Lec 13 (Cheat Sheet)

Question 1

What group and function does the sternocleidomastoid muscle have?

Answer 1

Group: Head movers

Both sides: Flexes head and neck

Right side: Rotates head to the left and laterally flexes to the right

Left side: Rotates head to the right and laterally flexes to the left

Question 2

What group and function do the splenius cervicis and capitis muscles have?

Answer 2

Group: Superficial intrinsic muscles

Both sides: Extension of head and neck

Right side: Rotation and lateral flexion to the right

Left side: Rotation and lateral flexion to the left

Question 3

What are the layers of the erector spinae group and their actions?

Answer 3

Group: Superficial intrinsic muscles

Layers:
- Iliocostalis (lateral)
- Longissimus (middle)
- Spinalis (medial)

Action: Extend the spine; ipsilateral lateral flexion and rotation

Question 4

What are the functions of interspinales muscles?

Answer 4

Group: Deep intrinsic muscles

Function: Extend the spine; connect spinous processes of adjacent vertebrae

Question 5

What are the functions of intertransversarii muscles?

Answer 5

Group: Deep intrinsic muscles

Function: Laterally flex the vertebral column; connect transverse processes of adjacent vertebrae

Question 6

What are the functions of rotatores muscles?

Answer 6

Group: Deep intrinsic muscles (transversospinalis group)

Function: Perform spinal rotation; connect transverse process of one vertebra to spinous process of another

Question 7

What is the function of the rectus abdominis muscle?

Answer 7

Group: Abdominal wall muscles

Both sides: Lumbar flexion

Side-specific: Lateral flexion to the same side

Question 8

What are the side-specific actions of the external oblique muscles?

Answer 8

Group: Abdominal wall muscles

Right side: Lateral flexion to the right, rotation to the left

Left side: Lateral flexion to the left, rotation to the right

Question 9

What are the side-specific actions of the internal oblique muscles?

Answer 9

Group: Abdominal wall muscles

Right side: Lateral flexion and rotation to the right

Left side: Lateral flexion and rotation to the left

Question 10

What is the function of the transversus abdominis muscle?

Answer 10

Group: Abdominal wall muscles

Function: Core stability and forced expiration by pulling the abdominal wall inward

Question 11

What is the function of the quadratus lumborum muscle?

Answer 11

Group: Posterior abdominal wall

Side-specific: Lateral flexion to the same side

Other functions: Stabilizes pelvis and extends the lumbar spine

Question 12

What are the intrinsic muscles of the spine?

Answer 12

Intrinsic muscles (deep stabilizers):
- Interspinales – spinal extension
- Intertransversarii – lateral flexion
- Rotatores – spinal rotation
- Erector spinae group (superficial intrinsic):
- Iliocostalis
- Longissimus
- Spinalis

These muscles are located deep and run vertically along the spine. They control posture and fine motor movement of the vertebrae.

Question 13

What are the major muscles of the spine?

Answer 13

Major (primary movers) muscles of the spine:
- Sternocleidomastoid – cervical flexion, rotation, lateral flexion
- Splenius cervicis and capitis – cervical extension, rotation, lateral flexion
- Erector spinae group – spinal extension, lateral flexion, ipsilateral rotation
- Rectus abdominis – lumbar flexion, lateral flexion
- External oblique – lumbar flexion, contralateral rotation, lateral flexion
- Internal oblique – lumbar flexion, ipsilateral rotation, lateral flexion
- Transversus abdominis – forced expiration, core stability
- Quadratus lumborum – lateral flexion, lumbar extension, pelvic stabilization