Class 4

Question 1

What is the Intermediate layer (of the deep muscles)?

Answer 1

• Muscles arise inferiorly from thoracolumbar fascia & spread out in superolateral direction
• Subdivided into 3 columns of muscles on either side of spine & each column has 3 segments
• Medial to lateral, they are spinalis, longissimus & iliocostalis

Question 2

What are the actions of the Intermediate layer (of the deep muscles)?

Answer 2

unilateral: lateral flexion of vertebral column
bilateral: extension of vertebral column

Question 3

Intermediate layer (of the deep muscles) key features of Spinalis?

Answer 3

• very thin
• shortest column
• sit in laminar groove (beside SPs)
• attach to SPs

(i) thoracis
(ii) cervicis
(iii) capitis

Question 4

Intermediate layer (of the deep muscles) key features of Longissimus?

Answer 4

• longest column
• most visible & palpable
• attach to TVPs

(i) thoracis
(ii) cervicis
(iii) capitis

Question 5

Intermediate layer (of the deep muscles) key features of Iliocostalis?

Answer 5

• attach to angles of ribs

(i) lumborum
(ii) thoracis
(iii) cervicis

Question 6

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) key features of Semispinalis?

Answer 6

• covers ½ of spinal column
• skips 3-6 vertebrae
• attaches superiorly to occipital bone between superior & inferior nuchal lines
• largest mass in posterior neck

Question 7

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) actions of Semispinalis?

Answer 7

bilateral: extension of head and neck
unilateral: contralateral rotation of neck

Question 8

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) key features of Multifidus?

Answer 8

• from S4 – C2 (skipping 1-3 vertebrae)
• only muscle whose fibres run across posterior sacrum

Question 9

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) actions of Multifidus?

Answer 9

bilateral: extension of the spine, stabilization
unilateral: contralateral rotation

Question 10

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) key features of Rotatores?

Answer 10

• deepest in laminar groove
• longus: skips 1 vertebra
• brevis: attaches to next highest vertebra

Question 11

Deep layer (of the deep muscles), Superomedial fibre direction (transversospinalis) actions of Rotatores?

Answer 11

bilateral: stabilization
unilateral: contralateral rotation

Question 12

Deep layer (of deep muscles) Vertical fibre direction, key features of Interspinales?

Answer 12

• paired muscles on either side of cervical & lumbar SPs

Question 13

Deep layer (of deep muscles) Vertical fibre direction, action of Interspinales?

Answer 13

extension

Question 14

Deep layer (of deep muscles) Vertical fibre direction, key features of Intertransversarii?

Answer 14

• attach TVPs of adjacent vertebrae of cervical & lumbar spine

Question 15

Deep layer (of deep muscles) Vertical fibre direction, action of Intertransversarii?

Answer 15

lateral flexion

Question 16

What vertebral bodies are classified as typical vertebrae?

Answer 16

T2-T9