Skeletal Muscles. Myology My = muscle ology = study of.

Skeletal MusclesSkeletal Muscles

MyologyMyology

My = muscleMy = muscle

ology = study ofology = study of

Muscles Muscles 650650

Males : 42% of body is muscle Males : 42% of body is muscle weight weight

Females : 35% muscle weight in Females : 35% muscle weight in the bodythe body

Voluntary - skeletalVoluntary - skeletal

Involuntary – cardiac & smoothInvoluntary – cardiac & smooth

Cardiac muscleCardiac muscle

HeartHeart

InvoluntaryInvoluntary

1-2 nuclei1-2 nuclei

Basket weaveBasket weave

StriatedStriated

Not regeneratedNot regenerated

Smooth musclesSmooth muscles

InvoluntaryInvoluntary

VisceralVisceral

1 nuclei1 nuclei

Spindle shapedSpindle shaped

Not striatedNot striated

Nerves – needed or not?Nerves – needed or not?

regeneratedregenerated

Skeletal musclesSkeletal muscles

StriatedStriated

Needs a lot of ATPNeeds a lot of ATP

Moves skeletonMoves skeleton

Attached to bone Attached to bone

Some regeneration occursSome regeneration occurs

Muscle slidesMuscle slides

Use the slides to view these – Use the slides to view these – discuss with your partner the discuss with your partner the differences differences

Print out & label a picture of Print out & label a picture of skeletal, cardiac and smooth skeletal, cardiac and smooth musclemuscle

Cardiac MuscleCardiac Muscle

Figure 7-10(a)

Figure 7-10(b)

Smooth Muscle TissueSmooth Muscle Tissue

Striated muscleStriated muscle

Functions of skeletal musclesFunctions of skeletal muscles

MovementMovement

Posture / body positionPosture / body position

Support of soft tissuesSupport of soft tissues

ProtectionProtection

Homeostasis - temperatureHomeostasis - temperature

Characteristics of musclesCharacteristics of muscles

Tissue typesTissue types

ConnectiveConnective

EpithelialEpithelial

MuscleMuscle

NeuralNeural

Muscle connectionsMuscle connections

Origin – muscle’s connection to Origin – muscle’s connection to the non-moveable bonethe non-moveable bone

Insertion – muscle’s connection Insertion – muscle’s connection to the moveable boneto the moveable bone

Action - joint movement Action - joint movement

Muscles work in pairsMuscles work in pairsFlexor – contracted muscle Flexor – contracted muscle (agonist)(agonist)

Extensor – relaxed muscle Extensor – relaxed muscle (antagonist)(antagonist)

Ex. Biceps & tricepsEx. Biceps & triceps

What would happen if muscles worked What would happen if muscles worked alone?alone?

Helper muscles = synergist Helper muscles = synergist

ex: brachioradialis- helps to ex: brachioradialis- helps to flex flex

the elbowthe elbow

Origins, Insertions, and ActionsOrigins, Insertions, and Actions– OriginOrigin

Muscle attachment that remains fixedMuscle attachment that remains fixed

– InsertionInsertion

Muscle attachment that movesMuscle attachment that moves

– ActionAction

What joint movement a muscle producesWhat joint movement a muscle produces

Anatomy of Skeletal MusclesAnatomy of Skeletal Muscles

The Organization of a Skeletal The Organization of a Skeletal MuscleMuscle

Figure 7-1

Neuromuscular Junction page 191Neuromuscular Junction page 191

Figure 7-4(a)

Essentials of Anatomy & Physiology, 4th EditionMartini / Bartholomew

PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University

The Muscular

System

The Muscular

System77

Figure 7.2aFigure 7.2a

Microanatomy page 188Microanatomy page 188

– SarcolemmaSarcolemmaMuscle cell membraneMuscle cell membrane

– SarcoplasmSarcoplasmMuscle cell cytoplasmMuscle cell cytoplasm

– SarcoplasmicSarcoplasmic reticulumreticulum (SR) (SR)Like smooth ERLike smooth ER

– Transverse tubulesTransverse tubules (T (T tubules)tubules)

– MyofibrilsMyofibrils (contraction (contraction organelle)organelle)

– SarcomeresSarcomeres

Movement due to Movement due to

Filaments:Filaments:

ActinActin

MyosinMyosin

Energy – will need ATP Energy – will need ATP

Sarcomere- smallest part of a Sarcomere- smallest part of a muscle that contractsmuscle that contracts

Relaxed muscleRelaxed musclePage 189Page 189

Figure 7-3 (2 of 2)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 7-51 of 7

Resting sarcomere

Myosin head

Myosin reactivation

Active-site exposure

Cross bridge detachment

Cross-bridge formation

Pivoting of myosin head

Troponin

ActinTropomyosin

ADP

P+

ADP

P +

ADP

P+

Active site

Sarcoplasm

Ca2+

Ca2+

ADP

P +

ADP

+ P

Ca2+

ADP+P

Ca2+

Ca2+

ADP + P

Ca2+

ADP + P

Ca2+

ATP

ATP

Ca2+

Ca2+

Ca2+

ADP

P +

+ P

ADP

Muscle ContractionMuscle Contraction 1. Neurotransmitter-1. Neurotransmitter-

AcetylcholineAcetylcholine (ACh) released (ACh) released

from the motor neuronfrom the motor neuron

ACh binds to receptors on the ACh binds to receptors on the

sarcolemmasarcolemma

Na ions enter cellNa ions enter cell

ACTION POTENTIAL generatedACTION POTENTIAL generated

2. Action potential travels 2. Action potential travels through the cell via the T-through the cell via the T-TUBULESTUBULES

3. Ca ions released from the 3. Ca ions released from the cisternaecisternae

and bind to troponin and bind to troponin

troponin change shape (twist) troponin change shape (twist) to expose the active site on to expose the active site on the actin the actin

4. Crossbridge forms as actin 4. Crossbridge forms as actin and myosin bind together using and myosin bind together using ATPATP

As actin slides toward center of As actin slides toward center of each sarcomere – CONTRACTION each sarcomere – CONTRACTION occursoccurs

5. Acetylcholinesterase 5. Acetylcholinesterase (AChase)is released - ACh is (AChase)is released - ACh is broken down, Ca crossbridges broken down, Ca crossbridges break, Ca goes back to the break, Ca goes back to the cisternae, actin returns to cisternae, actin returns to resting positionresting position

Rephosphorylation occurs - Rephosphorylation occurs - ATP from ADPATP from ADP


Figure 7-51 of 7

Resting sarcomere

Myosin head

Myosin reactivation

Active-site exposure

Cross bridge detachment

Cross-bridge formation

Pivoting of myosin head

Troponin

ActinTropomyosin

ADP

P+

ADP

P +

ADP

P+

Active site

Sarcoplasm

Ca2+

Ca2+

ADP

P +

ADP

+ P

Ca2+

ADP+P

Ca2+

Ca2+

ADP + P

Ca2+

ADP + P

Ca2+

ATP

ATP

Ca2+

Ca2+

Ca2+

ADP

P +

+ P

ADP

Essentials of Anatomy & Physiology, 4th EditionMartini / Bartholomew

PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University

The Muscular

System

The Muscular

System77

Table 7.1Table 7.1

Contractions need Contractions need

CalciumCalcium

Calcium is absorbed with the Calcium is absorbed with the help of vitamin Dhelp of vitamin D

How do you get vitamin D?How do you get vitamin D?

Vitamin DVitamin D

Sunlight- used by body to make Sunlight- used by body to make DD

Lack of vitamin D = rickettsLack of vitamin D = ricketts

Which system takes in the Which system takes in the sunlight and helps muscles have sunlight and helps muscles have a supply of Ca?a supply of Ca?

homeostasishomeostasis

What does the body do if it is What does the body do if it is cold? cold?

Muscle contraction and heat is Muscle contraction and heat is releasedreleased

ExercisesExercisesStretching – to prevent injury Stretching – to prevent injury

Resistance – to build muscleResistance – to build muscle

Aerobic - needing oxygen, efficient, Aerobic - needing oxygen, efficient, more ATP available through respiration more ATP available through respiration (which organelle?)(which organelle?)

Anaerobic – without oxygen, less Anaerobic – without oxygen, less oxygen – lactic acid buildupoxygen – lactic acid buildup

Lack of oxygen - muscle becomes soreLack of oxygen - muscle becomes sore

Lack of ATP – muscle can crampLack of ATP – muscle can cramp

Types of ContractionsTypes of Contractions

IsotonicIsotonic contractioncontractionconstant tension constant tension

((iso = iso = samesame, tonic = , tonic = tension)tension)

ex.ex.

Isometric contractionIsometric contraction The length of a muscle stays The length of a muscle stays constant (constant (isoiso = same, = same, metricmetric = = length)length)

ex.ex.

ATPATP Light activityLight activity

Aerobic Aerobic metabolism of metabolism of fatty fatty acidsacids

Storage of Storage of glucoseglucose as as glycogenglycogen

Moderate activityModerate activityBreakdown of Breakdown of glycogenglycogen to to glucoseglucose

GlycolysisGlycolysis of glucose of glucose

Peak activityPeak activityAnerobicAnerobic breakdown of glucose breakdown of glucose

Production of lactic acidProduction of lactic acid

Physical ConditioningPhysical Conditioning

– Anaerobic enduranceAnaerobic enduranceTime over which a muscle can contract Time over which a muscle can contract effectively under anerobic effectively under anerobic conditions.conditions.

– HypertrophyHypertrophy

Increase in muscle bulk. Can result Increase in muscle bulk. Can result

from anerobic training.from anerobic training.

– Aerobic enduranceAerobic endurance

Time over which a muscle can contract Time over which a muscle can contract

supported by mitochondria.supported by mitochondria.

steroidssteroids

Synthetic hormonesSynthetic hormones

Anabolic- builds muscle massAnabolic- builds muscle mass

AndrogenAndrogen

EstrogenEstrogen

Side effectsSide effects

AgingAgingReduceReduce

– Muscle sizeMuscle size– Muscle elasticityMuscle elasticity– Muscle strengthMuscle strength– Exercise toleranceExercise tolerance– Injury recovery Injury recovery abilityability

Disorders Disorders

Muscular dystrophyMuscular dystrophy

SprainsSprains

Case study Case study

Which organelle stores ATPWhich organelle stores ATP

Which releases more ATP- aerobic Which releases more ATP- aerobic or anaerobic respiration?or anaerobic respiration?

Which is the backup for the Which is the backup for the other?other?

Rigor mortis – ATP is decreased Rigor mortis – ATP is decreased so Ca permeability is increased, so Ca permeability is increased, muscle can’t movemuscle can’t move

The Appendicular MusclesThe Appendicular Muscles 2 groups2 groups

Muscles of the shoulder and Muscles of the shoulder and upper limbsupper limbs

Muscles of the pelvic girdle and Muscles of the pelvic girdle and lower limbslower limbs

Names of muscle- based onNames of muscle- based on

Size Size

ShapeShape

LocationLocation

ActionAction

OriginOrigin

insertioninsertion

Shoulder MusclesShoulder Muscles– TrapeziusTrapezius– RhomboidRhomboid– Levator scapulaeLevator scapulae– Serratus anteriorSerratus anterior– Pectoralis minorPectoralis minor

Muscles of the ShoulderMuscles of the Shoulder

Figure 7-17(a)

Anatomy of the Muscular Anatomy of the Muscular SystemSystemMuscles of the ShoulderMuscles of the Shoulder

Figure 7-17(b)

Figure 7-21

Muscles That Move the LegMuscles That Move the Leg

Figure 7-232 of 11

Removes excess body Removes excess body heat; synthesizes heat; synthesizes vitamin Dvitamin D33 for calcium for calcium and phosphate and phosphate absorption; protects absorption; protects underlying musclesunderlying muscles

Skeletal muscles pulling Skeletal muscles pulling on skin of face produce on skin of face produce facial expressionsfacial expressions


The Integumentary SystemThe Integumentary System

Figure 7-233 of 11Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Skeletal SystemThe Skeletal System

Maintains normal calcium and Maintains normal calcium and phosphate levels in body phosphate levels in body fluids; supports skeletal fluids; supports skeletal muscles; provides sites of muscles; provides sites of attachmentattachmentProvides movement and Provides movement and support; stresses exerted by support; stresses exerted by tendons maintain bone mass; tendons maintain bone mass; stabilizes bones and jointsstabilizes bones and joints

Figure 7-234 of 11

The Nervous SystemThe Nervous System

Controls skeletal muscle Controls skeletal muscle contractions; adjusts contractions; adjusts activities of activities of respiratory and respiratory and cardiovascular systems cardiovascular systems during periods of during periods of muscular activitymuscular activityMuscle spindles monitor Muscle spindles monitor body position; facial body position; facial muscles express emotion; muscles express emotion; muscles of the larynx, muscles of the larynx, tongue, lips and cheeks tongue, lips and cheeks permit speechpermit speech


Figure 7-235 of 11

The Endocrine SystemThe Endocrine System

Hormones adjust muscle Hormones adjust muscle metabolism and growth; metabolism and growth; parathyroid hormone and parathyroid hormone and calcitonin regulate calcitonin regulate calcium and phosphate calcium and phosphate ion concentrationsion concentrations

Skeletal muscles provide Skeletal muscles provide protection for some protection for some endocrine organsendocrine organs


Figure 7-236 of 11

The Cardiovascular SystemThe Cardiovascular System

Delivers oxygen and Delivers oxygen and nutrients; removes nutrients; removes carbon dioxide, lactic carbon dioxide, lactic acid, and heatacid, and heatSkeletal muscle Skeletal muscle contractions assist in contractions assist in moving blood through moving blood through veins; protects deep veins; protects deep blood vesselsblood vessels


Figure 7-237 of 11

The Lymphatic SystemThe Lymphatic System

Defends skeletal muscles Defends skeletal muscles against infection and against infection and assists in tissue assists in tissue repairs after injuryrepairs after injury

Protects superficial Protects superficial lymph nodes and the lymph nodes and the lymphatic vessels in the lymphatic vessels in the abdominopelvic cavityabdominopelvic cavity


Figure 7-238 of 11

The Respiratory SystemThe Respiratory System

Provides oxygen and Provides oxygen and eliminates carbon eliminates carbon dioxidedioxideMuscles generate carbon Muscles generate carbon dioxide; control dioxide; control entrances to respiratory entrances to respiratory tract, fill and empty tract, fill and empty lungs, control airflow lungs, control airflow through larynx, and through larynx, and produce soundsproduce sounds


Figure 7-239 of 11

The Digestive SystemThe Digestive System


Provides nutrients; liver Provides nutrients; liver regulates blood glucose regulates blood glucose and fatty acid levels and and fatty acid levels and removes lactic acid from removes lactic acid from circulationcirculation

Protects and supports Protects and supports soft tissues in abdominal soft tissues in abdominal cavity; controls cavity; controls entrances to and exits entrances to and exits from digestive tractfrom digestive tract

Figure 7-2310 of 11

The Urinary SystemThe Urinary System

Removes waste products Removes waste products of protein metabolism; of protein metabolism; assists in regulation of assists in regulation of calcium and phosphate calcium and phosphate concentrationsconcentrations

External sphincter External sphincter controls urination by controls urination by constricting urethraconstricting urethra


Figure 7-2311 of 11

The Reproductive SystemThe Reproductive System

Reproductive hormones Reproductive hormones accelerate skeletal accelerate skeletal muscle growthmuscle growth

Contractions of Contractions of skeletal muscles eject skeletal muscles eject semen from male semen from male reproductive tract; reproductive tract; muscle contractions muscle contractions during sex act produce during sex act produce pleasurable sensationspleasurable sensations


Skeletal Muscles. Myology My = muscle ology = study of.

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