Midterm (Lessons 1-4) Flashcards
Tendon connects ______ to ______
muscle to bone
Sheath of fibrous CT surrounding the entire muscle
Epimysium
Layer of CT surrounding a bundle of up to 150 fasciculi
Permysium
Bundle of muscle fibers
Fasciculi
A fine layer of CT wrapping each muscle fiber
Endomysium
Cylindrical, multinucleated fiber that makes up skeletal muscles
Muscle cell
Skeletal muscle structure from greatest to smallest
Muscle
Epimysium
Permysium
Fasciculi
Endomysium
Muscle Fiber
Myofibrils
What is the benefit of having a “fish net” capillary bed when supplying the muscles with blood?
Allows for increased oxygen supply and carbon dioxide removal during rhythmic contractions
During prolonged, high-force contractions, blood flow is _____ and anaerobic/aerobic energy systems provide fuel (ATP)
Occluded; anaerobic
Angiogenesis
Formation of new blood vessels
Capillary density
the number of capillaries per unit cross-sectional area of muscle
Capillary density increases with _____ training
chronic endurance/aerobic
Intramuscular PCr will increase with ______ training
chronic strength
Sarcolemma
thin, elastic membrane that encloses the fiber’s cellular contents
Plasmalemma
cell membrane that fuses with tendon and conducts an action potential
What are the precursor to muscle cells called?
Satellite cells
What are the functions of satellite cells?
muscle growth/development
Response to injury, immobilization, & training
The cytoplasm of the muscle cell is called _____
sarcoplasm
What are the unique features of sarcoplasm?
glycogen storage; myoglobin
Transverse-tubules
extensions of the plasmalemma that carry AP deep into the muscle fiber
The area of Ca2+ storage is the
Sarcoplasmic reticulum
What is the functional unit of the muscle fiber?
Sarcomere
The dark stripes of the muscle fiber:
A-bands
The light stripes of the muscle fiber:
I-bands
The middle of the A-band is the
H-zone
The middle of the H-zone is the
M-band
The common boundary structure of the sarcomere is
the z-bands
The I-band contains actin/myosin filaments
actin
The A-band contains actin/myosin filaments
actin AND myosin
The H-zone contains actin/myosin filaments
myosin
What are the 3 proteins that make up actin?
Actin
Troponin
Tropomyosin
Which protein fiber of the actin contains the myosin binding site?
Actin
The ______ of actin covers the active site
Tropomyosin
The _____ moves the tropomyosin
troponin
What is the purpose of the globular heads on the myosin?
Bind with actin and pull it close (wow, romantic), cause muscle contraction
Relaxed state of the sliding filament theory:
No actin-myosin interaction
Actin and myosin overlap a bit
Troponin covers myosin binding site
Contraction state of the sliding filament:
Globular head attaches to binding site
POWER STROKE pulls actin toward center
Actin and myosin slide past each other
