Lecture 16 - Muscles of the vertebral column and torso

Question 1

Posterior back muscles …

Answer 1

Muscles that support the back, and help with back movement

Question 2

Functions of the vertebral column

Answer 2

Posture - helps to keep balance and upright standing

Support head, neck, trunk

Protect spinal cord and spinal nerves

Trunk movement (flexion, extension, lateral flexion, rotation)

Question 3

The vertebral column has curvatures …

Answer 3

Alternation of kyphosis (primary) and lordosis (secondary)

Initially started as one kyphosis

Developed for upright position

Provide flexibility and shock absorbance (for movement especially with heavy loads)

Question 4

Curvature of vertebral column

Answer 4

cervical = secondary 
Thoracic = primary
lumbar = secondary 
sacral = primary

Question 5

Curvature cervical

Answer 5

Secondary

Question 6

Curvature thoracic

Answer 6

Primary

Question 7

Curvature lumbar

Answer 7

Secondary

Question 8

Curvature sacral

Answer 8

Primary

Question 9

Intrinsic back muscles (3 layers)

Answer 9

Superficial (spinotransversales) • Intermediate (erector spinae) • Deep (e.g., transversospinalis)

Question 10

Number of layers of intrinsic back muscles

Answer 10

3

Question 11

Spinotransversales general trend

Answer 11

Superficial intrinsic back muscle

runs from spinous process to transverse process

Question 12

erector spinae general trend

Answer 12

Intermediate intrinsic back muscle

more or less the length of the spine on the left and right

Question 13

transversospinalis general trend

Answer 13

Deep intrinsic back muscle

runs from transverse processes to spinous processes

Question 14

Spinotransversales muscles

Answer 14

superficial

muscles = splenius capitis (head) and splenius cervicis (cervical/neck)

splenius capitis = inserts to mastoid process of the temporal bone and originates from the lower half of the nuchal ligament and the spinous processes of the 7th cervical vertebra and the superior 3 thoracic vertebrae

splenius cervicis = origin is the spinous processes of T3-T6 and insertion are the transverse processes of C1-C3

Question 15

Spinotransversales function

Answer 15

Bilaterally contract, extend next
Individually, rotate head
Lateral flexion

Question 16

Erector spinae muscles

Answer 16

Pelvis to neck

liocostalis (lateral) - best seen in the lumbar region
Longissimus (intermediate)
Spinalis (medial) - thin muscles, best seen in the thoracic region

Question 17

Erector spinae functions

Answer 17

Bilaterally (contracting), extends back
Maintain posture
Individually, lateral flexion

Question 18

Back strain

Answer 18

Common injury from overly strong contraction (too sudden)

The muscles are stretched and may have microscopic tearing

Erector spinae muscles commonly affected

Question 19

Transversospinales muscles

Answer 19

Rotatores (short, entire length of vertebral column) 
Multifidus 
Semispinalis (long)

Question 20

Transversospinales muscle fibre orientation

Answer 20

They run upward, medially and obliquely from transverse processes to spinous processes

Question 21

Rotatores features

Answer 21

From the Transversospinales muscle group

Present throughout the entire length of the vertebral column

Extends from 1-2 vertebrae

Best seen in the thoracic area

Question 22

Rotatores functions

Answer 22

Stabilize vertebral column & maintain posture

Bilaterally, extend back

Ipsilaterally (same side of the body) , lateral flexion

Assist in rotation

(individually these muscles are small but when they work together they can create a big movement)

Question 23

Multifidus features

Answer 23

From the Transversospinales muscle group

Spans the entire length of the vertebral column

Extends from 2-4 vertebrae

Best seen in the lumbar area

Question 24

Multifidus functions

Answer 24

Bilaterally, extend back

Stabilize vertebral column & maintain posture

Ipsilaterally, laterally flex

Question 25

Semispinalis features

Answer 25

From the Transversospinales muscle group Runs for about half of the vertebral column Best seen at the back of the neck

Question 26

Semispinalis functions

Answer 26

Bilaterally extend back, posture Individually rotate vertebral column ***run obliquely so can help with ... ***

Question 27

Intercostal muscles

Answer 27

``` ribcage muscles (3 layers of muscle - external, internal and innermost ) ```

Question 28

external intercostals

Answer 28

Fibers run medially and inferiorly | For inspiration

Question 29

Internal intercostals

Answer 29

Fibers run laterally and inferiorly | For expiration

Question 30

Supply structures of intercostals

Answer 30

Veins, arteries, nerves (VAN) are found between the internal and innermost intercostals

Question 31

Innermost intercostals

Answer 31

Fibers run laterally and inferiorly | For expiration

Question 32

Diaphragm

Answer 32

Important muscle for breathing

Question 33

Important structures in the diaphragm

Answer 33

``` Inferior vena cava Central tendon Esophagus (embedded in diaphragm muscle, contraction helps to prevent reflux into the esophagus) Aorta (abdominal aorta) Phrenic nerve ```

Question 34

Features of the diaphragm

Answer 34

Separates thoracic and abdominal cavities Important muscle for inspiration Has a central tendon Has multiple openings for esophagus, inferior vena cava, and abdominal aorta

Question 35

Inspiration =

Answer 35

contraction of diaphragm and relaxation of abdominal muscles

Question 36

Expiration =

Answer 36

Relaxation of diaphragm and contraction of abdominal muscles

Question 37

Anterolateral wall muscles

Answer 37

(multiple layers) External oblique Internal oblique Transversus abdominis

Question 38

External oblique

Answer 38

Anterolateral wall The muscle fibers are running inferiorly and medially

Question 39

Internal oblique

Answer 39

Anterolateral wall The muscle fibers are running superiorly and medially

Question 40

Movement of oblique muscles in the anterolateral wall

Answer 40

The oblique muscles help with trunk rotation and lateral flexion

Question 41

Transversus abdominis

Answer 41

Increase abdominal cavity pressure | The muscle fibers are running transversely

Question 42

Rectus abdominis

Answer 42

Vertical muscle for trunk flexion