U2 day 2 Flashcards
Extrinsic back MM
back to upper limb, inn: ventral rami of spinal nerves, fnx: move upper limbs
Intrinsic back MM
attachments in axial skeleton, moves vertebra or skull, ‘true’ back muscles, inn: dorsal rami of spinal nn
Splenius muscle
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
Spinalis M. (most medial)
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
Longissimus M (middle)
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
Iliocostalis m (lateral)
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
Transverseospinalis mm
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
Spinal cord
Part of CNS, extension of brain stem, starts at foramen magnum
Spinal cord fnxs
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.
External anatomy of spinal cord
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.