Shoulder - Bones Flashcards
What are the 5 regions of the upper limb?
Pectoral girdle, Arm, Forearm, Wrist, Hand
What are the bones consisted in the pectoral girdle?
Clavicle and Scapula
What is the function of the pectoral girdle?
Connect UL to axial skeleton (skull, vertebral column, ribs, sternum)
What are the bones that make up the shoulder joint?
Clavicle and scapula
What bone is the only attachment from upper limb to trunk?
Clavicle
Why is the clavicle easily fractured?
It transmits forces from the upper limb to the trunk.
What is special about the ossification of the clavicle?
It is the first bone to ossify but last bone to finish. It is ossified by intramembranous ossification while other long bones normal ossify by endochondral ossification.
Describe shape of clavicle.
S-shaped.
Medial 2/3 convex anteriorly.
Lateral 1/3 concave anteriorly.
Where does the clavicle normally fracture?
Middle third. / Medial to the conoid tubercle.
Why does it normally fracture at the middle third?
Middle third not reinforced with muscles or ligaments.
Functions of clavicle?
- Bony boundary of the cervicoaxillary canal.
- Protects the neurovascular bundles there.
- Transmits shock from upper limb to skeleton.
- Allows free range of motion - moveable rigid support for scapula.
Special feature of clavicle?
Long bone but it doesnt have a medullary cavity. Has spongy bone with shell of compact bone.
What are the two articulations of clavicle?
Medial end –> manubrium of sternum at SC joint
Lateral end –> acromion of scapula at AC joint.
Which surface of the clavicle is rough and why?
The inferior surface bc strong ligaments bind it to the 1st rib at the sternal end. (costoclavicular ligament)
What is the significance of conoid tubercle?
Attachment for conoid ligament ( 1/2 of coracoclavicular ligament)
What is the significance of trapezoid line on clavicle?
Attachment for trapezoid ligament ( 2/2 of coracoclavicular ligament)
Where are conoid tubercle and trapezoid line located on the clavicle?
Near the acromial end?
Where does the subclavius muscle attach onto clavicle?
In the subclavian groove on the medial third of shaft of clavicle.
What is the name of the anterior surface of scapula?
The subscapular fossa.
Shape of the scapula and type of bone.
Triangular and flat bone.
Where is the scapula located?
From the 2nd (superior angle) - 7th ribs (inferior angle).
Which fossae are located in the posterior surface of scapula?
Supraspinous and Infraspinous fossa.
Which structure divides the two fossa at the posterior surface?
Spine of scapula.
Which of these three fossa are the largest?
The infraspinous fossa.
