Chapter 10: Skeletal Muscle Tissue

What are the three types of muscles

1. Skeletal: attach to bone and is voluntary

2. Cardiac: found in the heart and is involuntary

3. Smooth: lines hollow organs and is involuntary

What is Sacrolemma

plasma membrane of muscle cells

What is sarcoplasm

cytoplasm

What is sarcoplasmic reticulum

endoplasmic reticulum

“Muscle grows via hypertrophy”, what does that mean?

That means the protein mass increases but you do not gain more muscle cells, they can only get bigger

What are the functions of Skeletal muscle

1. Produce skeletal movement

2. Maintain posture and body position

3. support soft tissues

4. guard entrances and exits

5. Maintain body temperature

What does skeletal muscle consist of

• connective tissue

• blood vessels

• nerves

What are each skeletal muscle supplied by?

one nerve, one artery, one or more veins

What signals the muscle to contract?

neuromuscular junction

What is the origin

less movable, direct attachment

what is the insertion

more movable attachment, indirect attachment

Thin filament is composed of…

The contractile protein actin and regulatory proteins troponin and tropomyosin

Thick filament contains…

myosin molecules and ATPase enzymes that split ATP to release energy

What are Z discs?

boundaries of sarcomere

What is the I band

thin filaments only, the light color of the striation, and has Z disc running through its center

What is the H zone?

thick filaments only

What is the M line

center part of H zone

What is the A band

thick and thin filaments overlap, and the dark part of the striation

What are oxidative fibers

produce ATP aerobically

What is Glycolytic fibers

produce ATP anaerobically by glycolysis

What are slow oxidative fiber s

Slow oxidative fibers are muscle fibers that work slowly but can keep going for a long time without getting tired. They use oxygen to make energy and are good for activities like walking or keeping posture.

What are fast glycolytic fibers

Fast glycolytic fibers are muscle fibers that work quickly and with a lot of force but get tired fast. They use stored sugars (glucose) without oxygen to make energy and are good for short, powerful movements like sprinting or lifting heavy weights.

What are Fast oxidative fibers

Fast oxidative fibers are muscle fibers that contract quickly like fast fibers but don’t get tired as fast. They use both oxygen and sugars to make energy. These fibers are good for activities like middle-distance running or cycling—faster than slow fibers but more lasting than fast glycolytic ones.

Explain muscle tissue throughout life

1. muscle tissue develops from myoblasts

2. myoblasts fuse to form skeletal muscle fibers

3. skeletal muscles contract by the seventh week of development