Deep Back Muscles

Question 1

Axial Musculatures are derived from _____ and are arranged ______.

Answer 1

• Somites

- Into segments (Metamerically)

Question 2

The 3 groups of the back muscles.

Which ones are extrinsic or intrinsic?

Answer 2

1. Superficial (Extrinsic)
2. Intermediate (Extrinsic)
3. Deep (Intrinsic)

Question 3

Characteristics of the Superficial back muscles

Answer 3

• Connect Limb to Axial skeleton

- Innervated by Ventral Rami or CN 9 (accessory Nerve)

Question 4

What are the Sup Back muscles?

Answer 4

5 total

1. Trapezius
2. Lat Dorsi
3. Levator Scapulae
4. Rhomboid Major and Minor

Question 5

Characteristics of the Intermediate Muscles

Answer 5

• RESPIRATORY Muscles

- Innervated by the ventral rami

Question 6

What are the Intermediate Back muscles?

Answer 6

• Serratus POST Sup

- Serratus POST Inf

Question 7

Characteristics of the Deep back muscles

Answer 7

• True intrinsic
• Innervated by DORSAL rami
• Divided into 3 groups
  1. Sup
  2. Int
  3. Deep

Question 8

Muscles of the Deep Superficial Back Muscles

Answer 8

Splenius Capitis and Cervicis

DS = “SC squared”

Question 9

Muscles of the Deep Int Back Muscles

Answer 9

3 total

1. Iliocostalis
2. Longissimus
3. Spinalis

“I love Sushi”

Question 10

Muscles of the Deep Deep Back Muscles

Answer 10

3 total

1. Semispinalis
2. Multifidus
3. Rotatores

“Shake my rear”

Question 11

Deep intermediate muscles are also known as what?

Answer 11

Epaxial muscles

Or

Erector Spinae

Or

Sacrospinalis

Question 12

Epaxial muscles are reduced in what animal?

Answer 12

Turtles

Question 13

Deep Deep Back muscles are also know as what?

Answer 13

Transversospinalis

Question 14

Thoracolumbar Fascia

Answer 14

• Triangular shaped sheet of tough CT covering Lower back

- Partial site of origin of Lat Dorsi and Ab oblique

Question 15

Action of the Serratus Posterior SUP

Answer 15

To ELEVATE the UPPER ribs during Inspiration

Question 16

Actions of the Serratus Posterior INF

Answer 16

To pull LOWER ribs INF and Counteracts the DIAPHRAGM

Question 17

Deep Sup muscles are also known as what?

Answer 17

Spinotransversalis

Question 18

Deep Deep muscles are also known as what?

Answer 18

Transversospinalis

Question 19

Origin and Insertion of the Silenus Capitis

Answer 19

Think “Cap” over Cervicis

O: Spinous process of C7 and T1-4

I: Sup unchallenged line & Mastoid

Question 20

Origin and Insertion of the Silenus Cervicis

Answer 20

O: Spinous process of T3-6

I: C1-C4 transverse processes w/ Levator Scapulae

Question 21

Characteristics of Superficial (Spinotransversalis) Intrinsic muscles.

Answer 21

• Long muscles

- The ONLY large muscles that arise from the Midline and attach to the Transverse process and SKULL

Question 22

Characteristics of Intermediate (Sacrospinalis) Intrinsic muscles.

Answer 22

• Run Longitudinally UPWARD
• Transverse process to rib
• Rib to rib
• Rib to Cervical Tran Process
• Spinous process to spinous process

Question 23

Characteristics of Deep (Transversospinalis) Intrinsic muscles.

Answer 23

• From TP to TP
• CONCEALED by the Erector Spinae
• Muscle arise LATERALLY and Insert MEDIALLY

Question 24

What vertebra lacks a spinous process?

Answer 24

C1

Question 25

The Long Rotatores muscle span ___ and the Short Rotatores muscle span ___.

Answer 25

• 2 segments

- 1 segment