Back Of Body And Scapula

Question 1

What is the origin of the Trapezius muscle?

Answer 1

• Medial 1/3rd of superior nuchal line
• Ligamentum nuchae
• External occipital protuberance
• Spines of C7-T12 vertebrae

The trapezius muscle has multiple origins that contribute to its function in movement and stabilization of the scapula.

Question 2

What is the insertion point of the Trapezius muscle?

Answer 2

• Lateral 1/3rd of clavicle
• Medial margin of acromion
• Superior margin of spine of the scapula

The insertion points allow the trapezius to facilitate various movements of the shoulder girdle.

Question 3

What is the nerve supply for the Trapezius muscle?

Answer 3

• Spinal accessory (motor)
• C3, C4 spinal nerves (proprioceptive)

The trapezius receives motor innervation from the spinal accessory nerve, while proprioceptive fibers come from the cervical spinal nerves.

Question 4

What actions are performed by the upper fibers of the Trapezius muscle?

Answer 4

• Elevates the scapula

The upper fibers specifically assist in lifting the shoulder girdle during movements.

Question 5

What actions are performed by the middle fibers of the Trapezius muscle?

Answer 5

• Retracts the scapula

The middle fibers play a crucial role in pulling the shoulder blades together.

Question 6

What is the origin of the Latissimus dorsi muscle?

Answer 6

• Thoraco-lumbar fascia
• Iliac crest
• Lower 3 or 4 ribs

These origins provide a broad base for the latissimus dorsi, allowing it to perform multiple movements of the arm.

Question 7

What is the insertion point of the Latissimus dorsi muscle?

Answer 7

• Floor of intertubercular sulcus of the humerus

The insertion allows the latissimus dorsi to act effectively as a powerful arm adductor and extensor.

Question 8

What is the nerve supply for the Latissimus dorsi muscle?

Answer 8

• Thoraco-dorsal nerve (C6, C7, C8)

The thoraco-dorsal nerve provides the necessary motor control for the latissimus dorsi.

Question 9

What are the actions of the Latissimus dorsi muscle?

Answer 9

• Adduction
• Extension
• Medial rotation of the arm
• Raises body towards arm as in climbing

These actions are essential for various upper body movements and activities.

Question 10

What is the origin of the Levator scapulae muscle?

Answer 10

• Transverse processes of C1-C4 vertebrae

The levator scapulae originates from the cervical vertebrae, which allows it to elevate the scapula.

Question 11

What is the insertion point of the Levator scapulae muscle?

Answer 11

• Medial border of the scapula between the superior angle and root of spine

This insertion helps the levator scapulae fulfill its role in scapular elevation.

Question 12

What is the nerve supply for the Levator scapulae muscle?

Answer 12

• Dorsal scapular nerve (C5)
• C3 and C4 spinal nerves (proprioceptive)

The levator scapulae is innervated by the dorsal scapular nerve, along with contributions from cervical nerves.

Question 13

What is the action of the Levator scapulae muscle?

Answer 13

• Elevation and medial rotation of the scapula; tilts its glenoid cavity inferiorly

This action is important for shoulder movements and stability.

Question 14

What is the origin of the Rhomboideus minor muscle?

Answer 14

• Spines of C7 and T1 vertebrae

The rhomboideus minor originates from specific thoracic vertebrae, allowing it to assist in scapular retraction.

Question 15

What is the insertion point of the Rhomboideus minor muscle?

Answer 15

• Medial border of the scapula at the root of the spine

This insertion helps the rhomboideus minor retract the scapula effectively.

Question 16

What is the nerve supply for the Rhomboideus minor muscle?

Answer 16

• Dorsal scapular nerve (C5)

The dorsal scapular nerve is crucial for the motor function of the rhomboideus minor.

Question 17

What is the action of the Rhomboideus minor muscle?

Answer 17

• Retraction and elevation of the scapula

These actions help maintain proper posture and shoulder alignment.

Question 18

What is the origin of the Rhomboideus major muscle?

Answer 18

• Spines of T2-T5 vertebrae

The rhomboideus major has a broader origin compared to the minor, contributing to its strength in scapular movements.

Question 19

What is the insertion point of the Rhomboideus major muscle?

Answer 19

• Medial border of the scapula from root of spine to the inferior angle

This extensive insertion allows for effective retraction and stabilization of the scapula.

Question 20

What is the nerve supply for the Rhomboideus major muscle?

Answer 20

• Dorsal scapular nerve (C5)

Similar to the rhomboideus minor, the major is also innervated by the dorsal scapular nerve.

Question 21

What is the action of the Rhomboideus major muscle?

Answer 21

• Retraction, medial rotation, and elevation of the scapula

These actions are vital for shoulder movements and maintaining scapular position.