Upper Extremity Muscles and Bones

Study Notes

Upper Extremity Muscles

The upper extremity includes the shoulder, arm, forearm, and hand, with intricate muscle, bone, and joint networks enabling movement.
Muscles are vital for motion, controlled by signals from the spinal cord via nerves.
Key upper extremity muscles include the deltoids (shoulder abduction), biceps brachii (elbow flexion), triceps brachii (elbow extension), and various forearm muscles (wrist and hand movements).
Muscles often work in coordinated pairs, like biceps and triceps, as antagonists.
Healthy nerves and blood vessels are essential for muscle function.
Muscle groups are categorized by actions like flexion, extension, abduction, and adduction.

Upper Extremity Bones

The upper extremity's skeletal structure provides support and movement, composed of various bones.
Key bones include the clavicle, scapula, humerus, radius, ulna, carpals, metacarpals, and phalanges.
Each bone features distinctive parts (processes, condyles, fossae) impacting articulation and leverage.
Bones connect at joints, forming a supportive and mobile structure.
Bone density and strength prevent fractures and handle weight and movement stress.
The clavicle, scapula, and humerus link the upper extremity to the axial skeleton.

Upper Extremity Joints

The upper extremity has many joints, where bones meet and allow movement.
Key joints include the sternoclavicular, acromioclavicular, glenohumeral (shoulder), elbow (humeroradial/humeroulnar), radiocarpal (wrist), and interphalangeal (finger) joints.
Each joint's structure defines its movement types (flexion, extension, abduction).
Ligaments stabilize joints, preventing excessive motion and injury.
Cartilage cushions joints.
Tendons, connecting muscles to bones, support joint movement.

Boney Landmarks

Anatomical landmarks are significant reference points for upper extremity structures.
Clinicians use bony landmarks for precise injury assessment, diagnosis, and treatment.
Key landmarks include:
- Shoulder: acromion, coracoid process, greater tubercle, lesser tubercle, glenoid fossa.
- Arm: epicondyles (medial and lateral), olecranon process, capitulum, trochlea.
- Forearm: styloid processes of radius and ulna.
- Hand: carpal bones (scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate), metacarpal heads, and phalangeal bases.
Landmark knowledge facilitates precise injury location and treatment procedures, like injections.
Palpation affirms clinical examination and assessment.

Description

This quiz explores the muscles and bones of the upper extremity, including the shoulder, arm, forearm, and hand. You'll learn about key muscle functions, bone structure, and coordinated movements essential for upper limb functionality. Test your knowledge on the anatomy and physiology of the upper extremity.