Scapular Region Anatomy

These flashcards cover key concepts related to the anatomy and clinical relevance of the scapular region, focusing on muscles, nerves, and the structure of the shoulder.

What structures are included in the scapular region?

The scapular region comprises structures that surround the shoulder joint, including the scapula and the upper end of the humerus.

What muscle covers the upper half of the humerus?

The deltoid muscle covers the upper half of the humerus on its anterior, lateral, and posterior aspects.

What is the most lateral bony point of the shoulder?

The greater tubercle of the humerus is the most lateral bony point of the shoulder.

Which nerves supply the skin covering the shoulder region?

The skin covering the shoulder region is supplied by the lateral supraclavicular nerve, the upper lateral cutaneous nerve of the arm, and the dorsal rami of the upper thoracic nerves.

What are the components of the musculotendinous cuff of the shoulder?

The musculotendinous cuff, or rotator cuff, includes the subscapularis, supraspinatus, infraspinatus, and teres minor.

What is the origin of the deltoid muscle?

The deltoid muscle originates from the anterior border and adjoining surface of the lateral one-third of the clavicle, the lateral border of the acromion process, and the lower lip of the crest of the spine of the scapula.

How does the deltoid muscle aid in arm movement?

The deltoid is a powerful abductor of the arm at the shoulder joint and has anterior fibers that are flexors and medial rotators, while posterior fibers are extensors and lateral rotators.

What are the clinical implications of deltoid muscle injury?

Injury to the deltoid can impair arm abduction and may result in sensory loss over the lower half of the deltoid, known as the regimental badge area.

What is the clinical significance of the axillary nerve?

The axillary nerve supplies the deltoid muscle and is commonly involved in shoulder dislocations and fractures of the surgical neck of the humerus.

What are the boundaries of the quadrangular space in the scapula?

The boundaries of the quadrangular space are the subscapularis in front, teres minor behind, teres major below, and the surgical neck of the humerus laterally.

What structure is protected by the subacromial bursa?

The subacromial bursa protects the supraspinatus tendon against friction with the acromion process during movements like overhead abduction.

What nerves are found in the lower triangular space?

The lower triangular space contains the radial nerve and profunda brachii vessels.

Which muscles form the rotator cuff?

The rotator cuff is formed by the supraspinatus, infraspinatus, teres minor, and subscapularis.

What are the effects of axillary nerve damage?

Damage to the axillary nerve can lead to loss of deltoid function, resulting in loss of arm abduction up to 90° and sensory loss in the regimental badge area.

Which artery supplies the deltoid muscle?

The deltoid muscle is supplied by the posterior circumflex humeral artery.

What structures are included in the scapular region?

The scapular region comprises structures that surround the shoulder joint, including the scapula and the upper end of the humerus.

What muscle covers the upper half of the humerus?

The deltoid muscle covers the upper half of the humerus on its anterior, lateral, and posterior aspects.

What is the most lateral bony point of the shoulder?

The greater tubercle of the humerus is the most lateral bony point of the shoulder.

Which nerves supply the skin covering the shoulder region?

The skin covering the shoulder region is supplied by the lateral supraclavicular nerve, the upper lateral cutaneous nerve of the arm, and the dorsal rami of the upper thoracic nerves.

What are the components of the musculotendinous cuff of the shoulder?

The musculotendinous cuff, or rotator cuff, includes the subscapularis, supraspinatus, infraspinatus, and teres minor.

What is the origin of the deltoid muscle?

The deltoid muscle originates from the anterior border and adjoining surface of the lateral one-third of the clavicle, the lateral border of the acromion process, and the lower lip of the crest of the spine of the scapula.

How does the deltoid muscle aid in arm movement?

The deltoid is a powerful abductor of the arm at the shoulder joint and has anterior fibers that are flexors and medial rotators, while posterior fibers are extensors and lateral rotators.

What are the clinical implications of deltoid muscle injury?

Injury to the deltoid can impair arm abduction and may result in sensory loss over the lower half of the deltoid, known as the regimental badge area.

What is the clinical significance of the axillary nerve?

The axillary nerve supplies the deltoid muscle and is commonly involved in shoulder dislocations and fractures of the surgical neck of the humerus.

What are the boundaries of the quadrangular space in the scapula?

The boundaries of the quadrangular space are the subscapularis in front, teres minor behind, teres major below, and the surgical neck of the humerus laterally.

What structure is protected by the subacromial bursa?

The subacromial bursa protects the supraspinatus tendon against friction with the acromion process during movements like overhead abduction.

What nerves are found in the lower triangular space?

The lower triangular space contains the radial nerve and profunda brachii vessels.

Which muscles form the rotator cuff?

The rotator cuff is formed by the supraspinatus, infraspinatus, teres minor, and subscapularis.

What are the effects of axillary nerve damage?

Damage to the axillary nerve can lead to loss of deltoid function, resulting in loss of arm abduction up to 90^{\circ} and sensory loss in the regimental badge area.

Which artery supplies the deltoid muscle?

The deltoid muscle is supplied by the posterior circumflex humeral artery.

What is the motor innervation of the Trapezius muscle?

The Trapezius is supplied by the Spinal accessory nerve (CN XI).

Which muscle is the primary protractor of the scapula?

The Serratus anterior muscle.

Injury to which nerve results in 'Winging of the Scapula'?

The Long thoracic nerve (C5, C6, C7).

What are the contents of the Upper Triangular Space?

The circumflex scapular artery.

What is the primary action of the Supraspinatus muscle?

It initiates the first 15^{\circ} of arm abduction.

Which nerve supplies both the Supraspinatus and Infraspinatus muscles?

The Suprascapular nerve (C5, C6).

Where does the Subscapularis muscle insert?

The lesser tubercle of the humerus.

Which muscle inserts on the floor of the intertubercular sulcus?

The Latissimus dorsi.

What are the boundaries of the Triangle of Auscultation?

The Trapezius muscle, the Latissimus dorsi muscle, and the medial border of the scapula.

Which muscles are responsible for upward rotation of the scapula?

The Serratus anterior and the Trapezius (upper and lower fibers).

What passes through the suprascapular notch?

The suprascapular nerve (nerve passes below the ligament, artery passes above).

What is the nerve supply to the Rhomboid major and minor?

The dorsal scapular nerve (C5).

Which muscle is known as the 'boxer's muscle'?

The Serratus anterior.

What is the insertion of the Pectoralis minor?

The coracoid process of the scapula.

Which muscle inserts onto the lateral lip of the bicipital groove?

The Pectoralis major.

Which muscle inserts onto the medial lip of the bicipital groove?

The Teres major.

What is the innervation of the Teres major?

The lower subscapular nerve (C5, C6).

Which rotator cuff muscle is responsible for medial rotation?

The Subscapularis.

Name the three muscles that attach to the coracoid process.

Pectoralis minor, Short head of Biceps brachii, and Coracobrachialis.

What is the clinical term for the area over the deltoid supplied by the axillary nerve?

The regimental badge area.

Which space contains the circumflex scapular artery?

The upper triangular space.

What is the primary action of the Infraspinatus?

Lateral rotation of the arm.

Which humeral structure is most commonly fractured, risking the axillary nerve?

The surgical neck of the humerus.

What structure converts the scapular notch into a foramen?

The superior transverse scapular ligament.

Where does the long head of the triceps brachii originate?

The infraglenoid tubercle of the scapula.