Biology 211 Anatomy & Physiology I Gross Anatomy of the Muscular System

Gross Anatomy of Muscle In lab we identified a number of individual muscles including the origin, insertion, and function of some You will not be responsible for identifying those muscles in lecture but: You should understand some concepts of their structures

(Should understand some concepts) 1. Each muscle has a size and shape specialized for its function. Any muscle can get larger (and thus stronger) or smaller (and thus weaker) based on how much work it does. More work = more sarcomeres more myofibrils more myocytes

(Should understand some concepts) 1. Each muscle has a size and shape specialized for its function. 2. Muscles often act in groups.

(Should understand some concepts) 1. Each muscle: size and shape specialized for its function 2. Muscles often act in groups Each muscle may have different functions in different types of movement

(Each muscle may have different functions in different types of movement) 1. Prime mover or agonist 2. Synergist 3. Antagonist 4. Fixator Generates most of the force to produce movement Generates force to help the agonist produce movement

(Each muscle may have different functions in different types of movement) 1. Prime mover or agonist 2. Synergist 3. Antagonist 4. Fixator Generates force to oppose or stop movement Holds one or more bones steady so other muscles can pull from them

Go back over muscles you studied in lab and Be sure you understand how these act as agonists, antagonists, synergists, and fixators. On lecture exams: You may be asked to identify muscles with each of these four functions at the shoulder elbow wrist hip knee ankle