Applied Exercise Physiology Section 5: Body Systems Topic 1: Muscular System Prepared by Mr. Cerny...
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Transcript of Applied Exercise Physiology Section 5: Body Systems Topic 1: Muscular System Prepared by Mr. Cerny...
Applied Exercise Applied Exercise PhysiologyPhysiology
Section 5: Body Section 5: Body SystemsSystems
Topic 1: Muscular SystemTopic 1: Muscular System
Prepared byPrepared by
Mr. CernyMr. Cerny
Niagara Wheatfield Senior High SchoolNiagara Wheatfield Senior High School
Types of MuscleTypes of Muscle• CardiacCardiac
HeartHeart
• SmoothSmooth Organ liningOrgan lining
• SkeletalSkeletal MovementMovement 40% of total body mass40% of total body mass
Types of Muscle (con’t)Types of Muscle (con’t)
Cardiac
Smooth
Skeletal
Skeletal Skeletal Muscle Muscle • How many How many
different different muscles can muscles can there be? there be?
• ~660~660
Skeletal Muscle StructureSkeletal Muscle Structure• Cylindrical fibers bunched togetherCylindrical fibers bunched together
Cable wire c.s.
MacrostructureMacrostructure
• It is the number of muscle It is the number of muscle fibers packed into a given fibers packed into a given muscle cross-sectional area muscle cross-sectional area that determine overall that determine overall force-generating capacityforce-generating capacity
Skeletal muscle c.s. 40x
MicrostructureMicrostructureSarcomere:Sarcomere:• basic functional basic functional
unit of muscleunit of muscle• Striated (light Striated (light
& dark bands)& dark bands)• Contains Contains ACTINACTIN
& & MYOSIN MYOSIN filaments that filaments that are responsible are responsible for contractionfor contraction
ActinActin & & MyosinMyosin
Where did the CaWhere did the Ca++++ come come from?from?
• CaCa++++ is stored and released from the is stored and released from the sarcoplasmic reticulum (SR)sarcoplasmic reticulum (SR)
• SR is a network of tubules within the SR is a network of tubules within the muscle fibermuscle fiber
Sarcoplasmic ReticulumSarcoplasmic Reticulum
Excitation-Contraction Excitation-Contraction CouplingCoupling
1.1. Action potential travels along neuron by the temporary Action potential travels along neuron by the temporary changing of chargeschanging of charges
2.2. Nerve impulse causes the release of acetylcholine (ACh).Nerve impulse causes the release of acetylcholine (ACh).3.3. ACh travels across neuromuscular junction, binding to muscle ACh travels across neuromuscular junction, binding to muscle
cell membrane.cell membrane.4.4. ACh binding initiates an electrical impulse which travels across ACh binding initiates an electrical impulse which travels across
membrane and into T tubules.membrane and into T tubules.5.5. Impulse stimulates release of CaImpulse stimulates release of Ca+2+2 from SR. from SR.6.6. CaCa+2+2 binds with t-t complex of the actin filaments, shifting it's binds with t-t complex of the actin filaments, shifting it's
position, exposing myosin binding sites.position, exposing myosin binding sites.7.7. Myosin binds to actin; CaMyosin binds to actin; Ca+2+2 presence also causes enzymatic presence also causes enzymatic
actions of myosin to breakdown ATP into ADP + P + energy.actions of myosin to breakdown ATP into ADP + P + energy.8.8. Energy of ATP degradation causes shape change of myosin Energy of ATP degradation causes shape change of myosin
head, pulling actin molecule toward center of sacromere.head, pulling actin molecule toward center of sacromere.9.9. After sliding, a new ATP binds to myosin, breaking the myosin-After sliding, a new ATP binds to myosin, breaking the myosin-
actin bond, releasing the myosin head.actin bond, releasing the myosin head.10.10. If CaIf Ca+2+2 is still present, the process repeats itself until is still present, the process repeats itself until
sacromere has shortened completely.sacromere has shortened completely.11.11. If a nerve impulse ceases, the CaIf a nerve impulse ceases, the Ca+2+2 is reabsorbed by the SR is reabsorbed by the SR
and the muscle relaxes. and the muscle relaxes.
Muscle Fatigue Muscle Fatigue 11
What causes it?What causes it?• 1) Reduction in ATP1) Reduction in ATP
Under high stress, ATP utilization reduced Under high stress, ATP utilization reduced faster than ATP productionfaster than ATP production
• 2) Peripheral metabolic bi-products2) Peripheral metabolic bi-products Lactic acidLactic acid H (and other free radicals)H (and other free radicals)
Muscle FatigueMuscle Fatigue• 3) Dehydration3) Dehydration
Increases temp = decreases contractile Increases temp = decreases contractile propertiesproperties
• 4) Decrease nerve signals/action 4) Decrease nerve signals/action potentialspotentials
• 5) Reduction of Ca 5) Reduction of Ca ““leakage” 1leakage” 1 From decrease nerve connectionFrom decrease nerve connection
Muscle TypesMuscle Types
ForceForce SpeedSpeed # mit.# mit. Resistance Resistance to fatigueto fatigue
ActivityActivity # # capillariescapillaries
Oxidative / Oxidative / nonoxidativnonoxidativ
ee
Slow Slow twitchtwitch
(I)(I)SameSame
(slightly (slightly less)less)
SlowSlow ManyMany YesYes EndurancEndurancee
ManyMany OxidativeOxidative
Fast Fast twitchtwitch
(II)(II)SameSame
(slightly (slightly more)more)
FastFast FewFew NoNo Sprinting Sprinting /bursts/bursts
FewFew nonoxidativnonoxidativee
Muscle StrengthMuscle Strength““Bigger” muscles:Bigger” muscles:
Usually NOT increase in muscle cells (hyperplasia)Usually NOT increase in muscle cells (hyperplasia) Usually an increase in existing tissue size Usually an increase in existing tissue size
(hypertrophy)(hypertrophy)
Factors contributing:Factors contributing:• GeneticsGenetics• ExerciseExercise• NutritionNutrition• EndocrineEndocrine• EnvironmentalEnvironmental• Nervous Nervous
The Muscular The Muscular SystemSystem
11.0 Describe Animal Health Needs11.0 Describe Animal Health Needs
11.3 Describe the musculoskeletal system 11.3 Describe the musculoskeletal system
Function of the muscular Function of the muscular systemsystem
• Provides movement in Provides movement in conjunction with the conjunction with the skeletal systemskeletal system
• Important in life supportImportant in life support
• Used by humans and Used by humans and other animals for foodother animals for food
ClassificationsClassifications of Muscles of Muscles
• VoluntaryVoluntary: Movement of the muscle : Movement of the muscle is under the control of the animalis under the control of the animal
• InvoluntaryInvoluntary: Movement of the : Movement of the muscle is not controlled by the muscle is not controlled by the animalanimal
Types of MusclesTypes of Muscles• Smooth Smooth
MusclesMuscles: : Involuntary Involuntary muscles, muscles, found in the found in the walls of walls of internal internal organs and organs and the blood the blood vessels.vessels.
SmoothSmooth Muscles Muscles
• Are not under voluntary controlAre not under voluntary control
• Are spindle shaped and are not Are spindle shaped and are not striated. striated.
• Interlace to form Sheets of Interlace to form Sheets of smooth muscle tissue. smooth muscle tissue.
• Are found in many internal Are found in many internal organs: Stomach, Intestines, organs: Stomach, Intestines, Blood Vessel wallsBlood Vessel walls
Types of MusclesTypes of Muscles
• Cardiac Cardiac MusclesMuscles: : Muscles that Muscles that form a form a network to network to make up the make up the heart. Not heart. Not under active under active brain controllbrain controll
Cardiac MusclesCardiac Muscles
• Only found in the HeartOnly found in the Heart• Are StriatedAre Striated• Are NOT under Voluntary Are NOT under Voluntary
Control Control • Contract Without Direct Contract Without Direct
stimulation by the stimulation by the Nervous System Nervous System
Types of MusclesTypes of Muscles
• Skeletal MusclesSkeletal Muscles: : Have a striped Have a striped appearance, appearance, include voluntary include voluntary and involuntary, and involuntary, attached to and attached to and moves your moves your bones. This is a bones. This is a majority of the majority of the muscle tissue in muscle tissue in your body.your body.
Skeletal MusclesSkeletal Muscles
• Are made of Elongated Are made of Elongated Cells called Cells called MUSCLE MUSCLE FIBERSFIBERS
• Are grouped into dense Are grouped into dense bundles called bundles called FASCICLESFASCICLES
• Are LARGE and have MORE Are LARGE and have MORE than ONE NUCLEUS than ONE NUCLEUS
• Most are VoluntaryMost are Voluntary