Thoracic muscles

Question 1

Lower Trap

Answer 1

O: SP T5-T12

I:

1. Scapular
2. Lateral 1/3 clavicle
3. Acromion

N: Motor accessory N 11

F:

1. scapular D
2. UR: F couple with serat ant and upper trap

Question 2

Latissimus Dorsi

Answer 2

O:

1. SP T7-L5
2. lower ribs 8-9
3. sacrum
4. iliac crest
5. thoracodorsal fascia

I: intertubercular sulcus of humerus

N: Thoracodorsal N (C6-C8)

F: Shoulder IR, ADD, Ext

Question 3

Pec Major

Answer 3

O:

1. clavicle
2. sternum
3. 1st 7 costal cartilages
4. aponeurosis of external oblique

I: lateral lip of intertubercular sulcus of humerus

N: Medial and Lateral Pectoral N

F: Shoulder IR, ADD, Flex

Question 4

Pec Minor

Answer 4

O: Ant surface of ribs 3-5

I: coracoid process of scapula

N: Medial Pectoral N

F: Scapular prot, resp

Question 5

Serat Ant

Answer 5

O: upper ribs 8-9

I: med border of scapula

N: Long thoracic N (C5-C7)

F: 
Scapular: 
1. prot
2. UR
3. stabilizes med border and inf angle of scapula on thoracic wall

Question 6

Serat Post Sup

Answer 6

O: SP C7-T3, Supraspinous ligs, lower portion of ligamentum nuchae

I: A. borders of ribs B. just lateral to their angles
A. upper
B. T2-5

N: Ant rami of A. thoracic N’s ( B. )
A. “
B. “

F: E. of ribs 2-5

Question 7

Serat Post Inf

Answer 7

O: SP T11-L3

I: [A.] borders of ribs [B.] just lateral to their angles
A. lower
B. T9-12

N: Ant rami of [A.] thoracic N’s ( B. )
A. “
B. “

F:

1. D of ribs 9-12
2. may prevent lower rib E. when diaphragm contracts

Question 8

Diaphragm

Answer 8

O: margins of inf thoracic aperture:

1. ends of ribs 11 & 12
2. costal margin of thoracic wall
3. ligs that span across structs of post abd wall
4. vert of L region
5. Xiphoid process of sternum 

I: central tendon of diaphragm

N: Phrenic N (C3, C4 - major contribution, C5)

F: 1. Active during inspiration
2. assists in increase intrabdominal p

Question 9

Iliocostalis

Answer 9

O: - cervicis: ribs 3-6

- thoracis: ribs 7-12
- lumborum: 1. sacrum
                     2. iliac crest 
                     3. thoracodorsal fascia

I: - cervicis: TP C4-6

- thoracis: ribs 1-6 & TP C7
- lumborum: ribs 6-12

N: spinal Ns (C8-L1)

F: 1. neck ext (B)
2. ipsilateral lateral flexion of spine (U)

Question 10

Spinalis

Answer 10

O: - capitis: blends with semispinalis capitis

- cervicis: 1. lower part of lig nuchae
                2. SP C7 (sometimes T1-2)
- thoracis: SP of T10/11-L2)

I: - capitis: w/ semispinalis capitis

• cervicis: SP C2 - axis
• thoracis: SP T1-8

N: Spinal N (post rami)

F: Spine: 1. ext C & T (B)
2. ips lat flex C & T (U)

Question 11

Longissimus

Answer 11

O: - capitis: 1. AP of lower 3 or 4 C vert

               2. TP of upper 4 or 5 T vert
- cervicis: TP of upper 4 or 5 T vert
- thoracis: 1. blends with iliocostalis in L region
                 2. TP of L vert

I: - capitis: post margin of mastoid process

- cervicis: TP C2-6
- thoracis: TP of T vert

N: Spinal N C1-L5 (post rami, lateral branches)

F: 
- capitis: 
Head: 
1. ext (B)
2. ips lat flex / rot (U)
- cervicis/thoracis: 
Spine: 
1. ext (B)
2. ips lat flex (U)