Muscular System: Axial and Appendicular Muscles

These flashcards cover the key concepts and terminology from the lecture on the muscular system, specifically focusing on axial and appendicular muscles, muscle organization, naming conventions, actions, and clinical considerations.

Axial muscles

Muscles that have both origins and insertions on the axial skeleton, supporting and moving the head and vertebral column.

Appendicular muscles

Muscles that control movement of the upper and lower limbs and the pectoral and pelvic girdles.

Tendon

A structure that attaches muscle to bone, skin, or another muscle.

Aponeurosis

A thin, flattened sheet-like tendon.

Agonist

The prime mover muscle that contracts to produce a movement.

Antagonist

A muscle whose contraction opposes that of the agonist, allowing for smooth movement.

Synergist

A muscle that assists an agonist by contributing tension or stabilizing the origin.

Pennate muscles

Muscles with fascicles organized as if part of a large feather; they generate more tension.

Circular muscles

Muscles with concentrically arranged fascicles that create a sphincter to control material passage.

Skeletal muscle fiber organization

Refers to the arrangement of muscle fibers into types such as circular, parallel, convergent, and pennate.

Muscle naming criteria

Muscles can be named based on action, location, attachments, orientation, shape, size, and number of heads.

Proximal attachment

The attachment of a muscle that is usually less moveable.

Distal attachment

The attachment of a muscle that is usually more moveable.

Mastication

The process of chewing, facilitated by specific muscles like the temporalis and masseter.

Facial nerve (CN VII)

The cranial nerve that innervates most of the muscles of facial expression.

Suprahyoid muscles

Muscles located above the hyoid bone that elevate the hyoid during swallowing.

Infrahyoid muscles

Muscles located below the hyoid bone that depress the hyoid and thyroid cartilage.

Erector spinae

A group of muscles that maintain upright posture and can extend the vertebral column.

Congenital muscular torticollis

A condition where the sternocleidomastoid muscle is shortened, leading to tilting of the head.