4. Back Myology Flashcards
Where do serrated muscles attach?
The ribs.
What does “fusiform” mean?
Big in the middle, small on the ends
What do Multicaudal muscles have that other’s don’t?
Multiple tendons
Functionally, what do Agonists do?
Flex a joint
Functionally, what do Antagonists do?
Extend a joint
What do Synergist muscles do?
Assists the agonists
Trapezius
Origin, Attachment, Action, Innervation and Artery
Orign: ligamentum nucahe, all C and T, occipital lobe
Attachment: clavical, acromion, and scapular spine
- Whole muslce: rotate point of glenoid cavity superiory and retract the scapula
- upper fibers: elevate scapula
- lower fibers: depress scapula
- while the scapula fixed: upper fibers will extend the neck working bilaterally, laterally flex the neck and rotate the face away when woring unilaterally
- Spinal Accessory Nerve (CN XI)
- Transverse Cervical Artery
Latissimus Dorsi
Origin, insertion, action, Innervation and Artery
- Origin: lower throacic, ribs 9-12, illica crest, L1-5 spinous process and median scaral crest via throacolmbar fascia
- insertion: anterior side of humerous (intertubrcular groove)
- Action: extend, adduct and medially rotate the huemrus. Also rotate the glenoid cavity (point of shoulder) inferiorly
- Thoracodorsal Nerve
- Thoracodorsal Artery
For Rhomboid Minor, Rhomboid Major and Levator Scaupluae
Innervation and Artery
Dorsal Scapular Nerve
Dorsal Scapular Artery
Rhomboid Major
O: SPINOUS PROCES OF t2-5
I: medial border of scapula (inferior scapula spine)
A: retract and elevate scapula, rotate the glenoid cavity down
Rhomboid Minor
O: SPINOUS PROCES OF C7 to T 1
I: medial border of scapula (at scapular spine)
A: retract and elevate scapula, rotate the glenoid cavity down
Levator Scapulae
O: posteior tubercles of transferese process c1-4
I: medial borders of scapula above the spine
A: elevate the scapula, rotate the glenoid cavity inferiorly. will also extend and laterally flex the neck WHEN SCAPULA IS FIXED.
Serratus Posterior Superior
Origin, Insertion, Action, Innervation and Artery
- O: spinous process of C7-T3
- I: superior surfaces of ribs 2-4
- ELEVATE RIBS WITH FORCED INSPIRATION (primarily proprioceptive)
- Intercostal Nerve
- Intercostal Artery
For Serratus Posterior Inferior
Origin, insertion, Action, Innervation and Artery
- spinous process of T11-12
- inferior surface of ribs 8-12
- Depress ribs with forced exipration (primarly propoceptive)
- Anterior Ramus of T9-12
- Intercostal Arteries
What three segments are there to the Iliocostalis Muscle?
Iliocostalis Lumborum (this is the only Lumborum)
Iliocostalis Thoracis
Iliocostalis Cervicis
splenius capitius
O: lower half of nucal ligmanet and C7 to mid T spinous process
I: temproal bone and occpital bone
A: extend neck when working bilaterally and latarally flex neck and rotate face towards when working unilatarally
N: Posterior Rami (c3-5)
Splenius cervicis
O: spinous process T3-6
I: transverse process C1-3
A:extend the neck when working bilaterally, latarally flex neck and roate face towards when working unilaterally
N: posterior Rami
What three segments are there for Longissimus?
Which portion is the largest for this muscle?
Longissimus Thoracis (largest)
Longissimus Cervicis
Longissimus Capitis (Inserts at the Mastoid process, to help locate it)
ILS Muscles are _____. They are also called _____. Their action is to _______. They are innervated by _____.
- largest layer
- erector spinae group
- maintain erect posture and extend the vertebral columb and head when working bilatarlly. They also latearlly flex thev ertebral column when working unilatarally.
- posterior rami
What region of Spinalis is likely to be visable?
Spinalis Thoracis (Even still is often confusible with Longissimus because it is small)
What is damaged in a back strain?
What is damaged in a back sprain?
A strain is damage to a muscle fiber by excessive stretching of a muscle due to contraction.
A sprain is injury to the ligamentous attachment between bones.
Remember that a sprained ankle has nothing to do with muscles.
What are the four types of Transversospinalis muscles?
How far (in number of vertebrae) does each one go up?
(From largest to smallest)
Semispinalis (5-6)
Multifidus (3-4)
Rotatores Longus (2)
Rotatores Brevis (1)
Within the group of Transversospinalis muscles, what are the three Semispinalis muscles? What are the rest?
- Semispinalis Capitis
- Semispinalis Cervicis
- Semispinalis Thoracis (just a transversospinalis muscle that goes up 5-6)
- Multifidus M: Extending 3-4 spinal segments, best in lumbar region
- Rotatores Longus: extending 2 spinal segments
- Rotatores Brevis: extends to the adjacent spinal segment
What is the collective name of the muscles which traverse between spinous processes?
Interspinalis Muscles. Travel from one spinous process to the other. Best developed in lumbar and cervical regions. They extend the spine.
