U2 day 2

Question 1

Extrinsic back MM

Answer 1

back to upper limb, inn: ventral rami of spinal nerves, fnx: move upper limbs

Question 2

Intrinsic back MM

Answer 2

attachments in axial skeleton, moves vertebra or skull, ‘true’ back muscles, inn: dorsal rami of spinal nn

Question 3

Splenius muscle

Answer 3

superficial muscle
A: spinous process and nuchal ligament
B: transverse processes and skull
Ax: bilateral contraction - extension of vertebral column/back/neck. Unilateral contraction - lateral flexion and rotation of VC/back/neck
Inn: Dorsal rami

Question 4

Spinalis M. (most medial)

Answer 4

Intermediate group: erector spinae mm group
A/B: Spinous process all the way down column
Ax: bilateral contraction - extension of VC/back/trunk. Unilateral contraction - lateral flexion of VC/back/trunk
inn: dorsal rami

Question 5

Longissimus M (middle)

Answer 5

Intermediate group: erector spinae mm group
A/B: transverse processes descending the column.
Ax: Bilateral contraction: extension of VC/Back/trunk. Unilateral contraction: lateral flexion of VC/Back/Trunk.
inn: dorsal rami

Question 6

Iliocostalis m (lateral)

Answer 6

Intermediate group: erector spinae mm group
A: Ilium
B: Rib
Ax: Bilateral contraction: extension of VC/Back/Trunk. Unilateral contraction: lateral flexion VC/Back/Trunk
inn: Dorsal rami

Question 7

Transverseospinalis mm

Answer 7

Deep muscle group
A: transverse process
B: spinous process
Ax: Bilateral contraction: extension of VC/Back/Trunk. Unilateral contraction: rotation of VC/Back/Trunk.
inn: dorsal rami
fnx: stabilize vertebral column

Question 8

Spinal cord

Answer 8

Part of CNS, extension of brain stem, starts at foramen magnum

Question 9

Spinal cord fnxs

Answer 9

Sensory processor: brainstem, cerebellum, cerebrum, regions of spinal cord.
Motor Outflow: lower motor neuron in ventral horn, influenced by upper motor neurons and interneurons, common final pathway.
Reflexes: independent from consciousness, stereotyped motor response.

Question 10

External anatomy of spinal cord

Answer 10

Spinal cord segments give rise to bilateral pair of spinal nn. 8 cervical S.C. segments with 7 spinal vertebrae because first nerve exits above C1. the rest of the segments match the amount of vertebrae.
Enlargement of SC in cervical and lumbar regions. More neurons to innervate UL and LL
Conus Medularis: end of spinal cord, ends at L2 vertebrae in adults.