NSCA CHAPTER 1:

STRUCTURE AND FUNCTION OF THE MUSCULAR, NERVOUS, AND

SKELETAL SYSTEMPower point made by Reece Hobday and Anthony Lord

INTRO TO THE MUSCULAR 3 types of muscle tissue Cardiac Muscle- makes up walls of heart, involuntary muscle Smooth Muscle, lines internal organs, also involuntary as well Skeletal Muscle- muscle that attaches to the skeleton via tedons,

not involuntary

Muscle fibers. Myofilament- myofibril, fibers, fasciclus All are key to making a muscle work

Myofilament- the filaments of myofibrils constructed from proteins. The principal types of muscle are striated muscle, obliquely striated muscle and smooth muscle. Various arrangements of myofilaments create different muscles.

Myofibrl- element that allows muscles to contract, made of 2 proteins- actin & myosin (which make up the myofilament.

Muscle fiber- structural component of skeletal muscle. Cylindrical cell that contains hundreds of nuclei

Fascicles; where muscle fibers are grouped into different sized bundles that compose muscles, grouped together into Epimysium that attach to tendons. Which cling to bones.

FIBER TYPES Fast twitch- type II- Ability to generate rapid, and powerful muscle

reactions. Type of muscle for football players Slow-Twitch- Type I- involved in energy production for prolonged

activity- long distance runners

SLIDING FILAMENT THEORY The Myofilamnets don’t actually change length at all. The

sarcomere shortens (concentric action- when a mucle overcomes a load and shortens like bicep curls) or lengthening (eccentric action- when mucles cannot develop sufficient tension and is overcome by and external load and progressively lengthes like walking down stairs) which results in force

Energy comes from the body breaking down ATP

STUDY QUESTION #1 Which of the following is the correct sequence of components from

the smallest muscle structure to the largest muscle structure?A. Fascia, Perimysium, Epimysium, and EndomysiumB. Myofilament, Myofibril, Fiber, and FasciculusC. Endomysium, Epimysium, Perimysium, FasciaD. Muscle Cell, Fasciculus, Myofibril, Fiber

STUDY QUESTION #1 ANSWER B: Myofilament, Myofibril, Fiber, and Fasciculus Page 5- Myofibrils are the elements of skeletal muscle that allows

the muscle to contract. Myofibrils consist of two proteins, actin and myosin which are referred to as myofilaments.

The structural component of the skeletal muscle is the muscle fiber. The fasciculus contains up to 150 muscle fibers.

STUDY QUESTION #2 Which of the following describes the properties of Type I and Type II

muscle fibers?Type I Type II A. High Force Slow Speed B. Fast Speed High Endurance

C. High endurance High Force D. Slow Speed Low Force

STUDY QUESTION #2 ANSWER C: High Endurance, High Force Page 10- Fast twitch (type 2) and slow twitch (type 1) are

differentiated by their metabolic and contractile properties. Fast twitch fibers generate rapid, powerful muscle actions. These

fibers have a speedy level of calcium ion release, and a high level of myosin.

Slow twitch fibers are involved in energy production for prolonged aerobic activities these fibers have a slower calcium ion handling capability and a lower level of myosin.

STUDY QUESTION #3 Which of the following changes in muscle length and tension are

associated with a muscle spindle and Golgi tendon? Muscle Spindle Golgi Tendon Organ A. Rapid Muscle Length Change Increase in Muscle Tension B. Decrease in Muscle Tension Slow Muscle Length Change C. Slow Muscle Length Change Decrease in Muscle Tension D. Increase in Muscle Tension Fast Muscle Length Change

STUDY QUESTION #3 ANSWER A: rapid muscle length change, increase in muscle tension Page 14- Muscle spindles Provide sensory feedback concerning the

length change and the speed of length change of muscle fibers. Golgi tendon organs recognize changes in the tension in the

muscle.

STUDY QUESTION #4 Which of the following is true regarding bone health?I. Decrease bone material density is related to an increase risk of fractureII. The most common sites for fracture are the humorous, tibia, and femurIII. Bone material density is promoted by chronic participation in a physically-

active lifestyleIV. Exercise may be beneficial in fractures by decreasing the concentration of

osteocytes A. I and III onlyB. II and IV onlyC. I, II, and III onlyD. II, III, IV only

STUDY QUESTION #4 ANSWER A: I and III only Page 16- Bone resorption means loss of a substance, specifically

bone tissue. In elderly people, bone respiration is greater that bone formation. Resulting in loss of bone mineral density.

Bone mineral density is highly related to long- term physical activity

Exercise may be beneficial in preventing fractures by increasing strength

APPLIED KNOWLEDGE