Anatomy
4 questionsAll of the following arteries are branches of the coeliac trunk, EXCEPT which one?
From which ribs does the spleen extend?
Which of these best describes the renal angle?
The thyrocervical trunk is a branch of which part of subclavian artery?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 221: All of the following arteries are branches of the coeliac trunk, EXCEPT which one?
- A. Splenic artery
- B. Left gastric artery
- C. Common hepatic artery
- D. Right gastric artery (Correct Answer)
Explanation: ***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.
Question 222: From which ribs does the spleen extend?
- A. 5th to 9th rib
- B. 2nd to 5th rib
- C. 11th to 12th rib
- D. 9th to 11th rib (Correct Answer)
Explanation: ***9th to 11th rib*** - The **spleen** is located in the **left upper quadrant** of the abdomen, deep to the 9th, 10th, and 11th ribs. - Its protected position beneath these ribs makes it vulnerable to injury from trauma to the left lower chest or upper abdomen. *5th to 9th rib* - This range primarily covers the location of the **heart** and the upper part of the **lungs**. - While the spleen is superior to other abdominal organs, it does not extend as high as the 5th rib. *2nd to 5th rib* - This region is mainly associated with the **upper lobes of the lungs** and the **superior mediastinum**. - The spleen is an abdominal organ and is situated much lower in the thoracic cavity. *11th to 12th rib* - This range is too low and posterior for the typical position of the spleen, especially for its superior border. - The 12th rib primarily overlies the **kidneys** and the more inferior aspects of the diaphragm.
Question 223: Which of these best describes the renal angle?
- A. The angle between the latissimus dorsi and the 12th rib
- B. The angle between the erector spinae and the iliac crest
- C. The angle between the 12th rib and the erector spinae (Correct Answer)
- D. The angle between the 12th rib and the rectus abdominis
Explanation: ***The angle between the 12th rib and the erector spinae*** - The **renal angle** (also known as the costovertebral angle) is the space formed by the junction of the **12th rib** and the **erector spinae muscles** laterally. - This anatomical landmark is clinically significant for assessing **kidney pain** or inflammation (e.g., in pyelonephritis) through percussion. *The angle between the latissimus dorsi and the 12th rib* - While the **latissimus dorsi** is a significant back muscle, it is not the primary anatomical landmark that defines the renal angle. - The renal angle specifically refers to the relationship between the rib cage and the deeper spinal muscles. *The angle between the erector spinae and the iliac crest* - This description refers to a region lower down on the back, closer to the **pelvis**, and not directly related to the position of the kidneys. - The **iliac crest** defines the upper border of the pelvis, far from the kidney's typical location relative to the 12th rib. *The angle between the 12th rib and the rectus abdominis* - The **rectus abdominis** muscle is located on the anterior (front) aspect of the abdomen, involved in trunk flexion. - This muscle is anatomically distinct and separate from the posterior flank region where the kidneys are located and where the renal angle is assessed.
Question 224: The thyrocervical trunk is a branch of which part of subclavian artery?
- A. 1st part (Correct Answer)
- B. 2nd part
- C. 3rd part
- D. 4th part
Explanation: ***1st part*** - The **thyrocervical trunk** is one of the three primary branches arising from the **first part** of the subclavian artery. - The first part lies medial to the **anterior scalene muscle**. *2nd part* - The **second part** of the subclavian artery gives rise to the **costocervical trunk**. - This part lies posterior to the **anterior scalene muscle**. *3rd part* - The **third part** of the subclavian artery typically has no branches or may give off the **dorsal scapular artery**. - This part lies lateral to the **anterior scalene muscle**. *4th part* - This option is incorrect as the **subclavian artery has only three parts**, divided by their relationship to the anterior scalene muscle. - There is no anatomical fourth part of the subclavian artery.
Physiology
6 questionsWhat is the consequence of tibial nerve injury/palsy?
In bladder injury, pain is referred to which of the following areas?
What is the difference between the amount of Oxygen consumed and Carbon Dioxide produced per minute at rest?
Which of the following statements is true regarding the function of the spinocerebellar tract?
What is the fixed length of a myosin filament?
What is the average daily volume of pancreatic secretion in humans?
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 221: What is the consequence of tibial nerve injury/palsy?
- A. Loss of plantar flexion (Correct Answer)
- B. Dorsiflexion of foot at ankle joint
- C. Loss of sensation of dorsum of foot
- D. Paralysis of muscles of anterior compartment of leg
Explanation: **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.
Question 222: In bladder injury, pain is referred to which of the following areas?
- A. Flank
- B. Upper part of thigh
- C. Lower abdominal wall (Correct Answer)
- D. Penis
Explanation: ***Correct Option: Lower abdominal wall*** - **Referred pain** from the bladder is typically felt in the **suprapubic region** of the lower abdominal wall due to shared visceral and somatic afferent innervation. - The **parietal peritoneum** overlying the bladder is innervated by somatic nerves that also supply the abdominal wall. - This convergence of visceral afferents from the bladder and somatic afferents from the abdominal wall at the spinal cord level (particularly S2-S4) results in referred pain to the suprapubic area. *Incorrect Option: Upper part of thigh* - Pain in the upper thigh is more commonly associated with conditions affecting the **hip joint**, **femoral nerve**, or **inguinal region**. - Bladder innervation does not primarily refer pain to the upper thigh. *Incorrect Option: Flank* - Flank pain is typically associated with conditions of the **kidneys** or **ureters**, such as **nephrolithiasis** or **pyelonephritis**. - The bladder's referred pain pattern does not usually extend to the flank. *Incorrect Option: Penis* - While bladder irritation can sometimes cause sensations in the penis, it is more often associated with conditions like **urethritis**, **cystitis**, or **prostatitis**. - Direct referred pain from bladder injury to the penis is less common than to the lower abdominal wall.
Question 223: What is the difference between the amount of Oxygen consumed and Carbon Dioxide produced per minute at rest?
- A. 20 ml/min
- B. 50 ml/min (Correct Answer)
- C. 75 ml/min
- D. 100 ml/min
Explanation: ***50 ml/min*** - The body typically consumes about **250 ml/min of oxygen** at rest and produces approximately **200 ml/min of carbon dioxide**. - The difference between oxygen consumed and carbon dioxide produced is therefore **50 ml/min** (250 - 200 = 50). - This difference exists because the **respiratory quotient (RQ)** is approximately **0.8** (200/250), meaning less CO2 is produced than O2 consumed on a molar basis. *20 ml/min* - This value is **too low** and underestimates the physiological difference between oxygen consumption and carbon dioxide production. - With typical O2 consumption of 250 ml/min and RQ of 0.8, the difference cannot be this small. *75 ml/min* - This value represents an **overestimation** of the difference between oxygen consumption and carbon dioxide production under normal resting conditions. - This would imply an RQ of approximately 0.7, which is lower than the typical mixed diet RQ of 0.8. *100 ml/min* - This value is a significant **overestimation** of the physiological difference. - This would suggest an RQ of 0.6, which is not physiologically normal for resting conditions on a mixed diet.
Question 224: Which of the following statements is true regarding the function of the spinocerebellar tract?
- A. Smoothens and coordinates movements (Correct Answer)
- B. Involved in planning and programming motor activities
- C. Involved in maintaining equilibrium
- D. Facilitates learning through vestibulo-ocular reflex changes
Explanation: ***Smoothens and coordinates movements*** - The spinocerebellar tract provides the cerebellum with **unconscious proprioceptive information** from muscle spindles and Golgi tendon organs. - This information allows the cerebellum to compare intended movements with actual movements, thereby **smoothing and coordinating voluntary motor activity**. *Involved in planning and programming motor activities* - This function is primarily attributed to the **cerebral cortex** (e.g., premotor and supplementary motor areas) and the **basal ganglia**. - While the cerebellum is involved in motor learning and fine-tuning, the initial **planning and programming** of complex movements are cortical functions. *Involved in maintaining equilibrium* - Maintaining equilibrium and balance is primarily a function of the **vestibulocerebellum** (flocculonodular lobe), which receives input from the vestibular system. - While the spinocerebellum indirectly influences balance by coordinating limb movements, its direct role is less pronounced than that of the vestibulocerebellum. *Facilitates learning through vestibulo-ocular reflex changes* - This function is specific to the **vestibulocerebellum** and is crucial for adapting the vestibulo-ocular reflex (VOR) to maintain visual stability during head movements. - The spinocerebellar tract's primary role is proprioception for limb coordination, not VOR adaptation.
Question 225: What is the fixed length of a myosin filament?
- A. 0.16 nm
- B. 1.6 micrometers (Correct Answer)
- C. 16 nm
- D. 1.6 mm
Explanation: ***1.6 micrometers*** - Myosin filaments, also known as **thick filaments**, are integral components of muscle contraction and have a characteristic fixed length. This length is precisely **1.6 micrometers** in mammalian skeletal muscle. - This consistent length is crucial for the **sliding filament model** of muscle contraction, ensuring proper overlap with actin filaments and efficient force generation. *0.16 nm* - This value is significantly too small; **nanometers (nm)** are typically used for atomic or molecular distances, not for entire protein filaments like myosin. - A myosin filament is composed of hundreds of myosin molecules, making its overall length much larger than a fraction of a nanometer. *16 nm* - While nanometers are used for molecular structures, 16 nm is still too small for a myosin filament. The entire filament is roughly **100 times larger** than this value. - This dimension might be more appropriate for the diameter of a single myosin molecule's head region, but not the entire filament's length. *1.6 mm* - This value is significantly too large; **millimeters (mm)** are visible to the naked eye and represent macroscopic objects. - Muscle filaments are microscopic structures, and a length of 1.6 mm would imply they are many times longer than an entire muscle cell.
Question 226: What is the average daily volume of pancreatic secretion in humans?
- A. 5.0 L
- B. 10 L
- C. 1.5 L (Correct Answer)
- D. 2.5 L
Explanation: ***1.5 L*** - The **pancreas** produces approximately **1.5 liters (1200-1500 mL) of pancreatic juice** daily in humans. - This secretion is rich in **digestive enzymes** (amylase, lipase, proteases) and **bicarbonate** for neutralization of gastric acid in the duodenum. - This is the standard value cited in **major physiology textbooks** (Ganong, Guyton & Hall). *2.5 L* - **2.5 liters** overestimates the typical daily pancreatic secretion volume. - This value may represent **combined secretions** from multiple sources or confuse pancreatic output with total upper GI secretions. - Normal pancreatic secretion ranges from **1-2 liters**, making 2.5 L above the physiological range. *5.0 L* - **5.0 liters** represents an abnormally high volume for daily pancreatic secretion alone. - This volume is closer to the **total daily secretions** from stomach, pancreas, and bile combined. - Not consistent with **normal pancreatic physiology**. *10 L* - **10 liters** is grossly excessive for pancreatic secretion and represents approximately the **total volume of all gastrointestinal secretions** (saliva, gastric, pancreatic, bile, intestinal) combined daily. - This is **not physiologically realistic** for pancreatic output alone.