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Spinal Anatomy > Muscles > Flashcards

Flashcards in Muscles Deck (60)
1

Origin:

- Medial Crest of sacrum (Via broad tendon)

- Lateral Crests of Sacrum

- Dorsal SI and Sacrotuberous Ligament

- Posterior part of Medial Lip of Iliac Crest

- T11-L5 SP's

- Supraspinous Ligament

Insertion:

- Inferior border of angles of lower 6 or 7 ribs

FD:

Mostly vertical but somewhat lateral

Action:

- Extension of the vertebral column

- Side bending

- Rotation

R:

- Sacrum stuck in a flexed position will affect Iliocostalis lumborum

- Pulls on Sacrotuberous ligament which then pulls on biceps femoris

 

 

Iliocostalis Lumborum 

 

2

 

Longissimus Thoracis 

 

Origin:

- Iliocostalis Lumborum

- TP's T11-L5

- TLF

Insertion: (2 tendons)

- Thoracic TPs T12-T2

- Lower 9 or 10 Ribs (between tubercles and angles)

Action:

- Extension and SB

 

2

 

Semispinalis Capitis 

Origin:

- Upper 6 or 7 Thoracic TP's

- C7 TP

- Cervical Articular Processes C4-6

Insertion:

- Between superior and inferior nuchal lines of occipital bone

R:

Much larger in comparison to semispinalis cervicis If a muscle attaches into the processes it helps with joint position sense 2-3x larger than SCM is CSA (Cross sectional area)

Nerve: Greater occipital artery + nerve

 

2

Origin:

- C7-T11 TP

Insertion:

- Rib below respective TP

Action:

- rotation of vertebrae

- lateral flexion of vertebrae

- elevates the ribs (aids in respiration)

-Stabilizes the rib

FD:

Inferior and lateral

Nerve:

Innervation is from lateral branches of the dorsal rami of the corresponding thoracic spinal nerves

D:

-12 pairs -on internal aspect of thoracic cage

-The lower 4 muscle pairs may have an additional attachment to the second rib below their origin 

 

Levator Costarum

 

3

 

Rectus Abdominus 

 

Origin:

- Symphysis Pubis

- Pubic Crest

Insertion:

- Anterior Surface of Xiphoid Process

- Anterior Surface of Costal Cartilages 5-7

Action:

- flexes pelvis and vertebral column

-compresses abdomen

- supports viscera

Nerve:

ventral rami of T7-11

Role:

The role of the transverse lines between the abs is to prevent compression of the abdominal organs during flexion

divided by 3 horizontal lines of connective tissue which divide RA and tighten it down to increase mechanical advantage

One large strap muscle would lead to increased force production over a greater range of motion

The sectioned RA limits bulking upon shortening, but also leads to a bead effect, facilitating torso flexion and extension as the visceral contents change volume

 

4

 

Levator Costarum

 

Origin:

- C7-T11 TP

Insertion:

- Rib below respective TP

Action:

- rotation of vertebrae

- lateral flexion of vertebrae

- elevates the ribs (aids in respiration)

-Stabilizes the rib

FD:

Inferior and lateral

Nerve:

Innervation is from lateral branches of the dorsal rami of the corresponding thoracic spinal nerves

D:

-12 pairs

-on internal aspect of thoracic cage

-The lower 4 muscle pairs may have an additional attachemtn to the second rib below their origin

 

5

 

Quadratus Lumborum 

Origin:

- Iliolumbar Ligament (Superior/Posterior aspect)

- Posterior aspect Iliac Crest

- TLF

Insertion:

- Lower border of 12th Rib

- L1-4 TP's

Action:

- depresses 12th rib in respiration

- aids in extension of the trunk

-unilaterally side bends the trunk

-closely related with psoas

Nerve:

dorsal rami of the spinal segment (T12-L3)

R:

- Merges with the diaphram and thus assits in breathing

- if it goes into spasm affecting the thoracic diaphram something else needs to compensate and help us breathe properly

– which is usually are neck muscle (Scalenenes) which increase in tone to lift up the first and second ribs more. Person could come in with TOS but real cause is QL disfunction.

What has a great PSCA QL or glute med? QL

Trendelenburg is both a glute med and QL test

 

5

 

Transverse Abdominus

Origin:

- Lower 6 CC (Inner Surface)

- Middle layer of Fascia

- Anterior 2/3 of inner lip of Iliac Crest -

Lateral 1/3 of Inguinal Ligament

Insertion:

- Linea Alba

- Pubic crest

- Pectineal line

Action:

force attenuation

Stabilization

Protection of organs

Nerve:

T7-12, L1 iliohypogastric and ilioinguinal ligament

R:

A weakness of the internal obliques permits a bulging of the anterior abdominal wall, which indirectly tends to increase lordosis. It also helps to stabilize the linea alba, permitting better action by the anterolateral trunk muscles

 

6

Iliocostalis Lumborum

 

 

Origin:

- Medial Crest of sacrum (Via broad tendon)

- Lateral Crests of Sacrum

- Dorsal SI and Sacrotuberous Ligament

- Posterior part of Medial Lip of Iliac Crest

- T11-L5 SP's

- Supraspinous Ligament

Insertion:

- Inferior border of angles of lower 6 or 7 ribs

FD:

Mostly vertical but somewhat lateral

Action:

- Extension of the vertebral column

- Side bending

- Rotation

R:

- Sacrum stuck in a flexed position will affect Iliocostalis lumborum

- Pulls on Sacrotuberous ligament which then pulls on biceps femoris

 

7

Origin:

- Lower 6-10 Thoracic TP's

Insertion:

- Upper 4-8 Thoracic SP's

- Lower 2 Cervical SP's

FD:

Vertical, slightly oblique

Action:

Aids in proprioception and segmental stabilization, A little extension, A little side bending, Some rotation

R:

Part of the transversospinalis group Acts as static postural muscles of the vertebral column affects OA joint

 

 

Semispinalis Thoracis 

 

7

Origin:

- 3-6 Thoracic SP

Insertion:

- Posterior Tubercles of Upper 2 or 3 Cervical TP's

Action:

side bends and rotates upper thoracic, cervical and OA joints

Relationship: Deeper

 

 

Splenius Cervicis 

 

8

 

Spinalis Thoracis 

 

Origin:

- T11-L2 SP's

Insertion:

- Upper 4-8 Transverse SP's

 

9

 

Longissimus Capitus 

 

Origin:

- Upper 4 or 5 Thoracic TPs

- Lower 3 or 4 Cervical Articular Processes

Insertion:

- Mastoid Process

Action:

- Extension, lateral flexion and rotation of the cervical spine; turning the head to face toward the same side

- Extension of the the neck and head, rotation and a little side bending of neck and head

 

11

 

Spinalis Capitis 

 

Origin:

- Upper 6 or 7 Thoracic TP's

- C7 TP

- 4th-6th Cervical Articular Processes

Insertion:

- Area between Superior/Inferior Nuchal Lines

Relationship:

- inseparably connected with semispinalis capitis

 

12

 

Splenius Capitis 

 

Origin:

- Lower ½ of Ligamentum Nuchae

- C7 SP - Upper 3 or 4 Thoracic SP

Insertion:

- Mastoid Process

- Occipital Bone inferior to lateral 1/3 of Superior Nuchal Line

FD:

ascend laterally

Action: 

- extension, lateral flexion and rot’n

Role:

more superficial

 

13

 

Spinalis Cervicis 

 

Origin:

- Lower 1/2 Ligamentum Nuchae

- C7 SP

Insertion:

- SP of Axis (C2)

- Occasionally into SP's of C3 + C4

Relationships:

Extension of supraspinous ligament

50% of your rotation occurs at C2

 

13

Origin/Insertion:

- Between SP's

- Cervical = 6 pairs

- Thoracic = 2 or 3 pairs

- Lumbar = 4 pairs

Function/Role:

- aids Erector Spinae in extension

-placed in pairs between spinous processes of continuous vertebrae

 

 

Interspinales 

 

14

 

Obliqus Externus 

Origin:

- External Surface Lower 8 Ribs

Insertion:

- Anterior ½ Iliac Crest

- Linea Alba

- Inguinal ligament

Action:

- compresses abdomen

-supports viscera

-forced expiration

-first part of trunk flexion

Nerve:

T7-11

Role:

The upper portion merges with seratus anterior

Lower portion merges with the lats

 

16

 

Intertransversarii 

 

Origin/Insertion:

- Between TP's

Action:

side bends vertebral column

Role:

- small muscles placed between Tp’s of continuous vertebrae in cervical, thoracic and lumbar regions

- 4.5 – 7.3 times the muscles spindles than multifidus

- Length transducers

– position sensors

 

17

Origin:

- Iliocostalis Lumborum

- TP's T11-L5

- TLF

Insertion: (2 tendons)

- Thoracic TPs T12 - T2

- Lower 9 or 10 Ribs (between tubercles and angles)

Action:

- Extension and SB

 

 

Longissimus Thoracis 

 

18

 

Transverse Thoracus

 

Origin:

- Xiphoid Process (Inner Surface)

- Sternum up to Rib 3 (Inner Surface)

Insertion:

- Ribs 2-7 + CC (Inner Surface)

Action:

- aids in expiration and depression of ribs 2-7

Nerve:

Innervation is from the corresponding intercostal nerves

 

19

Origin:

- External Surface Lower 8 Ribs

Insertion:

- Anterior ½ Iliac Crest

- Linea Alba

- Inguinal ligament

Action:

- compresses abdomen

-supports viscera

-forced expiration

-first part of trunk flexion

Nerve: T7-11

Role: The upper portion merges with seratus anterior Lower portion merges with the lats

 

 

Obliqus Externus 

 

20

Origin:

- Upper 6 or 7 Thoracic TP's

- C7 TP

- 4th-6th Cervical Articular Processes

Insertion:

- Area between Superior/Inferior Nuchal Lines

Relationship:

- inseparably connected with semispinalis capitis

 

 

Spinalis Capitis 

20

Origin:

- Lower Thoracic or Upper Lumbar TP's

Insertion:

- Brevis = Lamina of vertebrae above  

- Longus = 2 above

Action: Side bend, rot, ext

Stress: Flexion will stretch or lengthen Rotatores

Role: - 4.5 – 7.3 times the muscles spindles than multifidus - Length transducers – position sensors

-Brevis spans one segment

-Longus spans up 2 segments above -11 pairs

 

 

Rotatores (Third Layer)

 

21

Origin:

- Lower ½ of Ligamentum Nuchae

- C7 SP

- Upper 3 or 4 Thoracic SP

Insertion:

- Mastoid Process

- Occipital Bone inferior to lateral 1/3 of Superior Nuchal Line

FD: ascend laterally

Action:

- extension, lateral flexion and rot’n

Role: more superficial

 

 

Splenius Capitis 

 

22

Origin:

- Superior borders of angles of lower 6 ribs

Insertion:

- Superior border of angles of upper 6 ribs

- C7 TP

Action:

- extension

- side bending

 

 

Iliocostalis Thoracis 

 

23

Origin:

- Upper 6 or 7 Thoracic TP's

- C7 TP

- Cervical Articular Processes C4-6

Insertion:

- Between superior and inferior nuchal lines of occipital bone

Role:

Much larger in comparison to semispinalis cervicis If a muscle attaches into the processes it helps with joint position sense 2-3x larger than SCM is CSA (Cross sectional area)

Nerve: Greater occipital artery + nerve

 

 

Semispinalis Capitis 

 

24

 

Semispinalis Thoracis 

 

Origin:

- Lower 6-10 Thoracic TP's

Insertion:

- Upper 4-8 Thoracic SP's

- Lower 2 Cervical SP's

FD:

Vertical, slightly oblique

Action:

Aids in proprioception and segmental stabilization, A little extension, A little side bending, Some rotation

Role:

Part of the transversospinalis group Acts as static postural muscles of the vertebral column affects OA joint

 

25

Origin:

- T11-L2 SP's

Insertion:

- Upper 4-8 Thoracic SP's

 

 

Spinalis Thoracis 

 

26

Origin:

- Superior Border of Ribs + CC

Insertion:

- Rib + CC above

FD:

-is up and medial (perpendicular to Externi)

-Up & lateral on the posterior aspect

Action:

- supports intercostal space (maintains space)

- lowers rib in forces expiration

D: 11 pairs

Role: From the rib angles, they continue as an aponeurotic layer called the internal intercostal membrane and blend with the superior CT ligament

 

 

Intercostales Interni

 

27

Origin:

- Angles of Ribs 3-6

Insertion:

- Posterior Tubercles of TP’s C4-6

Action:

- extension

 

 

Iliocostalis Cervicis 

 

28

Origin:

- Upper 4 or 5 Thoracic TPs

- Lower 3 or 4 Cervical Articular Processes

Insertion:

- Mastoid Process

Action:

- Extension, lateral flexion and rotation of the cervical spine; turning the head to face toward the same side

- Extension of the the neck and head, rotation and a little side bending of neck and head

 

 

Longissimus Capitus 

 

28

Origin:

- T11, T12, L1, L2 Sp's

- lumbar fascia

- Also the supraspinous ligament

Insertion:

- inferior border of lower 4 ribs just beyond their angles

FD: Oblique and lateral

Action:

-aids respiration & lowers ribs

Nerve:

-9th – 11th intercostal nerve

Role: lies immediately posterior to erector spinae

 

 

Serratus Posterior Inferior

 

29

Origin:

- Posterior Surface of Sacrum

- Medial Surface of PSIS

- Dorsal SI Ligament

- L5 - C4 TP's

Insertion:

- SP's above (Spans 2 - 4 segments)

Fibre Direction:

- Superior, Oblique and Medial

Function/Role:

Segemental stability (Large amount)

Relationships:

- If a spinal segment is in disfunction, not neccesarily pain, multifidus will start to atrophy within 24 hours -Some of the fibres will merge with the zygoapopheseal joint capsule - so able to give feedback to the body with regard to where the facets are, side bent, rotated etc. - Fibres arent neccesarily merging *Majority of the fibres will go from segment to segment

 

 

Multifidi 

 

30

 

Interspinales 

Origin/Insertion:

- Between SP's

   - Cervical = 6 pairs

   - Thoracic = 2 or 3 pairs

   - Lumbar = 4 pairs

Function/Role:

- aids Erector Spinae in extension

Relationship:

placed in pairs between spinous processes of continuous vertebrae

 

31

Origin:

- Sp’s of C7, T1, T2, T3

- lower part of ligamentum nuchae

- Supraspinous ligament

Insertion:

- upper border of ribs 2-5

- Inserts just lateral to the rib angles on their superior and superfical surfaces

Action:

-aids in respiration & elevates ribs

Nerve:

- 2nd – 4th intercostal nerves

 

 

Serratus Posterior Superior

 

33

 

Intercostales Externi

 

Origin:

- Inferior border of Rib below Tubercle

Insertion:

- Superior border of Rib below

FD:

is down & medial (Ant), down & lat (Post)

Action:

- supports intercostal space (protective)

- elevates rib in inspiration

D:

11 pairs

R: 

Orginates from the tubercles of the rib, blending with the posterior fibres of the CT ligaments

 

36

 

Iliocostalis Cervicis

Origin:

- Angles of Ribs 3-6

Insertion:

- Posterior Tubercles of TP’s C4-6

Action:

- extension

 

38

Iliocostalis Thoracis 

 

Origin:

- Superior borders of angles of lower 6 ribs

Insertion:

- Superior border of angles of upper 6 ribs

- C7 TP

Action:

- extension

- side bending

 

39

Origin:

- Xiphoid Process (Inner Surface)

- Lower 6 Ribs + CC (Inner Surface)

- Anterior Surface L1-L3

- Right/Left Crura

- Anterior Longitudinal Ligament

- IVD - Medial / Lateral Arcuate Ligaments

Insertion:

- Central Tendon

FD:

The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of the aorta known as the median arcuate ligament; this arch is often poorly defined. The area behind this arch is known as the aortic hiatus.

N:

-innervated by phrenic nerve C3, C4, C5

R:

At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column. The right crus, larger and longer than the left, arises from the anterior surfaces of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebrae. The left crus arises from the corresponding parts of the upper two lumbar vertebrae only. The medial fibers of the right crus ascend on the left side of the esophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward the vena caval foramen. pericardial sac attaches to the diaphragm made up of 3 parts right, which is the largest and corresponds to right lung anterior, corresponding to heart left, which is the smallest and correspond to left lung

Holes of the Diaphragm: -vena cava -esophageal hiatus (formed by right crus) -aortic hiatus (formed where right and left crura meet superiorly)…aorta sits posterior to diaphragm and anterior to the vertebral column -phrenic nerve

 

 

Thoracic Diaphragm

 

40

 

Origin:

- Upper 5 or 6 Thoracic TP's

Insertion:

- C2-C5 SP's

 

 

Semispinalis Cervicis 

 

41

Origin:

- Upper 4 or 5 Thoracic TPs

Insertion:

- Posterior Tubercles of TP's C2-6

Action:

- Extension and SB

 

 

Longissimus Cervicis

42

Origin: 

- Symphysis Pubis

- Pubic Crest

Insertion:

- Anterior Surface of Xiphoid Process

- Anterior Surface of Costal Cartilages 5-7

Action:

- flexes pelvis and vertebral column

-compresses abdomen

- supports viscera

Nerve:

ventral rami of T7-11

Role: The role of the transverse lines between the abs is to prevent compression of the abdominal organs during flexion divided by 3 horizontal lines of connective tissue which divide RA and tighten it down to increase mechanical advantage One large strap muscle would lead to increased force production over a greater range of motion The sectioned RA limits bulking upon shortening, but also leads to a bead effect, facilitating torso flexion and extension as the visceral contents change volume

 

 

Rectus Abdominus 

 

43

Origin:

- TLF

- Anterior 2/3 of Iliac Crest (middle lip)

- Lateral 2/3 of Inguinal Ligament

Insertion:

Lower 3 CC

Linea Alba

Pubic Crest

Pectineal Line

Action:

Force closure of symphasis pubis compresses abdomen aids in expiration supports viscera flex the vertebral column

Nerve:

T9-12, L1 Iliohypogastric and ilioinguinal nerve

Role:

The more inferiorly placed portion of the muscle exerts a pull on the pelvis, a motion that is medially directed, effectively increasing compression of the pubic symphysis. This muscle can exert a powerful forward and elevation movement of the pelvis, a motion that is essential in sprinting

 

 

Obliqus Internus 

 

45

Obliqus Internus 

Origin:

- TLF

- Anterior 2/3 of Iliac Crest (middle lip)

- Lateral 2/3 of Inguinal Ligament

Insertion:

Lower 3 CC

Linea Alba

Pubic Crest

Pectineal Line

Action:

Force closure of symphasis pubis

compresses abdomen

aids in expiration

supports viscera

flex the vertebral column

Nerve:

T9-12, L1 Iliohypogastric and ilioinguinal nerve

R:

The more inferiorly placed portion of the muscle exerts a pull on the pelvis, a motion that is medially directed, effectively increasing compression of the pubic symphysis. This muscle can exert a powerful forward and elevation movement of the pelvis, a motion that is essential in sprinting

 

46

 

Longissimus Cervicis 

 

Origin:

- Upper 4 or 5 Thoracic TPs

Insertion:

- Posterior Tubercles of TP's C2-6

Action:

- Extension and SB

 

47

Origin:

- Xiphoid Process (Inner Surface)

- Sternum up to Rib 3 (Inner Surface)

Insertion:

- Ribs 2-7 + CC (Inner Surface)

Action:

- aids in expiration and depression of ribs 2-7

N:

-Innervation is from the corresponding intercostal nerves

 

 

Transverse Thoracus

 

48

Origin:

- Lower 1/2 Ligamentum Nuchae

- C7 SP

Insertion:

- SP of Axis (C2)

- Occasionally into SP's of C3 + C4

R:

Extension of supraspinous ligament

50% of your rotation occurs at C2

 

 

Spinalis Cervicis 

 

49

 

Splenius Cervicis 

 

Origin:

- 3-6 Thoracic SP

Insertion:

- Posterior Tubercles of Upper 2 or 3 Cervical TP's

A:

side bends and rotates upper thoracic, cervical and OA joints

R: Deeper than Splenius Capitus

 

50

 

Semispinalis Cervicis 

Origin:

- Upper 5 or 6 Thoracic TP's

Insertion:

- C2-C5 SP's

 

50

 

Multifidi 

 

Origin:

- Posterior Surface of Sacrum

- Medial Surface of PSIS

- Dorsal SI Ligament

- L5 - C4 TP's

Insertion:

- SP's above (Spans 2 - 4 segments)

Fibre Direction:

- Superior, Oblique and Medial

Function/Role:

Segemental stability (Large amount)

Relationships:

- If a spinal segment is in disfunction, not neccesarily pain, multifidus will start to atrophy within 24 hours

-Some of the fibres will merge with the zygoapopheseal joint capsule - so able to give feedback to the body with regard to where the facets are, side bent, rotated etc.

- Fibres arent neccesarily merging *Majority of the fibres will go from segment to segment

 

51

Origin:

- Inferior border of Rib below Tubercle

Insertion:

- Superior border of Rib below

FD:

is down & medial (Ant), down & lat (Post) Action:

- supports intercostal space (protective)

- elevates rib in inspiration

D: 11 pairs

R: Orginates from the tubercles of the rib, blending with the posterior fibres of the CT ligaments

 

 

Intercostales Externi

 

53

Origin:

- Lower 6 CC (Inner Surface)

- Middle layer of Fascia

- Anterior 2/3 of inner lip of Iliac Crest

- Lateral 1/3 of Inguinal Ligament

Insertion:

- Linea Alba

- Pubic crest

- Pectineal line

A:

force attenuation Stabilization Protection of organs Nerve:

T7-12, L1 iliohypogastric and ilioinguinal ligament

Role:

A weakness of the internal obliques permits a bulging of the anterior abdominal wall, which indirectly tends to increase lordosis. It also helps to stabilize the linea alba, permitting better action by the anterolateral trunk muscles

 

 

Transverse Abdominus 

 

54

 

Rotatores 

Origin:

- Lower Thoracic or Upper Lumbar TP's

Insertion:

- Lamina of vertebrae above (Brevis)

- Longus = 2 above

A:

Side bend, rot, ext

S:

Flexion will stretch or lengthen Rotatores

R:

- 4.5 – 7.3 times the muscles spindles than multifidus

- Length transducers

– position sensors

-Brevis spans one segment

-Longus spans up 2 segments above

-11 pairs

 

55

Origin:

- Iliolumbar Ligament (Superior/Posterior aspect)

- Posterior aspect Iliac Crest

- TLF

Insertion:

- Lower border of 12th Rib

- L1-4 TP's

Action:

- depresses 12th rib in respiration

- aids in extension of the trunk

-unilaterally side bends the trunk

-closely related with psoas

Nerve:

dorsal rami of the spinal segment (T12-L3)

Role:

Merges with the diaphram and thus assits in breathing - if it goes into spaasm affecting the thoracic diaphram something else needs to compensate and help us breathe properly – which is usually are neck muscle (Scalenenes) which increase in tone to lift up the first and second ribs more. Person could come in with TOS but real cause is QL disfunction. What has a great PSCA QL or glute med? QL Trendelenburg is both a glute med and QL test

 

 

Quadratus Lumborum 

 

56

 

Intercostales Interni

 

Origin:

- Superior Border of Ribs + CC

Insertion:

- Rib + CC above

FD:

-is up and medial (perpendicular to Externi) (Posterior aspect) 

 

Action:

- supports intercostal space (maintains space)

- lowers rib in forces expiration

D:

11 pairs

R:

From the rib angles, they continue as an aponeurotic layer called the internal intercostal membrane and blend with the superior CT ligament

 

57

 

Serratus Posterior Inferior

 

Origin:

- T11, T12, L1, L2 Sp's

- TLF 

- Supraspinous ligament

Insertion:

- Inferior border lower 4 ribs (just beyond their angles)

FD:

Oblique and lateral

Action:

-aids respiration & lowers ribs

Nerve:

-9th–11th intercostal nerve

R:

lies immediately posterior to erector spinae

 

58

 

Thoracic Diaphragm

 

Origin:

- Xiphoid Process (Inner Surface)

- Lower 6 Ribs + CC (Inner Surface)

- Anterior Surface L1-L3

   - Right/Left Crura

   - Anterior Longitudinal Ligament  

   - Medial / Lateral Arcuate Ligaments

Insertion:

- Central Tendon

FD:

The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of the aorta known as the median arcuate ligament; this arch is often poorly defined. The area behind this arch is known as the aortic hiatus.

N:

innervated by phrenic nerve C3, C4, C5

R:

At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column.

The right crus, larger and longer than the left, arises from the anterior surfaces of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebrae.

The left crus arises from the corresponding parts of the upper two lumbar vertebrae only. The medial fibers of the right crus ascend on the left side of the esophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward the vena caval foramen.

pericardial sac attaches to the diaphragm made up of 3 parts right, which is the largest and corresponds to right lung anterior, corresponding to heart left, which is the smallest and correspond to left lung

Holes of the Diaphragm:

-vena cava

-esophageal hiatus (formed by right crus)

-aortic hiatus (formed where right and left crura meet superiorly)…aorta sits posterior to diaphragm and anterior to the vertebral column -phrenic nerve

 

59

Origin/Insertion:

- Between TP's

Action:

side bends vertebral column

Role:

- small muscles placed between Tp’s of continuous vertebrae in cervical, thoracic and lumbar regions - 4.5 – 7.3 times the muscles spindles than multifidus - Length transducers – position sensors

 

 

Intertransversarii 

 

60

 

Serratus Posterior Superior

 

Origin:

- C7-T3 SP 

- Lower 1/2 Ligamentum Nuchae

- Supraspinous ligament

Insertion:

- upper border of ribs 2-5

- Inserts just lateral to the rib angles on their superior and superfical surfaces

Action:

-aids in respiration & elevates ribs

Nerve:

- 2nd–4th intercostal nerves