Back (Muscles) Flashcards
What are 5 extrinsic (superficial) muscles?
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid major
- Rhomboid minor
*Not true muscles of the back because they don’t articulate to the vertebrae
What are the 2 Intermediate extrinsic muscles?
- Serratus posterosuperior
2. Serratus posteriorinferior
What are Deep muscles (Intrinsic)?
- Put into motion the vertebral column
2. Broken into three layers (superficial, intermediate, and deep)
What are 2 Deep superficial muscles?
- Splenius capitis
2. Splenius cervicis
What is the Thoracolumbar fascia?
- Encloses the deep muscles of the back
* The lumbar part of the deep fascia is situated in the interval between the iliac crest and the 12th rib
What is the deep intermediate layer muscle?
- Erector Spinae (broken into three columns)
a. Iliocostalis (lateral column)
b. Longissimus (intermediate column)
c. Spinalis (medial column)
What is the Deep deeper layer muscle?
- Transversospinalis (contain 3 components)
a. Semispinalis (spanning four to six segments)
b. Multifidus (spanning two to four segments)
c. Rotatores (spanning one to two segments)
Where can the Splenius muscles be found?
- Origin: Ligamentum nuchae and Spinous processes of C7-T3
- Insertion for Splenius capitis: Mastoid process(occipital bone)
- Insertion for the Splenius cervicis: C1-C3 transverse processes
*Muscle fibers run upward/laterally
Where can the Erector spinae muscles be found?
- Origin: from the sacrum, ilium, ribs, and spinous processes of lumbar and lower
thoracic vertebrae - Insertion of ILIOCOSTALIS: to angles of lower ribs
- Insertion of LONGISSIUMUS: on the ribs, transverse processes, and mastoid process
- Insertion of SPINALIS: to the Spinous processes
Where can the Transversospinalis muscles be found?
- Origin: Transverse processes C4-T12;
- Insertion of SEMISPINALIS: occipital bone and spinous process
- Insertion of MULTIFIDUS: spinous processess (also originates from sacrum)
- Insertion of ROTATORES: spinous processes
*Fibers run upward/medially
Where is the location of the Interspinalis muscle?
From the superior surface of the spinous processes to the inferior surface of the vertebra above
Where is the location of the Intertransversarrii?
Transverse to transverse processes of adjacent vertebrae
What is the muscular action of the Splenius?
- Bilateral: Extension of the head/neck
2. Unilateral: Ipsilateral rotation of the Head/neck
What is the muscular action of Erector spinae?
- Bilateral: Extension of VC
2. Unilateral: Ipsilateral flexion of VC
What is the muscular action of Transversospinalis?
- Bilateral: Extension of VC
2. Unilateral: Contralateral rotation of VC
What is the muscular action of Interspinales?
Bilateral: Extension of VC
What is the muscular action of Intertransversarii?
Unilateral: Ipsilateral flexion of VC
What are Postural muscles?
Stabilize adjoining vertebrae, controlling their movement during motion of VC as a whole
What nerve supplies the deep muscles?
- Dorsal (posterior) rami of the spinal nerves
What is the Suboccipital triangle?
- Lies deep to the trapezius and semispinalis capitis muscle
- Is bound medially by the rectus capitis posterior major muscle
- Laterally by the obliquus capitis superior muscle
- Inferiorly by the obliquus capitis inferior muscle
*Roof formed by the semispinalis capitis
- Floor formed Posterior atlanto-occipital
membrane
What is the Rectus capitis posterior major?
- Suboccipital muscle
- Origin: C2
- Insertion: Skull
What is the Rectus capitis posterior minor?
- Suboccipital muscle
- Origin: C1
- Insertion: Skull
What is the Obliquus capitis inferior?
- Suboccipital muscle
- Origin: C2
- Insertion: C1 transverse process
What is the Obliquus capitis superior?
- Suboccipital muscle
- Origin: C1 transverse process
- Insertion: Skull
What are the Contents of the suboccipital triangle?
- Vertebral artery
2. Suboccipital nerve (derived from the dorsal ramus of C1)
What does the Suboccipital nerve supply?
- Suboccipital muscles
2. Semispinalis capitis
What is the muscular action of the Suboccipital region?
- Extension of head (except for Obliquus capitis inferior)
- Ipsilateral rotation of the head (Except for Obliquus capitis superior)
*Obliquus capitis superior: Lateral flexion of the head
What is the Triangle of Auscultation?
- Bounded by the latissimus dorsi, trapezius, and scapula
* To hear the sounds of the respiratory organs clearly (posterior on the 6th intercostal space level to listen)
What is the Lumbar triangle?
Bounded by the External abdominal oblique (laterally), Latissimus dorsi (medially), and Iliac crest (inferiorly)
- Also called Petit triangle
- Site of an abdominal hernia (Inferior lumbar hernia)
