The Muscular System Tour

The Muscular System Muscles are Needed for all types of movement Needed to pump blood Needed to breathe (diaphragm muscle) Needed to produce body heat and regulate body temperature Needed to protect internal organs

Three Types of Muscle Muscle Tutorial Video Clip (Open in New Window) Skeletal: Voluntary (under your conscious control), movement of your bones, face, eyes,etc. Cardiac Muscle: Involuntary (not under your conscious control), movement of your heart and certain blood vessels Smooth: Involuntary (not under your conscious control), movement of your intestines, stomach and other internal organs                                    

Skeletal Muscle 400 X striations nuclei Move your bones(also your face,eyes, etc.) Voluntary (you can control them) Over 400 skeletal muscles in your body Long cells with several nuclei (along edges of cell) Stripes called striations (visible under high power)

Cardiac Muscle 400 X nuclei The muscle of the heart                                     The muscle of the heart Involuntary (you cannot control them) Works 24 hours a day your entire life Strongest type of muscle Only one nucleus per cell (usually in center of cell) Some striping (some striations) but not as much as skeletal muscle

Smooth Muscle 400X nuclei The muscles of the esophagus, stomach, intestines and other internal organs Involuntary (you cannot control them) Contract slowly and smoothly Can remain contracted for long periods of time Usually one nucleus per cell (Usually in the center of the cell) No striping (striations)

Anatomy of a Muscle Animation Open in New Window

Interactive Muscle Review Maricopa Muscle Tutorial Interactive Muscle Review

Label & Color the Muscles of the Head Anterior Body Posterior Body Thigh/Leg Posterior Shoulder Anterior Shoulder Maricopa Muscle Tutorial

Maricopa Muscle Tutorial Label and color these muscles of the head: (you can draw arrows) Sternocleidomastoid Obicularis Oculi Obicularis Oris Zygomaticus Masseter Trapezius Frontalis

Maricopa Muscle Tutorial Label and color these muscles of the Anterior body: Pectoralis major Serratus anterior Deltoid Rectus Abdominus External oblique Biceps brachii Brachialis Triceps brachii Latissimus dorsi

Maricopa Muscle Tutorial Label and color these muscles of the Posterior body: (you can draw arrows) Deltoid Trapezius Latissimus dorsi Gluteus medius Gluteus maximus Infraspinatus Teres major Triceps brachii

Label and color these muscles of the Thigh/Leg: (you can draw arrows) Vastus medialis Vastus lateralis Satorius Adductor longus Adductor mangus Gracilis Rectus femoris Gastrocnemius Soleus Tibialis anterior Maricopa Muscle Tutorial

Maricopa Muscle Tutorial Posterior Shoulder Label/color: Deltoid Infraspinatus Supraspinatus Teres minor Teres major

Maricopa Muscle Tutorial Anterior Shoulder Label/color: Subscapularis Coracobrachialis Supraspinatus

The Sliding-Filament Theory of Muscle Action The "Sliding-Filament Theory of Muscle Action" explains how the movement of thick- and thin-filaments relative to each other leads to the contraction and relaxation of whole muscles - hence ultimately to the movement of the limbs or tissues attached to those muscles: There are two physical units that are important for the action of muscles. They are thick filaments (Protein myosin) and thin filaments. (Protien actin). Muscle tissue can be described in terms of units called sacromeres. These units are defined in terms of groups of overlapping filaments (the thin and thick filaments previously described). Sacromeres are arrangements of thick and thin filaments.

The length of a sacromere and the zones (H zone, I band and A band) within each sacromere, are determined by the positions of the thick and thin filaments relative to each other. This is illustrated in the three diagrams to the left showing the relative length and configuration of two sacromeres of relaxed muscle (top), partially contracted muscle (centre) and lengthened muscle (bottom diagram).

The sliding filament theory is the basic summary of the process of skeletal muscle contraction. Myosin moves along the filament by repeating a binding and releasing sequence that causes the thick filament to move over the thinner filament. This progresses in sequential stages. By progressing through this sequence the filaments slide and the skeletal muscles contract and release.

Muscular System