Bio pack lab and muscle fatigue

muscle fatigue

The decline in muscle tension is due to previous contractile activity

• slower to contract and takes longer to relax

the onset of fatigue depends on …

• The duration of the activity

• the type of skeletal muscles

• the fitness of the individual

athletic training is designed to delay the

onset of muscle fatigue and increases the speed of recovery

How many molecules of ATP are produced when oxygen levels are aerobically high and anaerobically low

32-36

Lactic acid is a

by product of anaerobic respiration and only produces 2 STP mols per glucose

causes of muscle fatigue

• The buildup of lactic acid can disable muscle function at the synapse

• Not enough concentration of Na⁺ and K+ due to continuous contraction ( not enough Na+ and K+ to cause an AP across the sarcoma, or even recive an AP )

• Not enough concentration of Ca⁺⁺ to allow the synapse to reset

grip strength

A measure of muscular strength. or the maximin fore/tension generated by one’s forearm

• can be used as a screening tool for the measurement of the upper body strength and overall strength

• Most useful over time to track performance; is considered a consistent measurement of overall strength and upper limb function, bone mineral density, fractures, falls, malnutrition, cognitive impairment, depression, sleep problems ETC

muscle tone

A state of partial tension in muscle fibers that keeps the fiber in a slight, constant state of contraction while the muscle is at rest. SO, even if our muscles are relaxed, they have tone, which aids in support, as seen in postural muscles that keep us upright

muscle strength

Different from muscle tone, which is the muscle’s ability to contract and generate force. Therefore, when we speak of muscle strength, muscle fibers are no longer considered in a resting state

cardiac muscle

found only in the heart, when it contracts, blood circulates, delivering to cells and removing cell waste

smooth muscle

Located in the wall so hollow organs, such as the intestine, blood vessels or lungs. Contraction of these muscles changes the internal diameter of hollow organs and is thereby used to regulate the passage of material through the digestive tract, control blood pressure and flow, or regulate airflow during the respiratory cycle

skeletal muscles

Derives its name from the fact that it is usually attached to the skeleton; contraction of skeletal muscle moves one part of the body relative to another, as in flexing the forearm. Contraction of several skeletal muscles in a coordinated manner moves the entire body in its environment, as in walking or swimming

The primary function of muscle, regardless of its kind, is to

convert chemical energy into mechanical work, and in doing so shorting and elongating the muscles

the size of the motor unit arranfement if a skeletal muscle is determined by it

function and location in the body

The smaller the size of the muscle motor units

The greater the number of neurons needed for control of that muscle, and the greater the degree of control the brain has over the extent of the shortening

( ex, fingers have very small motor units, allowing precise control, whereas the spine has very large motor units )

tonus

The constant state of slight tension that serves to maintain the muscle state of readiness

• caused by an alternate periodic activation of a small number of motor units within the muscle by motor centers in the brain and spinal cord

Smooth muscle movements are produced through

graded muscle contraction of the skeletal muscles

grading

means changing the strength of muscle contraction or the extent of shortening in proportion to the load placed on the muscles, allowing skeletal muscle to react to different loads accordingly

electromyography

the detecting, amplification and recording of changes in skin produces by underlying skeletal muscles ( recorded through an electromyogram ( EMG) )