Chapter: Thorax; Topic: Great Vessels and Fetal Circulation; Subtopic: Derivatives of Embryonic Ducts
Keyword Definitions:
• Ductus arteriosus: A fetal blood vessel that connects the pulmonary artery to the descending aorta, bypassing nonfunctional fetal lungs.
• Ligamentum arteriosum: The postnatal remnant of the ductus arteriosus, connecting the aorta to the pulmonary trunk.
• Ductus venosus: A fetal vessel that shunts oxygenated blood from the umbilical vein to the inferior vena cava, bypassing the liver.
• Foramen ovale: A fetal cardiac opening between the right and left atria allowing blood flow to bypass the lungs.
• Prostaglandins: Substances that maintain ductus arteriosus patency in the fetus by causing smooth muscle relaxation.
Lead Question - 2015
Ligamentum arteriosum is derived from:
a) Ductus arteriosus
b) Ductus venosus
c) Ductus utriculosaccularis
d) Ductus reunions
Answer: a) Ductus arteriosus
Explanation: The ligamentum arteriosum is a small fibrous band connecting the pulmonary artery to the aortic arch, derived from the fetal ductus arteriosus. During fetal life, this vessel shunts blood from the pulmonary trunk to the descending aorta. After birth, closure occurs due to decreased prostaglandins and increased oxygen tension.
1. Which fetal vessel connects the umbilical vein to the inferior vena cava?
a) Ductus arteriosus
b) Ductus venosus
c) Foramen ovale
d) Umbilical artery
Answer: b) Ductus venosus
Explanation: The ductus venosus carries oxygen-rich blood from the placenta via the umbilical vein to the inferior vena cava, bypassing the liver. After birth, it closes to form the ligamentum venosum. This ensures the fetal brain receives oxygenated blood efficiently during intrauterine life, essential for growth and development.
2. The foramen ovale allows blood flow between which heart chambers in the fetus?
a) Right atrium and right ventricle
b) Right atrium and left atrium
c) Left atrium and left ventricle
d) Right ventricle and left ventricle
Answer: b) Right atrium and left atrium
Explanation: The foramen ovale is an opening between the right and left atria of the fetal heart, enabling oxygenated blood from the inferior vena cava to bypass the non-functional lungs. Postnatally, it closes to become the fossa ovalis, separating systemic and pulmonary circulations completely.
3. The ductus arteriosus connects the:
a) Pulmonary artery and descending aorta
b) Pulmonary vein and left atrium
c) Right atrium and left atrium
d) Aortic arch and right ventricle
Answer: a) Pulmonary artery and descending aorta
Explanation: The ductus arteriosus connects the pulmonary artery to the descending aorta, allowing blood to bypass the fetal lungs. After birth, the rise in oxygen tension and decline in prostaglandins cause its closure, forming the ligamentum arteriosum. Persistent patency leads to left-to-right shunt and heart failure if untreated.
4. Which fetal vessel becomes the ligamentum teres hepatis after birth?
a) Umbilical vein
b) Umbilical artery
c) Ductus venosus
d) Vitelline vein
Answer: a) Umbilical vein
Explanation: The umbilical vein, which carries oxygenated blood from the placenta to the fetus, closes after birth and becomes the ligamentum teres hepatis. This fibrous remnant runs along the free margin of the falciform ligament of the liver. Its closure redirects circulation through the portal system postnatally.
5. Which prostaglandin maintains patency of the ductus arteriosus during fetal life?
a) PGE1
b) PGI2
c) PGF2α
d) TXA2
Answer: a) PGE1
Explanation: Prostaglandin E1 (PGE1) is crucial for maintaining ductus arteriosus patency in utero by promoting smooth muscle relaxation. After birth, decreased prostaglandin levels due to lung function lead to ductal closure. Clinically, PGE1 infusion is used to keep the ductus open in neonates with duct-dependent congenital heart diseases.
6. A newborn with continuous murmur at the left upper sternal border most likely has:
a) Patent foramen ovale
b) Ventricular septal defect
c) Patent ductus arteriosus
d) Atrial septal defect
Answer: c) Patent ductus arteriosus
Explanation: A continuous “machinery” murmur at the left upper sternal border is characteristic of patent ductus arteriosus (PDA). The persistence of this fetal vessel leads to a left-to-right shunt, pulmonary hypertension, and left heart volume overload. Treatment includes indomethacin or surgical ligation depending on severity.
7. Which congenital infection is most commonly associated with patent ductus arteriosus?
a) Cytomegalovirus
b) Rubella
c) Herpes simplex
d) Toxoplasmosis
Answer: b) Rubella
Explanation: Congenital rubella infection is strongly associated with PDA due to damage to the fetal ductus arteriosus wall. Other anomalies include cataracts, microcephaly, and sensorineural deafness. Early maternal vaccination prevents congenital rubella syndrome and its cardiac manifestations like PDA and pulmonary artery stenosis.
8. Which nerve loops around the ligamentum arteriosum?
a) Right recurrent laryngeal nerve
b) Left recurrent laryngeal nerve
c) Left phrenic nerve
d) Right vagus nerve
Answer: b) Left recurrent laryngeal nerve
Explanation: The left recurrent laryngeal nerve loops around the arch of the aorta near the ligamentum arteriosum and ascends between the trachea and esophagus to supply intrinsic laryngeal muscles. Damage during surgery or aortic aneurysm may lead to hoarseness due to vocal cord paralysis.
9. In the fetus, blood bypasses the nonfunctional lungs through which structures?
a) Foramen ovale and ductus arteriosus
b) Ductus venosus and foramen ovale
c) Ductus arteriosus and ductus venosus
d) Umbilical arteries
Answer: a) Foramen ovale and ductus arteriosus
Explanation: Fetal blood bypasses the nonfunctional lungs through two shunts: the foramen ovale between atria and the ductus arteriosus between pulmonary artery and aorta. These ensure oxygenated blood from the placenta reaches systemic circulation efficiently. Both close soon after birth with the onset of lung respiration.
10. Surgical ligation of patent ductus arteriosus is performed between:
a) Aortic arch and pulmonary artery
b) Aorta and pulmonary vein
c) Aortic arch and right ventricle
d) Pulmonary vein and atrium
Answer: a) Aortic arch and pulmonary artery
Explanation: PDA ligation is carried out between the aortic arch and pulmonary artery to stop abnormal shunting. This reduces pulmonary overcirculation and cardiac overload. Proper timing and surgical precision are crucial to avoid injury to adjacent structures like the left recurrent laryngeal nerve and thoracic duct.
Chapter: Thorax; Topic: Heart and Great Vessels; Subtopic: Borders of the Heart
Keyword Definitions:
• Heart borders: The external boundaries of the heart seen on radiographs or during dissection, formed by different chambers.
• Right atrium: Forms the right border of the heart and receives blood from the SVC, IVC, and coronary sinus.
• Left ventricle: Forms the left border of the heart and the cardiac apex.
• Right ventricle: Constitutes the anterior surface and lower border of the heart.
• Cardiac silhouette: The outline of the heart visible on chest X-ray, representing its anatomical borders.
Lead Question - 2015
Right border of heart is formed by ?
a) Right ventricle
b) Right atrium
c) SVC
d) IVC
Answer: b) Right atrium
Explanation: The right border of the heart on the chest X-ray and in anatomical position is formed mainly by the right atrium, extending between the openings of the superior and inferior vena cava. It lies about 1.25 cm from the right sternal margin and represents the systemic venous component of the heart.
1. Which chamber forms the left border of the heart?
a) Right atrium
b) Right ventricle
c) Left ventricle
d) Left atrium
Answer: c) Left ventricle
Explanation: The left border of the heart is formed mainly by the left ventricle and partly by the left auricle. It extends from the second left costal cartilage to the apex beat in the fifth intercostal space. It represents the systemic pumping chamber of the heart and is thicker than the right ventricle.
2. The inferior border of the heart is formed mainly by:
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Answer: a) Right ventricle
Explanation: The inferior or lower border of the heart is formed chiefly by the right ventricle with a small contribution from the left ventricle near the apex. It separates the anterior (sternocostal) surface from the diaphragmatic surface and is related to the central tendon of the diaphragm.
3. Which structure forms the upper border of the heart?
a) Right ventricle
b) Atria and great vessels
c) Left ventricle
d) Right atrium
Answer: b) Atria and great vessels
Explanation: The upper border of the heart is formed by both atria and the great vessels emerging from them, including the ascending aorta, pulmonary trunk, and superior vena cava. It lies opposite the third costal cartilage and represents the base of the heart in radiological views.
4. The left atrium forms which surface of the heart?
a) Anterior surface
b) Posterior surface
c) Inferior surface
d) Right border
Answer: b) Posterior surface
Explanation: The posterior surface, also called the base of the heart, is formed mainly by the left atrium and partially by the right atrium. It lies opposite the fifth to eighth thoracic vertebrae and receives four pulmonary veins. It is related posteriorly to the esophagus and descending thoracic aorta.
5. A chest X-ray showing right atrial enlargement will have which feature?
a) Bulging of right heart border
b) Elevation of left dome of diaphragm
c) Double cardiac shadow
d) Upward shift of apex
Answer: a) Bulging of right heart border
Explanation: Right atrial enlargement causes outward bulging of the right cardiac border on chest X-ray due to dilation. Common causes include tricuspid stenosis, pulmonary hypertension, or congenital heart defects. The right border appears more prominent without a change in the left heart silhouette, helping distinguish atrial from ventricular enlargement.
6. Which chamber of the heart is most anterior in position?
a) Right ventricle
b) Right atrium
c) Left atrium
d) Left ventricle
Answer: a) Right ventricle
Explanation: The right ventricle forms the anterior (sternocostal) surface of the heart. It lies directly behind the sternum and costal cartilages, making it the most anterior chamber. This surface is important clinically as it is most susceptible to injury in penetrating chest trauma or cardiac tamponade.
7. Which chamber of the heart forms the apex beat felt in the 5th intercostal space?
a) Right atrium
b) Left atrium
c) Left ventricle
d) Right ventricle
Answer: c) Left ventricle
Explanation: The apex of the heart, located in the fifth left intercostal space about 9 cm from the midline, is formed by the left ventricle. The apex beat corresponds to the point of maximal impulse and indicates left ventricular contraction. Its displacement laterally suggests left ventricular hypertrophy or cardiomegaly.
8. The base of the heart is related posteriorly to which structure?
a) Sternum
b) Diaphragm
c) Esophagus
d) Right lung
Answer: c) Esophagus
Explanation: The base of the heart lies posteriorly and is mainly formed by the left atrium. It is closely related to the esophagus and descending thoracic aorta. This anatomical relationship explains why transesophageal echocardiography provides a clear view of the left atrium and mitral valve in clinical imaging.
9. In a pericardial effusion, which border of the heart appears enlarged on chest X-ray?
a) Right border only
b) Left border only
c) Both borders symmetrically
d) Apex only
Answer: c) Both borders symmetrically
Explanation: In pericardial effusion, accumulation of fluid in the pericardial sac causes a globular enlargement of the cardiac silhouette, with symmetrical widening of both heart borders. The characteristic “water bottle” or “flask-shaped” appearance helps differentiate effusion from chamber hypertrophy or localized cardiac pathology.
10. During cardiac catheterization, a catheter passed from the femoral vein first enters which chamber?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Answer: a) Right atrium
Explanation: A catheter introduced via the femoral vein travels through the inferior vena cava into the right atrium. It is then directed to the right ventricle and pulmonary artery for diagnostic or interventional procedures. Knowledge of cardiac chamber sequence ensures accurate navigation and prevents vascular injury during catheterization.
Chapter: Thorax; Topic: Heart Anatomy; Subtopic: Right Ventricle
Keyword Definitions:
• Right Ventricle: One of the four heart chambers that pumps deoxygenated blood into the pulmonary artery.
• Tricuspid Valve (TV): Valve between right atrium and right ventricle preventing backflow during ventricular contraction.
• Pulmonary Valve (PV): Valve at the opening of the pulmonary artery that prevents backflow of blood into the right ventricle.
• Crista Supraventricularis: A muscular ridge separating the inflow and outflow tracts of the right ventricle.
• Trabeculation: The irregular muscular ridges seen inside the ventricular walls.
Lead Question - 2015
True about anatomy of right ventricle:
a) TV & PV Share fibrous continuity
b) More prominent trabeculation
c) Crista supraventricularis separates Tricuspid valve & Pulmonary valve and Apex trabeculated both
d) All
Explanation: The right ventricle has coarse trabeculations, a prominent crista supraventricularis separating tricuspid and pulmonary valves, and both inflow and apex are trabeculated. TV and PV do not share fibrous continuity. The correct answer is (c) Crista supraventricularis separates Tricuspid valve & Pulmonary valve and Apex trabeculated both. It aids in ventricular outflow coordination.
1. Which structure separates inflow and outflow tracts of the right ventricle?
a) Moderator band
b) Crista supraventricularis
c) Septomarginal trabecula
d) Papillary muscle
Explanation: The crista supraventricularis is a muscular ridge that separates the inflow tract (leading to the tricuspid valve) from the outflow tract (leading to the pulmonary valve). This separation ensures proper direction of blood flow within the right ventricle, preventing turbulence. Hence, the correct answer is (b) Crista supraventricularis.
2. The moderator band is found in which chamber of the heart?
a) Right atrium
b) Right ventricle
c) Left atrium
d) Left ventricle
Explanation: The moderator band or septomarginal trabecula is a muscular band connecting the interventricular septum to the anterior papillary muscle of the right ventricle. It carries part of the right bundle branch of the conduction system, ensuring synchronized contraction. Correct answer: (b) Right ventricle.
3. Which valve lies most anterior in the heart?
a) Aortic valve
b) Pulmonary valve
c) Tricuspid valve
d) Mitral valve
Explanation: The pulmonary valve is the most anteriorly located among all cardiac valves. It lies in front of the aortic valve and facilitates blood flow from the right ventricle to the pulmonary trunk. Its anterior position is critical during cardiac imaging. Correct answer: (b) Pulmonary valve.
4. Which structure forms the majority of the sternocostal surface of the heart?
a) Left atrium
b) Right atrium
c) Right ventricle
d) Left ventricle
Explanation: The right ventricle forms most of the anterior or sternocostal surface of the heart. It lies just behind the sternum and costal cartilages, making it most prone to trauma. This surface also includes a portion of the right atrium. Correct answer: (c) Right ventricle.
5. Which of the following statements about the right ventricle is true?
a) Wall thickness is equal to the left ventricle
b) Contains coarse trabeculae carneae
c) Outflow tract is called infundibulum
d) Both b and c
Explanation: The right ventricle has coarse trabeculae carneae and an outflow tract called the infundibulum or conus arteriosus. The wall is thinner compared to the left ventricle as it pumps blood at lower pressure to the lungs. Correct answer: (d) Both b and c.
6. A patient with a defect in the moderator band would experience?
a) Decreased right ventricular conduction
b) Left atrial enlargement
c) Pulmonary vein obstruction
d) Aortic regurgitation
Explanation: The moderator band carries the right bundle branch of the AV bundle to the anterior papillary muscle. Its defect can impair electrical conduction, causing dyssynchronous right ventricular contraction and possible arrhythmias. Hence, correct answer: (a) Decreased right ventricular conduction.
7. Which surface of the heart is formed mainly by the right atrium and right ventricle?
a) Diaphragmatic
b) Anterior (sternocostal)
c) Posterior
d) Left border
Explanation: The anterior (sternocostal) surface is formed largely by the right atrium and right ventricle, with a minor contribution from the left ventricle. It faces the sternum and ribs, explaining the susceptibility of the right ventricle to chest trauma. Correct answer: (b) Anterior (sternocostal).
8. In echocardiography, the infundibulum is best visualized in which view?
a) Apical four-chamber view
b) Parasternal short-axis view
c) Subcostal view
d) Suprasternal view
Explanation: The infundibulum, also called the conus arteriosus, is the smooth-walled outflow tract of the right ventricle leading to the pulmonary valve. It is best seen in the parasternal short-axis view during echocardiography. Correct answer: (b) Parasternal short-axis view.
9. In a trauma patient, rupture of the right ventricle would most likely cause?
a) Left-sided hemothorax
b) Cardiac tamponade
c) Pulmonary embolism
d) Aortic dissection
Explanation: The right ventricle, being most anterior, is most likely to rupture in blunt chest trauma. This can cause cardiac tamponade due to pericardial blood accumulation leading to obstructive shock. Rapid diagnosis and pericardiocentesis are life-saving. Correct answer: (b) Cardiac tamponade.
10. Which part of the right ventricle opens into the pulmonary trunk?
a) Apex
b) Inflow tract
c) Outflow tract
d) Trabeculated portion
Explanation: The outflow tract of the right ventricle, called the infundibulum or conus arteriosus, opens into the pulmonary trunk. It is smooth-walled to reduce turbulence and ensure efficient blood flow into pulmonary circulation. Correct answer: (c) Outflow tract.
Chapter: Head and Neck; Topic: Tongue Anatomy; Subtopic: Nerve Supply of Tongue
Keyword Definitions:
• Lingual nerve: A branch of the mandibular nerve (V3) providing general sensation to the anterior two-thirds of the tongue.
• Glossopharyngeal nerve: Cranial nerve IX, supplying both general and special (taste) sensation to the posterior one-third of the tongue.
• Vagus nerve: Cranial nerve X, contributing to sensation near the epiglottis and root of the tongue.
• Taste sensation: Perception of taste mediated by special visceral afferent fibers.
Lead Question - 2015
Sensory supply to tongue is by all, EXCEPT?
a) Lingual nerve
b) Vagus nerve
c) Glossopharyngeal nerve
d) None of the above
Explanation: The sensory innervation of the tongue is complex. The lingual nerve supplies general sensation to the anterior two-thirds, the chorda tympani (via facial nerve) carries taste fibers for the same region, the glossopharyngeal nerve supplies both taste and general sensation to the posterior one-third, and the vagus nerve supplies the epiglottic region. Therefore, all the listed nerves supply the tongue. Correct answer: (d) None of the above.
1. Which nerve provides taste sensation to the anterior two-thirds of the tongue?
a) Lingual nerve
b) Chorda tympani
c) Glossopharyngeal nerve
d) Vagus nerve
Explanation: Taste sensation from the anterior two-thirds of the tongue is carried by the chorda tympani, a branch of the facial nerve (VII). These fibers hitchhike along the lingual nerve, reaching the tongue through the mandibular division of the trigeminal nerve. Correct answer: (b) Chorda tympani.
2. A lesion of the lingual nerve before joining chorda tympani causes loss of:
a) Taste and general sensation anterior 2/3
b) Taste only
c) General sensation only
d) Taste posterior 1/3
Explanation: The lingual nerve carries general sensation, while the chorda tympani carries taste fibers. A lesion of the lingual nerve before it joins the chorda tympani leads to loss of general sensation only in the anterior two-thirds of the tongue. Taste remains intact. Correct answer: (c) General sensation only.
3. Taste buds at the posterior one-third of the tongue are supplied by:
a) Glossopharyngeal nerve
b) Lingual nerve
c) Facial nerve
d) Hypoglossal nerve
Explanation: The glossopharyngeal nerve (cranial nerve IX) provides both general and taste sensation to the posterior one-third of the tongue, including vallate papillae. It plays an important role in swallowing and taste reflexes. Correct answer: (a) Glossopharyngeal nerve.
4. Loss of gag reflex occurs due to lesion of:
a) Hypoglossal nerve
b) Vagus nerve
c) Glossopharyngeal nerve
d) Lingual nerve
Explanation: The glossopharyngeal nerve provides the sensory limb, and the vagus nerve provides the motor limb of the gag reflex. Damage to either may cause absence of the reflex. However, sensory loss is primarily due to glossopharyngeal nerve involvement. Correct answer: (c) Glossopharyngeal nerve.
5. Which cranial nerve does NOT carry taste fibers?
a) Facial nerve
b) Glossopharyngeal nerve
c) Vagus nerve
d) Trigeminal nerve
Explanation: The trigeminal nerve (V) carries general sensory fibers but does not transmit taste sensation. Taste fibers are carried by the facial (VII), glossopharyngeal (IX), and vagus (X) nerves. Hence, loss of taste is not associated with trigeminal nerve lesions. Correct answer: (d) Trigeminal nerve.
6. A patient with right hypoglossal nerve palsy will show:
a) Deviation of tongue to left
b) Deviation of tongue to right
c) Deviation upward
d) No deviation
Explanation: The hypoglossal nerve supplies all intrinsic and extrinsic muscles of the tongue except palatoglossus. A lesion causes ipsilateral tongue weakness. On protrusion, the tongue deviates toward the affected side due to unopposed action of contralateral genioglossus. Correct answer: (b) Deviation to right.
7. Injury to chorda tympani leads to loss of taste in:
a) Anterior 2/3 of tongue
b) Posterior 1/3 of tongue
c) Base of tongue
d) Tip only
Explanation: The chorda tympani carries taste sensation from the anterior two-thirds of the tongue via the facial nerve. Damage results in loss of taste and reduced salivation from submandibular and sublingual glands. Correct answer: (a) Anterior 2/3 of tongue.
8. Which nerve supplies the vallate papillae taste buds?
a) Facial nerve
b) Glossopharyngeal nerve
c) Lingual nerve
d) Vagus nerve
Explanation: Although vallate papillae are located in the anterior two-thirds of the tongue, their taste buds are supplied by the glossopharyngeal nerve, not by the facial nerve. This is an important clinical exception. Correct answer: (b) Glossopharyngeal nerve.
9. Sensory supply of epiglottis is through:
a) Lingual nerve
b) Glossopharyngeal nerve
c) Superior laryngeal branch of vagus
d) Hypoglossal nerve
Explanation: The internal laryngeal branch of the vagus nerve supplies both general and taste sensation to the epiglottis and region near the root of the tongue. It plays a protective role during swallowing. Correct answer: (c) Superior laryngeal branch of vagus.
10. A tumor compressing the glossopharyngeal nerve at the jugular foramen will cause:
a) Loss of taste posterior 1/3
b) Absent gag reflex
c) Difficulty swallowing
d) All of the above
Explanation: The glossopharyngeal nerve carries taste fibers, sensory fibers for the gag reflex, and motor fibers to stylopharyngeus. Compression at the jugular foramen leads to loss of taste in posterior one-third, absent gag reflex, and dysphagia. Correct answer: (d) All of the above.
Chapter: Abdomen; Topic: Anal Canal] Subtopic: Sphincters of Anal Canal
Keyword Definitions:
• Internal anal sphincter: Involuntary smooth muscle derived from the inner circular layer of rectal muscularis.
• External anal sphincter: Voluntary skeletal muscle controlled by inferior rectal branch of pudendal nerve.
• Puborectalis: Part of levator ani forming a sling around the anorectal junction to maintain continence.
• Pectinate line: Anatomical line dividing upper and lower anal canal with different nerve and blood supply.
Lead Question - 2015
Internal anal sphincter is a part of:
a) Puborectalis muscle
b) Deep perineal muscles
c) Internal longitudinal fibers
d) Internal circular fibers
Explanation: The internal anal sphincter is a thickened continuation of the inner circular layer of smooth muscle from the rectum. It provides involuntary control over defecation and remains tonically contracted to maintain continence. It relaxes reflexly during rectal distension. Correct answer: (d) Internal circular fibers.
1. The external anal sphincter is supplied by:
a) Pudendal nerve
b) Pelvic splanchnic nerve
c) Inferior mesenteric plexus
d) Sacral sympathetic chain
Explanation: The external anal sphincter consists of skeletal muscle fibers under voluntary control and is innervated by the inferior rectal branch of the pudendal nerve. This nerve maintains tonic contraction for continence and is essential during voluntary defecation. Correct answer: (a) Pudendal nerve.
2. Which muscle forms the anorectal angle?
a) Pubococcygeus
b) Puborectalis
c) Iliococcygeus
d) Ischiococcygeus
Explanation: The puborectalis muscle, a part of levator ani, forms a sling around the anorectal junction. Its contraction pulls the junction forward, creating the anorectal angle that aids continence. Relaxation of this muscle straightens the canal during defecation. Correct answer: (b) Puborectalis.
3. A patient with injury to the inferior rectal nerve will have:
a) Fecal incontinence
b) Constipation
c) Loss of anal reflex
d) Both a and c
Explanation: The inferior rectal nerve (branch of pudendal nerve) supplies the external anal sphincter and perianal skin. Damage causes fecal incontinence due to paralysis of sphincter and loss of anal reflex. Correct answer: (d) Both a and c.
4. The nerve supply of internal anal sphincter is:
a) Pudendal nerve
b) Pelvic splanchnic nerves and hypogastric plexus
c) Sacral spinal nerves
d) Inferior mesenteric ganglion
Explanation: The internal anal sphincter is supplied by autonomic fibers: sympathetic nerves from the hypogastric plexus maintain contraction, and parasympathetic fibers (pelvic splanchnic nerves S2–S4) mediate relaxation during defecation. Correct answer: (b) Pelvic splanchnic nerves and hypogastric plexus.
5. The upper part of the anal canal drains into:
a) Internal iliac vein
b) Inferior rectal vein
c) Superior rectal vein
d) Middle rectal vein
Explanation: The upper part of the anal canal, above the pectinate line, drains into the superior rectal vein, which continues as the inferior mesenteric vein and joins the portal circulation. This explains the development of internal hemorrhoids in portal hypertension. Correct answer: (c) Superior rectal vein.
6. A chronic alcoholic presents with bleeding from internal hemorrhoids. The venous communication is between:
a) Superior and middle rectal veins
b) Superior and inferior rectal veins
c) Middle and inferior rectal veins
d) Middle and superior iliac veins
Explanation: Internal hemorrhoids occur due to engorgement of the internal rectal venous plexus, representing a portosystemic anastomosis between the superior (portal) and middle or inferior rectal veins (systemic). Correct answer: (b) Superior and inferior rectal veins.
7. Which of the following is not true about the pectinate line?
a) Marks embryological junction
b) Above it – endodermal origin
c) Below it – visceral innervation
d) Below it – insensitive to pain
Explanation: Below the pectinate line, the epithelium is ectodermal, supplied by the inferior rectal nerve, making it sensitive to pain. Above the line, the mucosa is visceral and insensitive. Hence, the statement “below it – insensitive to pain” is false. Correct answer: (d) Below it – insensitive to pain.
8. In Hirschsprung’s disease, the internal anal sphincter fails to relax because of absence of:
a) Myenteric plexus
b) Submucosal plexus
c) Pelvic splanchnic nerves
d) Pudendal nerve
Explanation: Hirschsprung’s disease results from aganglionosis of the distal colon due to absence of myenteric (Auerbach’s) and submucosal (Meissner’s) plexuses. The internal anal sphincter remains contracted, causing functional obstruction. Correct answer: (a) Myenteric plexus.
9. The epithelial lining above the pectinate line is:
a) Stratified squamous epithelium
b) Simple columnar epithelium
c) Transitional epithelium
d) Ciliated pseudostratified columnar epithelium
Explanation: The upper anal canal, derived from the endoderm of hindgut, is lined by simple columnar epithelium, continuous with rectal mucosa. Below the pectinate line, the lining changes to stratified squamous epithelium of ectodermal origin. Correct answer: (b) Simple columnar epithelium.
10. During posterior midline fissure surgery, which muscle needs care to prevent incontinence?
a) Puborectalis
b) External anal sphincter
c) Coccygeus
d) Deep transverse perineal muscle
Explanation: Surgical dissection in the posterior midline of the anal canal risks damaging the external anal sphincter, a skeletal muscle vital for voluntary continence. Its preservation is essential to prevent postoperative fecal leakage. Correct answer: (b) External anal sphincter.
Chapter: Urogenital System; Topic: Male Urethra; Subtopic: Parts of Male Urethra
Keyword Definitions:
• Male urethra: A fibromuscular tube about 18–20 cm long that conducts urine and semen to the exterior.
• Prostatic urethra: The widest part, passing through the prostate gland.
• Membranous urethra: The shortest and narrowest part, passing through the urogenital diaphragm.
• Spongy (penile) urethra: The longest part passing through the corpus spongiosum of the penis.
Lead Question – 2015
Shortest part of male urethra is:
a) Prostatic
b) Membranous
c) Bulbar
d) Penile
Explanation: The membranous urethra is the shortest and least dilatable portion of the male urethra, measuring about 1.5–2 cm. It lies between the apex of the prostate and the bulb of the penis, passing through the deep perineal pouch surrounded by the external urethral sphincter. Correct answer: (b) Membranous.
1. The longest part of the male urethra is:
a) Prostatic
b) Membranous
c) Spongy
d) Bulbar
Explanation: The spongy (penile) urethra is the longest portion, measuring about 15 cm, running through the corpus spongiosum of the penis. It opens at the external urethral meatus and serves as a common passage for urine and semen. Correct answer: (c) Spongy.
2. The urethral crest is found in which part of the urethra?
a) Prostatic
b) Membranous
c) Penile
d) Bulbar
Explanation: The urethral crest is a vertical ridge in the posterior wall of the prostatic urethra. It contains the prostatic utricle and ejaculatory ducts on either side, forming the seminal colliculus. It plays a role in preventing retrograde ejaculation. Correct answer: (a) Prostatic.
3. During catheterization, resistance is commonly felt at:
a) Prostatic urethra
b) Membranous urethra
c) Bulbar urethra
d) External meatus
Explanation: The greatest resistance during catheterization is at the membranous urethra due to its narrow lumen and passage through the urogenital diaphragm. Improper catheter insertion may cause injury or stricture formation here. Correct answer: (b) Membranous.
4. A 40-year-old man develops urine leakage after perineal injury. The rupture likely involves:
a) Prostatic urethra
b) Membranous urethra
c) Spongy urethra
d) External urethral sphincter
Explanation: Trauma to the perineum, especially from a fall on a hard object, may rupture the spongy (bulbar) urethra. Urine and blood extravasate into the superficial perineal pouch and scrotum but not the thigh due to fascial attachments. Correct answer: (c) Spongy urethra.
5. External urethral sphincter surrounds which part of the urethra?
a) Prostatic
b) Membranous
c) Penile
d) Bulbar
Explanation: The external urethral sphincter (sphincter urethrae) encircles the membranous urethra within the deep perineal pouch. It is composed of skeletal muscle fibers under voluntary control supplied by the pudendal nerve. Correct answer: (b) Membranous.
6. A patient presents with urine leakage into the pelvis after a pelvic fracture. The likely site of rupture is:
a) Prostatic urethra
b) Membranous urethra
c) Bulbar urethra
d) Penile urethra
Explanation: Pelvic fractures commonly disrupt the membranous urethra as it is fixed between the prostate and the perineal membrane. Urine extravasates into the deep perineal pouch and pelvis. Correct answer: (b) Membranous urethra.
7. The ejaculatory ducts open into:
a) Urethral crest
b) Prostatic utricle
c) Seminal colliculus
d) Bulbar urethra
Explanation: The paired ejaculatory ducts pierce the posterior wall of the prostate and open on either side of the prostatic utricle within the seminal colliculus. This allows semen to enter the prostatic urethra during ejaculation. Correct answer: (c) Seminal colliculus.
8. In urethral stricture disease, which part is most commonly affected?
a) Prostatic
b) Membranous
c) Bulbar
d) Penile
Explanation: The bulbar urethra is the most common site for stricture formation following trauma, infection, or instrumentation. The curvature and narrow lumen make it susceptible to fibrosis and scarring. Correct answer: (c) Bulbar.
9. Which part of the urethra receives ducts of bulbourethral glands?
a) Prostatic
b) Membranous
c) Bulbar
d) Penile
Explanation: The bulbourethral glands (Cowper’s glands) open into the proximal spongy urethra near the bulb. Their secretion lubricates the urethra and neutralizes acidity before ejaculation. Correct answer: (c) Bulbar.
10. A male patient develops urine in the scrotum after straddle injury. Urine spread is limited by:
a) Colles’ fascia attachments
b) Deep perineal fascia
c) Buck’s fascia
d) Dartos fascia
Explanation: In bulbar urethral rupture, urine collects in the superficial perineal pouch and scrotum, limited by Colles’ fascia which prevents spread into the thigh. Correct answer: (a) Colles’ fascia attachments.
Chapter: Abdomen; Topic: Pancreas; Subtopic: Relations of Neck of Pancreas
Keyword Definitions:
• Pancreas: A retroperitoneal gland with both exocrine (digestive enzymes) and endocrine (hormones like insulin, glucagon) functions.
• Neck of pancreas: The constricted part between the head and body of the pancreas, about 2.5 cm long.
• Portal vein: Formed behind the neck of the pancreas by the union of the splenic and superior mesenteric veins.
• IVC (Inferior vena cava): The largest vein, lying posterior and slightly to the right of the pancreas.
Lead Question – 2015
Posterior relation of neck of pancreas?
a) IVC
b) Origin of portal vein
c) Aorta
d) Common bile duct
Explanation: The neck of the pancreas lies anterior to the formation of the portal vein, which is formed by the union of the splenic and superior mesenteric veins. Posteriorly, it also relates to the aorta and the beginning of the portal vein but not the IVC directly. Correct answer: (b) Origin of portal vein.
1. The pancreas is primarily located in which region of the abdomen?
a) Right lumbar
b) Left hypochondrium and epigastrium
c) Umbilical
d) Right hypochondrium
Explanation: The pancreas lies obliquely across the posterior abdominal wall in the epigastrium and left hypochondrium. The head lies in the C-shaped curve of the duodenum, and the tail extends toward the spleen. Correct answer: (b) Left hypochondrium and epigastrium.
2. Which structure is related anteriorly to the neck of pancreas?
a) Transverse colon
b) Pylorus
c) Portal vein
d) Left kidney
Explanation: Anterior to the neck of the pancreas lie the pylorus and the first part of the duodenum. The portal vein is posterior, and the stomach lies superiorly separated by the lesser sac. Correct answer: (b) Pylorus.
3. During surgery, the portal vein is formed behind the neck of the pancreas by the union of:
a) Inferior mesenteric and splenic veins
b) Superior mesenteric and splenic veins
c) Left gastric and splenic veins
d) Inferior vena cava and splenic vein
Explanation: The portal vein forms behind the neck of the pancreas by the union of the splenic vein (from the spleen) and the superior mesenteric vein (from the small intestine). This vein transports nutrient-rich blood to the liver. Correct answer: (b) Superior mesenteric and splenic veins.
4. In carcinoma of the neck of pancreas, which vessel is most likely compressed?
a) Inferior vena cava
b) Portal vein
c) Aorta
d) Common hepatic artery
Explanation: Carcinoma of the neck of the pancreas can compress the portal vein, leading to portal hypertension, splenomegaly, and varices. Early detection is crucial because such tumors may obstruct bile flow and venous return from the gastrointestinal tract. Correct answer: (b) Portal vein.
5. Which structure lies posterior to the head of the pancreas?
a) IVC
b) Aorta
c) Portal vein
d) Left renal vein
Explanation: The head of the pancreas lies in the C-shaped curve of the duodenum, and IVC passes posterior to it. Other posterior relations include the right renal vessels and the bile duct. Correct answer: (a) IVC.
6. A 60-year-old male presents with obstructive jaundice and a mass in the head of the pancreas. The most likely cause is obstruction of:
a) Portal vein
b) Common bile duct
c) Hepatic artery
d) Left renal vein
Explanation: Carcinoma of the head of the pancreas commonly compresses the common bile duct, leading to jaundice and pale stools. The bile duct passes posteriorly through the head before joining the main pancreatic duct to form the hepatopancreatic ampulla. Correct answer: (b) Common bile duct.
7. The tail of pancreas lies within which structure?
a) Renal fascia
b) Splenorenal ligament
c) Gastrosplenic ligament
d) Hepatorenal pouch
Explanation: The tail of the pancreas extends into the splenorenal ligament and lies near the hilum of the spleen. This part is the only intraperitoneal portion of the pancreas. Correct answer: (b) Splenorenal ligament.
8. Which artery runs posterior to the neck of the pancreas?
a) Superior mesenteric artery
b) Inferior mesenteric artery
c) Celiac trunk
d) Renal artery
Explanation: The superior mesenteric artery (SMA) arises from the aorta just below the pancreas and runs posterior to the neck of the pancreas before entering the root of the mesentery. Correct answer: (a) Superior mesenteric artery.
9. In a patient with trauma, pancreatic injury at the neck region can lead to:
a) Splenic vein rupture
b) Portal vein thrombosis
c) IVC tear
d) Mesenteric vein obstruction
Explanation: Injury at the neck of pancreas can damage the portal vein or its tributaries, leading to thrombosis or massive bleeding. This may result in portal hypertension and impaired venous return from abdominal organs. Correct answer: (b) Portal vein thrombosis.
10. During Whipple’s procedure, which structure is preserved posterior to the neck of the pancreas?
a) Portal vein
b) Bile duct
c) Celiac trunk
d) Aorta
Explanation: In pancreaticoduodenectomy (Whipple’s procedure), the portal vein behind the neck of the pancreas must be carefully preserved to maintain hepatic circulation. Its relation is surgically important during mobilization of the pancreas. Correct answer: (a) Portal vein.
Chapter: Abdomen; Topic: Adrenal (Suprarenal) Glands; Subtopic: Venous Drainage of Suprarenal Glands
Keyword Definitions:
• Suprarenal gland: Endocrine gland located above the kidneys, consisting of a cortex and medulla that secrete steroid and catecholamine hormones.
• Suprarenal vein: Drains venous blood from the gland into systemic veins.
• IVC (Inferior vena cava): The main vein returning deoxygenated blood from the lower body to the heart.
• Renal vein: Vein draining the kidneys; receives the left suprarenal and gonadal veins.
Lead Question – 2015
The right suprarenal vein drains into the:
a) Inferior vena cava
b) Right renal vein
c) Right gonadal vein
d) Left renal vein
Explanation: The right suprarenal vein is short and drains directly into the inferior vena cava (IVC), whereas the left suprarenal vein drains into the left renal vein. This asymmetry is due to the position of the IVC on the right side of the vertebral column. Correct answer: (a) Inferior vena cava.
1. The left suprarenal vein drains into:
a) IVC
b) Left renal vein
c) Left gonadal vein
d) Portal vein
Explanation: The left suprarenal vein joins the left renal vein before it reaches the IVC. This pattern is due to the IVC being positioned on the right side. This venous route is significant in adrenal surgeries. Correct answer: (b) Left renal vein.
2. The right suprarenal gland is related posteriorly to:
a) Diaphragm
b) IVC
c) Right kidney
d) All of the above
Explanation: The right suprarenal gland lies posterior to the IVC and the right crus of the diaphragm. It also contacts the upper pole of the right kidney. Correct answer: (d) All of the above.
3. Which artery supplies the suprarenal glands?
a) Inferior phrenic artery
b) Aorta
c) Renal artery
d) All of the above
Explanation: The suprarenal glands receive a rich blood supply from three sources: the superior suprarenal arteries (from the inferior phrenic), middle suprarenal artery (from the aorta), and inferior suprarenal artery (from the renal artery). Correct answer: (d) All of the above.
4. During adrenalectomy, which vein is most important to identify early?
a) Right renal vein
b) Suprarenal vein
c) Gonadal vein
d) Inferior phrenic vein
Explanation: The suprarenal vein must be identified and ligated early during surgery to prevent massive bleeding because it directly drains the adrenal gland’s venous blood. Correct answer: (b) Suprarenal vein.
5. A 45-year-old woman with Cushing’s syndrome has a right adrenal tumor. Which vessel drains the affected gland?
a) Left renal vein
b) IVC
c) Right gonadal vein
d) Portal vein
Explanation: The right suprarenal vein drains directly into the IVC. Therefore, a right adrenal tumor drains its blood into the IVC, which may complicate surgical removal due to proximity. Correct answer: (b) IVC.
6. Which of the following statements is TRUE regarding venous drainage of adrenal glands?
a) Both veins drain into IVC
b) Both veins drain into renal vein
c) Right vein → IVC; Left vein → Left renal vein
d) Right vein → Renal vein; Left vein → IVC
Explanation: The right suprarenal vein drains directly into the IVC, whereas the left suprarenal vein drains into the left renal vein. This difference is due to the asymmetrical position of the IVC. Correct answer: (c) Right vein → IVC; Left vein → Left renal vein.
7. The right suprarenal gland lies anterior to which structure?
a) Diaphragm
b) Liver
c) IVC
d) Aorta
Explanation: The right suprarenal gland lies posterior to the liver and anterior to the diaphragm and IVC. It is triangular in shape and located superior to the right kidney. Correct answer: (b) Liver.
8. A patient undergoing left nephrectomy is at risk of injuring which vessel draining suprarenal gland?
a) Right suprarenal vein
b) Left suprarenal vein
c) Left gonadal vein
d) Inferior phrenic vein
Explanation: The left suprarenal vein joins the left renal vein near the hilum of the kidney. During nephrectomy, this vein may be accidentally injured, leading to adrenal venous congestion. Correct answer: (b) Left suprarenal vein.
9. Which structure passes posterior to both suprarenal glands?
a) Renal artery
b) Crus of diaphragm
c) Inferior mesenteric artery
d) Portal vein
Explanation: The crura of the diaphragm lie posterior to both suprarenal glands. The right crus is more closely related to the right gland and forms part of the posterior abdominal wall. Correct answer: (b) Crus of diaphragm.
10. A CT scan reveals a mass compressing the left renal vein. Which suprarenal gland drainage is affected?
a) Right
b) Left
c) Both
d) None
Explanation: The left suprarenal vein drains into the left renal vein. Compression of this vein leads to venous congestion of the left adrenal gland and may result in hormonal dysfunction. Correct answer: (b) Left.
Chapter: Abdomen & Pelvis; Topic: Suprarenal Gland; Subtopic: Blood Supply
Keyword Definitions:
Suprarenal gland: Also known as the adrenal gland; located above each kidney and produces hormones like cortisol, adrenaline, and aldosterone.
Blood supply: Refers to the arterial vessels that deliver oxygenated blood to an organ or tissue.
Renal artery: The main artery supplying the kidney, also giving a branch to the adrenal gland.
Inferior phrenic artery: Supplies the diaphragm and gives superior suprarenal branches to the adrenal gland.
Aorta: The main artery from the heart that gives rise to middle suprarenal arteries.
Lead Question - 2015
Suprarenal gland gets its blood supply from all of the following arteries except:
a) Aorta
b) Renal artery
c) Inferior phrenic artery
d) Superior mesentric artery
Answer: d) Superior mesenteric artery
Explanation: The adrenal gland receives blood from three sources—superior suprarenal arteries (from inferior phrenic), middle suprarenal arteries (from aorta), and inferior suprarenal arteries (from renal artery). The superior mesenteric artery does not supply the adrenal gland. Its branches mainly supply the midgut structures. Hence, option (d) is correct.
1. Which vein drains blood from the right suprarenal gland?
a) Right renal vein
b) Right gonadal vein
c) Inferior vena cava
d) Left renal vein
Answer: c) Inferior vena cava
Explanation: The right suprarenal vein is short and drains directly into the inferior vena cava, while the left suprarenal vein drains into the left renal vein. This venous drainage is asymmetrical due to the relative positions of the IVC and aorta. Understanding this helps during adrenal vein catheterization.
2. Which of the following arteries gives rise to the superior suprarenal arteries?
a) Aorta
b) Inferior phrenic artery
c) Renal artery
d) Celiac trunk
Answer: b) Inferior phrenic artery
Explanation: The superior suprarenal arteries originate from the inferior phrenic artery. These arteries enter the superior surface of the adrenal gland. The middle suprarenal arteries arise from the aorta, and the inferior ones from the renal artery. This tripartite supply ensures rich perfusion for hormone synthesis.
3. Middle suprarenal arteries are direct branches of:
a) Celiac trunk
b) Aorta
c) Inferior phrenic artery
d) Renal artery
Answer: b) Aorta
Explanation: The middle suprarenal arteries arise directly from the abdominal aorta, usually at the level of the superior mesenteric artery. These arteries supply the central part of the adrenal gland, particularly the medulla. They play a vital role in maintaining consistent blood flow under stress.
4. Inferior suprarenal arteries are branches of:
a) Inferior phrenic artery
b) Aorta
c) Renal artery
d) Lumbar artery
Answer: c) Renal artery
Explanation: The inferior suprarenal arteries arise from the renal artery before it enters the kidney. They ascend to supply the inferior portion of the adrenal gland. This connection between kidney and adrenal blood supply explains their shared embryological origin from mesodermal tissue.
5. Clinically, ligation of which artery may compromise adrenal gland blood flow?
a) Aorta
b) Renal artery
c) Celiac trunk
d) Inferior mesenteric artery
Answer: b) Renal artery
Explanation: The adrenal gland receives its inferior arterial supply from the renal artery. Therefore, ligation or obstruction of the renal artery can reduce adrenal blood flow, potentially impairing hormone production like aldosterone and cortisol, especially in hypertensive or renal surgery cases.
6. A patient undergoes nephrectomy. During surgery, an artery entering the adrenal gland superiorly is ligated. This artery is most likely derived from:
a) Aorta
b) Renal artery
c) Inferior phrenic artery
d) Lumbar artery
Answer: c) Inferior phrenic artery
Explanation: The superior suprarenal arteries originate from the inferior phrenic artery. These branches supply the upper part of the adrenal gland. During nephrectomy, surgeons must preserve them to prevent ischemic damage to adrenal tissue and subsequent hormonal insufficiency.
7. A tumor compressing the left renal vein will most directly affect drainage of which structure?
a) Right adrenal gland
b) Left adrenal gland
c) Right gonadal vein
d) Hepatic vein
Answer: b) Left adrenal gland
Explanation: The left suprarenal vein drains into the left renal vein, unlike the right which drains directly into the IVC. Compression of the left renal vein causes congestion of both left adrenal and gonadal veins, potentially leading to varicocele and adrenal dysfunction.
8. Which hormone is secreted by the adrenal medulla under sympathetic stimulation?
a) Cortisol
b) Aldosterone
c) Adrenaline
d) Estrogen
Answer: c) Adrenaline
Explanation: The adrenal medulla, supplied by preganglionic sympathetic fibers, secretes adrenaline and noradrenaline in response to stress. These hormones increase heart rate, blood pressure, and glucose levels. Their secretion is rapid due to the rich vascular supply from multiple adrenal arteries.
9. A lesion in which artery may compromise both the adrenal gland and diaphragm?
a) Inferior phrenic artery
b) Renal artery
c) Lumbar artery
d) Aorta
Answer: a) Inferior phrenic artery
Explanation: The inferior phrenic artery supplies the diaphragm and gives rise to superior suprarenal arteries to the adrenal gland. Hence, damage to this artery may affect both organs. This shared supply is clinically significant during upper abdominal surgeries.
10. During adrenalectomy, the surgeon must be cautious of a short vein draining directly into the IVC. Which gland is it?
a) Left adrenal
b) Right adrenal
c) Both
d) None
Answer: b) Right adrenal
Explanation: The right suprarenal vein is short and drains directly into the inferior vena cava, making it prone to avulsion during surgery. The left suprarenal vein, being longer and draining into the left renal vein, is comparatively safer to handle during adrenalectomy.
Chapter: Abdomen & Gastrointestinal Tract; Topic: Pancreas & Duodenum; Subtopic: Arterial Supply of Pancreas and Duodenum
Keyword Definitions:
Pancreas: A mixed gland that functions both as an endocrine and exocrine organ, located in the retroperitoneal region of the abdomen.
Duodenum: The first part of the small intestine, divided into four parts, receiving bile and pancreatic ducts at the second part.
Pancreaticoduodenal arteries: Arteries that connect the celiac trunk and superior mesenteric artery, supplying blood to the pancreas and duodenum.
Superior mesenteric artery (SMA): A major branch of the abdominal aorta supplying the midgut structures including lower duodenum and pancreas.
Gastroduodenal artery: A branch of the common hepatic artery supplying the upper part of the duodenum and pancreas.
Lead Question - 2015
Inferior pancreaticoduodenal artery is a branch of which of the following artery?
a) Splenic artery
b) Left gastric artery
c) Gastroduodenal artery
d) Superior mesenteric artery
Answer: d) Superior mesenteric artery
Explanation: The inferior pancreaticoduodenal artery arises from the superior mesenteric artery just below the origin of the gastroduodenal artery. It supplies the lower part of the head of the pancreas and the lower duodenum. It forms an anastomosis with the superior pancreaticoduodenal artery, providing a crucial collateral link between the celiac and SMA territories.
1. The superior pancreaticoduodenal artery is a branch of:
a) Common hepatic artery
b) Splenic artery
c) Left gastric artery
d) Superior mesenteric artery
Answer: a) Common hepatic artery
Explanation: The superior pancreaticoduodenal artery arises from the gastroduodenal branch of the common hepatic artery. It supplies the upper duodenum and head of the pancreas. Its anastomosis with the inferior pancreaticoduodenal artery ensures dual blood supply to the duodenal loop and pancreatic head.
2. The inferior pancreaticoduodenal artery anastomoses with which artery?
a) Left gastric artery
b) Superior pancreaticoduodenal artery
c) Splenic artery
d) Cystic artery
Answer: b) Superior pancreaticoduodenal artery
Explanation: The inferior pancreaticoduodenal artery anastomoses with the superior pancreaticoduodenal artery, linking the superior mesenteric and celiac arterial systems. This anastomosis maintains duodenal perfusion even when one of the major arteries is obstructed, making it an essential collateral route.
3. Which structure lies between the superior and inferior pancreaticoduodenal arteries?
a) Portal vein
b) Bile duct
c) Head of pancreas
d) Tail of pancreas
Answer: c) Head of pancreas
Explanation: The head of the pancreas is supplied by a rich arterial arcade formed between the superior and inferior pancreaticoduodenal arteries. These vessels provide continuous blood flow to the duodenal loop and the pancreatic head, vital during pancreatic or duodenal surgeries.
4. The inferior pancreaticoduodenal artery supplies which part of the duodenum?
a) First part
b) Second and third parts
c) Fourth part only
d) All parts
Answer: b) Second and third parts
Explanation: The inferior pancreaticoduodenal artery supplies the lower half of the second part and most of the third part of the duodenum. It provides an important midgut contribution, while the superior pancreaticoduodenal artery supplies the upper duodenum from the foregut.
5. During pancreatic surgery, ligation of which artery can cause ischemia to both the pancreas and duodenum?
a) Splenic artery
b) Inferior pancreaticoduodenal artery
c) Left gastric artery
d) Middle colic artery
Answer: b) Inferior pancreaticoduodenal artery
Explanation: The inferior pancreaticoduodenal artery supplies both the pancreas and duodenum. Ligation or injury to it may cause ischemia to these structures. Surgeons must preserve this vessel to prevent postoperative necrosis and maintain the anastomotic arcade between SMA and celiac systems.
6. A patient with blockage of the superior mesenteric artery can still receive blood to the lower duodenum due to collateral flow from:
a) Left gastric artery
b) Superior pancreaticoduodenal artery
c) Splenic artery
d) Right gastric artery
Answer: b) Superior pancreaticoduodenal artery
Explanation: Collateral circulation through the superior pancreaticoduodenal artery (from celiac trunk) can maintain blood flow to the duodenum and pancreas when the SMA is blocked. This important anastomotic connection is a classic example of vascular redundancy between the foregut and midgut.
7. Which of the following best describes the position of the inferior pancreaticoduodenal artery?
a) Runs posterior to the pancreas
b) Runs anterior to the head of the pancreas
c) Encircles the duodenum
d) Passes between the pancreas and duodenum
Answer: d) Passes between the pancreas and duodenum
Explanation: The inferior pancreaticoduodenal artery courses between the head of the pancreas and the duodenum, forming anterior and posterior branches. These branches anastomose with the superior pancreaticoduodenal arteries, creating a vital network around the pancreatic head.
8. A tumor at the pancreatic head compressing the inferior pancreaticoduodenal artery may lead to ischemia of:
a) Tail of pancreas
b) Duodenal bulb
c) Distal duodenum
d) Jejunum
Answer: c) Distal duodenum
Explanation: Compression of the inferior pancreaticoduodenal artery compromises blood supply to the distal duodenum and the lower pancreatic head. This can lead to duodenal ulceration or necrosis, particularly in tumors involving the uncinate process or lower head of the pancreas.
9. The inferior pancreaticoduodenal artery arises just below the origin of which artery?
a) Celiac trunk
b) Gastroduodenal artery
c) Inferior mesenteric artery
d) Right renal artery
Answer: b) Gastroduodenal artery
Explanation: The inferior pancreaticoduodenal artery arises from the superior mesenteric artery immediately below the level where the gastroduodenal artery branches from the common hepatic artery. This proximity facilitates their functional anastomosis through the pancreaticoduodenal arcades.
10. A radiologist tracing SMA angiography identifies a branch supplying both pancreas and duodenum. This vessel is:
a) Inferior pancreaticoduodenal artery
b) Cystic artery
c) Right gastric artery
d) Splenic artery
Answer: a) Inferior pancreaticoduodenal artery
Explanation: During SMA angiography, the inferior pancreaticoduodenal artery is visualized as a key branch supplying the lower duodenum and pancreatic head. Its identification confirms the integrity of SMA–celiac collateral flow. This finding is essential in evaluating ischemic bowel diseases and vascular tumors.