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ANA534 T2 Back
learning objective answers to intrinsic back muscles
Question | Answer |
---|---|
What comprises the functional unit of the vertebral column? | Two vertebral bodies, the intervening intervertebral disc, and 2 pairs of facet joints. |
What is meant by amplification by summation? | Taking a small amount of movement exhibited at a single functional unit of the vertebral column and multiplying it by the number of vertebra. Small amounts of motion are amplified into larger flexion/extension movements. |
Where could you find a zygophyseal joint? Classify it. | Between inferior and superior articulating facets. They are synovial in nature. |
Name the vertebral lever arms of the functional unit of the vertebral column. | Each vertebra has 3 pairs of lever arms: spinous process (fused in the midline into a single entity), transverse processes and costal elements (ribs). |
What is the general function of the vertebral lever arms? | Serve as attachments for intrinsic mm. of the back. |
List the superficial extrinsic mm. of the back. | Rhomboideus minor and major, levator scapulae, trapezius, latissimus dorsi. |
What is the function of the superficial extrinsic mm. of the back? | They serve in attaching the upper limb to the torso (trunk). |
List the intermediate extrinsic mm. of the back. | The serratus posterior superior and the serratus posterior inferior. |
What is the general function of the intermediate extrinsic mm. of the back? | They act as accessory muscles of respiration. |
What is the function of the intrinsic back mm.? | Postural in nature. Extension/flexion and lateral flexion of the vertebral column. |
Anatomically how are the intrinsic back muscles grouped? | Into three layers: superficial, intermediate and deep. |
Name the components of the Superficial muscle group | splenius capitis, splenius cervicis; Name the components of the intermediate muscle group |
Name the components of the deep muscle group | semispinalis, multifidus, rotatores, intertransversarii and interspinales. |
How are the intrinsic muscles innervated? | Segmentally, by individual dorsal rami along their length. |
Which of these intrinsic muscle groups is most superficial? | Components of the erector spinae (spinalis, longissimus, iliocostalis). |
Which of these intrinsic muscle groups is deepest? | Rotatores |