Chapter 9 Muscle Types of muscle -Skeletal muscle. Striated muscle Cardiac muscle Smooth muscle
Types of muscle – Skeletal muscle – Cardiac muscle – Smooth muscle Striated muscle Chapter 9 Muscle
CopyrightThe McGra-Hill Companies,Inc.Permission required or reproduction or display. (a)Skeletal muscle (b)Cardiac muscle (e)Smooth muscle
Chapter 9 Muscle (cont.) The sliding filament mechanism,in which myosin filaments bind to and move actin filaments,is the basis for shortening of stimulated skeletal,smooth,and cardiac muscles. In all three types of muscle,myosin and actin interactions are regulated by the availability of calcium ions. Changes in the membrane potential of muscles are linked to internal changes in calcium release (and contraction)
• The sliding filament mechanism, in which myosin filaments bind to and move actin filaments, is the basis for shortening of stimulated skeletal, smooth, and cardiac muscles. • In all three types of muscle, myosin and actin interactions are regulated by the availability of calcium ions. • Changes in the membrane potential of muscles are linked to internal changes in calcium release (and contraction). Chapter 9 Muscle (cont.)
Chapter 9 Muscle (cont.) Neuronal influences on the contraction of muscles is affected when neural activity causes changes in the membrane potential of muscles. Smooth muscles operate in a wide variety of involuntary functions such as regulation of blood pressure and movement of materials in the gut
• Neuronal influences on the contraction of muscles is affected when neural activity causes changes in the membrane potential of muscles. • Smooth muscles operate in a wide variety of involuntary functions such as regulation of blood pressure and movement of materials in the gut. Chapter 9 Muscle (cont.)
Structure of skeletal muscle Structure of a Skeletal Muscle Perimysium Bone Blood vessel Muscle fiber Fascicle Tendon Epimysium Endomysium
Structure of skeletal muscle
Skeletal muscles are attached to the skeleton by tendons. Thin (actin)tme Skeletal muscles typically contain many,many muscle fibers
Skeletal muscles are attached to the skeleton by tendons. Skeletal muscles typically contain many, many muscle fibers
6 CopgteTmecravtmconpeniea.hc2zoeonrqutadioreproaucteonorisp Z line Z line Titin Thin filament M line Thick filament The sarcomere is composed of: thick filaments called myosin,anchored in place by titin fibers,and thin filaments called actin,anchored to Z-lines
The sarcomere is composed of: thick filaments called myosin, anchored in place by titin fibers, and thin filaments called actin, anchored to Z-lines
opyrightThe McGrw-Hil Companles,nc.requlred tor reproduction or dlsplay. Figure 9-4b hick Thin filament filament (b) ● ●● ● ● ●0●●●●●●●● A cross section through a sarcomere shows that: each myosin can interact with 6 actin filaments,and each actin can interact with 3 myosin filaments
A cross section through a sarcomere shows that: • each myosin can interact with 6 actin filaments, and • each actin can interact with 3 myosin filaments. Figure 9-4b
Copyright The Mc-Hll Companies,nc.Permisslon rquired tor roproduction or display CopyrightThe McG-Hi Companies. (a) Z line Titin Thin filament Mline Thick filament Sarcomere structures in an electron micrograph
Sarcomere structures in an electron micrograph
Myosin filaments Filaments Actin filaments Actin filaments Z disk Z disk AI Zone -I band--水 A band- 米-I band Sarcomere
Filaments