Anatomy of Muscles: Nerve Supply and Types

Introduction to Anatomy

• Terminology is important for clear communication among professionals, demonstrating knowledge and competence, and enhancing leadership/mentoring roles.
• Using common terms enables effective communication with clients and caregivers, and promotes a unified understanding.

Anatomic Position and Planes of the Body

• The anatomic position is a standardized position used worldwide to describe the human body.
• The anatomic position is used to describe the body in any position (e.g., lying, sitting).
• There are three planes of the body: median (right and left), sagittal (parallel to the median), and coronal (front and back).

Directional Terminology

• Anterior (ventral) refers to the front of the body, while posterior (dorsal) refers to the back.
• Superior (cranial) refers to the upper part of the body, while inferior (caudal) refers to the lower part.
• Proximal refers to a position closer to the trunk, while distal refers to a position farther from the trunk.
• Medial (ulnar) refers to a position closer to the midline, while lateral (radial) refers to a position farther from the midline.
• Superficial refers to a position near the surface, while deep refers to a position farther from the surface.

Anatomical Regions

• The cephalic region includes the head and face.
• The spinal region includes the thoracic and lumbar spine.
• The upper extremity includes the shoulder, arm, forearm, wrist, and hand.
• The pelvic region includes the pelvis and perineum.
• The lower extremity includes the thigh, leg, ankle, and foot.

Anatomic Structure, Supply, and Function

• The nervous system includes the central nervous system (brain and spinal cord) and peripheral nervous system (cranial and spinal nerves).
• The muscular system includes skeletal muscle (voluntary), smooth muscle (involuntary), and cardiac muscle (heart).
• Skeletal muscle has three layers: epimysium (outer), perimysium (middle), and endomysium (inner).
• Muscle fibers have multiple nuclei and are multinucleated.

Muscle Classification and Function

• Muscles can be classified as skeletal (voluntary), smooth (involuntary), or cardiac (heart).
• Muscles can also be classified based on their shape: flat, pennate, fusiform, or quadrate.
• Muscle function includes movement, stability, and support.

Nerve Supply and Muscle Action

• Motor units consist of a motor neuron and the muscle fibers it innervates.
• The nervous system regulates muscle tone and movement.

Joint Classification and Function

• Joints can be classified as fibrous, cartilaginous, or synovial.
• Joint stability depends on articular shape, ligaments, and muscle tone.
• Synovial joints have a joint cavity and are lined with a synovial membrane.
• Joints can be classified based on their movement: pivot, hinge, condyloid, saddle, or ball-and-socket.