11.2: 11.2: Muscles & MovementMuscles & Movement

Which structure is responsible for passing messages directly

to effector organs?

11.2.1 State the roles of ...in human 11.2.1 State the roles of ...in human movement.movement.• BonesBones

– Lever for movementLever for movement– Frame to support bodyFrame to support body– Protect tissue/organsProtect tissue/organs– Form blood cells (marrow)Form blood cells (marrow)– Store mineralsStore minerals

• LigamentsLigaments– Strengthen jointStrengthen joint– stabilize bone to bone connectionsstabilize bone to bone connections

• MusclesMuscles– Provide force for movemt by contractingProvide force for movemt by contracting– Shortening length of cells Shortening length of cells – Occur in antagonistic pairsOccur in antagonistic pairs

• TendonsTendons– Attach muscle to boneAttach muscle to bone

• NervesNerves– Sensory ends @ ligaments and muscles Sensory ends @ ligaments and muscles – Help prevent over-extension @ jointsHelp prevent over-extension @ joints– Coordinate muscle contractionCoordinate muscle contraction

11.2.2 Label a diagram of human elbow joint: 11.2.2 Label a diagram of human elbow joint: cartilage, synovial fluid, joint capsule, named cartilage, synovial fluid, joint capsule, named bones (humerus, radius, ulna), antagonistic bones (humerus, radius, ulna), antagonistic muscles (biceps, triceps)muscles (biceps, triceps)

11.2.2 Label a diagram of human elbow joint: 11.2.2 Label a diagram of human elbow joint: cartilage, synovial fluid, joint capsule, named cartilage, synovial fluid, joint capsule, named bones (humerus, radius, ulna), antagonistic bones (humerus, radius, ulna), antagonistic muscles (biceps, triceps)muscles (biceps, triceps)

http://www.asmi.org/sportsmed/anatomy/elbow.html

www.Click4biology.com

http://www.youtube.com/watch?v=SOMFX_83sqk

11.2.3 Outline the functions of the 11.2.3 Outline the functions of the structures in the human elbow joint.structures in the human elbow joint.• Hinge jointHinge joint• Synovial fluid w/in synovial cavity, w/in joint capsuleSynovial fluid w/in synovial cavity, w/in joint capsule

—dense connective tissue, continuous w/bone —dense connective tissue, continuous w/bone membranesmembranes

www.heinemann.co.uk/hotlinks 4242P; weblink 11.1

Joint partJoint part FunctionFunction

CartilageCartilage Reduces friction, absorbs compressionReduces friction, absorbs compression

Synovial fluidSynovial fluid Lubricates to reduce friction; provides nutrients Lubricates to reduce friction; provides nutrients to cells of cartilageto cells of cartilage

Joint capsuleJoint capsule Surrounds joint; encloses syn cavity; unites Surrounds joint; encloses syn cavity; unites connecting bonesconnecting bones

TendonsTendons Attach muscle to boneAttach muscle to bone

LigamentsLigaments Connect bone to boneConnect bone to bone

BicepsBiceps Contracts Contracts flexion (bending) of arm flexion (bending) of arm

TricepsTriceps Contracts Contracts extension (straightening) extension (straightening)

HumerusHumerus Lever, allows anchorage of elbow musclesLever, allows anchorage of elbow muscles

RadiusRadius Lever for bicepsLever for biceps

UlnaUlna Lever for tricepsLever for triceps

http://www.youtube.com/watch?v=SOMFX_83sqk

11.2.4 Compare the movements at the hip 11.2.4 Compare the movements at the hip and knee joint.and knee joint.

Hip JointHip Joint Knee JointKnee Joint

Freely movableFreely movable Freely movableFreely movable

Angular motions in many Angular motions in many directions & rotational directions & rotational movementsmovements

Angular motion in one directionAngular motion in one direction

Motions possible: Motions possible: flexion, extension, flexion, extension, abduction, adduction, abduction, adduction, circumduction, and circumduction, and rotationrotation

Flexion and extension onlyFlexion and extension only

Ball-like structure fits into Ball-like structure fits into a cup-like depression a cup-like depression (ball-and-socket joint)(ball-and-socket joint)

Convex surface fits into a Convex surface fits into a concave surface (hinge joint)concave surface (hinge joint)

11.2.4 Compare the movements at the hip 11.2.4 Compare the movements at the hip and knee joint.and knee joint.

11.2.5 Describe the structure of striated muscle fibers: 11.2.5 Describe the structure of striated muscle fibers: myofibrils w/light and dark bands, mitochondria, myofibrils w/light and dark bands, mitochondria, sarcoplasmic reticulum, nuclei, sarcolemmasarcoplasmic reticulum, nuclei, sarcolemma

• Skeletal movementSkeletal movement• Muscle fibers = cellsMuscle fibers = cells

– MultinucleateMultinucleate– Plasma membrane = sarcolemmaPlasma membrane = sarcolemma

• T tubules = “tunnels” penetrating cell’s interiorT tubules = “tunnels” penetrating cell’s interior– Cytoplasm = sarcoplasmCytoplasm = sarcoplasm

• LOTS of stored glycogen (glycosomes)LOTS of stored glycogen (glycosomes)• LOTS of myoglobin (protein)LOTS of myoglobin (protein)

– SR = sarcoplasmic reticulum = smooth ERSR = sarcoplasmic reticulum = smooth ER– Myofibrils = rod-shaped bodies, run length of cellMyofibrils = rod-shaped bodies, run length of cell

• Lots, packed parallel to each other, lots mitochondria in b/wLots, packed parallel to each other, lots mitochondria in b/w• Contractile units of the muscle cell; give it striated patternContractile units of the muscle cell; give it striated pattern

• ““muscle” = 1000s of cells, nerves, vesselsmuscle” = 1000s of cells, nerves, vessels

• Myofibrils:Myofibrils:– Sarcomere = unit of movemtSarcomere = unit of movemt– Z lines @ endsZ lines @ ends– A bands (dArk), length of myosin filamentsA bands (dArk), length of myosin filaments– H band (narrow) @ middle of A band (myosin H band (narrow) @ middle of A band (myosin

only, no actin) w/M line in middle—supporting only, no actin) w/M line in middle—supporting protein for myosin filamentsprotein for myosin filaments

– I bands (LIght), only actin—no myosinI bands (LIght), only actin—no myosin

– http://entochem.tamu.edu/http://entochem.tamu.edu/musclestruccontractswf/index.html musclestruccontractswf/index.html

11.2.6 Draw and label a diagram to show structure of a 11.2.6 Draw and label a diagram to show structure of a sarcomere: z lines, actin filaments, myosin filaments with sarcomere: z lines, actin filaments, myosin filaments with heads, and resultant light and dark bands.heads, and resultant light and dark bands.

11.2.6 Draw and label a diagram to show structure of a 11.2.6 Draw and label a diagram to show structure of a sarcomere: z lines, actin filaments, myosin filaments with sarcomere: z lines, actin filaments, myosin filaments with heads, and resultant light and dark bands.heads, and resultant light and dark bands.

ActinActin MyosinMyosin

Thin (8nm diam)Thin (8nm diam) Thick (16 nm diam)Thick (16 nm diam)

Contains myosin-Contains myosin-binding sitesbinding sites

Contains myosin Contains myosin heads that have heads that have actin-binding sitesactin-binding sites

Individual Individual molecules form molecules form helical structureshelical structures

Individual molecules Individual molecules form a common shaft-form a common shaft-like region w/outward like region w/outward protruding headsprotruding heads

Includes 2 Includes 2 regulatory proteins regulatory proteins (tropomyosin & (tropomyosin & troponin)troponin)

Heads referred to as Heads referred to as cross-bridges, cross-bridges, contain ATP-binding contain ATP-binding sites and ATPase sites and ATPase enzymesenzymes

11.2.7 Explain how skeletal muscle contracts, including the release of 11.2.7 Explain how skeletal muscle contracts, including the release of calcium ions from the SR, the formation of cross-bridges, sliding calcium ions from the SR, the formation of cross-bridges, sliding action of actin and myosin filaments, and use of ATP to break cross action of actin and myosin filaments, and use of ATP to break cross bridges and re-set myosin heads. bridges and re-set myosin heads.

• Sliding filament theorySliding filament theory

• Actin myofilaments slide over myosin Actin myofilaments slide over myosin myofilaments—they don’t shorten!myofilaments—they don’t shorten!

• The The sarcomeresarcomere shortens when they slide shortens when they slide over each otherover each other

• http://3dotstudio.com/zz.html http://3dotstudio.com/zz.html

• www.thelifewire.com www.thelifewire.com

Sliding Filament Theory: Sliding Filament Theory:

1.1. Motor neuron carries action potential Motor neuron carries action potential to NMJ (neuromuscular junction)to NMJ (neuromuscular junction)

2.2. Neurotransmitter, acetylcholine, Neurotransmitter, acetylcholine, released into gap b/w axon terminal released into gap b/w axon terminal and sarcolemma of muscle fiberand sarcolemma of muscle fiber

3.3. ACh binds to receptors on ACh binds to receptors on sarcolemmasarcolemma

4.4. Sarcolemma ion channels open, Sarcolemma ion channels open, Na+ move throughNa+ move through

5.5. Generates muscle action potentialGenerates muscle action potential

6.6. Moves along membrane, through T Moves along membrane, through T tubulestubules

7.7. ACh broken down by ACh broken down by acetylcholinesterase to make sure acetylcholinesterase to make sure one nerve action potential causes one nerve action potential causes only one muscle action potentialonly one muscle action potential

Sliding Filament Theory: Sliding Filament Theory:

8. Muscle action potential going through T tubules causes release of 8. Muscle action potential going through T tubules causes release of Ca ions from SR. Flood into sarcoplasm.Ca ions from SR. Flood into sarcoplasm.

9. Ca ions bind to troponin on actin—exposes myosin-binding sites9. Ca ions bind to troponin on actin—exposes myosin-binding sites

10. Myosin heads include ATPase which splits ATP and releases 10. Myosin heads include ATPase which splits ATP and releases energyenergy

Sliding Filament Theory: Sliding Filament Theory:

11. Myosin heads bind to myosin-binding sites on actin with help of 11. Myosin heads bind to myosin-binding sites on actin with help of tropomyosin (protein)tropomyosin (protein)

12. Myosin-actin crossbridges rotate toward center of sarcomere, 12. Myosin-actin crossbridges rotate toward center of sarcomere, producing the “power stroke”producing the “power stroke”

13. ATP binds again to myosin head, resulting in detachment of myosin 13. ATP binds again to myosin head, resulting in detachment of myosin from actinfrom actin

14. If no more action potentials, Ca ion level in sarcoplasm falls. 14. If no more action potentials, Ca ion level in sarcoplasm falls. Troponin-tropomyosin complex moves to its original position, Troponin-tropomyosin complex moves to its original position, blocking myosin binding sites...muscle relaxes.blocking myosin binding sites...muscle relaxes.

WHOAAAA.... WHOAAAA....

• When you die...Ca++ leak out of SR, bind to When you die...Ca++ leak out of SR, bind to troponin...allows actin to slide. But, no ATP produced troponin...allows actin to slide. But, no ATP produced when you’re dead, so myosin heads can’t detach from when you’re dead, so myosin heads can’t detach from actin: RIGOR MORTIS! Lasts ~24 hrs until muscles actin: RIGOR MORTIS! Lasts ~24 hrs until muscles deteriorate.deteriorate.

• Muscle filaments don’t change in length during Muscle filaments don’t change in length during contraction.contraction.

• The sarcomere shortens (Z line to Z line)...can see in The sarcomere shortens (Z line to Z line)...can see in electromicrographs.electromicrographs.

11.2.8 Analyze electron micrographs to find 11.2.8 Analyze electron micrographs to find the state of contraction of muscle fibers. the state of contraction of muscle fibers.

• Which is relaxed, which is contracted?Which is relaxed, which is contracted?

• You should also be able to label this!You should also be able to label this!