Muscular-Skeletal System and Sarcomere Structure ch 10 part 2

Sarcomere

Functional unit of skeletal muscle contraction.

Sarcoplasmic Reticulum

Surrounds sarcomeres, stores calcium ions.

I Bands

Regions with only thin filaments in sarcomeres.

A Bands

Regions with both thick and thin filaments.

H Bands

Central part of A bands with thick filaments.

M Lines

Middle line of H bands in sarcomeres.

Z Lines

Bisect I bands, anchoring thin filaments.

Myosin

Thick filament protein involved in muscle contraction.

Actin

Thin filament protein forming muscle structure.

Titin

Protein stabilizing thick filaments at Z line.

Sliding Filament Theory

Explains muscle contraction via filament sliding.

Excitability

Muscle's ability to respond to stimuli.

Contractility

Ability of muscle cells to shorten.

Extensibility

Ability of muscle cells to stretch.

Elasticity

Ability of muscle cells to recoil.

Neurotransmitter

Chemical signal prompting muscle contraction.

G-actin

Globular actin subunit in thin filaments.

F-actin

Polymerized form of G-actin in filaments.

Troponin-tropomyosin complex

Regulates actin-myosin interactions in muscle.

Myofibril

Contractile unit within muscle fibers.

Gastrocnemius

Calf muscle containing sarcomeres.

Mastering CH 9

Due March 7, covers bone tissue and joints.

Exam 2

Scheduled for March 26.