Kinesiology Unit 10 1

Bones And Joints Provide The Framework Of The Body. However, Functional Muscular Tissue Is Necessary For The Body To Reach Its Movement Potential 2

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 The characteristics of muscle tissue enable it to perform some important functions, including:  Movement – both voluntary & involuntary  Maintaining posture  Supporting soft tissues within body cavities  Guarding entrances & exits of the body  Maintaining body temperature 4

 Each Muscle Fibre Has Four Distinct Properties:  Irritability: Muscle Has The Capability Of Receiving And Responding To Various Stimuli  Contractility: When A Stimuli Is Received The Muscle Has The Capability Of Shortening  Extensibility: Able To Lengthen – Passive Or Active  Elasticity: The Ability To Return To Normal Resting Length Or Shape 5

MUSCLE  The distinguishing characteristic of muscle is its ability to actively shorten and produce tension.

 Types Of Muscular Tissue:  Skeletal Muscle: Attached To Skeletal. Striped Muscle. Voluntary Muscle Associated with & attached to the skeleton Under our conscious (voluntary) control Microscopically the tissue appears striated Cells are long, cylindrical & multinucleate 7

 Types Of Muscular Tissue:  Smooth Muscle: Involuntary Muscle Regulated By Autonomic Nervous System Makes up walls of organs & blood vessels Tissue is non-striated & involuntary Cells are short, spindle-shaped & have a single nucleus Tissue is extremely extensible, while still retaining ability to contract 8

 Types Of Muscular Tissue:  Cardiac Muscle: Heart. Controlled By Autonomic Nervous System. Consists Of Individual Cells Makes up myocardium of heart Unconsciously (involuntarily) controlled Microscopically appears striated Cells are short, branching & have a single nucleus 9

MUSCLE A COUPLE OF LONG STRAIGHT CYLINDERS FIBERS NUCLEI SARCOPLASMA IN CELL MEMBRANE CALLED THE SARCOLEMMA 10

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Anatomy of skeletal muscles Skeletal muscle fiber (cell) Muscle Fascicle Surrounded by perimysium Surrounded by endomysium endomysium perimysium Skeletal muscle Surrounded by epimysium epimysium tendon

MUSCLE TONE -State of continuous partial contractions (maintains posture)  Hypertrophy - muscle enlargement - occurs with use of muscle  Atrophy - muscle size, tone, and power decrease - occurs with lack of use - injury

 Two Types Of Muscle Fibers:  Fast-twitch (White) Fibers  High Glycolytic  Low Oxidative  High Myofibrillar Atp-ase  Example: Sprinter  Slow-twitch (Red) Fibers  Low Glycolytic  High Oxidative  Low Myofibrillar Atp-ase  Example: Marathon Runner 14

 Fiber Arrangement And Direction  Longitudinal Muscle: When All The Fibers And Groups Of Fibers Within A Muscle Are Parallel With Log Axis Of The Muscle. Example: Sartorius And Rectus Abdominus  Fusiform Muscle: If The Muscle Fibers Are In The Form Of A Spindle. Example: Biceps Brachii  Radiate Muscle: If The Fibers Fan Out From A Single Attachment. Example: Gluteus Medius And Minimus And Pectoralis Major And Minor 15

 Penniform Muscles: When The Group Of Fibers Within A Muscle Are Attached To The Side Of A Tendon That Runs The Length Of The Muscle, A Featherlike Appearance. There Are Three Types Of These Muscles:  Unipennate Muscles – Origin From A Large Area Of Bone And Run Obliquely To A Single Tendon  Bipennate Muscles – Obliques Fibers Are Attached To Both Borders Of Central Tendon  Multipennate Muscles – Combination Of Several Bipennate Muscles 16

 Fasciae: Membranous Sheaths That Enclose Structures Of The Body  Superficial Fasciae: Immediately Beneath The Skin And Covers The Entire Body  Deep Fasciae: Series Of Dense, Membranous Sheaths That Vary In Shape, Size And Strength Depending On Their Function  Intramuscular Septa: Fascial Sheaths Between Muscles 17

 Motor Units: Consists Of A Number Of Fibres Each Innervated Separately By A Nerve Branch From A Motor Neuron  Motor Neuron Provides Stimuli 18

 Isometric Contraction: No Joint Movement. Muscle Tension Is Equal To Resistance  Isotonic Contraction: Joint Movement. Tension Causes Muscle To Move. Muscle Shortens  Eccentric Contraction: Joint Movement. Gravity Causes Muscle To Move. Muscle Lengthens  Isokinetic Exercise: Refers To Specific Isotonic Exercise In Which Angular Velocity At A Joint Is Kept Constant Through Range Of Contraction 19

ISOMETRIC CONTRACTION  Produces no movement  Used in  Standing  Sitting  Posture

ISOTONIC CONTRACTION  Produces movement  Used in  Walking  Moving any part of the body

EFFECTS OF EXERCISE ON MUSCLES  Aerobic (endurance) - results in stronger, more flexible muscles, with a high resistance to fatigue - will not produce large size change ex. jogging, biking  Anaerobic - results in larger, stronger muscles with little resistance to fatigue (occurs within 2 minutes of start of activity) ex. 50 meter sprint, competitive weight lifting

Anatomy of the Muscular System Origin Muscle attachment that remains fixed Insertion Muscle attachment that moves Action What joint movement a muscle produces i.e. flexion, extension, abduction, etc.

For muscles to create a movement, they can only pull, not push Muscles in the body rarely work alone, & are usually arranged in groups surrounding a joint A muscle that contracts to create the desired action is known as an agonist or prime mover A muscle that helps the agonist is a synergist A muscle that opposes the action of the agonist, therefore undoing the desired action is an antagonist

 Movers – Responsible For Performing Movement  Antagonists – Opposite Muscle To Joint Of Muscle That Is Prime Mover  Stabilizers – Stabilizing The Movers So They Can Work Effectively  Synergists – Increase The Efficiency Of Prime Movers By Preventing Inhibiting Movements While Movement Is Being Performed 25

ELBOW JOINT  The best known example of antagonistic muscles are the bicep & triceps muscles

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