WEEK 11 (Muscles of back) Flashcards
Which muscles are Extrinsic muscles?
Muscles in the SUPERFICIAL and INTERMEDIATE groups
Muscles of the back and organised into which groups?
- Superficial
- Intermediate
- Deep
What are the characteristics of extrinsic muscles?
- Innervated by anterior rami of spinal nerves
- SUPERFICIAL GROUP consists of muscles related to and involved in movements of the UPPER LIMB
- INTERMEDIATE GROUP consists of muscles attached to RIBS & serve a RESPIRATORY FUNCTION
Which muscles are Intrinsic muscles?
Muscles of the DEEP group are INTRINSIC MUSCLES
[Innervated by the posterior rami of spinal nerves and are directly related to movements of the vertebral column and head]
What are the properties of the Superficial group of back muscles?
- Immediately deep to the skin and superficial fascia
- Attach superior appendicular skeleton (clavicle, scapula & humerus) to the axial skeleton
- Also called the APPENDICULAR GROUP
- Muscles include TRAPEZIUS, LATISSIMUS DORSI, RHOMBOID MAJOR, RHOMBOID MINOR and LEVATOR SCAPULAE
What is the function of the Trapezius/
Elevates the scapula
Where does the blood supply of the trapezius come from?
- SUPERFICIAL BRANCH OF THE TRANSVERSE CERVICAL ARTERY
- ACROMIAL BRANCH OF THE SUPRASCAPULAR ARTERY
- DORSAL BRANCHES OF POSTERIOR INTERCOSTAL ARTERIES
What is the function of the Latissmus dorsi?
- Extension
- Adduction
- Medial rotation of the upper limb
- Depresses shoulder preventing its upward movement
Where does the blood supply of the Latissimus dorsi come from?
- THORACODORSAL ARTERY (primary blood supply)
- Small arteries from DORSAL BRANCHES of POSTERIOR INTERCOSTAL and LUMBAR ARTERIES
What are the functions of the Levator Scapulae muscle?
- Elevates the scapula
- Assists other muscles in rotating the lateral aspect of the scapula inferiorly
Where does the blood supply of the Levator scapulae come from?
Branches from the TRANSVERSE and ASCENDING CERVICAL ARTERIES
What is the function of the Rhomboid minor & major?
The two rhomboid muscles work together to retract or pull the scapula toward the vertebral column
Which muscles are the Intermediate group of back muscles?
SERRATUS POSTERIOR SUPERIOR & SERRATUS POSTERIOR INFERIOR
[two thin muscular sheets in the superior & inferior regions of the back & positioning suggests a respiratory function]
Which muscles are Deep group muscles?
- SPLENIUS CAPITIS & CERVICIS (SPINOTRANSVERSALES)
- ERECTOR SPINAE & TRANSVERSOSPINALES
- INTERSPINALES & INTERTRANSVERSAARII
What us unique about the Semispinalis Capitis?
It attaches to the skull
BILATERAL CONTRACTION pulls the head posteriorly whereas UNILATERAL CONTRACTION pulls the head posteriorly and turns it causing the CHIN to move SUPERIORLY and turn towards the side of the contracting muscle
What is the function of Lavatores Rostrum muscles?
Contraction elevates the ribs
What is the function of the Interspinales nd intertransversarii muscles?
Stabilise adjoining vertebrae during movements of the vertebral column to allow more effective action of the large muscle groups
What is the function of the Suboccipital muscles?
- They move the head
- Contraction extends and rotates the head and the ATLANTO-OCCIPITAL and ATLANTO-AXIAL JOINTS
What are the Suboccipital muscles?
- RECTUS CAPITIS POSTERIOR MAJOR
RECTUS CAPITIS POSTERIOR MINOR - OBLIQUUS CAPITIS INFERIOR
- OBLIQUUS CAPITIS SUPERIOR
What are the contents of the Suboccipital triangle?
- Posterior ramus of C1
- Vertebral artery
- Veins
What are the boundaries of the Suboccipital triangle?
- Superomedially - RECTUS CAPITIS POSTERIOR MAJOR MUSCLE
- Superolaterally - OBLIQUUS CAPITIS SUPERIOR MUSCLE
- Inferolaterally - OBLIQUUS CAPITIS INFERIOR MUSCLE
