tissues

• Skeletal
• Cardiac
• Smooth

• *Comprised of very long muscle cells
• *Found in the muscles that move the skeleton
• *Able to be controlled VOLUNTARIY
• *Display light & dark bands giving appearance of strips or STRIATIONS

• Found only in the heart
• Have striations
• Involuntary muscle
• Have some neutonal regulation that controls the beating of the heart(subconscious level)

• Found in the walls of hollow visceral organs e.g:stomach & bladder
• Lack Striations
• Can not be consciously regulated or controlled (involuntary)

• Excitability
• Contractility
• Extensibility
• Elasticity

The ability to receive or respond to stimuli

The ability to shorten forcibly when adequately stimulated

The ability to be stretched or extended

The ability of a muscle fiber to recoil and resume its normal resting length after being stretched or contracted

• Producing Movement
• Maintianing Posture
• Stabilizing Joints
• Generating Heat

The movement of the skeleton

The ability to make minute changes in positon to maintain normal positioning

Muscle tissue and muscle connections surround joints and keep them in position

Muscles generate heat as they contract thereby maintaining normal body temp

• Muscle - a bundle of muscle fascicles
• Fascicle - A bundle of muscle fibers
• Muscle fiber - the muscle cell
• Muscle Cell- Contains Myosin and Actin

“within the muscle” A sheath of primarily reticular fibers that covers the muscle fiber

“around the muscle” A sheath of fibrous connective tissue that covers the muscle fascicle

“outside the muscle” - A sheath of dense irregular connective tissue that covers the whole muscle

The place of attachment which provides little to no movement

The place of attachment which provides the most movement (moveable bone)

The epimysium fuses to the periosteum of a bone or perichondrium of a cartilage

The connective tissue wrappings of the muscle extend beyond the muscle to form either a rope like tendon or a sheet like aponeurosis

Cell membrane of the muscle cell

Cytoplasm of the muscle cell

Red pigment that stores oxygen in the muscle

Rod-like fibers that run parallel down the length of the muscle fiber. Hundreds to thousands of myofibrils can be found in one fiber and account for approximately 80% of the cellular volume

Primarily made up of thick filaments and thin filaments

Primarily composed of a protein called myosin

Globular heads on Myosin (thick) that can attach to actin.

Primarily composed of actin

A thin strand that wraps around Actin (thin) and blocks the actin binding sites

A three polypeptide complex that regulates the position of tropomyosin relative to the actin binding sites.

An elaborate smooth endoplasmic reticulum that’s primary function is to regulate intercellular levels of calcium

• A long tube-like structure that are continuous with the sarcolemma
• Runs in between two sarcoplasmic reticulums.
• Action of the T Tubule:to initiate the release of calcium from the sarcoplasmic reticulum.

Shortening of the muscle fibers by the activation and movement of actin fibers over myosin fibers causing overlap (Sliding filament theory of contraction)

when nerves excite the muscles by secreting a neurotransmitter called acetylcholine (ACH)

Causes sarcolemma of the muscle fiber to produce an action potential which travels down the T tubule

Neurons initiate the muscle contraction by secreting a chemical called Acetylcholine (ACH). This causes an action potential to occur on the surface of the Sarcolemma. The action potential then travels down the T-Tubule to activate the secretion of calcium from the Sarcoplasmic Reticulum. The calcium is then able to bind to Troponin which changes configuration. This change in configuration causes Tropomyosin to shift out of position allowing the globular head of Myosin to bind to the active site found on Actin.

• Cross Bridge formation
• The Power stroke
• Cross Bridge detachment
• Cocking the myosin head

This is when the Myosin head is attached to actin

The changing of the myosin head configuration from a high energy position (straight) to low energy position (bent) causes movement of the actin fiber

This is when a new ATP molecule binds to the Myosin head causing the head to loose its grip on actin

Once ATP is bound it is quickly converted to ADP causing the myosin head to go back into its high energy position

Dark band where actin and myosin overlap

Light band where only actin can be found

the area where only myosin filaments can be found

The midline in the I band where actin filaments can connect to each other

The mid-line in the H - Zone where Myosin fibers are anchored