Podcast
Questions and Answers
What function does the musculospiralgroove on the lateral surface of the humerus serve?
What function does the musculospiralgroove on the lateral surface of the humerus serve?
Which structure is found proximal to the middle of the humerus?
Which structure is found proximal to the middle of the humerus?
How is the cranial surface of the humerus characterized?
How is the cranial surface of the humerus characterized?
Which muscle is associated with the rounded caudal surface of the humerus?
Which muscle is associated with the rounded caudal surface of the humerus?
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What is the primary shape description of the body or shaft of the humerus?
What is the primary shape description of the body or shaft of the humerus?
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What is the significance of the crest of the humerus?
What is the significance of the crest of the humerus?
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Which surface of the humerus is primarily involved with nutrient supply?
Which surface of the humerus is primarily involved with nutrient supply?
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Study Notes
The Humerus
- The humerus forms the skeletal structure of the arm, also known as the brachium.
- The humerus is a long bone, positioned obliquely (at an angle) downwards and backwards.
- It extends between the shoulder joint above and the elbow joint below.
- The humerus is the largest bone in the upper limb.
- It is composed of a body (shaft) and two extremities (ends).
- The body of the humerus is irregularly cylindrical and has a twisted appearance.
- It possesses four surfaces:
- The lateral surface is smooth, featuring a spiral groove (sulcus musculi brachialis) that accommodates the radial nerve.
- The medial surface is almost straight and hosts the brachialis muscle.
- The cranial surface is triangular, broad and smooth proximally (near the shoulder), narrowing and becoming rough distally (near the elbow). This area provides attachment for the coracobrachialis muscle.
- The caudal surface is rounded and smooth, presenting a nutrient foramen (a small opening) in its distal third.
- The humerus has a crest, where the deltoid tuberosity is located.
- The crest provides insertion points for the brachiocephalicus, deltoid, and superficial pectoral muscles.
- The deltoid tuberosity is a prominent bump that serves for the deltoid muscle insertion.
- A curved line extends upwards and backwards from the deltoid tuberosity, offering attachment for the lateral head of the triceps brachii muscle (the triceps).
- The curved line also displays a tubercle (small prominence), the teres minor tuberosity, providing insertion for the teres minor muscle.
- Proximal to its middle, the medial surface of the body presents the teres tubercle (teres major tuberosity), serving as an attachment site for the latissimus dorsi and teres major muscles.
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Description
Test your knowledge about the humerus, the largest bone in the upper limb. This quiz covers its structure, surfaces, and functional relevance in the arm. Perfect for students studying anatomy or medical professionals looking to refresh their knowledge.
