Senin, 17 April 2017

Factors Affecting Human Muscle Tension

Factors Affecting Human Muscle Tension

Factors affecting development of muscle muscle tension:
1. Frequency of stimulation
2. Number of motor units recruited
3. Degree of muscle stretch
The strength of a muscle contraction is determined not only by the frequency of stimulation, but also by the number and size of motor units

Rabu, 12 April 2017

How Mechanism Summation of Multiple Stimuli in Skeletal Muscle



How Mechanism Summation of Multiple Stimuli in Skeletal Muscle

Five region when multiple stimuli
1. Treppe (Staircase Effect)
First few contractions demonstrate treppe. Even though the strength of contraction increased, relaxation was complete (temporal summation not responsible). Increase in tension may result from increased muscle warming and efficiency of enzymes.
2. Temporal Summation
After the first five stimuli, frequency was increased, which caused temporal summation. Resulted in a continual increase in tensions as one contraction was added to the previous contraction. Increase in tension may result from increased availability of intracellular calcium.
3. Incomplete Tetanus
4. Complete Tetanus
5. Fatigue



Senin, 10 April 2017

Temporal summation of two stimuli in human skeletal muscle

Temporal summation of two stimuli
- Second stimulus of same intensity is applied
- Applied before completion of relaxation
- Second contraction added to first contraction
- Temporal (wave) summation increases muscle tension

Kamis, 06 April 2017

How Mechanism of Human Muscle Twitch



How Mechanism of Human Muscle Twitch

A Muscle contraction in response to a single stimulus of adequate strength is called a muscle twitch.
A complete muscle twitch is divided into three phases: Latent period, contracted period and relaxation period.



Selasa, 04 April 2017

How Metabolism Red Muscle Fibers

How Metabolism Red Muscle Fibers

Features of Red Muscle Fibers
- About half the diameter of white fibers
- Dark red in color due to large quantity of myoglobin
- Surrounded by many capillaries
- Numerous mitochondria
- Low glycogen content
To synthesize ATP, red muscle fibers mainly use the Krebs cycle and oxidative phosphorylation, which require mitochondria and oxygen. Oxygen come from the abundant myoglobin and capillaries. Oxygen diffuses rapidly throughout these small cells.

Sabtu, 01 April 2017

Metabolism in Human White Muscle Fibers



Metabolism in Human White Muscle Fibers

Because our bodies use muscles for wide range of activities, different types of muscle fibers use different methods of synthesizing ATP, which are reflected in their cellular structure.

This cross-section of skeletal muscle shows two major types of muscle cells which differ in size and coloration. These structural differences relate to their method of metabolism.

Features of White Muscle Fibers
- Large in Diameter
-  Light in color due to reduced myoglobin
- Surrounded by few capillaries
- Relatively few mitochondria
- High glycogen content