Test: Back Region - NEET PG MCQ

• Serratus anterior is inserted on the medial border of scapula but lies anterior to scapula. Hence, it is not in the triangle of auscultation.
• Triangle of Auscultation is bounded by 2 muscles and scapula. Superiorly – Trapezius, Inferiorly – Latissimus dorsi and Laterally – medial wall of Scapula.
• Rib 7 and Rhomboideus major lie in the floor of the triangle. Since minimal muscle fibers lie over the triangle, auscultation by stethoscope is better over this triangle, especially, the sounds of swallowed fluids. Cardiac end of the stomach lies deep to this triangle.

Triangle of auscultation has trapezius (superior), latissimus dorsi (inferior) and medial wall of scapula (as lateral boundary).

Petit’s (lumbar) triangle lies just lateral to the highest point of the iliac crest, between the inferolateral border of latissimus dorsi, the posterior-free border of external oblique and the iliac crest.

Internal abdominal oblique muscle is present at the floor of Petit’s triangle.

• Cervical vertebra is characterized by foramina in its transverse process—foramen transversarium
• Cervical & lumbar vertebrae have oval bodies and are triangular in thoracic region.
• Superior articular facets are directed backwards & upwards in both the cervical as well as thoracic vertebrae.
• Cervical vertebra has a small body; the lumbar vertebra bodies are the largest.

• Vertebral body is the smallest in the cervical region. Large vertebral body is present at the level of lumbar vertebra.
• Vertebral foramen is triangular and large in the cervical vertebra.
• The foramen is small and circular in thoracic vertebra.
• Cervical vertebrae are identified by the foramen transversarium in their transverse process.
• Superior articular facets are directed backwards & upwards in the cervical and thoracic regions.

• Superior articular facet is directed backwards & upwards in both the cervical as well as thoracic vertebrae, and hence cannot help us to differentiate the two from each other. Thoracic vertebra is in addition directed laterally (BUL – backward/upward/lateral).
• The vertebral canal in cervical vertebrae is triangular, which is oval in thoracic vertebrae.
• Vertebral vessels (artery & vein) pass through the upper six foramina transversaria present in the cervical vertebrae.
• Cervical vertebrae have the smallest bodies, whereas, lumbar are the largest.

• There are total thirty-three vertebrae, upper twenty-four are articulating and separated from each other by intervertebral discs, seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae.
• The lower nine are fused, five in the sacrum and four in the coccyx.
• The number of vertebrae in a region can vary but overall the number remains the same. The number of those in the cervical region however is only rarely changed.

The number of vertebrae in a region can vary but overall the number remains the same. The number of those in the cervical region however is only rarely changed.

• Cervical curvature is a secondary curvature, with a posterior concavity.
• Secondary curvatures develop after birth-like cervical & lumbar curvatures.
• These curvatures are convex anteriorly and concave backwards.
• Primary curvatures like thoracic and sacral & coccygeal curvatures are present since birth and are concave anteriorly.

• Vertebral column has four curvatures that occur in the cervical, thoracic, lumbar, and sacral regions.
• The fetal thoracic and sacral kyphoses are concave anteriorly, whereas the acquired cervical and lumbar lordoses are concave posteriorly.
• The cervical lordosis becomes evident when an infant begins to raise (extend) the head while prone and to hold the head erect while sitting.
• The lumbar lordosis becomes apparent when the child learns to assume the upright posture for standing and walking.
• Thoracic curve is a Primary curve 

• Lumbar region shows restricted rotation movement.
• The interlocking articular processes prevent rotation.

• Maximum thoracic flexion occurs in the lower thoracic spine because the vertebrae start to orient their facets similar to the lumbar spine where the most flexion and extension occurs.
• Also, the lower thoracic spine is not as cemented in place by the floating ribs

In lumbar puncture posterior longitudinal ligament is not pierced. Though it may be reached accidently if the needle has been advanced too far anteriorly

• The classical “popping” sensation occurs when the needle has passed through the ligamentum flavum.
• The needle then be advanced in 2 mm intervals until a second pop is felt (dura mater is pierced) and CSF is obtained.