Questions and Answers
What is the primary function of the scapula?
The upper limb is a part of the appendicular skeleton.
True
Name one feature of the scapula.
It has three angles.
The bones of the upper limb include the scapula, humerus, ______ and ______.
Signup and view all the answers
Match the following regions of the upper limb with their descriptions:
Signup and view all the answers
Which angle of the scapula is covered by the trapezius muscle?
Signup and view all the answers
The lateral angle of the scapula faces medially and includes the glenoid cavity.
Signup and view all the answers
What covers the inferior angle of the scapula?
Signup and view all the answers
The lateral border of the scapula is the ________ part, which is the thickest.
Signup and view all the answers
Match the following parts of the scapula with their descriptions:
Signup and view all the answers
Which nerve passes posterior to the medial epicondyle?
Signup and view all the answers
The axillary nerve and posterior circumflex artery are located anterior to the surgical neck of the humerus.
Signup and view all the answers
What is the anatomical structure that is commonly fractured at the surgical neck of the humerus?
Signup and view all the answers
The _____ arises from the posterior surface of the lateral epicondyle.
Signup and view all the answers
Match the following features of the humerus with their descriptions:
Signup and view all the answers
Which structure attaches to the medial tip of the scapula?
Signup and view all the answers
The suprascapular ligament comes from the lower end of the scapula.
Signup and view all the answers
At what age does the ossification center for the medial epicondyle appear?
Signup and view all the answers
The humerus is the longest bone in the ______ limb.
Signup and view all the answers
Match the following ossification centers with their appearance ages:
Signup and view all the answers
Which of the following structures is NOT an attachment site for the rotator cuff muscles?
Signup and view all the answers
The upper end of the humerus has both greater and lesser tubercles.
Signup and view all the answers
What articulates with the trochlea of the humerus?
Signup and view all the answers
What is the characteristic shape of the ulna's shaft?
Signup and view all the answers
The ulna ossifies from two primary centers and one secondary center.
Signup and view all the answers
At what age does the ossification of the inferior part of the ulna appear?
Signup and view all the answers
The rounded head of the ulna is located __ to the pointed styloid process.
Signup and view all the answers
Which border of the ulna is described as thick and rounded?
Signup and view all the answers
Match the stages of ulna ossification with their respective timelines:
Signup and view all the answers
The shaft of the ulna has three surfaces.
Signup and view all the answers
What is the primary ossification center for the ulna?
Signup and view all the answers
Study Notes
Overview of Upper Limb Bones
- Upper limb bones include scapula, humerus, radius, and ulna.
- Connected to the axial skeleton (skull, vertebral column, thoracic cage) and part of the appendicular skeleton.
Osteology of the Upper Limb Regions
- Shoulder: Pectoral, deltoid, and scapular areas.
- Arm (brachium).
- Forearm (antebrachium).
- Hand: Comprises wrist, palm, dorsum, and digits.
Scapula
- Thin, triangular shape with two surfaces, three angles, three borders, and three processes.
- Superior angle covered by trapezius; inferior angle covered by latissimus dorsi.
- Lateral angle contains glenoid cavity for shoulder joint.
Scapula Processes
- Coracoid process: Directed forward and laterally, has a facet for clavicle.
- Dorsal surface divided into two fossae.
Scapula Side Determination
- Lateral angle (glenoid) is large and faces laterally; thick lateral border.
- Dorsal surface is convex with a prominent spinous process.
Attachments of the Scapula
- Coracobrachialis inserts from the medial tip.
- Short head of biceps originates from the lateral tip.
Scapula Ligament Attachments
- Suprascapular ligament bridges the suprascapular notch, forming the suprascapular foramen for nerves and vessels.
Humerus
- Longest bone of the upper limb, comprising an upper end, shaft, and lower end.
- Ossifies from one primary center and seven secondary centers.
- Upper end features greater and lesser tubercles, critical for rotator cuff muscle attachments.
Humerus Ossification
- Primary ossification begins during the 8th intrauterine week.
- Secondary ossification centers develop from the first year to the 12th year, with fusion to the shaft between ages 14 and 20.
Humerus Ends
- Upper end provides attachment for rotator cuff muscles.
- Lower end features condyles: capitulum (articulates with radius) and trochlea (articulates with ulna).
- Prominent medial epicondyle; ulnar nerve passes posteriorly to it.
Humerus Shaft
- Features three borders and surfaces; posterior surface not shown in key illustrations.
- Surgical neck is clinically significant, often fractured and risks damage to the axillary nerve and surrounding vessels.
Attachments to Humerus
- Intertubercular groove houses tendon of long head of biceps.
- Coracobrachialis inserts along the middle of the medial border.
Humerus Side Determination
- Rounded upper end with head directed medially; lower end flattened.
- Lesser tubercle limited laterally by the intertubercular groove, sharp interosseous border on the radius.
Ulna
- Medial bone of the forearm, homologous to the fibula in the lower limb.
- Consists of upper end, shaft, and narrower lower end.
Ulna Ossification
- Ossifies from one primary center and two secondary centers.
- Shaft and upper end begin ossification during the 8th intrauterine week; olecranon develops by the 10th year and fuses by 16.
- Lower end ossifies around the 5th year, fusing with the shaft by 18 years.
Ulna Side Determination
- Upper end has a hook-like structure with a sharp, crest-like lateral border.
- Pointed styloid process sits medial to the rounded head of the ulna.
Attachments to Ulna
- Significant anatomical landmarks inform the understanding of muscular and ligamentous connections within the upper limb.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the anatomy of the bones in the upper limbs, including the scapula, humerus, radius, and ulna. This quiz covers each bone's features, attachments, ossification, and side determination, providing a comprehensive understanding of upper limb anatomy. Perfect for students in clinical anatomy courses.
