Chapter 9 PART 2
Slow twitch red fibers
Also known as Type 1 fibers
Fast twitch white fibers
Also known as Type 2x fibers
Fast switch Red Intermediate type
Also known as type 2a fibers
Slow twitch red fibers
Are red because of the increased umber of hemoglobin and myoglobin that are a result of the many capillaries
Lockjaw
Caused by toxic bacteria which causes complete tenting in jaw, neck, and respiratory muscles
All the individual fibers in single motor unit must contract once or not at all. However, when a muscle contracts, sometimes only a few motor units that innervate a muscle may contract. When this happens, there is not as strong of a contraction. However, when Multiple motor units contract at once, you get a far more powerful contraction than if a single motor unit was contracting on its own. The number of motor units that contracted is based on the sensory input the brain receives. If your sensory info tells the brain you need to lift a pillow, this is going to cause a lot fewer motor units to contract than the sensory info telling your brain you want to lift a car.
Compare the "All or Nothing" principle of muscle cells/fibers with the graded strength principle of entire muscle contraction.
Fast switch Red Intermediate type
Contain a mix of the characteristics of both fast and slow twitch fibers
Muscle contracts, then suddenly relaxes
Define twitch
1. In muscle atrophy, the size of a muscle is decreased due to a decrease in the amount of Myosin and Actin inside of muscle cells. 2. Muscle atrophy will result in weaker, smaller muscles. 3. Muscle atrophy generally occurs due to a lack of using the muscle for a long period of time
Describe the concept of muscle atrophy?
Fast twitch white fibers
Don't have any mitochondria
The all or nothing principle states that individual muscle fibers in a motor unit either all contract, or none of them contract. There is no way for only "some" muscle fibers within a motor unit to contract while others do not. If one muscle fiber in a in a motor contracts, they all do.
Explain the "all of nothing" principle of muscle cells/fibers
When an exercise requires more Oxygen for muscles than the body is able to breathe in. The lack of Oxygen for muscles results in the build up lactic acid, a lesser ability to create ATP, and a weaker and weaker contraction ability by the muscles. After the intense activity is ceased, Oxygen Debt is the amount of Oxygen needed to get rid of built up Lactate, Replenish Creatine Phosphate, and increase the levels of Oxygen in the body back to normal levels.
Explain the relationship between oxygen debt and muscle fatigue
Fast twitch white fibers
Fatigue very quickly
Slow twitch red fibers
Fibers that are used primarily for aerobic actives like endurance training
After you finish a run, you are still breathing hard because your body is still trying to make up for the Oxygen you used during exercise. This Oxygen will be used to eliminate Lactic Acid which will help eliminate muscle fatigue. This Oxygen will also be used to bring ATP stores that were used back to normal resting levels.
Give an example of oxygen debt and explain its effects.
Fast twitch white fibers
Have less capillaries since there is less of need to supply oxygen
Slow twitch red fibers
Have lots of mitochondria and capillaries
Resistance training; through this, muscles will increase in both power and size
How is hypertrophy usually achieved?
Tetanus
Increased, sustained contractions
Fast switch Red Intermediate type
Most skeletal muscles are made of these fibers
Twitch
Muscle contracts, then suddenly relaxes
Isometric
Muscles are contracting and causing a force, but they are not lengthening or shortening a muscle. No movement of an object is occurring,
Twitch
Rapid single response to one stimulus
Slow twitch red fibers
Resist fatigue and have long contraction times
Oxygen debt
The oxygen needed after exercise to bring body back to regular homeostatic levels.
Where muscle is partially contracted, but not fully. Happens during things like standing or sitting where the muscle contract just enough to hold you upright.
Tonus
Isotonic
Type of contraction where your muscle shortens or lengthens (limb flexes and extends).
Fast twitch white fibers
Used primarily for very quick powerful movements such as hitting a baseball or performing a jump which involve anaerobic ATP production
1. Most human skeletal muscles use this type 2. Contain various combinations of slow twitch red and fast twitch white from muscle to muscle 3. More fast twitch fibers produces a quick response (EX. eye muscles) 4. Slow twitch used more in posture and endurance activities (EX. calf muscles, standing for long periods of time) 5. Number and distribution of fibers is partially determined by genetics
What are 5 characteristics of Fast switch Red Intermediate type?
1. Long contraction time 2. Resist fatigue 3. Perform for long time periods 4. Aerobic ATP production 5. Extensive capillaries 6. More mitochondria 7. Red due to increased myoglobin, hemoglobin, and cytochromes 8. Dark meat
What are 8 characteristics of the Slow Twitch Red Fibers?
1. Partial includes some relaxation 2. Complete has no relaxation due to Temporal summation (stimulus applied again before muscle can relax) and Spatial summation (stimulus at same time but different end plate) 3. Most of our motions are partial tetany; smooth sustained contraction (Calcium remains present as more is added... Ex. biceps flexion) 4. Tetanus or Lockjaw
What are characteristics of Tetanus?
1. Minimal shortening but increased tension in muscle as muscle contraction is counteracted by stretching 2. Amount of tension is determined by the number of fibers involved 3. Muscle training is easy with no equipment, time-saving, boring, and static 4. May tend to raise blood pressure
What are characteristics of isometric contraction
1. Abnormal tonus- rhythmic jerks 2. Indicate fatigue, excitement, anxiety, or fear 3. Brain can initiate to produce heat and warmth 4. "Screws up" sequence of nerve stimulation as it causes exaggerated back and forth pull of stretch reflex
What are characteristics of the contraction, Clonus?
1. Muscle contracts more forcefully in response to same stimulus after is has contracted a few times 2. Due to increased availability of calcium ions and improved internal conditions such as higher temperatures and optimal pH levels
What are characteristics of the muscle contraction, Treppe?
1. Short contraction 2. Increased sarcoplasmic reticulii which increases calcium release 3. Anaerobic ATP production 4. Fewer mitochondria 5. Less capillaries because they are less oxygen dependent 6. Fatigue quickly 7. White meat
What are the 7 characteristics of the Fast twitch white fibers?
Twitch, tonus, clonus, treppe, tentany of tetanus, isotonic, isometric
What are the 7 types of muscle contractions?
1. Normal firmness/tension in muscle (posture) 2. Where muscle is partially contracted, but not fully. Happens during things like standing or sitting where the muscle contract just enough to hold you upright. 3. Occurs during sleep 4. Absent only in deep anesthesia or severe unconsciousness; limp, intent, flaccid 4. Rotating system- a number of fibers in the muscle are contracting while other fibers relax 5. Spindle fibers- stretch receptors; via feedback to brain- modifies stimulus, maintains tone 6. Hypertonic- spastic or rigid muscles 7. Hypotonic- flaccid muscles
What are the characteristics of the contraction, tonus?
1. Contract quickly 2. High myoglobin content 3. Contain many mitochondria and capillaries 4. Fatigue at an intermediate rate 5. Used for actives like walking and sprinting
What are the characteristics that fast twitch red intermediate type share with slow twitch red fibers and fast twitch white fibers?
Treppe
What contraction has the following characteristics? 1. Muscle contracts more forcefully in response to same stimulus after is has contracted a few times 2. Due to increased availability of calcium ions and improved internal conditions such as higher temperatures and optimal pH levels
Tetanus
What contraction has the following characteristics? 1. Partial includes some relaxation 2. Complete has no relaxation due to Temporal summation (stimulus applied again before muscle can relax) and Spatial summation (stimulus at same time but different end plate) 3. Most of our motions are partial tetany; smooth sustained contraction (Calcium remains present as more is added... Ex. biceps flexion)
Clonus
What contraction has the following characteristics? 1. Abnormal tonus- rhythmic jerks 2. Indicate fatigue, excitement, anxiety, or fear 3. Brain can initiate to produce heat and warmth 4. "Screws up" sequence of nerve stimulation as it causes exaggerated back and forth pull of stretch reflex
Tonus
What contraction has the following characteristics? 1. Normal firmness/tension in muscle (posture) 2. Where muscle is partially contracted, but not fully. Happens during things like standing or sitting where the muscle contract just enough to hold you upright. 3. Occurs during sleep 4. Absent only in deep anesthesia or severe unconsciousness; limp, intent, flaccid 4. Rotating system- a number of fibers in the muscle are contracting while other fibers relax 5. Spindle fibers- stretch receptors; via feedback to brain- modifies stimulus, maintains tone 6. Hypertonic- spastic or rigid muscles 7. Hypotonic- flaccid muscles
Treppe
What contraction is the staircase phenomenon- warm up effect?
1. More actin and myosin result in bigger muscle fibers and stronger contractions. This also results in an increase in muscle size. 2. increased mitochondria, sarcoplasmic reticuli, ATP, and CP
What happens in hypotrophy?
Testosterone and growth hormone
What influences hypertrophy in muscles?
A bodybuilder or Power lifter who stops lifting for 6 months will go through a high amount of muscle atrophy. This will result in smaller, weaker muscles.
What is an example of atrophy?
Pushing a wall, performing planks, holding a squat position.
What is an example of isometric contraction?
The loss of muscle
What is atrophy?
Oxygen Debt
What is heavy breathing after an exercise due to?
An increase in muscle mass
What is hypertrophy?
The oxygen needed after exercise to bring body back to regular homeostatic levels.
What is oxygen debt?
The belief behind this principle is that in order to improve in strength or any kind of athletic performance, you must challenge the body. Doing the same workout over and over will eventually lead you to no longer get results. This means increasing repetitions, duration, intensity, or weight in order to improve in a workout.
What is the belief behind the progressive principle overload?
1. Individual cells/fibers decrease in size due to progressive loss of myofibrils (actin and myosin) 2. Nerve innervation occurs causing loss of mass with nonuse of muscle 3. Denervation occurs after 6 months to 2 years of no use as the muscle becomes a quarter of the original size and lost muscle fibers are replaced with fibrous connective tissue
What is the physiology behind why atrophy occurs?
In order for a muscle to grow, strength to be gained, performance to increase, or for any similar improvement to occur, the human body must be forced to adapt to a tension that is above and beyond what it has previously experienced.
What is the progressive principle overload?
Contraction, Muscle shortens, tension constant, pulls tendon, pulls bone, motions results
What is the sequence of steps for an isotonic contraction?
Isotonic
What is the type of muscle training that works all of he muscles over entire range?
Clonus
What muscle contraction is responsible for shivering?
Slow Twitch Red Fibers
What muscle fiber has the following characteristic? 1. Long contraction time 2. Resist fatigue 3. Perform for long time periods 4. Aerobic ATP production 5. Extensive capillaries 6. More mitochondria 7. Red due to increased myoglobin, hemoglobin, and cytochromes 8. Dark meat
Fast twitch white fibers
What muscle fiber has the following characteristics: 1. Short contraction 2. Increased sarcoplasmic reticulii which increases calcium release 3. Anaerobic ATP production 4. Fewer mitochondria 5. Less capillaries because they are less oxygen dependent 6. Fatigue quickly 7. White meat
Fast switch Red Intermediate type
What muscle fiber has the following characteristics: 1. Most human skeletal muscles use this type 2. Contain various combinations of slow twitch red and fast twitch white from muscle to muscle 3. More fast twitch fibers produces a quick response (EX. eye muscles) 4. Slow twitch used more in posture and endurance activities (EX. calf muscles, standing for long periods of time) 5. Number and distribution of fibers is partially determined by genetics
Slow twitch fibers
What type of muscle fibers do elite endurance runners have?
Fast twitch fibers
What type of muscle fibers do elite powerlifters have?
When you push weight during a bench press
What's an example of isotonic contraction?
Isotonic
When force caused from muscle contraction is enough to overcome an opposing force.
Smooth
Which type of muscle can be multi unit whose individual fibers are stimulated motor-end units (eye or hair muscle)
Smooth
Which type of muscle can be single unit sheet that contracts entirely (blood vessels, walls of organs)
Cardiac
Which type of muscle contains intercalated disks made of gap junction that separate fibers (which allows it to contract all at once)
Smooth
Which type of muscle has 1 central nucleus?
Cardiac
Which type of muscle has T-tubules that get larger going into Z-line?
Cardiac
Which type of muscle has fibers that branch and interconnect rather than parallel; network
Cardiac
Which type of muscle has more mitochondria?
Smooth
Which type of muscle has no striations?
Cardiac
Which type of muscle has one centralized nucleus
Cardiac
Which type of muscle has sarcoplasmic reticulii that is present, but less developed
Smooth
Which type of muscle has smaller tapered fibers?
Smooth
Which type of muscle has some fibers attached to z-line?
Smooth
Which type of muscle is innervated (has nerves)?
Cardiac
Which type of muscle is intrinsic-auto rhythmic- external innervation not required- pacemaker is only neural control needed to initiate contraction
Cardiac
Which type of muscle is involuntary?
Smooth
Which type of muscle is involuntary?
Smooth
Which type of muscle is non striated- have thick and thin filaments but not orderly sarcomere arrangement
Cardiac
Which type of muscle is striated?