Week 1 - Trunk-to-Limb muscles Flashcards
How is the scapula attached to the trunk?
Solely by muscles
How does the clavicle develop?
It ossifies in membrane, but is still a long bone
Which joint would muscles that run from the trunk to the girdle move?
Only the girdle - the sternoclavicular joint
Which joint would muscles that run from the trunk to the humerus move?
The glenohumeral joint
What is the socket on the scapula called?
The glanoid fossa
Describe the anterior compartment of the arm muscles
These are flexors of the elbow
Includes biceps - two heads, originate from scapula
Includes brachialis, which has a bigger and deeper humeral attachment
Describe the posterior compartment of the arm muscles
Extensors of the elbow
Made up of triceps. These have three heads, one scapular and two humeral in origin
What is the large landmark on the posterior side of the scapula?
The spine of the scapula. Broadens on the outer side to form the acromedium, the tip of the shoulder
Where does the supraspinatus/infraspinatus/Teres minor attach to the scapula?
Supra - above the spine
Infra- below the spine
Teres minor - below the infra, attaches to the greater tuberosity of the humerus
What is the key muscle on the lateral side of the scapula?
The deltoid.
Attached to the acromion (bony process on the scapula), and the clavicle.
Front, side and back of the girdle
Central part is the thickest and multipennate
What does multipennate describe?
A muscle with several central tendons towards which the muscles fibres converge like barbs on a feather
Where is the insertion point of the deltoid?
In the middle of the shaft of the humerus
Which three muscles make up the rotator cuff?
Supraspinatus, Infraspinatus and Teres minor
Which is the large muscle on the anterior side of the scapula?
Subscapularis
Origin - entire subscapular fossa
Insertion - humeral lesser tuberosity
Give the origin, insertion and parts of the Pectoralis major
Origin - clavicle, sternum, neighbouring ribs
Insertion - front, upper part of humerus
Two functional parts: clavicular and sternocostal
Where is pectoralis minor in relation to PM?
Deep to the major
What are the boundaries of the axilla?
Thoracic wall, pectoralis major latissimus dorsi + T major, and part of the humerus
What is contained in the axilla?
Blood vessels, part of the brachial plexus, lymph nodes nad fat
What is the cervico-axillary canal?
A narrow space, which creates a passage from the neck and thorax, to get to the axilla. It’s found between the first rib and the clavicle/scapula
Describe the brachial plexus
Formed by the C5-T1 rami (5)
Three trunks: 2-1-2
Each trunk is made up of two divisions. Anterior divisions = medial and lateral cords, innervate flexors
Posterior cord innervates extensor compartment muscles
Where are the roots and the trunks of the brachial plexus found? Where are the divisions, cords and branches?
Roots/trunk: In the neck, aside from T1
Divisions: on level with the clavicle
Cords/branches: axilla
What are the two superficial, large muscles of the back?
The Trapezius and the Latissimus dorsi
Describe the Traps
Two, both quadrangular.
Trunk to scapular muscle, moves only the girdle
Attached to skull and vertebrae
Describe the Lats
Attached to lower vertebrae
Trunk to humerus muscle, so moves only the humerus
Attaches anterior to the humerus
What are the two relevant, deeper back muscles?
Levator scapulae and the rhomboids
What does the Levator scapulae do?
Pulls the scapula up.
Attached to cervical vertebrae and scapula
Describe the serratus anterior
Attached to 7-8 ribs from bundles, which ran out into a continuous sheet of muscle as you approach the scapula
