Muscle Types

• Skeletal

• Smooth

• Cardiac

• Until further notice, we are discussing skeletal muscle

Connective Tissue in Skeletal Muscle

• Tendon: attaches muscle to bone

• Fascia: layers of connective tissue that separates an individual muscle from adjacent muscles. Holds muscle in position.

Connective Tissue in Skeletal Muscle

• Epimysium: layer of connective tissue that directly surrounds the skeletal muscle

• Perimysium: layer of connective tissue that extends inward and separates a muscle into fascicles

Connective Tissue in Skeletal Muscle

• Fascicle: compartment that contains a bundle of muscle fibers

• Endomysium: connective tissue that surrounds an individual muscle fiber(cell) in the fascicle

Connective Tissue in Skeletal Muscle

• Myo-

• Sarco-

• See Figure 9.2 and 9.3

• Draw circles

• Practice with junk

Muscle Fiber (Cell) Structure

• A muscle fiber is an elongated single cell of a muscle

• See Figure 9.2 and 9.7 (8.2 and 8.4)

Muscle Fiber (Cell) Structure

• Sarcolemma: cell membrane of a muscle cell

• Sarcoplasm: cytoplasm of a muscle cell, contains many nuclei and mitochondria

Muscle Fiber (Cell) Structure

• Nuclei: many per cell, site of transciption

• Mitochondria: many per cell, site for Cellular respiration

Muscle Fiber (Cell) Structure

• Transverse Tubules: (T tubules), tubes that extend inward and pass all the way through the cell. Each tube opens to the outside

Muscle Fiber (Cell) Structure

• Sarcoplasmic Reticulum: SR, network of channels in the sarcoplasm. These run parallel to the myofibrils.

Muscle Fiber (Cell) Structure

• Myofibrils: threadlike structures that lie parallel to each other in the sarcoplasm– Major function is

muscle contraction

Muscle Fiber (Cell) Structure

• Draw

• Practice

• Junk

• Figure 9.7

Myofibril Structure

• Remember: Myofibrils are threadlike structures that lie parallel to each other in the sarcoplasm. Their major function is muscle contraction

Myofibril Structure

• Made of 2 types of filaments(proteins):– Actin: thin filament, it

appears light

– Myosin: thick filament, it appears dark

Myofibril Structure

• A Band: darkest area where actin and myosin overlap.

• H Band: part of A band, lighter area because only made of myosin and M line.

• M Line: structural protein that anchors the myosin.

Myofibril Structure

• I Band: lightest band; only actin and Z line.

• Z Line: structural protein that anchors the actin.

• Sarcomere: Z line to Z line; is a contractile unit

Myofibril Structure

• See Figure 9.4 and 9.5 or 9.6

• Draw

• Practice

• Build