Muscular SystemMuscular System

Human A & PHuman A & P

1/28/091/28/09

IntroIntro

What causes movement of the human body?What causes movement of the human body?– Contraction/Relaxation of musclesContraction/Relaxation of muscles

How much body weight do muscles comprise?How much body weight do muscles comprise?– 40-50%40-50%

What is the scientific study of muscles called?What is the scientific study of muscles called?– MyologyMyology

What is the scientific study of movement What is the scientific study of movement called?called?– KinesiologyKinesiology

Types of Muscle TissueTypes of Muscle Tissue

1. Skeletal—striated (light and dark bands), 1. Skeletal—striated (light and dark bands), attached to bones; voluntaryattached to bones; voluntary

Types of Muscle TissuesTypes of Muscle Tissues

2. Cardiac—heart muscle, striated and has 2. Cardiac—heart muscle, striated and has intercalated disks, involuntary, cannot intercalated disks, involuntary, cannot regenerateregenerate

Types of Muscle TissueTypes of Muscle Tissue

3. Smooth—lines blood vessels & airways 3. Smooth—lines blood vessels & airways and digestive tract, non-striated, and digestive tract, non-striated, involuntaryinvoluntary

Functions of Muscle TissueFunctions of Muscle Tissue

To produce _______________To produce _______________ ____________body positions____________body positions

ex) hold head up, posture, stand, sitex) hold head up, posture, stand, sit To regulate organ _________To regulate organ _________

– Sphincters—mouth, stomach, and colonSphincters—mouth, stomach, and colon Moving substances within the bodyMoving substances within the body To produce __________by contraction To produce __________by contraction

or _____________or _____________

Characteristics of Muscle Characteristics of Muscle TissueTissue

Excitability-respond Excitability-respond to __________to __________

Extensibility—Extensibility—stretch without stretch without being damagedbeing damaged

Elasticity—return to Elasticity—return to its original shapeits original shape

Contractility—Contractility—shorten and shorten and thicken when thicken when stimulatedstimulated

Structure of Muscle TissueStructure of Muscle Tissue

Skeletal MuscleSkeletal Muscle FascicleFascicle FiberFiber MyofibrilMyofibril SarcomereSarcomere FilamentsFilaments

Connective Tissue Connective Tissue ComponentsComponents

Fascia—fibrous Fascia—fibrous connective tissue that connective tissue that lies beneath the skin lies beneath the skin and around muscleand around muscle– Superficial—sub QSuperficial—sub Q– Deep—holds and Deep—holds and

separates musclesseparates muscles Rolfing story hereRolfing story here

Epimyseum-wraps Epimyseum-wraps around the entire around the entire musclemuscle

Perimyseum-covers Perimyseum-covers fascicles (looks like tofu)fascicles (looks like tofu)

Endomyseum—wraps Endomyseum—wraps around each muscle around each muscle fiberfiber

Cellular ComponentsCellular Components Cellular components are Cellular components are

located in muscle fiberslocated in muscle fibers Instead of cytoplasm, it has Instead of cytoplasm, it has

________________________________________ Within this sarcoplasm are Within this sarcoplasm are

many _________________, as many _________________, as you recall as the you recall as the “powerhouse” of the cell“powerhouse” of the cell

• • Instead of endoplasmic Instead of endoplasmic reticulum, it has reticulum, it has __________________reticulum, __________________reticulum, which stores which stores ___________________required ___________________required for muscular contractionfor muscular contraction

• • Its plasma membrane is Its plasma membrane is called a _________________called a _________________

Muscular ContractionMuscular Contraction TO UNDERSTAND HOW MUSCLES TO UNDERSTAND HOW MUSCLES

CONTRACT/RELAX, YOU MUST FIRST CONTRACT/RELAX, YOU MUST FIRST IDENTIFY THE STRUCTURE OF IDENTIFY THE STRUCTURE OF SARCOMERESSARCOMERES

Each sarcomere is separated by zig Each sarcomere is separated by zig zags called _________ zags called _________

MYOFIBRILS are made up of several MYOFIBRILS are made up of several ______________, or compartments, ______________, or compartments, that contain the thick and thin that contain the thick and thin protein filaments _____________ and protein filaments _____________ and __________________________________

______________are the thin filaments______________are the thin filaments– connected to z discsconnected to z discs

_______________are the thick _______________are the thick filamentsfilaments– form ________________________, form ________________________,

which look like two golf clubs which look like two golf clubs twisted together. (myosin twisted together. (myosin heads)heads)

Muscular ContractionMuscular Contraction For a muscle to contract, it must be For a muscle to contract, it must be

stimulated by electrical signal called a stimulated by electrical signal called a ______________ _____________ ______________ _____________ ____________ ____________

Muscle nerve cells or ____________ Muscle nerve cells or ____________ ______________ have long tails called ______________ have long tails called ______________, which carry a chemical ______________, which carry a chemical neurotransmitter called neurotransmitter called _____________________. _____________________.

This nerve impulse must “jump” over a This nerve impulse must “jump” over a gap called a_____________gap called a_____________

Where this ‘jump’ takes place is called Where this ‘jump’ takes place is called

the ________________ _________________the ________________ _________________

_________________is constantly being _________________is constantly being released and broken down to trigger released and broken down to trigger muscle action potential.muscle action potential.

EX) _______________________-affects EX) _______________________-affects events at NMJ. Bacteria which blocks events at NMJ. Bacteria which blocks release of ACh, and may cause release of ACh, and may cause suffocation by paralyzing the suffocation by paralyzing the ________________ ________________

Muscle Contraction (cont)Muscle Contraction (cont)

After muscle action potential takes place, the ________________ After muscle action potential takes place, the ________________ ____________________ _________________ as you viewed in the kickoff ____________________ _________________ as you viewed in the kickoff video, occurs.video, occurs.

For this mechanism to take place, the body’s high energy For this mechanism to take place, the body’s high energy molecule must be available.molecule must be available.

ATP structure review:ATP structure review: • • adenineadenine • • riboseribose • • 3 __________groups3 __________groups Energy is made available when the bond between last two Energy is made available when the bond between last two

____________ is broken, creating _________. The constant cycle of ____________ is broken, creating _________. The constant cycle of ATP - ADP is what gives us energy. Also, ______________ ions must ATP - ADP is what gives us energy. Also, ______________ ions must be available. Recall, they are stored in the___________ be available. Recall, they are stored in the___________ _________________._________________.

Steps in Muscle ContractionSteps in Muscle Contraction

1. Muscle action potential (electrical impulse--_____ions) created by release 1. Muscle action potential (electrical impulse--_____ions) created by release of_____________________ of_____________________

2. Stimulation of sarcoplasmic reticulum by ___________ions triggers 2. Stimulation of sarcoplasmic reticulum by ___________ions triggers release of ________into ______________release of ________into ______________

3. Calcium ions trigger _________________________ mechanism by binding to 3. Calcium ions trigger _________________________ mechanism by binding to troponin and tropomyosin on __________and changing the shape of troponin and tropomyosin on __________and changing the shape of proteins.proteins.

4. ATP splits, producing ____________needed to form ______________between 4. ATP splits, producing ____________needed to form ______________between ________ and _____________filaments.________ and _____________filaments.

5. Myosin heads swivel, actin (thin filaments) slides past _____________ thick 5. Myosin heads swivel, actin (thin filaments) slides past _____________ thick filaments toward center of sarcomere, causing contractionfilaments toward center of sarcomere, causing contraction

6. Energy from ATP causes crossbridges to break, and the enzyme 6. Energy from ATP causes crossbridges to break, and the enzyme _______________________ breaks down acetylcholine, _________________ions _______________________ breaks down acetylcholine, _________________ions go back to the sarcoplasmic reticulum. go back to the sarcoplasmic reticulum.

Define the following Define the following diseases/disorders diseases/disorders

A. Charley horseA. Charley horse B. HypertoniaB. Hypertonia C. HypotoniaC. Hypotonia D. Muscular DystropyD. Muscular Dystropy E. MyalgiaE. Myalgia F. tremorF. tremor

tic tic spasmspasm I. crampI. cramp J. paralysisJ. paralysis K. twitch K. twitch

L. patellofemoral L. patellofemoral

stress syndromestress syndrome

DIFFERENTIATE BETWEEN THE DIFFERENTIATE BETWEEN THE THE PAIRS OF TERMS BELOWTHE PAIRS OF TERMS BELOW

– ISOMETRIC/ISOTONIC CONTRACTIONISOMETRIC/ISOTONIC CONTRACTION– ORIGIN/INSERTION OF MUSCLESORIGIN/INSERTION OF MUSCLES– SLOW TWITCH/FAST TWITCH FIBERSSLOW TWITCH/FAST TWITCH FIBERS– PRIME MOVER (AGONIST)/ANTAGONISTPRIME MOVER (AGONIST)/ANTAGONIST

DiagramsDiagrams

Label the following:Label the following:– H ZoneH Zone– I bandI band– Z-disksZ-disks– A bandA band– ActinActin– MyosinMyosin