- Anatomical terminology
- Skeletal system
- Joints
- Muscles
- Head muscles
- Neck muscles
- Muscles of upper limb
- Thoracic muscles
- Muscles of back
- Superficial back muscles
- Intermediate back muscles
- Deep back muscles
- Muscles of lower limb
- Heart
- Blood vessels
- Lymphatic system
- Nervous system
- Respiratory system
- Digestive system
- Urinary system
- Female reproductive system
- Male reproductive system
- Endocrine glands
- Eye
- Ear
Serratus posterior superior
The serratus posterior superior (Latin: musculus serratus posterior superior) is a broad rectangular-shaped muscle of the back that is located in the upper back between the cervical and thoracic regions. It lies deep to the rhomboid muscles. The serratus posterior superior extends between the vertebrae of the spine and ribs of the thorax. It is smaller than the inferiorly located serratus posterior inferior muscle, and both muscles are separated by a wide distance. Together with the serratus posterior superior, the serratus posterior superior forms the intermediate layer of the back muscles.
Serratus posterior superior | |
Origin | Spinous processes of cervical and thoracic vertebrae (C7 - T3) |
Insertion | Superior borders of ribs 2 - 5 |
Action | Elevation of ribs 2 - 5, aids in inspiration |
Innervation | Intercostal nerves 2nd - 5th |
Blood supply | Posterior intercostal arteries |
Origin
The serratus posterior superior muscle originates from the inferior part of the nuchal ligament and the spinous processes of the cervical and thoracic vertebrae (usually C7 - T3).
Insertion
The muscle fibers go in an inferolateral direction and insert on the superior borders of the 2nd to 5th ribs lateral to their angles.
Action
The serratus posterior superior muscle elevates ribs 2 to 5. It is also one of the accessory respiration muscles and aids in inspiration.
Innervation
The serratus posterior superior is innervated by the 2nd to 5th intercostal nerves.
Blood supply
The serratus posterior superior muscle receives arterial blood supply from the posterior intercostal arteries - branches of the thoracic aorta.