Principles of Strength & Conditioning Exam

how many bones are in the human body?

206

bone functions

to provide leverage, support, and production

can bones by themselves initiate or sustain movement?

no

what body systems are involved in initiating and sustaining movement?

muscular, cardiovascular, respiratory

what skeleton consists of the skull, vertebral column, ribs, and sternum?

axial

what skeleton includes the shoulder girdle, bones of the arms, wrist, hands, pelvic girdle, and bones of the legs, ankles, and feet?

appendicular

what is the vertebral column made up of?

several bones that are separated by flexible disks that allow movement to occur

how many cervical vertebrae?

7

how many thoracic vertebrae?

12

how many lumbar vertebrae?

5

how many sacral vertebrae?

5

how many coccygeal vertebrae?

3-5

connection point between bones

joint

what is attached to bones at each of their ends?

skeletal muscles

how many skeletal muscles?

more than 430

is each skeletal muscle an organ?

yes

what is in a skeletal muscle?

muscle tissue, connective tissue, nerves, blood vessels

muscles are attached to bones by the means of

tendons

limb muscles anatomical terms

proximal and distal

two attachments of trunk muscles

superior and inferior

epimysium

surrounds outer layer of the muscle

perimysium

surrounds a group of muscle fibers/fascicle

endomysium

surrounds individual muscle fibers

what do signals have to pass through in order for muscular activity to occur?

motor units

what is included in motor units?

motor fibers it innervates and motor nuerons

how many muscle fibers are in a single motor unit?

several hundred muscle fibers

where does the signal pass through?

the motor neuron and continues until it reaches the axon terminal

what does the signal cause after it passes through?

an action potential to pass over the sarcolemma and down the T-tubules

where does the action potential expand from?

the T-tubules to the sarcoplasmic reticulum

what is released as the potential passes through the SR?

calcium

what happens after the calcium has been released from the sarcoplasmic reticulum?

the muscle fibers are given the ability to contract

smallest unit of skeletal muscle

sarcomere

what is the thick filament?

myosin

what is the thin filament?

actin

what does the z-line do?

separate sarcomeres

what is the A-band and what does it contain?

dark zone, actin and myosin

what is the I-band and what does it contain?

light zone, actin only

what is the H-zone and what does it contain?

center of the sarcomere, myosin only

what is the M-line?

middle of the H-zone

what theory states that actin filaments slide inward on myosin filaments, pulling the z-lines towards the center of the sarcomere, thus shortening the muscle fiber

sliding filament theory

what occurs as the muscle fiber shortens?

movement

what must be present in order for the sliding filament theory and muscular contraction to occur?

ATP and Calcium

Where is calcium released from?

the sarcoplasmic reticulum

where do signals reach as they pass through the nervous system?

the motor neuron

parts of a motor neuron

dendrite, axon, axon terminals

where does the signal pass onto after the motor neuron?

to the muscle fibers it innervates by initiating an action potential

initiating an action potential is equivalent to

excitation of the sarcolemma

When is calcium released?

when the action potential travels through the muscle fiber until it reaches the sarcoplasmic reticulum

action potential pathway

sarcolemma to T-tubules to sarcoplasmic reticulum

what moves towards what in muscle contraction?

actin moving inward on myosin

what is dependent on the number of muscle fibers within each motor unit?

the extent of control of a muscle fiber

what muscles may have as few as one muscle fiber per motor neuron

muscles that function with great precision like the eyes

what muscles may have several hundred fibers per motor neuron

muscle that require less precision quadriceps

all of the muscle fibers in the motor unit contract and develop force at the same time

all or nothing principle

can we select only certain fibers in a motor unite to contract?

NO

what is a twitch?

early action potential resulting in a short period of activation of the muscle fibers

what happens if a second twitch is elicited before the fiber relaxes?

the forces summate

what is the result of the forces summating?

a force greater than that of a single twitch

what results in greater summation and force?

decreasing the time between twitches

at high frequencies, twitches begin to merge and eventually completely fuse is known as

tetanus

Type I muscle fibers

slow twitch muscle fibers

what fibers produce force slowly and a very fatigue resistant?

slow twitch

Type II muscle fibers

fast twitch muscle fibers

what fibers produce force quickly and fatigue very quickly?

fast twitch

types of type II muscle fibers

Type IIa and Type IIb/x

Type I fibers are

slow oxidative

Type IIa fibers are

fast oxidative

Type IIx/b fibers are

fast glycolytic

two primary factors that control motor unit recruitment patterns

frequency of stimulation and number of motor units activated

proprioception

a conscious awareness of the body in 3D space, knowing the position of body parts without looking

where are proprioceptors located?

within the joints, muscles, and tendons

what are proprioceptors sensitive to?

pressure, tension, and stretch

do proprioceptors have a protective function?

yes

muscle spindles

modified muscle fibers enclosed in a sheath of connective tissue

what information do muscle spindles provide?

information about muscle length and rate of change of length

engagement of muscle spindles results in ____ of the muscle

greater activation

where are golgi tendon organs located?

near the musculotendinous junction

when do golgi tendon organs become activated?

when the tendon is stretched

engagement of the golgi tendon organ (GTO) _____ muscular contraction

detects

A very brief activation of a muscle fiber.

twitch

what proprioceptors cause activation of muscle fibers?

muscle spindles

anaerobic training is characterized by

high-intensity, intermittent bouts of exercise

examples of anaerobic training

resistance training, plyometric drills, speed, agility, interval training

what energy systems does anaerobic training involve?

phosphagen and glycolytic energy systems

what causes motor cortex activity to increase?

intent to produce maximal levels of muscular force and power

examples of motor cortex activity increasing

progressive increase in anaerobic training, learning a new exercise or movement

what units are elevated in recruitment to support force expression after anaerobic training

fast-twitch motor units

the functional unit of the neuromuscular system

motor unit (motor neuron and the muscle fibers it innervates)

what are gains in muscular strength and power generally associated with?

increased muscle recruitment, improved neural firing rates, greater synchronization in timing of neural discharge

The recruitment of motor units is governed by the _____ principle.

Henneman’s size

What is the Henneman’s size principle?

motor units are recruited in an ascending order according to their recruitment thresholds and firing rates

Can an athlete inhibit low-threshold motor units and activate high-threshold motor units in its place?

yes, under certain circumstances

Inhibiting low-threshold motor units and activate high-threshold motor units in its place

selective recruitment

skeletal muscle adaptations following anaerobic training

increases in muscle fiber size, muscle fiber transitions

what do skeletal muscle adaptations result in?

enhanced performance characteristics such as strength, power, and endurance

muscle hypertrophy

enlargement of muscle fiber cross-sectional area

muscle hyperplasia

increase in the number of muscle fibers

the magnitude of hypertrophy is associated with what?

the muscle fiber type (type I and type II)

which type of individual has a greater potential for increasing muscle mass?

those who have larger proportions of Type II fibers

can muscle fiber types change based on training?

yes