Scapula - The Shoulder Blade(s)
Scapula (= 'shoulder blade' or 'shoulder bone') is a bone of the human body.
A normal, complete, human skeleton includes two shoulder blades, which are also called scapulae (plural).
When learning about the scapula (or both scapulae) as part of a course in human anatomy or human biology the first step is to be able to recognise the scapula bone (or scapulae bones) on the human skeleton. Then you may also be required to explain some of the functions of the scapulae and be able to identify and label the features on a scapula bone (see below).
What is a scapula bone ?
(or, What are scapulae bones ?) ... and where in the body are they located ?
The photograph above shows the two scapulae bones on a model of a human skeleton.
This shows that there is a scapula bone on both the (right- and left-) sides of the body. They are located behind the ribs on each side of the spine, which is also known as the vertebral column.
More about the scapula
The scapula is a large flat triangular bone located in the posterior part of the thorax.
Due to its triangular shape the features of the scapula bone include three angles and three borders.
A prominent ridge called the 'spine of the scapula' extends diagonally across the posterior surface of the triangular body of the scapula. At the lateral (i.e. the furthest from the vertebral column) end of the spine of the scapula is a high-point of the scapula bone known as the acromion or 'acromion process'. That is the point of articulation with the clavicle bone. Below the acromion there is a depression called the glenoid cavity which is the point of articulation of the scapula (shoulder) bone with the humerus (upper-arm bone), forming the shoulder-joint. Another important feature on the scapula bone is the coracoid process, which is important because it is a point of attachment for important muscles of the upper body.
Label the Features of the Scapula
The scapula is a flat bone so it is conveniently described by two diagrams, one to label the features of the posterior surface of the scapula and the other to label the anterior surface of the scapula. (Some descriptions also include a lateral view of the scapula - not shown here.)
Posterior (dorsal) surface of the left scapula - compare with photo above |
List of features on the scapula (bone):
Notice that some of the above are labelled on both of these diagrams (on the left and left-below). Why learn the features on the scapula ? The scapula bone includes the points of attachments of many ligaments, tendons and muscles. For example, specific muscles are attached to specific parts of the scapulae bones. Students of a wide range of health-related subjects (including medicine, nursing, physiotherapy, massage and sports science) need to learn about the muscles of the body and how they work. That involves learning the points of attachment of muscles and, therefore, about the different parts / areas of important bones such as the scapulae. E.g. the teres major (a deep shoulder muscle) has its origin on the lower lateral border of the scapula and its point of insertion on the medial lip of the bicipital groove of the humerus, which enables its action of adducting, extending and inwardly rotating the arm. |
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Anterior (costal) surface of the left scapula |
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Note: Some of the words used to describe the features on the scapula bone are also used to describe other similar features on other bones. It is useful to be familiar with the words used to refer to bone markings and features on bones.
Muscles attached to the Scapula Bone
Attachment to which part of the Scapula ? |
Names of muscle(s) |
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Anterior surface |
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subscapularis |
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Posterior surface |
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Vertebral border of scapula |
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serratus magnus |
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Axillary border of scapula |
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Apex of glenoid cavity: |
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long head of the biceps |
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short head of biceps |
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(sometimes, a few fibres of) Latissimus dorsi |
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See also the pages about the 3 angles of the scapula and how many bones in the human body ?
Related topics include the structure and functions of bones, cranial and facial bones, the vertebral column, bones of the feet and hands and bone markings.