MUSCLE TISSUE PPT1 What are the parts of muscles?

Muscles are covered by skin

Each muscle is distinct and named

Muscle tendons attach to bone

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EPImysium wraps whole muscle ENDOomysium PERImysium Each part of the muscle is wrapped in a connective tissue wrapping (fascia) which protects the cells, and gives some stretch and strength to the muscle EPImysium wraps whole muscle Tendon (b) ENDOomysium (wraps individual muscle cells) Fascicle: A bundle of muscle cells PERImysium Wraps a bundle of muscle cells Muscle CELL (somethimes called a fiber) Figure 9.1

Parts of a muscle cell

Each sarcomere is covered by sarcoplasmic reticulum (SR)(blue) Width of one sarcomere Part of a skeletal muscle fiber (cell) Z disc Z disc Myofibril Sarcolemma Triad: • T tubule • Terminal cisternae of the SR (2) Sarcolemma Tubules of the SR Myofibrils Mitochondria Each sarcomere is covered by sarcoplasmic reticulum (SR)(blue) Each sarcomere has T tubules (white tube) running over the Z disc Underneath the T tubules and SRs are the thin and thick filaments Figure 9.5

MYOFIBRILS are broken into smaller units called SARCOMERES SARCOMERES are made of smaller units called FILAMENTS (myofilaments) Z disc Z disc (c) Small part of one myofibril enlarged to show the myofilaments responsible for the banding pattern. Each sarcomere extends from one Z disc to the next. Sarcomere Z disc Z disc Thin (actin) filament Elastic (titin) filaments Thick (myosin) filament (d) Enlargement of one sarcomere (sectioned lengthwise). Notice the myosin heads on the thick filaments. Figure 9.2c, d