Chpt. 6 Review Anatomy

What two factors of a muscle are influenced by the pattern of fascicle arrangement of a muscle?

What two factors of a muscle are influenced by the pattern of fascicle arrangement of a muscle?

muscles range of motion and power

What must happen for a skeletal muscle fiber to contract?

As a muscle cell contracts, its sarcomeres shorten and the distance between successive Z lines is reduced As length of sarcomeres decreases, myofibrils shorten as well, resulting in shortening of the cell as a whole

Name the three types of muscle tissue.

skeletal, cardiac, smooth

Name the four most common patterns or arrangement of fascicles within the muscles. Give an example of each type.

Parallel - sartorius Pennate - deltoid Convergent - pectoralis circular - orbicularis

What are the three phases of muscle contraction?

latent period, contraction period, relaxation period

The ability of a muscle to shorten when an adequate stimulus is received is called _______________.

contractibility

Know the four functions of muscles.

movement, maintain posture, generate heat, stabilize joints

Name the two ways that muscles are attached to bones.

Direct and indirect

Name the two ways that muscular contractions can be graded.

increase rapidity of stimulation to produce wave summation

recruitment of larger and larger #'s of motor units to produce multiple motor unit summation

Which division of the nervous system is responsible for stimulation and control of skeletal muscles?

motor neurons of the somatic (voluntary) division

Slow Acting/ Long Duration

Name

Length

Energy Source

Limiting factors

Aerobic respiration

Hours

glucose; pyruvic acid; free fatty acids; amino acids

oxygen debt; availability of glucose; fatty acids

Very fast/ very short duration

Name

Length

Energy Source

Limiting factors

Direct phosphorylation

15 sec

Creatine Phosphate (CP)

availability of CP

Fast acting/ Short duration

Name

Length

Energy Source

Limiting factors

Anaerobic respiration

30-60 sec

glucose

build up of lactic acid; availability of glucose

The muscle tissue, which is striated and voluntary, is known as ______________________.

skeletal muscle

What is meant by the phrase "all-or-none response"?

either all the muscle cells will respond to a stimulation or none will.

The muscle tissue that is striated and involuntary is known as ___________________.

Cardiac

The ability of a muscle to receive and respond to a stimulus is called ____________________.

excitability/irritability

A _____________ _____________ consists of a motor neuron and all of the muscle fibers it supplies.

motor unit

The ability of a muscle to be stretched or extended is known as ______________.

extensibility

The muscle tissue without striations and under involuntary control is known as ______________.

smooth

Muscles that require fine control have _______ motor units, whereas large, weight-bearing muscles have _______ motor units.

small ; large

The ability of a muscle fiber to resume its resting length after it has contracted or has been stretched is known as ________________.

elasticity

What is the sliding filament theory of contraction and how does it work?

the contraction mechanism involves a sliding of the thin (actin) filaments past the thick (myosin) ones so that the extent of myofilament overlap increases.Muscle fibers are stimulated by the nervous system, the cross bridges attach to active sites on the actin (thin) filaments, and the sliding begins.

Each cross bridge attaches and detaches several times during a contraction, acting like a tiny oar or rachet to generate tension and pull the thin filaments toward the center of the sarcomere (contractile unit)

Be able to relate the three phases of a muscle contraction to a graph depicting the force generated during a concentric and eccentric contraction.

concentric = muscle is shortening and loading

eccentric = muscle is lengthening, more force is generated

(both is during period of contraction)

What is the difference between Isotonic and Isometric contraction?

Isotonic contraction is when the muscle shortens when contracted (same tension) ; isometric has no shortening of the muscles upon contraction (same length)

What are the 2 phases of an Isotonic contraction:

Concentric and Eccentric

What are the 3 types of skeletal muscle fibers?

type 1, type 2a, type 2b

What is the characteristics of type 1 skeletal muscle fiber?

red, low intensity but long endurance, lots of mitochondria

What is the characteristics of type 2a skeletal muscle fiber?

red/pink, medium intensity and speed

What is the characteristics of type 2b skeletal muscle fiber?

white, short bursts of speed and strength, largest in diameter