Lecture 4: Back Myology

Question 1

What is an aponeurosis?

Answer 1

White fibrous tissue that takes place of a tendon in flat muscles having a wide area of attachment

Question 2

What are pennate muscles?

Answer 2

Defines where muscles are

Unipennate: Muscles are one side of tendon

Bipennate: Muscles on both sides

Multipennate: Muscles all over the place

Question 3

What does “fusiform” mean?

Answer 3

Muscles are big in the middle, small on the ends

Question 4

What are digastric muscles?

Answer 4

2 muscle bellies connected by tendon

Question 5

What are multiventral muscles?

Answer 5

Muscles with tendinous inscriptions?

Example: Recturs Abdominis

Question 6

What makes multicaudal muscles unique?

Answer 6

Multiple tendons (looks like tails)

Common in extremities (fingers and toes)

Question 7

Where do serrated muscles attach?

Answer 7

The ribs.

Question 8

Functionally, what do Agonists do?

Answer 8

Flex a joint

Question 9

Functionally, what do Antagonists do?

Answer 9

Extend a joint

Question 10

What do Synergist muscles do?

Answer 10

Assists the agonists

Question 11

What is the action of the trapezius muscle?

Answer 11

Whole Muscle: Retracts the scapula and Rotates glenoid cavity superiorly

Superior Part: elevate scapula

Inferior Part: depress scapula

Scapula fixed: Extend neck (bilaterally), Laterally flex neck and rotate face away (unilaterally)

Question 12

What is the innervation and blood supply for the trapezius muscle?

Answer 12

Innervation: Spinal Accessory Nerve (CN XI)

Blood Supply: Transverse Cervical Artery

Question 13

What is the action of the latissimus dorsi?

Answer 13

Extends and adduct humerus

Medially rotate humerus

Rotate glenoid cavity inferiorly

Question 14

What is the innervation and blood supply for Latissimus Dorsi?

Answer 14

Innervation: Thoracodorsal Nerve

Blood Supply: Thoracodorsal Artery

Question 15

What is the action of the rhomboid major and minor?

Answer 15

Retract scapula

Elevate scapula

Rotate glenoid cavity inferiorly

Question 16

What is the action of levator scapulae?

Answer 16

Retract scapula

Elevate Scaupla

Rorate glenoid cavity inferiorly

With Scapula Fixed:

Extend neck bilaterally

Laterally flex neck unilaterally

Question 17

What is the innervation and blood supply for Rhomboid Minor, Rhomboid Major and Levator Scaupluae?

Answer 17

Innervation: Dorsal Scapular Nerve

Blood Supply: Dorsal Scapular Artery

Question 18

What is the action of the Serratus Posterior Superior muscle?

Answer 18

Elevates rib (for inspiration)

Proprioception

Question 19

What is the innervation and blood supply for Serratus Posterior Superior?

Answer 19

Innervation: Intercostal Nerve

Blood Supply: Posterior Intercostal Artery

Question 20

What is the action of Serratus Posterior Inferior muscle?

Answer 20

Depresses rib (for expiration)

Proprioception

Question 21

What is the innervation and blood supply for Serratus Posterior Inferior muscle?

Answer 21

Innervation: Anterior Ramus of T9-12

Blood Supply: Posterior Intercostal Arteries

Question 22

What is the action of Splenius Capitis and Splenius Cervicis?

Answer 22

Extends neck bilaterally

Laterally flexes the neck unilaterally

Rotates the face towards the muscle unilateraly

Question 23

What is the innervation and blood supply of Splenius Capitis and Cervicis?

Answer 23

Innervation: Posterior Rami

Blood Supply: Deep Cervical Artery

Question 24

In general, what is the action of the erector spinae muscles?

Answer 24

Maintain erect posture

Extend and laterally flex vertebral column and neck

Question 25

What is the innervation and blood supply of erector spinae muscles?

Answer 25

Innervation: Posterior rami

Blood Supply: Deep Cervical Artery/Intercostal artery

Question 26

What are the three segments of Iliocostalis Muscle?

Answer 26

Iliocostalis Lumborum (only Lumborum)

Iliocostalis Thoracis

Iliocostalis Cervicis

Question 27

What are the three segments for Longissimus?

Answer 27

Longissimus Thoracis (largest)

Longissimus Cervicis

Longissimus Capitis (Inserts at the Mastoid process, to help locate it)

Question 28

What are the three segments for Spinalis?

Answer 28

Spinalis Thoracis (Often confusible with Longissimus because it is small)

Spinalis Cervicis (Can’t see)

Spinalis Capitis (Can’t see)

Question 29

What is damaged in a back strain?

What is damaged in a back sprain?

Answer 29

A strain is damage to a muscle fiber by excessive stretching of a muscle due to contraction. (think tendon)

A sprain is injury to the ligamentous attachment between bones. (think ligamet)

Remember that a sprained ankle has nothing to do with muscles.

Question 30

What are the four types of Transversospinalis muscles?

How far (in number of vertebrae) does each one go up?

Answer 30

Semispinalis (5-6)

Multifidus (3-4)

Rotatores Longus (2)

Rotatores Brevis (1)

Question 31

What are the three Semispinalis muscles?

Answer 31

Semispinalis Thoracis

Semispinalis Cervicis (ends right below suboccipital triangle)

Semispinalis Capitis (on top of cervicis)

Question 32

What muscles traverse between spinous processes?

Answer 32

Interspinalis Muscles

Question 33

What muscles traverse between transverse processes?

Answer 33

Intertransversearii Muscles

Question 34

What is the innervation and blood supply of the suboccipital muscles?

Answer 34

Innervation: Suboccipital Nerve

Blood Supply: Occipital Artery

Question 35

What are the four muscles of the Suboccipital region?

Answer 35

Rectus Capitis Posterior Major

Rectus Capitis Posterior Minor

Obliquus Capitis Superior

Obliquus Capitis Inferior

Question 36

Which three muscles make up the Suboccipital Triangle?

Answer 36

Rectus Capitis Posterior Major

Obliquus Capitis Inferior

Obliquus Capitis Superior

Question 37

What nerve and artery is found in the suboccipital triangle?

Answer 37

Suboccipital nerve

Vertebral artery