BIOL 109 Lab: Muscle Vocabulary and Key Concepts

BIOL 109 Lab: What You Need

Muscles Vocabulary

  • Abduction: Movement away from the midline of the body.

  • Action: The specific movement produced by a muscle contraction.

  • Adduction: Movement toward the midline of the body.

  • Antagonist: A muscle that opposes the action of another muscle.

  • Extension: Increasing the angle between body parts, typically resulting in straightening.

  • Flexion: Decreasing the angle between body parts, typically resulting in bending.

  • Pronation: Rotating the forearm or foot inward.

  • Rotation: A circular movement around an axis.

  • Supination: Rotating the forearm or foot outward.

Key Ideas

  • Agonist/Antagonist Pairs: Almost all skeletal muscles exist in pairs, where one muscle (agonist) contracts to produce movement while the other (antagonist) relaxes or lengthens. Common examples include:

    • Biceps and Triceps: The biceps brachii flexes the elbow, whereas the triceps brachii extends it.

    • Flexors and Extensors: Flexors reduce the angle at joints, whereas extensors increase it.

  • Muscle Size and Strength: There is a relationship between muscle size and strength that does not solely depend on the person's overall size. Larger muscles generally exert more force due to greater cross-sectional area.

  • Tendon Anchoring: All muscle groups discussed have tendons that attach them to bones or to other tendons, allowing muscle actions to move the skeleton effectively.

Things to Know

  • Antagonistic Muscle Pairs: These pairs work against each other to facilitate fine muscle control and execute precise movements.

  • Muscle Span Across Joints: Muscles span joints, providing necessary range of motion for various physical activities. Their influence on joint movement is crucial for overall mobility.

  • Identification of Muscles: You are required to identify the muscles covered in the lab session, including their names, actions, and antagonists. Focus on the following:

    • Familiarize yourself with t\he 4 pairs of muscle actions discussed: Flexion vs Extension and similar movements.

    • Recognize that each muscle operates in conjunction with another muscle, categorizing them as agonist or antagonist based on their opposing functions.

    • Understand that skeletal muscles are responsible for moving muscles, bones, or tendons, ultimately enabling the movement of the skeletal system.