Laboratory 6: Articulations, Movements, and Muscle Organization

Exercise 13 and 14


Lab 6 presents the various types of articulations (joints) and their anatomy and movements (Ex. 13).  In Ex. 14 you will learn the organization of skeletal muscle cells and the anatomy and physiology of the neuromuscular junction.  Muscle physiology (how contraction is achieved) will be address later in the semester, using interactive software (ADAM). 


Exercise 13: Articulations and Body Movements

A. Classification of Articulations

1. Structural anatomy

2. Function

B. Connections between bones

1. Fibrous joints

            a. Connective tissue

2. Cartilagenous joints

            a. Cartilage

3. Synovial joints

            a. Cavity surrounds both ends

C. Classification based on function (amount of movement)

1. Synarthroses

a. Immovable joints

2. Amphiarthroses

a. Slightly moveable

3. Diarthroses

a. Freely moveable


Use the figures in Ex. 13 to learn both classification schemes and be able to classify any given joint, both on its structure and function. Learn the major structures of synovial joints. 


You are not required to know the detailed anatomy of either the knee or the shoulder, as outlined in your manual. Review but don’t memorize Fig. 13.7 (a-c, e) and 13.8 (a-c).  Please learn Fig. 13.7 (d), as an introduction to the mechanics of body movements. 


Exercise 14:  Microscopic Anatomy, Organization, and Classification of Skeletal Muscle

The cells of skeletal muscle tissue are highly specialized.  Some of the terminology of general cell anatomy has been adapted to refer specifically to muscle cells.  A review of the few adaptations ought to avoid some confusion:

1. Plasma membrane is called the sarcolemma

2. Cytoplasm is called the sarcoplasm

3. Individual muscle cells are called a fibers


Use the figures in Ex. 14 to learn the anatomy of skeletal muscle fibers.  Under the microscope examine skeletal muscle (prepared slides, we will not make our own), and the neuromuscular junction (motor unit).  In the next three weeks you will learn the names of many muscles.  This task might be easier if you know something about the way muscles are named. Frequently, the name of the muscle tells you something about its location or function. Please read the section “Naming Skeletal Muscles”. In the next several weeks you will also learn the action (the body movement produced upon contraction) of many muscles.  Muscles frequently act in concert to produce a particular movement.  For any given movement, certain muscles are primarily responsible for the movement (agonists), while others aid the movement (synergists), oppose the movement (antagonists), or stabilize some body part that might otherwise get in the way of the desired movement (fixators).