Podcast
Questions and Answers
What is the primary action of the Serratus Anterior muscle?
What is the primary action of the Serratus Anterior muscle?
Which muscle is innervated by the dorsal scapular nerve?
Which muscle is innervated by the dorsal scapular nerve?
Which muscle is responsible for the lowering and forward movement of the clavicle?
Which muscle is responsible for the lowering and forward movement of the clavicle?
What is the origin of the Pectoralis Minor muscle?
What is the origin of the Pectoralis Minor muscle?
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Which of the following muscles provides the action of elevation of the scapula?
Which of the following muscles provides the action of elevation of the scapula?
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What nerve innervates the Pectoralis Minor?
What nerve innervates the Pectoralis Minor?
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Which muscle is involved in the rotation of the scapula so the glenoid cavity moves downwards?
Which muscle is involved in the rotation of the scapula so the glenoid cavity moves downwards?
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Which of the following muscles does NOT originate from the vertebral column?
Which of the following muscles does NOT originate from the vertebral column?
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Study Notes
Muscles Stabilizing the Scapular Girdle
- Table 11.1: Categorizes muscles based on origin, insertion, action, and innervation.
Muscle: Levator Scapulae
- Origin: Transverse processes of the first four cervical vertebrae
- Insertion: Superior vertebral border of the scapula, near the superior angle
- Action: Elevates the scapula
- Innervation: Cervical nerves C₃-C₄ and dorsal scapular nerve (C₅)
Muscle: Pectoralis Minor
- Origin: Anterior surfaces and superior margins of ribs 3-5, or 2-4, and the fascia overlying external intercostal muscles.
- Insertion: Coracoid process of the scapula
- Action: Depresses and forwardly pulls the scapula; rotates the scapula so glenoid cavity moves inferiorly, and elevates ribs if the scapula is fixed
- Innervation: Medial and lateral pectoral nerves (C₅-C₈, T₁)
Muscle: Rhomboideus Major
- Origin: Spinous processes of vertebrae T₂ to T₅
- Insertion: Vertebral border of the scapula, from the spine to inferior angle
- Action: Elevates and retracts the scapula.
- Innervation: Dorsal scapular nerve (C₅-C₇)
Muscle: Rhomboideus Minor
- Origin: Spinous processes of vertebrae C₇ to T₁
- Insertion: Vertebral border of the scapula near the spine
- Action: Elevates and retracts the scapula
- Innervation: Dorsal scapular nerve (C₅-C₇)
Muscle: Serratus Anterior
- Origin: Anterior margins of ribs 1-8, 1-9, or 1-10
- Insertion: Anterior aspect of the vertebral margin of the scapula.
- Action: Pulls the scapula forward, holds the scapula against the thoracic cage, and rotates the scapula.
- Innervation: Long thoracic nerve (C₅-C₇)
Muscle: Subclavius
- Origin: First rib
- Insertion: Clavicle (medial 1/3 of inferior surface).
- Action: Depresses and stabilizes the clavicle.
- Innervation: Nerve to subclavius (C₅-C₆)
Muscle: Trapezius
- Origin: Occipital bone, nuchal ligament, and spinous processes of C₇ to T₁₂
- Insertion: Clavicle, acromion, and spine of scapula
- Action: Variable depending on the portion contracting: elevation, retraction, depression, rotation; elevates or depresses the scapula; stabilizes the scapula; extends the neck when scapula is fixed
- Innervation: Accessory nerve (XI)
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Description
Test your knowledge on the muscles stabilizing the scapular girdle with this quiz. Questions cover the origin, insertion, action, and innervation of key muscles like the Levator Scapulae, Pectoralis Minor, and Rhomboideus Major. Perfect for students of anatomy and physiology.
