control. *Posteroinferior nasal septum* - The **posterior nasal septum** is supplied by different arteries, such as branches of the **sphenopalatine artery**. - Bleeding from this part of the septum is also considered **posterior epistaxis** and is not typically associated with Kiesselbach's plexus.

Q: Which of the following statements regarding the lower esophageal sphincter is TRUE?

It relaxes in response to swallowing.. ***It relaxes in response to swallowing.*** - The **lower esophageal sphincter (LES)** normally maintains high resting tone to prevent gastroesophageal reflux but **relaxes completely during swallowing** to allow passage of food into the stomach. - This relaxation (called **receptive relaxation**) is mediated by **vagal nerve stimulation** through release of nitric oxide (NO) and vasoactive intestinal peptide (VIP). - The relaxation occurs **before the peristaltic wave arrives**, allowing coordinated transit of the bolus. *It remains contracted during swallowing to prevent regurgitation.* - This is **incorrect** - the LES must **relax during swallowing** to allow food passage into the stomach. - Failure of LES relaxation during swallowing is the pathophysiology of **achalasia**, leading to dysphagia. - The LES only maintains contraction between swallows to prevent reflux. *Its tone is primarily influenced by the myogenic properties of the smooth muscle.* - While the LES contains smooth muscle with intrinsic myogenic properties, its tone is **predominantly regulated by neural and hormonal factors**. - **Neural control:** Vagal cholinergic pathways (increase tone), non-adrenergic non-cholinergic (NANC) pathways with NO and VIP (decrease tone). - **Hormonal factors:** Gastrin increases tone, while progesterone, CCK, and secretin decrease tone. *It contracts in response to gastric distension.* - This is **incorrect** - gastric distension actually triggers **transient LES relaxations (TLESRs)**, which are the primary mechanism of physiological reflux. - TLESRs are vagally mediated reflex responses that allow venting of gastric air. - Increased LES contraction in response to gastric distension would be counterproductive.

Question 1

Which of the following is NOT a branch of 1st part of maxillary artery?

Accepted Answer

Greater palatine artery

Answer

Accessory meningeal artery

Answer

Inferior alveolar artery

Answer

Middle meningeal artery

Question 2

What does Chamberlain's line refer to in anatomical terms?

Accepted Answer

Palate to foramen magnum

Answer

Palate to occiput

Answer

Palate to temporal

Answer

Palate to parietal

Question 3

The nutrient artery to the femur is?

Accepted Answer

Profunda femoris artery

Answer

Femoral artery

Answer

Popliteal artery

Answer

Medial circumflex femoral artery

Question 4

What is the consequence of tibial nerve injury/palsy?

Accepted Answer

Loss of plantar flexion

Answer

Dorsiflexion of foot at ankle joint

Answer

Loss of sensation of dorsum of foot

Answer

Paralysis of muscles of anterior compartment of leg

Question 5

All of the following arteries are branches of the coeliac trunk, EXCEPT which one?

Accepted Answer

Right gastric artery

Answer

Splenic artery

Answer

Left gastric artery

Answer

Common hepatic artery

Question 6

Coronary sinus develops from?

Accepted Answer

Sinus venosus

Answer

Truncus arteriosus

Answer

Conus

Answer

AV canal

Question 7

The anticodon region is an important part of which type of RNA?

Accepted Answer

t-RNA

Answer

r-RNA

Answer

m-RNA

Answer

hn-RNA

Question 8

What is Little's area, also known as Kiesselbach's plexus?

Accepted Answer

Anteroinferior nasal septum

Answer

Anteroinferior lateral wall

Answer

Posteroinferior lateral wall

Answer

Posteroinferior nasal septum

Question 9

What is the Bohr effect in relation to hemoglobin's affinity for oxygen?

Accepted Answer

Decrease in O2 affinity of hemoglobin when the pH of blood falls

Answer

Decrease in CO2 affinity of hemoglobin when the pH of blood falls

Answer

Decrease in O2 affinity of hemoglobin when the pH of blood rises

Answer

Decrease in CO2 affinity of hemoglobin when the pH of blood rises

Question 10

Which of the following statements regarding the lower esophageal sphincter is TRUE?

Accepted Answer

It relaxes in response to swallowing.

Answer

It remains contracted during swallowing to prevent regurgitation.

Answer

Its tone is primarily influenced by the myogenic properties of the smooth muscle.

Answer

It contracts in response to gastric distension.

NEET-PG 2012

Anatomy

Biochemistry

ENT

Physiology