Questions and Answers
What is the action associated with the upper fibers of the trapezius muscle?
Which statement accurately describes the function of the lower fibers of the trapezius muscle?
Which action is primarily performed by the middle fibers of the trapezius muscle?
What nerve supplies the trapezius muscle?
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Which muscle is NOT involved in shoulder depression?
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Which of the following muscles is considered part of the rotator cuff?
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What is the primary function of the rotator cuff muscles?
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Which muscle is NOT part of the rotator cuff?
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Which muscle is involved in elevating the scapula and is innervated by the accessory nerve?
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Which of the following is NOT an action of the trapezius muscle?
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What is the primary action of teres major?
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What is the main role of the teres major muscle?
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Which muscles are responsible for shoulder abduction above 90 degrees?
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Which nerve does NOT supply the infraspinatus muscle?
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Which of the following is incorrectly matched to its function?
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Which muscle plays a minimal role in medial rotation of the shoulder joint?
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What is the primary action of the lower fibers of the trapezius muscle?
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Which muscle is NOT part of the rotator cuff group?
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Which nerve supplies the teres minor muscle?
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What is an action primarily performed by the supraspinatus muscle?
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Which of the following structures is associated with the surgical neck of the humerus?
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Which nerve is responsible for innervating the deltoid muscle?
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Which of the following muscles inserts into the medial lip of the intertubercular sulcus of the humerus?
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The action of the rhomboids major and minor muscles primarily includes which of the following?
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Study Notes
Anatomy of Muscles in the Upper Body
- Pectoralis major is inserted into the floor of the intertubercular groove of the humerus, serving as a prime mover in pushing movements.
- Latissimus dorsi is also inserted into the medial lip of the intertubercular sulcus of the humerus, recognized as one of the main swimming muscles.
- Teres major likewise has its insertion in the medial lip of the intertubercular sulcus of the humerus.
- Serratus anterior originates from the outer surfaces of the upper eight ribs, playing a critical role in scapular protraction and rotation.
Muscle Actions
- Trapezius upper fibers elevate the scapula, while the lower fibers depress the medial part and lower the shoulder.
- Middle fibers of trapezius are primarily responsible for retracting the scapula.
- Pectoralis minor is identified as one of the climbing muscles, aiding in limb movements.
Nerve Supply
- Serratus anterior muscle is innervated by the long thoracic nerve.
- Trapezius muscle is supplied by the accessory nerve.
- Latissimus dorsi receives innervation from the thoracodorsal nerve.
Additional Muscle Facts
- Deltoid muscle forms the rounded contour of the shoulder and is supplied by the axillary nerve, essential for shoulder flexion and abduction.
- Supraspinatus is recognized as the chief abductor of the humerus, playing a pivotal role in shoulder movement.
- Teres minor is categorized as one of the rotator cuff muscles and is supplied by the lower subscapular nerve.
Common Injury Locations
- The most common site for clavicle fractures is at the junction of the lateral two-thirds and the medial third.
- The surgical neck of the humerus is notably related to the axillary nerve, a critical consideration in shoulder surgeries.
Rotator Cuff and Muscular Actions
- The rotator cuff consists of supraspinatus, infraspinatus, teres minor, and subscapularis, excluding teres major.
- Depression of shoulders is accomplished by lower fibers of trapezius, pectoralis minor, and subclavius, while the upper fibers do not contribute to this action.
- Flexion of the shoulder joint is facilitated by biceps brachii, pectoralis major, and anterior deltoid, while latissimus dorsi does not participate in this motion.
Innervation
- Serratus anterior is innervated by the long thoracic nerve.
- Incorrect innervations to note include latissimus dorsi being supplied by the dorsal scapular nerve, which is not accurate.
True or False Statements
- Pectoralis major is supplied by the medial and lateral pectoral nerves.
- Pectoralis minor is positioned at the tip of the coracoid process of the scapula.
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Description
Test your knowledge on important muscles and their functions, including the origin and insertion points of key muscles like the Pectoralis major and Latissimus dorsi. This quiz will challenge your understanding of human anatomy related to muscle actions and their roles in movement.
