Chapter 10/Lab 11 Anatomy

A muscle generates force while lengthening - essential for controlled movement and resistance to gravity. Exist in movements that resist gravity. 

A muscle generates force while shortening. Explained by the sliding filament mechanism. Contraction results as the mysoin heads of the thick filaments attach to the thin filaments at both ends of the sacromere and pull the thin filaments toward the center of the sacromere by swiveling inward. After a myosin head pivots at it's hinge - it lets go and returns to its original position, binds to the thin filaments farther along its length, and pivots again. The process is powered by ATP.

A type of neuron that innervates muscle fibers causing the release of calcium and muscle contraction. 

The point at which the nerve ending and the fiber meet. 

The end of the axonal process that stores chemical messenger molecules called neurotransmitters. 

The space between the terminal boutons and the muscle fiber. 

Acetylcholine. 

A motor neuron and all the muscle fibers it innervates. Large muscles cause several muscle fibers to fire at once as the impulse runs through the muscle. Fine motor movement has more neurons per muscle fiber groups. If more muscle fibers are needed, recuitment occurs. 

Slow oxidative fibers - obtain energy from aerobic metabolic reactions. Large number of mitochondria. Prolonged contraction - maintain posture. 

Fast glycolytic fibers - pale because they contain little myoglobin. Depend on anaerobic pathways. Generate much more power quickly. Common in strong muscles that lift heavy objects. 

Fast Oxidative Fibers - aerobic, lower limbs, in the middle of slow oxidative and fast glycolytic as far as performance goes. 

People are born with a certain amount of muscle fibers of each type, however training does increase different types of needed muscle fibers. This goes away if training stops, however there is an overshoot period when you stop training where an overgrowth of fibers occur. 

A group o f inherited muscle destroying disesase that generally appear in childhood. The affected muscles enlarge with fat and connective tissue while the muscle fibers degenerate. 

A group o f inherited muscle destroying disesase that generally appear in childhood. The affected muscles enlarge with fat and connective tissue while the muscle fibers degenerate. 

The breakdown of muscle. Can be caused by starvation in which the brain starts to steal resrouces from the rest of the body. Or by lack of use - for example the breakdown of the legs of a parapalegic. 

Tetanus is a microbiological bacteria anerobic bacteria - does not use O2 thrives in low O2 enviornments. When you step on a nail, you create a puncture wound where O2 floods the area. These causes the tetanus to secrete a toxin which stimulates muscle contraction leading to hypercontractility. leads to lock jaw. 

Hypo = low

oxo = oxygen

ic = everywhere. 

You need ATP to decontract muscles, if there is no ATP being created muscles go stiff. This happens at death when the body is no longer creating ATP. You can also overuse a certain part of the body and cause temporal rigamortus. 

1. produce movement

2. open and close body passageways

3. maintain posture and stabalize joints

4. generate heat. 

1. Skeletal - attach to and move the skeleton. Voluntary, striated, multinucleate. 

2. Cardiac - Heart, striated, monounucleate, involuntary. 

3. Smooth - hallow internal organ walls (other than heart), non striated, mononucleate, involuntary. 

The outter layer of DENSE IRREGULAR CONNECTIVE TISSUE that surround the WHOLE SKELETAL MUSCLE. the name means - outside muscle. 

Covers the groups of muscle fibers called FASCICLES. Fibrous connective tissue. 

S fine sheath of LOOSE CONNECTIVE TISSUE CONSISTING OF MOST RETICULAR FIBERS THAT SURROUNDS EACH MUSCLE FIBER. (name means - within the muscle).

A tendon connects muscle to muscle or muscle to bone. It is made up of the epimysium, perimysium and the endomysium. They converge to create the tendon. 

It means that when pull is exerted on one layer via the tendon a sequence transments the force of contractoin through all sheaths. 

- Each skeletal muscle is generally provided with one nerve, one artery, and one or more veins - all enter or exit the muscle near the middle of its length. They then branch repeatedly in the intramusclar connective tissue - with the smallest branches serving individual fibers. There is a rich supply of blood because there is gigantic depand for oxygen in muscles. 

Orgin - the more fixed, or less movable attachment

Insertion - the more movable bone attachment. 

When the muscle contracts the insertion moves towards the orgin. 

Direct: the attaching strangs of connective tissue are so short that the muscle fasciles themselves appear to attach direct to the bone. 

Indirect: The connective tissue extends well beyound the end of the muscle fibers to form either a cordlike tendon or a flat sheet called an APONEURPSOS. 

A seam of fibrous tissue that tendons and aponeuroses attach to if not attached to bones, skin or cartilage. 

Long cylindrical cells that are very large. Multinucleate - with nuclei that are just deep to th esacrolemma. 

TheLong rod-hsaped organelles. They are unbranched cylinders that are present in large numbers, making up more than 80% of the sarcoplasm. They are specialized contractile organelles unique to muscle tissue. They contain myofilaments - the contractile protiens myosin and actin. They are spearated from one another by other components of the sarcoplasm including mitochondria and glycosomes which supply energy for the muscle contraction. 

The repeating segments a myofibril is composed of. It's the basic unit of contraction in skeletal muscle is the area from Z disc to Z disc.