1. Axial Musculature Biology 323 Human Anatomy for Biology Majors
Lecture 6
Dr. Stuart S. Sumida
Axial Musculature

3. Superficial Layer Erector Spinae Insertion = ribs
Origin = sacrum/iliac crest
Iliocostalis
Insertion = ribs

4. Superficial Layer Erector Spinae Longissimus Insertion = transverse
Origin = sacrum/iliac crest
Longissimus
Insertion = transverse
processes

5. Superficial Layer Erector Spinae Spinalis Insertion = spinous
Origin = sacrum/iliac crest
Spinalis
Insertion = spinous
processes

7. Intermediate Layer Multifidus Insertion = spinous processes
Origin = sacrum/iliac crest
Insertion = spinous processes

8. Intermediate Layer Semispinalis processes Insertion =spinous
Origin = transverse
processes
Insertion =spinous

10. Short slips of muscle, connecting adjacent vertebrae
Deep Layer
Short slips of muscle, connecting adjacent vertebrae

13. Three Divisions
Body Wall
Limbs
Prevertebral

14. Subdivision of Body Wall Group
Abdominal
Thoracic
Perineal
Neck

16. Subdivision of the Abdominal Group
Superficial =
external Oblique
Origin: Lower 8 ribs
Insertion: top of rectus sheath

17. Subdivision of the Abdominal Group
Intermediate =
Internal Oblique
Origin: Iliac crest
Insertion: Rectus sheath

18. Subdivision of the Abdominal Group
Deep = Transversus
Origin: Thoracolumbar
fascia
Insertion: Sheath below
abdominus rectus

20. Subdivision of the Thoracic Group
External intercostal
Internal Intercostal
Transversus thoracis

24. Subdivision of the Perineal Group
Superficial =
Urogenital/anal
external anal
sphinceter

25. Subdivision of the Perineal Group Intermediate = Pelvic Diaphragm:
- Coccygeus
- Levator ani

26. Subdivision of the Perineal Group Deep = Transversalis Fascia

30. Subdivision of the Neck Region
Diaphragm ripped out early in development
Scalenes are what are left.

34. Strap muscles
Rectus Abdominus

40. Strap muscles
Rectus Series
Geniohyoid

41. Strap muscles
Rectus Series
Omohyoid

42. Strap muscles
Rectus Series
Sternohyoid
Sternothyroid

43. Strap muscles
Pyramidalis

44. Appendicular Musculature

45. Innervation: Dorsal Ramus Hypaxial Distal Dorsal Branch Epaxial Distal
Limb receives branches from ventral ramus of spinal nerves
Dorsal mass or musculature from distal dorsal branch
Ventral mass from distal ventral branch
Distal
Ventral
Branch
Ventral
Ramus

46. Each limb receives more than 1 nerve:
Usually about 6

47. Posterior branches extend more distally

48. Limb Quadrants 1: Introduction
Limb muscular is very complex.It’s best to look at it on a very simplified level, then add detail
How do we do this?
Most primitive limbs are the fins of fished: musculature is the same as a human embryo

49. elevates (extends) limb depresses (flexes) limb
Dorsal Mass
elevates (extends) limb
Ventral Mass
depresses (flexes) limb

50. Caudal (Inferior) Cranial (Superior) Dorsal (Posterior)
Muscles can be subdivided according to where they attach
Each set of muscles is served by a different nerve
Caudal (Inferior)
Ventral (Anterior)
Cranial (Superior)
Ventral (Anterior)

51. Cranial (Superior) Dorsal (Posterior) Ventral (Anterior)
Caudal (Inferior)
Ventral (Anterior)
Muscles can be subdivided according to where they attach
Each set of muscles is served by a different nerve

53. Cranial/Ventral:
(Superior/Anterior)
Attaches to pubic bone

54. Caudal/Ventral
Inferior/Anterior):
Attaches to Ischium

55. Cranial/Dorsal
Superior/Posterior):
Attaches to upper part of ilium

56. Caudal/Dorsal
Inferior/Posterior):
Attaches to lower part of ilium

57. Cranial/Ventral
Superior/Anterior
Cranial/Dorsal
Superior/Posterior
Caudal/Ventral
Inferior/Anterior
Caudal/Dorsal
Inferior/Posterior

58. Caudal view Dorsal view Ventral view Lateral view Ventral (Anterior)
Cranial (Superior)
Dorsal (Posterior)
Caudal (Inferior)
Ventral (Anterior)
Dorsal view
Ventral view
Lateral view

59. Mammals = “Non- Sprawling” Posture Reptiles= “Sprawling” Posture
Cranial (Superior)
Dorsal (Posterior)
Caudal (Inferior)
Ventral (Anterior)
Mammals =
“Non- Sprawling”
Posture
Reptiles=
“Sprawling”
Posture

60. Ventral
(Anterior)
view
Lateral view

61. The Lumbosacral Plexus