Anatomy
7 questionsThe blood supply to femoral head is mostly by?
Which of the following statements about the great saphenous vein is true?
Which muscles are known as 'Triceps surae'?
Sacrotuberous ligament is pierced by
Sacral promontory is the landmark for
Which muscle is attached to the lateral surface of the greater trochanter?
Line from midinguinal point to adductor tubercle represents?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 141: The blood supply to femoral head is mostly by?
- A. Lateral epiphyseal artery
- B. Medial epiphyseal artery
- C. Artery of ligamentum teres
- D. Profunda femoris (Correct Answer)
Explanation: ***Profunda femoris*** - The profunda femoris artery (deep femoral artery) gives rise to the **medial and lateral circumflex femoral arteries**, which are the primary blood supply to the femoral head in adults - Specifically, the **medial circumflex femoral artery** and its branches (lateral epiphyseal arteries and retinacular arteries) form an extracapsular arterial ring and penetrate the joint capsule to supply the femoral head - The profunda femoris is thus the main parent vessel responsible for femoral head blood supply *Lateral epiphyseal artery* - This artery is a branch of the **medial circumflex femoral artery**, which originates from the profunda femoris - While it directly supplies the femoral head and is the dominant terminal branch, it represents a more specific component of the arterial network rather than the main source vessel - It provides blood to the lateral and superior portions of the femoral head *Medial epiphyseal artery* - This artery is also a branch of the circumflex femoral arteries, which originate from the profunda femoris - It contributes to the blood supply but is less dominant than the lateral epiphyseal branches - Similar to lateral epiphyseal artery, it is part of the retinacular arterial system *Artery of ligamentum teres* - The **artery of the ligamentum teres** (foveal artery) is an inconsistent and often small vessel, typically a branch of the **obturator artery** or medial circumflex femoral artery - While it contributes to blood supply especially in children, its contribution is usually minor in adults and often insufficient to sustain the femoral head alone - It enters through the fovea capitis and its contribution diminishes with age
Question 142: Which of the following statements about the great saphenous vein is true?
- A. It begins at lateral end of dorsal venous arch
- B. It runs anterior to medial malleolus (Correct Answer)
- C. Terminates into popliteal vein
- D. It is accompanied by the sural nerve
Explanation: **It runs anterior to medial malleolus** - The **great saphenous vein** originates from the medial end of the **dorsal venous arch** of the foot and ascends anterior to the **medial malleolus** [1]. - This anatomical relationship makes it accessible for various clinical procedures, such as **venous cutdown** for rapid intravenous access [1]. *It begins at lateral end of dorsal venous arch* - The **great saphenous vein** actually begins at the **medial end** of the dorsal venous arch, not the lateral end [1]. - The **small saphenous vein** arises from the lateral end of the dorsal venous arch [1]. *It is accompanied by the sural nerve* - The **sural nerve** typically accompanies the **small saphenous vein**, not the great saphenous vein, in the posterior leg [1]. - The **saphenous nerve**, a branch of the femoral nerve, accompanies the great saphenous vein throughout its course in the leg. *Terminates into popliteal vein* - The **great saphenous vein** normally terminates by draining into the **femoral vein** in the femoral triangle, not the popliteal vein [1]. - The **small saphenous vein** is the one that typically drains into the popliteal vein [1].
Question 143: Which muscles are known as 'Triceps surae'?
- A. Popliteus
- B. Extensor hallucis longus
- C. Extensor digitorum longus
- D. Gastro-soleus (Correct Answer)
Explanation: ***Gastro-soleus*** - The **Triceps surae** refers to the two heads of the **gastrocnemius muscle** and the **soleus muscle**, which together form the powerful calf muscle. - These three muscles converge to form the **Achilles tendon** (calcaneal tendon) and are prime movers for **plantarflexion** of the ankle. *Popliteus* - The popliteus muscle is located behind the knee joint and acts to **unlock the knee** during flexion. - It does not contribute to the bulk of the calf and is not part of the Triceps surae group. *Extensor hallucis longus* - This muscle is located in the **anterior compartment** of the leg and is responsible for **dorsiflexion** of the ankle and extension of the great toe. - It is an antagonist to the Triceps surae, which primarily performs plantarflexion. *Extensor digitorum longus* - The extensor digitorum longus is also in the **anterior compartment** of the leg, responsible for **dorsiflexion** of the ankle and extension of the lateral four toes. - It is functionally opposite to the actions of the Triceps surae and in a different muscle compartment.
Question 144: Sacrotuberous ligament is pierced by
- A. Perforating cutaneous nerve (Correct Answer)
- B. Posterior femoral cutaneous nerve
- C. Superior gluteal nerve
- D. Sciatic nerve
Explanation: ***Perforating cutaneous nerve*** - The **perforating cutaneous nerve** typically pierces the sacrotuberous ligament to innervate the skin over the medial part of the lower gluteal region. - This nerve originates from the **S2 and S3 anterior rami**. *Posterior femoral cutaneous* - The **posterior femoral cutaneous nerve** runs inferior to the piriformis muscle, superficial to the sacrotuberous ligament, but does not pierce it. - It supplies the skin on the posterior thigh and popliteal fossa. *Superior gluteal nerve* - The **superior gluteal nerve** exits the pelvis through the greater sciatic foramen, superior to the piriformis muscle, and does not interact with the sacrotuberous ligament in this manner. - It innervates the **gluteus medius, gluteus minimus**, and **tensor fasciae latae muscles**. *Sciatic nerve* - The **sciatic nerve** exits the pelvis via the greater sciatic foramen, inferior to the piriformis muscle, and passes superficial to the sacrotuberous ligament. - It does not pierce the ligament, but rather lies in close proximity to its inferior border.
Question 145: Sacral promontory is the landmark for
- A. Termination of presacral nerve (Correct Answer)
- B. None of the options
- C. Origin of inferior mesenteric artery
- D. Origin of superior mesenteric artery
Explanation: ***Termination of presacral nerve*** - The **sacral promontory** is the key anatomical landmark where the **superior hypogastric plexus** (presacral nerve) **bifurcates** into the right and left hypogastric nerves. - This bifurcation typically occurs at the level of the **sacral promontory**, making it a crucial landmark for **presacral neurectomy** procedures. - The superior hypogastric plexus is formed by the fusion of sympathetic fibers and lies anterior to the L5 vertebra and sacral promontory. - Clinically important for **pelvic surgery** and **pain management** procedures. *Origin of superior mesenteric artery* - The **superior mesenteric artery (SMA)** originates from the **anterior aspect of the abdominal aorta** at the level of the **L1 vertebra**. - This is far superior to the sacral promontory, which is at the lumbosacral junction (L5-S1). - The SMA supplies the midgut derivatives. *Origin of inferior mesenteric artery* - The **inferior mesenteric artery (IMA)** originates from the **anterior aspect of the abdominal aorta** at the level of the **L3 vertebra**. - This is also well above the sacral promontory. - The IMA supplies the hindgut derivatives. *None of the options* - This is incorrect as the sacral promontory is indeed a recognized landmark for the **bifurcation/termination of the presacral nerve** (superior hypogastric plexus).
Question 146: Which muscle is attached to the lateral surface of the greater trochanter?
- A. Gluteus maximus
- B. Gluteus medius (Correct Answer)
- C. Gluteus minimus
- D. Piriformis
Explanation: ***Gluteus medius*** - The **gluteus medius** inserts onto the **lateral surface of the greater trochanter** of the femur. - Its primary actions include **abduction** and **internal rotation** of the hip. *Gluteus maximus* - The **gluteus maximus** inserts primarily into the **iliotibial tract** and the **gluteal tuberosity** of the posterior femur, not the lateral greater trochanter. - Its main roles are **hip extension** and **external rotation**. *Gluteus minimus* - The **gluteus minimus** inserts onto the **anterior part of the lateral surface (anterolateral aspect)** of the greater trochanter, anterior to the gluteus medius insertion. - Like the gluteus medius, it also contributes to **hip abduction** and **internal rotation**. *Piriformis* - The **piriformis** muscle inserts onto the **superior and medial aspect of the greater trochanter**. - Its main actions are **external rotation** and **abduction** of the hip, particularly when the hip is flexed.
Question 147: Line from midinguinal point to adductor tubercle represents?
- A. Inferior epigastric artery
- B. Femoral artery (Correct Answer)
- C. Superior epigastric artery
- D. None of the options
Explanation: The line from the **midinguinal point** to the **adductor tubercle** accurately maps the anatomical course of the **femoral artery** in the thigh. This anatomical landmark is crucial for palpating the **femoral pulse** and locating the artery for clinical procedures like catheter insertion. *Inferior epigastric artery* - The **inferior epigastric artery** originates from the external iliac artery and ascends superiorly in the anterior abdominal wall [1]. - Its course is significantly more medial and superior, far from the line described. *Superior epigastric artery* - The **superior epigastric artery** is a terminal branch of the internal thoracic artery, descending into the rectus sheath in the upper abdomen [1]. - Its location is entirely within the anterior abdominal wall, high above the inguinal region. *None of the options* - This option is incorrect because the line from the midinguinal point to the adductor tubercle clearly represents the anatomical course of the femoral artery. - The other arteries listed are not found along this specific anatomical path.
Physiology
3 questionsP wave is due to:
By what percentage can cardiac output increase in a healthy adult during intense physical activity compared to resting levels?
Deoxygenated blood is not seen in which of the following?
NEET-PG 2013 - Physiology NEET-PG Practice Questions and MCQs
Question 141: P wave is due to:
- A. Atrial depolarization (Correct Answer)
- B. Atrial repolarization
- C. Ventricular depolarization
- D. Ventricular repolarization
Explanation: **Atrial depolarization** - The **P wave** on an electrocardiogram (ECG) represents the electrical activity associated with the **depolarization of the atria**. - This depolarization leads to **atrial contraction**, pushing blood into the ventricles. *Atrial repolarization* - **Atrial repolarization** also occurs but is usually hidden within the **QRS complex** and thus not separately visible as a distinct wave on a standard ECG. - While it's an electrical event, it does not produce the P wave. *Ventricular depolarization* - **Ventricular depolarization** is represented by the **QRS complex** on an ECG. - This electrical activity leads to **ventricular contraction**, pumping blood out of the heart. *Ventricular repolarization* - **Ventricular repolarization** is represented by the **T wave** on an ECG. - This process allows the ventricles to relax and refill with blood.
Question 142: By what percentage can cardiac output increase in a healthy adult during intense physical activity compared to resting levels?
- A. 300 - 400 % (Correct Answer)
- B. 0 - 50 %
- C. 50 - 100 %
- D. 100 - 200 %
Explanation: ***300 - 400 %*** - In a healthy adult, **cardiac output** can increase remarkably during intense physical activity. - The heart can increase its output by **3 to 4 times** (or 300-400%) above resting levels during peak exertion. - At rest, cardiac output is approximately **5 L/min**, but during maximal exercise, it can reach **20-25 L/min** in well-conditioned individuals. - This represents the heart's **reserve capacity** to meet increased metabolic demands during exercise. *0 - 50 %* - This range represents a very **limited increase** in cardiac output and would be indicative of significant underlying cardiac impairment or **heart failure**. - A healthy individual would experience a much greater increase in cardiac output during intense activity than this small percentage. *50 - 100 %* - This range also suggests a **suboptimal cardiac response** for a healthy adult undergoing intense physical activity. - While some increase is present, it does not reflect the full capacity of a healthy cardiovascular system to adapt to extreme demands. *100 - 200 %* - While a 100-200% increase is substantial, it still **underestimates the maximal capacity** achievable in a healthy, well-conditioned individual during intense physical exertion. - The heart has a greater capacity for increasing its output to meet metabolic demands during peak exercise.
Question 143: Deoxygenated blood is not seen in which of the following?
- A. Pulmonary artery
- B. Umbilical artery
- C. Pulmonary vein (Correct Answer)
- D. Right atrium
Explanation: ***Pulmonary vein*** - The pulmonary veins carry **oxygenated blood** from the lungs back to the left atrium of the heart. - Their primary function is to transport blood that has undergone **gas exchange** in the lungs, making it rich in oxygen. *Pulmonary artery* - The pulmonary artery carries **deoxygenated blood** from the right ventricle of the heart to the lungs. - This is an exception to the general rule that arteries carry oxygenated blood, as its purpose is to deliver blood for **oxygenation**. *Right atrium* - The right atrium receives **deoxygenated blood** from the systemic circulation via the superior and inferior vena cava. - It acts as a collecting chamber for blood that has supplied oxygen to the body's tissues before it is pumped to the lungs. *Umbilical artery* - The umbilical arteries carry **deoxygenated blood** and waste products from the fetus to the placenta. - In fetal circulation, these arteries are responsible for removing metabolic wastes and carbon dioxide from the fetal circulation.