CHPT 10 Flashcards
Define Electrical Excitability
ability of a muscle fibre/ cell to respond to ap (muscle and nerve cell communication)
Contractibility
ability of muscular tissue to contract forceful by ap
Extensibility
ability of tissue to stretch to an extent without rupturing
Elasticity
ability of tissue to return to go length and shape after contraction
Belly
main body of muscle, connected by tendons to skeleton
Structures of Skeletal Muscles
Belly, 3 CT layers
Epimysium
dict, outer covering of entire muscle
Perimysium
covers muscle fascile
Endomysium
covers muscle fiber/cell
Fasicle
bundle of muscle
Deep fascia structure
dict
Deep fascia function
- separate individual muscle
- bind muscles with similar function
- form sheath to help distribute nerves, bv, lymphatic vessels
- fill spaces b/w muscles
Myofibrils
- contain alternative lighter and darker bands, tiny strutter in sarcoplasm
- contain contractile and structural proteins
Sarcolemma
plasma membrane of muscle fibre
Sarcoplasm
cytoplasm of a muscle fibre
T Tubules
fluid channels that carry ap
Sarcoplasmic Reticulum (SR)
- similar to ER, fluid-filled
- contains terminal cisterna
Cisterna
store and Ca2+ for muscle contraction
Myosin
- thick filament
- contractile protein
- motor protein (converts chem e to mechanical e)
what moves during muscle contractions
myosin heads
Actin
- thin filament
- contractile protein
- contain regulatory proteins
contractile protein
actin and myosin
Regulatory protein
troponin and tropomyosin
tropomyosin
covers myosin binding sites on actin
troponin
- chills on actin
- moves tropomyosin during muscle contraction when Ca2+ attaches to it
Sarcomere
- distance between z-lines
- function unit of muscle contraction since filaments don’t cover entire cell
H-zone
think filament only
I-zone
- thin filament + z-line
- light
A band
-covers entire length of myosin
M-line
holds myosin in middle
Z-line
- actin only
- separates sarcomeres
What happens to the Z-line during muscle contraction?
distance b/w shortens