Lecture on Upper Limb Muscles

Introduction

• Presenter: Patrick
• Focus: Tips and tricks for remembering skeletal muscles of the upper limb, especially for anatomy class.
• Method: Divided into smaller chunks of 4-8 muscles for easier learning.

Muscles that Control Arm Movement

Trapezius

• Originates from the base of the skull to the lowest thoracic vertebra.
• Inserts on the scapula and clavicle.
• Commonly referred to as upper, middle, and lower traps in fitness.
• Named for its trapezoid shape.

Latissimus Dorsi

• Widest muscle in the body, spans shoulder to shoulder and thoracic vertebrae to sacrum.
• Inserts on the humerus.
• Named from Latin: "latissimus" (lateral) and "dorsi" (back).

Rhomboid Major and Minor

• Originate from the spine, insert on the scapula.
• Aid in retracting shoulder blades and maintaining posture.
• Rhomboid Major is rhomboid-shaped; Minor is more cylindrical.

Serratus Posterior Superior

• Located deep to the rhomboids.
• Easily confused with rhomboid major due to proximity.

Levator Scapulae

• Elevates the scapula.
• Only muscle attaching high in the neck to the top of the scapula.

Chest Muscles

Pectoralis Major and Minor

• Pectoralis Major: Large chest muscle.
• Pectoralis Minor: Smaller, lies underneath Major.

Serratus Anterior

• Named for its serrated appearance.
• Contracts when punching forward with a straight arm.

Intercostal Muscles

• Located between each rib.
• "Intercostal" translates to "between the ribs".

Shoulder Muscles

Deltoid

• Named for its triangular (delta) shape.

Rotator Cuff (SITS Muscles)

• Supraspinatus: Above spine of scapula.
• Infraspinatus: Below spine of scapula.
• Teres Minor: Forms an "M" angle with the humerus.
• Subscapularis: Located under the scapula.

Teres Major

• Positioned further down on the scapula and humerus.
• Functions similarly to the latissimus dorsi.

Upper Arm Muscles

Biceps Brachii and Triceps Brachii

• Biceps: Two-headed upper arm muscle.
• Triceps: Three-headed upper arm muscle.

Coracobrachialis

• Connects coracoid process of shoulder blade to upper arm.

Brachioradialis

• Connects humerus to radius.

Brachialis

• Identified by process of elimination among arm muscles.

Anconeus

• Small muscle on back of arm, assists in elbow extension.

Forearm Muscles

• Flexor Carpi Radialis and Ulnaris: Flex the wrist, located on respective sides.
• Palmaris Longus: Long tendon inserts at the base of the palm.
• Pronator Teres and Quadratus: Pronate the arm.

Deep Forearm Muscles

• Flexor Digitorum Superficialis and Profundus: Flex fingers at different joints.
• Flexor Pollicis Longus: Bends thumb.

Posterior Forearm Muscles

• Extensor Carpi Ulnaris and Radialis (Longus/Brevis): Extend the wrist.
• Extensor Digitorum and Digiti Minimi: Extend fingers and pinky.
• Extensor Indicis: Extends index finger.

Thumb Muscles

• Abductor Pollicis Longus: Pulls thumb sideways.
• Extensor Pollicis Longus and Brevis: Extend thumb.
• Supinator: Only muscle controlling supination of forearm.

Hand Muscles

Thenar Mass

• Flexor Pollicis Brevis: Flexes thumb.
• Opponens Pollicis: Responsible for thumb opposition.
• Adductor and Abductor Pollicis: Bring thumb towards and away from midline.

Hypothenar Mass

• Opponens Digiti Minimi: Opposes the pinky.
• Flexor and Abductor Digiti Minimi: Flexes and abducts pinky.
• Palmaris Brevis: Assists in gripping.

Interossei and Lumbricals

• Lumbricals: Flex carpometacarpal joints and extend interphalangeal joints.
• Interossei Muscles: Palmar (adduct) and Dorsal (abduct) interossei.

Conclusion

• Encouragement to use Kenhub for further anatomy learning.
• Promo for Kenhub services and features.
• Mention of future videos in the muscle memorization series.

These notes provide a comprehensive overview of the lecture's main points regarding anatomy of the upper limb muscles, making them a helpful study aid for anatomy students.