Test #1: Muscle Physiology & Muscle Actions of the Lower Extremity Flashcards
What is a by-product of Glucose metabolism?
ATP (adenosine triphosphate)
Where is ATP stored?
Skeletal muscle
How much and for what purpose is ATP stored in skeletal muscle?
Small amounts to initiate contraction.
How many seconds does this initial amount of ATP fuel activity?
About 6 seconds
Once the initial small amount of ATP is depleted, what must occur for muscle contraction to continue?
New supplies of ATP must be regenerated
What is a secondary source of energy in skeletal muscle after the 6 seconds of ATP is depleted?
Creatine Phosphate (CP)
How many seconds does Creatine Phosphate fuel activity?
About 20 seconds
Once the Creatine Phosphate is depleted, what must occur for muscle contraction to continue?
More energy must be generated
How many pathways for generating energy for skeletal muscle?
2 pathways
What are 2 pathways for energy to be generated for skeletal muscle?
- Aerobic respiration; and 2. Anaerobic respiration
Aerobic Respiration
a. Requires O2
b. In Mitochondria
c. Is a slow process
d. High yield of ATP (36 molecules)
e. No lactic acid
f. Glucose + O2 > CO2, H20 + 36 ATP
Anearobic Respiration
a. Does not require O2
b. In Cytosol
c. Is a fast process
d. Low yield of ATP (2 molecules)
e. Lactic acid is a by-product
f. Glucose > Pyruvic Acid + 2 ATP; Pyruvic Acid > Lactic Acid + H+
How quickly is lactic acid reused within the body?
30-60 minutes after activity
Liver (converts back to glycogen)
Heart or Kidneys (uses as fuel)
Sweat it out
During activity, what is the cause of muscle burn?
Lactic acid and hydrogen ions (H+) from anaerobic respiration.
What is muscle pain the day after an activity?
Delayed Onset Muscle Soreness (DOMS)
How long after an activity for DOMS?
12-24 hours
What is the cause of DOMS?
Microtears in connective tissue or muscle tissue.
What is muscle fatigue?
Occurs when a muscle is no longer able to contract even though it’s stimulated to do so.
How many causes for muscle fatigue?
3 causes
What are the 3 causes for muscle fatigue?
- Lack of oxygen; 2. Change in Ph; and 3. Electrolyte Imbalance
Muscle Fatigue: Lack of O2
A lack of O2 forces the use of anaerobic pathway which builds lactic acid.
Muscle Fatigue: Change in Ph
Lactic acid gives off Hydrogen ions (H+); this greatly lowers Ph which irritates muscle physiology.
Muscle Fatigue: Electrolyte Imbalance
Sodium (Na), Potassium (K) and Calcium (Ca) need to be in proper balance or muscles cannot contract.
Muscle Contraction: All or none principal
When a skeletal muscle cell is stimulated to contract it contracts fully or not at all.
Muscle Contraction: Motor unit recruitment (grades of contraction)
The more work a skeletal muscle does the more motor units. If a skeletal muscle does less work it will have fewer motor units. Range is 4-700; average is 150 per muscle.
Muscle ContractIon: How many types?
2 types
What are the 2 types of muscle contraction?
- Isotonic; and 2. Isometric
Muscle Contraction: Isotonic
A contraction where there is a visible change in the length of muscle.
How many types of Isotonic muscle contraction?
2 types
What are the 2 types of isotonic muscle contraction?
- Concentric; and 2. Eccentric
Isotonic Muscle Contraction: Concentric
The muscle shortens as it works.
Isotonic Muscle Contraction: Eccentric
The muscle lengthens as it works.
What type of isotonic muscle contraction creates the most injury?
Eccentric
Muscle Contraction: Isometric
A contraction of a muscle where no visible change in length occurs.
What is an example of an isometric muscle contraction?
Pushing against a wall
How many different muscle tones are there?
7 muscle tones
What are the 7 muscle tones?
- Normal tone; 2. Hypotonia; 3. Flaccid; 4. Hypertonia; 5. Spasticity; 6. Atrophy; and 7. Hypertrophy
Muscle Tone: Normal tone
A skeletel muscle which displays a healthy resistance to active or passive stretch at rest.
Muscle Tone: Hypotonia
A decrease in muscle tone due to inactivity or pathology.
Muscle Tone: Flaccid
An extreme case of hypotonia. The muscle has become “flabby”.
Muscle Tone: Hypertonia
An increase in muscle tone to rigidity. Unhealthy! Blood flow slowly causing ischemia (a lack of O2 in the tissue due to a decrease in blood supply).
Muscle Tone: Spasticity
Muscle contracts involuntarily due to a nervous system problem. Massage Therapy is indicated!
Muscle Tone: Atrophy
A “wasting away” of muscle. Muscle shrinking in size.
Muscle Tone: Hypertrophy
An increase in muscle size due to exercise (body builders).
How many types of mechanical levers?
3 types
What are the 3 types of mechanical levers?
- First Class Lever; 2. Second Class Lever; and 3. Third Class Lever.
1st class lever
The joint lies between the muscle and the load. This is the most efficient class of lever.
i.e. Tilting head via atlas and occipital bones.
2nd class lever
The load lies between the joint and the pulling muscle.
i.e. The only example in the human body is the “toe raise”
3rd class lever
The muscle lies between the joint and the load. This is the most common class of lever (but not the most efficient).
i.e. Bicep curl
How many benefits of massage therapy on the muscles?
5 benefits
What are the 5 benefits of massage therapy on muscles?
- Improved range of motion; 2. Improved general tissue flexibility and muscle relaxation; 3. Reduction of muscle cramps and spasms; 4. Relief of myofascial trigger points and neuromuscular tender points; and 5. Reduction of adhesions and enhanced collagen remodeling during healing cycle
Agonist
Is the muscle doing the action; the prime mover.
Antagonist
Is the muscle doing the opposite action; or yielding to the agonist
Synergist
Is any muscle which is considered a “helper” to the agonist by performing the same action
Stabilizer or Fixator
Is a muscle which acts to stabilize the origin of the agonist.
How many joints in the lower extremity?
3 + 1 = 4 joints
What are the 4 joints of the lower extremity?
- Hip; 2. Knee; and 3. Ankle + 4. Waist
How many movements possible at the waist joint?
1 movement
What is the 1 movement at the waist joint?
- Flexion
What body part is moved at the waist joint?
The trunk or torso
How many muscles create flexion of the trunk at the waist?
1 muscle
What muscle creates flexion of the trunk at the waist?
- Psoas Major
Psoas Major*
GL: Abdominal/Pelvic Cavity, Deep
O: Bodies, discs and transverse processes of the lumbar vertebrae
I: Lesser trochanter of the Femur