Skeletal Muscles Flashcards
Bands of tough, fibrous connective tissue that connects muscle to bone (distal and proximal end)
Tendon
Small bundles of muscle fibers
Fasciculus
Long, multinucleated cell that generates force when stimulated
Muscle Fiber
Portion of muscle composed of thin and thick myofilaments (actin and myosin)
Myofibril
Contractile proteins in muscle = ?
Contractile Proteins in Muscle:
- 1) Actin
- 2) Myosin
What is the role of connective tissue?
- Stabilizes and supports components of skeletal muscle
- Surrounds muscle at each organizational level
What are the 3 layers of connective tissue in muscle?
- Epimysium: covers whole muscle
- Perimysium: covers bundles of muscle fibers (fasciculi)
- Endomysium: covers individual muscle fibers
What phase of movement requires overcoming gravity and/or load = ?
What phase of movement requires overcoming gravity and/or load = Concentric phase
- Concentric phase = Muscle contracts/shortens
What phase of movement requires resisting gravity and/or load = ?
What phase of movement requires resisting gravity and/or load = Eccentric phase
Eccentric phase = Muscle lengthens/elongates; stores energy
Components of a Sarcomere…
- Z-line = ?
- H-zone = ?
- I-band = ?
- A-Band = ?
- M-Line = ?
Components of a Sarcomere:
- Z line: At each end of sarcomere
- H zone: In middle of sarcomere, contains myosin
- I bands: At edges of sarcomere, contain actin
- A band: Overlapping acting and myosin
- M line: Middle of H zone, holds myosin in place
Characteristics of Type 1 fibers include = ?
Type 1 Fibers (slow twitch):
- Slow to reach peak force production
- Low peak force production
- High capacity for oxidative metabolism (lots of mitochondria, higher capillary density, high ATP production)
- Fatigue-resistant
- Endurance performance
Explain about Type 2 (fast twitch) fibers
- Rapidly develop force
- High peak force
- Low capacity for oxidative metabolism
- Fatigue easily
- Sprint, short term performance
(Anaerobic glycolysis, stores more ATP-PC in muscle)
Steps mediating the contraction process
Steps Mediating Muscle Contraction Process:
- Electrical impulse generated at neuromuscular junction
- Impulse spreads across sarcolemma into T-tubules
- Receptors release Ca++ into muscle fibers
- Ca++ binds to troponin
- Tropomyosin uncovers active sites of actin
- Myosin crossbridges heads bind actin, form actomyosin complex
- Heads pull actin toward center of sarcomere (power stroke)
- Force is produced
What is muscle strength?
The amount of force generated by a group of muscles in one contraction
What is muscular endurance?
The ability of a muscle group to contract repeatedly without fatigue
What is hypertrophy?
The enlargement of muscle tissue on a cellular level
Effects of resistance (weight) training include = ?
Effects of resistance (weight) training:
- ↑ in size of muscle fibers
- Results from addition of protein and new myofibrils to existing fibers, making them larger
Effects of muscular endurance training
(-) Increase in delivery of oxygen to muscle, caused by:
- ↑ in number of capillaries per muscle fiber
- ↑ in capillary density
- ↑ in concentration of myoglobin, which ↑ rate of oxygen transport from capillaries to mitochondria
(-) Enhanced ability for aerobic metabolism, caused by:
- ↑ in size and number of mitochondria in muscle
- ↑ in ability to produce ATP
Effects of concurrent resistance and endurance training = ?
Effects of concurrent resistance and endurance training =
(-) Overall ↓ in Anaerobic performance.
- ↓ in both strength & power
- Ability to express power is effected > than strength
Precautions before strength training
- Warm up
- Stretch
- Slowly move on to heavier weights
- Choose the right exercise for you
- Stop if you feel pain
- Proper breathing technique
- Proper body mechanics
5 variables to consider when picking between hypertrophy or strength are = ?
- Exercise selection
- Sets
- Reps
- Intensity
- Rest period
What affects how quickly your muscles reach fatigue?
Intensity
To be effective, the intensity you select needs to be what?
Intensity needs to generate stress, while allowing you to do enough reps to reach fatigue.
Strength:
- Rep range = ?
- Intensity = ?
Strength:
Higher levels of intensity, meaning that you will typically gain the most strength when performing…
- 1-5 reps
- 85-100 % 1RM
Hypertrophy:
- Rep range = ?
- Intensity = ?
Hypertrophy: High reps, lower level of intensity
- 6-12 reps
- 75-85 % of 1RM
Hypertrophy:
- Rest interval = ?
Hypertrophy:
- Rest interval = 2-5 min.
- Too long a rest period may prevent the hypertrophic effect from occuring
Strength training
- Rest interval = ?
Strength Training:
- Rest interval = 2-6 min.
- Without sufficient rest, you won’t be able to complete the necessary intensity needed to gain strength
Hypertrophy
- Optimal set range = ?
Hypertrophy
- Optimal set range = 4-8 / exercise
Strength Training:
- Sets / Exercise = ?
Strength Training:
- Sets / Exercise = 4-7
Magnitude of training effect is determined by = ?
Magnitude of training effect is determined by = Volume Load
- Volume Load = Set x Rep x Load
