Explain the difference between a simple twitch, treppe, summation, and tetanus.

What do these types of muscle contraction look like?

There are different types of twitches. One type is a fast twitch. The type of muscle involved with fast twitch is white muscle. This is when the contractions are fast and there is high tension. This contraction makes someone tired quickly. There is a limited blood supply, a few Mitochondria, and little myoglobin. This muscle is helpful to people who need short burst of energy like sprinters or baseball players.

Another type of twitch is known as a slow twitch. The muscle involved with slow twitch is red muscle. The slow twitch has a rich supply of blood, has many Mitochondria, and has a lot of myoglobin. The contractions are slow so a person can do an activity for a while and not be tired. This muscle is helpful to people who need endurance such as long distance runners or soccer players.

There are two types of muscle contractions.

The first is isometric muscle contraction. This is when muscle tension increases but the muscle length has very little change. In this type of contraction there is no movement. The load on the muscle exceeds the tension generated by the contracting muscle. This occurs when a muscle attempts to push or pull an immovable object.

The second type is Isotonic muscle contraction. With this type the muscle tension does not change but muscle length does change. It decreases. With this type of contraction there is movement of body parts.the tension generated by the contracting muscle exceeds the load on the muscle. This occurs when you use your muscles to successfully push or pull an object.

Isotonic contractions are further divided into two types:

concentric contraction This is a contraction in which the muscle decreases in length (shortens) against an opposing load, such as lifting a weight up.

eccentric contraction This is a contraction in which the muscle increases in length (lengthens) as it resists a load, such as lowering a weight down in a slow, controlled fashion.

A simple twitch is when a muscle reacts to a stimulus by contracting once and then relaxing, which lasts for only a fraction of a second and does not represent the maximum force that a particular muscle fiber can generate. This action is caused by a stimulus that activates the muscle's motor units.

A summation is when a muscle is exposed to a series of stimuli that occur in increasing frequencies. It occurs when the fibers are no longer able to completely relax between each contraction.

A tetanic contraction is the result of a forceful, sustained contraction when the muscles fibers do not get to relax at all. This type of contraction produces the greatest amount of force by the muscles and muscle fibers.
myogram is a recording of a muscle contraction by means of a graph. A twitch is an action from a single contraction that lasts for less than a second. This type of contraction occurs when a muscle is exposed to a single stimulus. A summation is a contraction where the twitches of muscles overlap each other. For example, one twitch occurs before the previous twitch has ended. These contractions are caused by increased force by a skeletal muscle fiber. If summation occurs without the slightest bit of relaxation, it is known as a tetanic contraction.

A treppe is the occurrence of a successive increase in amplitude of the first few contractions of cardiac muscle that has received a number of stimuli of the same intensity following a quiescent period. Also called staircase phenomenon.

Isometric contraction: when the muscle is activated instead of being allowed to lengthen or shorten it is held at a constant length.

Passive stretch: The muscles are being lengthened while in a passive state, which means they are not contracting or being stimulated. This is when you are stretching and you cause the muscles to lengthen with out them being active.


Muscle Tone:
When a muscle seems to be at rest, a certain amount of sustained contraction is still occurring in its fibers. This is known as muscle tone. It is a response to nerve impulses that originate repeatedly from the spinal cord and stimulate a few muscle fibers.

-Muscle tone is particularly important in maintaining posture. If muscle tone is lost the body then collapses. This occurs when a person loses consciousness.