A&P 3.4 (types of contractions, development, and disease diseases)

muscle fiber contraction is “____”

All or none

different degrees of skeletal muscle shortening

Graded responses

graded responses can be produced by changing two factors:

1. The frequency of muscle stimulation

2. The number of muscle cells being stimulated at one time

types of graded responses

• Single brief contraction

• Not a normal muscle function

twitch

types of graded responses

• One contraction is immediately followed by another

• The muscle does not completely return to a resting state

• The effects are added

tetanus (summing of contractions)

types of graded responses

• Some relaxation occurs between contractions

• The results are summed

• ex labor contractions

unfused (incomplete) tetanus

types of graded responses

• No evidence of relaxation before the following contractions

• The result is a sustained muscle contraction

fused (complete) tetanus

muscle force depends upon the number of ____ stimulated

Fibers

more fibers contracting results in greater muscle _____

Tension

muscles can continue to contract unless they run out of ____

Energy

• Myofilaments are able to slide past each other during contractions

• The muscle shortens and movement occurs

Isotonic contractions

• tension in the muscles increases

• The muscle is unable to shorten or produce movement

Isometric contractions

• movement that results when muscles contract

• ex contraction of biceps during elbow flexion

Concentric movements

• movement that results when muscles lengthen

• ex relaxation of the triceps during elbow flexion

eccentric movements

• some fibers are contracted, even in a relaxed muscle

• Different fibers contract at different times

• The process of stimulating various fibers is under involuntary control

muscle tone

_____ increases muscle size, strength, and endurance

Exercise

_____ (_____) exercise results in strong stronger, more flexible, muscles with greater resistance to fatigue

• makes body metabolism, more efficient

• Improves digestion and coordination

Aerobic (endurance)

_____ (____) exercise increases muscle size and strength

Resistance (isometric)

only_____ reflex movements are seen in infants

Gross

as the ____ system matures babies gain more control of ____ muscle movement

Nervous

Fine

skeletal muscle continues to develop throughout childhood and reaches its peak by _____

Mid adolescence

muscles become more ______ as we age because the amount of _____ tissue increase increases in the amount of ____ tissue decreases

Stringy

Connective

Muscle

muscle____ & ____ also decrease with age

Mass & strength

• A sudden involuntary contraction of one or more muscles

• Maybe be caused by: overuse of a muscle, dehydration, muscle strain, or holding a position for a prolonged period

Muscle cramp

• muscle strain muscle pull or a muscle tear refers to damage to a muscle or attaching tendons

• Damage is in the form of tearing (part or all) of the muscle fibers and attached tenants

muscle pull

• if the nerve supply to a muscle is destroyed, the muscle is no longer stimulated and becomes paralyzed

• The muscle will soon become flaccid (soft and flabby) and eventually atrophy

Paralysis

strains tears and inflammation are types of _____ injuries

Tendon

tendon sheath injuries or inflammation

Tendinitis

positional issues

subluxation

muscle fascia ____

tears

protein that protects muscle cells from bodies, destructive metabolic processes

Dystrophin

A genetic disorder characterized by progressive muscle, weakness, and degeneration, causing muscle fibers to breakdown and weaken overtime

Muscular dystrophy