Muscle Functions and Innervations

The video tutorial explores the muscles that move the pectoral girdle, including the subclavius, pectoralis minor, serratus anterior, trapezius, levator scapulae, and rhomboids. Each muscle's origin, insertion, action, and innervation are discussed, highlighting their roles in stabilizing and moving the scapula. The tutorial provides a detailed anatomical overview, emphasizing the importance of these muscles in shoulder and upper body movement.

What is the primary function of the subclavius muscle?

• To retract the scapula

• To rotate the scapula

• To stabilize the pectoral girdle

• To elevate the scapula

When the ribs are fixed, what action does the pectoralis minor perform?

• Stabilizes the pectoral girdle

• Draws the scapula upward and backward

• Draws the scapula downward and forward

• Rotates the scapula laterally

Which muscle is known for its serrated appearance and helps in rotating the scapula?

• Subclavius

• Pectoralis minor

• Trapezius

• Serratus anterior

What is the origin of the trapezius muscle?

• Inferior angle of the scapula

• Lateral third of the clavicle

• Medial border of the scapula

• Occipital bone and spinous processes of C7 to T12

Which nerve innervates the trapezius muscle?

• Radial nerve

• Dorsal scapular nerve

• Phrenic nerve

• Accessory nerve

What is the primary action of the levator scapulae muscle?

• To stabilize the pectoral girdle

• To elevate the scapula

• To retract the scapula

• To rotate the scapula

Where do the rhomboids major and minor insert?

• Spinous processes of C7 to T5

• Acromion process

• Medial border of the scapula

• Lateral third of the clavicle

Which muscle group originates from the vertebral column and helps stabilize the scapula?

• Trapezius

• Rhomboids

• Serratus anterior

• Pectoralis minor

What is the innervation of the rhomboids?

• Accessory nerve

• Radial nerve

• Dorsal scapular nerve

• Phrenic nerve

Which muscle is responsible for elevating the scapula and is located on the posterior side?

• Subclavius

• Serratus anterior

• Pectoralis minor

• Levator scapulae