thursday october 22, 2009

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Thursday October 22, 2009

Pick up the muscle note sheet!

Did you miss the test on Tuesday?

Did you complete virtual surgery? COOL!

The Man Whose Arms Exploded


Agenda & Homework

Agenda:

1) Cadaver visits December 8 & 10, 2009

2) Muscle Physiology

3) Muscle Anatomy

Homework:

Learning muscles by making flash cards

Use the website to study muscles


Muscle Overview

The three types of muscle tissue are skeletal, cardiac, and smooth

These types differ in structure, location, function, and means of activation


Muscle Tissue: Cardiac

Figure 4.11b


Muscle Tissue: Smooth

Figure 4.11c


Muscle Tissue: Skeletal

Long, cylindrical, multinucleate cells with obvious striations

Initiates and controls voluntary movement

Found in skeletal muscles that attach to bones or skin


Muscle Tissue: Skeletal

Figure 4.11a


Skeletal Muscle Tissue

Packaged in skeletal muscles that attach to and cover the bony skeleton

Has obvious stripes called striations

Is controlled voluntarily (i.e., by conscious control)

Contracts rapidly but tires easily

Is responsible for overall body motility

Is extremely adaptable and can exert forces ranging from a fraction of an ounce to over 70 pounds


Skeletal Muscle

Skeletal muscle cells are elongated and are called muscle fibers

Muscle contraction depends on two kinds of myofilaments (proteins) – actin and myosin

Muscle terminology

Sarcolemma – muscle cell membrane

Sarcoplasm – cytoplasm of a muscle cell

Prefixes – myo, mys, and sarco all refer to muscle


Muscle Function

1) Skeletal muscles are responsible for all locomotion

2) Muscles also maintain posture, stabilize joints, and generate heat (ex: shiver)


Structure and Organization of Skeletal Muscle

Table 9.1a


Structure and Organization of Skeletal Muscle

Table 9.1b


Skeletal Muscle

Each muscle is a discrete organ composed of muscle tissue, blood vessels, nerve fibers, and connective tissue


Skeletal Muscle

The three connective tissue sheaths are:

Endomysium – fine sheath of connective tissue composed of reticular fibers surrounding each muscle fiber (cell)

Perimysium – fibrous connective tissue that surrounds groups of muscle fibers called fascicles

Epimysium – an overcoat of dense regular connective tissue that surrounds the entire muscle


Skeletal Muscle

Figure 9.2a

Circle the Endomysium,Perimysium & Epimysium


Nerve and Blood Supply

Each muscle is served by one nerve, an artery, and one or more veins

Each skeletal muscle fiber is supplied with a nerve ending that controls contraction

Contracting fibers require continuous delivery of oxygen and nutrients via arteries

Wastes must be removed via veins


Skeletal Muscle: Attachments

Muscles attach:

1. Directly – epimysium of the muscle is fused to the periosteum of a bone

2. Indirectly – connective tissue wrappings extend beyond the muscle as a tendon or aponeurosis


LEARN THE MUSCLES!

thursday october 22, 2009

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