Main blood supply to the head and neck of femur comes from
Which of the following statements about the linea aspera is correct?
Which muscle is attached to the lateral surface of the greater trochanter?
Sacrotuberous ligament is pierced by
Line from midinguinal point to adductor tubercle represents?
What is the approximate length of the tibia in centimeters for an average adult?
Which is the earliest secondary ossification center to develop chronologically?
What anatomical structure is formed after the obliteration of the umbilical vein?
T cells in lymph node are present in:
In current medical practice, cephalic index is primarily used for
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 71: Main blood supply to the head and neck of femur comes from
- A. Lateral circumflex femoral artery
- B. Medial circumflex femoral artery (Correct Answer)
- C. Artery of ligamentum teres
- D. Popliteal artery
Explanation: ***Medial circumflex femoral artery*** - The **medial circumflex femoral artery** is the primary arterial supply to the **head and neck of the femur**, particularly via its **retinacular branches**. - These branches ascend along the femoral neck within the joint capsule, supplying most of the femoral head. *Lateral circumflex femoral artery* - The **lateral circumflex femoral artery** primarily supplies the muscles of the **anterior compartment of the thigh**, including the quadriceps femoris. - While it contributes to anastomoses around the hip, its direct supply to the femoral head and neck is less significant than the medial circumflex. *Artery of ligamentum teres* - The **artery of the ligamentum teres** (foveal artery) supplies a small, variable portion of the **femoral head**, mainly in children. - Its contribution to the overall blood supply to the adult femoral head and neck is often negligible or absent. *Popliteal artery* - The **popliteal artery** is located in the **popliteal fossa** behind the knee joint and is the continuation of the femoral artery. - Its branches supply the structures around the knee and lower leg, not the femoral head and neck.
Question 72: Which of the following statements about the linea aspera is correct?
- A. Forms lateral border of femur
- B. Continues as gluteal tuberosity (Correct Answer)
- C. Forms medial border of femur
- D. None of the options
Explanation: Correct: Continues as gluteal tuberosity - The lateral lip of the linea aspera continues superiorly as the gluteal tuberosity (also called the gluteal ridge or line) - This anatomical continuation is a key feature of the femur's posterior surface - The gluteal tuberosity serves as the attachment site for the gluteus maximus muscle - The medial lip continues superiorly as the pectineal line (spiral line), which then joins the lesser trochanter Incorrect: Forms lateral border of femur - The linea aspera is located on the posterior surface of the femoral shaft, not on the lateral border - The lateral border of the femur is formed by the smooth lateral surface of the shaft - The linea aspera's lateral lip is a posterior ridge, distinct from the true lateral border Incorrect: Forms medial border of femur - The linea aspera is on the posterior aspect of the femur, not the medial border - The medial border of the femur is formed by the smooth medial surface of the shaft - The medial lip of the linea aspera is a muscle attachment site on the posterior surface, not a border
Question 73: 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 74: 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 75: 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.
Question 76: What is the approximate length of the tibia in centimeters for an average adult?
- A. 30 cm
- B. 35 cm (Correct Answer)
- C. 40 cm
- D. 45 cm
Explanation: ***35 cm*** - The **tibia**, or shin bone, is the larger of the two bones in the lower leg and plays a crucial role in supporting body weight. - Its average length in adults is approximately **36-38 cm**, with **35 cm** being well within the normal range for an average adult. - Females typically have tibiae measuring **36-37 cm**, while males average **38-39 cm**. *30 cm* - A length of **30 cm** would be unusually short for an adult tibia, falling well below the normal range for average adults. - Such a short length might be associated with specific medical conditions or skeletal dysplasias. *40 cm* - A length of **40 cm** would be at the upper end or slightly above the typical average for an adult tibia. - This measurement might be seen in taller individuals, but it exceeds the average for most adults. *45 cm* - A length of **45 cm** would be comparatively long for an average adult tibia. - This measurement is significantly above average and would only be seen in very tall individuals.
Question 77: Which is the earliest secondary ossification center to develop chronologically?
- A. Lower end of femur (Correct Answer)
- B. Upper end of humerus
- C. Lower end of fibula
- D. Upper end of tibia
Explanation: ***Lower end of femur*** - The **distal femoral epiphysis** is typically the first secondary ossification center to appear, often present at birth or shortly before [1]. - Its presence at birth is an indicator of **fetal maturity**, making it a key developmental landmark [1]. *Upper end of humerus* - The **proximal humeral epiphysis** typically ossifies around 6 months of age, significantly later than the distal femur. - This center contributes to the growth of the humeral head and greater tubercle. *Lower end of fibula* - The **distal fibular epiphysis** appears around the first year of life, after both the distal femur and proximal humerus. - It forms part of the ankle joint and contributes to its stability. *Upper end of tibia* - The **proximal tibial epiphysis** typically ossifies around 6-12 months of age, well after the distal femur. - This center is crucial for the growth of the upper tibia and knee joint development.
Question 78: What anatomical structure is formed after the obliteration of the umbilical vein?
- A. Ligamentum venosum
- B. Ligamentum arteriosum
- C. Medial umbilical ligament
- D. Round ligament of the liver (ligamentum teres) (Correct Answer)
Explanation: ***Round ligament of the liver (ligamentum teres)*** - The **umbilical vein** carries oxygenated blood from the placenta to the fetus during development [1]. - After birth, the umbilical vein obliterates and forms the **round ligament of the liver**, also known as the **ligamentum teres hepatis**. *Ligamentum venosum* - This structure is the obliterated remnant of the **ductus venosus**, which shunted blood from the umbilical vein to the inferior vena cava, bypassing the fetal liver [1]. - It is located in a fissure on the posterior surface of the liver, separate from the round ligament. *Ligamentum arteriosum* - This ligament is the remnant of the **ductus arteriosus**, a fetal blood vessel connecting the pulmonary artery to the aorta. - Its obliteration allows blood to flow through the lungs after birth. *Medial umbilical ligament* - This ligament is formed from the obliterated **umbilical arteries**, which carry deoxygenated blood from the fetus back to the placenta. - There are two medial umbilical ligaments, one from each umbilical artery.
Question 79: T cells in lymph node are present in:
- A. Paracortical area (Correct Answer)
- B. Mantle layer
- C. Medullary cords
- D. Cortical follicles
Explanation: ***Paracortical area*** - The **paracortical area** contains a high concentration of **T cells**, particularly activated T cells in response to antigenic stimulation [1]. - It plays a crucial role in **immune responses**, bridging the cortex and medulla of the lymph node [1]. *Mantle layer* - The **mantle layer** surrounds the follicles and primarily consists of **B cells**, not T cells. - It is involved in the initial immune response but does not contain a significant number of T lymphocytes. *Medullary cords* - **Medullary cords** mainly contain **plasma cells** and macrophages, with very few T cells present. - Their primary function is the secretion of antibodies rather than T cell activation or response. *Cortical follicles* - **Cortical follicles** are primarily sites for **B cell activation and proliferation**. - While they may have some T cells at their periphery, the majority of T cells are located in the paracortical area.
Question 80: In current medical practice, cephalic index is primarily used for
- A. Evaluation of skull deformities
- B. Assessment of craniosynostosis (Correct Answer)
- C. Clinical documentation of head shape
- D. Neurosurgical planning
Explanation: ***Assessment of craniosynostosis*** - The **cephalic index** (ratio of maximum head width to maximum head length × 100) provides a quantitative measure of head shape that can help characterize types of **craniosynostosis** [1]. - It helps differentiate patterns: **scaphocephaly** (dolichocephaly, CI <76), **brachycephaly** (CI >81), and **normocephaly** (CI 76-81). - In current practice, while **CT imaging** is the gold standard for diagnosing craniosynostosis, the cephalic index remains a useful **anthropometric measurement** in clinical assessment and documentation of cranial deformities. - It is particularly helpful in distinguishing **positional plagiocephaly** from **true craniosynostosis** when combined with clinical examination. *Evaluation of skull deformities* - The cephalic index can be used to evaluate various skull deformities, but this is too broad a description. - Its most specific clinical utility is in the context of **craniosynostosis assessment** where quantitative head shape measurements are diagnostically relevant [1]. - Many other skull deformities are assessed through direct clinical observation or specialized imaging rather than anthropometric indices. *Clinical documentation of head shape* - While the cephalic index does provide objective documentation of head shape, this describes its function rather than its primary **clinical indication**. - Documentation alone lacks the diagnostic and therapeutic implications that make cephalic index measurement clinically valuable. - In modern practice, simple descriptive terms (dolichocephaly, brachycephaly) are often used without calculating the precise index. *Neurosurgical planning* - Neurosurgical planning for craniosynostosis repair relies primarily on **CT scans with 3D reconstruction** to visualize suture fusion patterns, bone thickness, and intracranial anatomy. - The cephalic index provides diagnostic context but does not directly guide surgical technique, approach, or reconstruction planning. - Surgical decisions are based on imaging findings, age of the patient, and specific suture involvement rather than the numerical cephalic index value.