Unit 4 Exam
what is the length of the force-time relationship?
20 to 100ms
describe the quadrilateral muscle arrangement
4 sided and usually flat
Which neurons run towards the spinal cord?
Afferent
When a muscle is in a state of tetanus or tetany, why can't there be any more force in the muscle?
All of the actin-myosin cross-bridges that can be formed are formed
How does the stretch reflex work in standing posture?
Alpha efferent sets sensitivity of soleus. Afferent signal sent from soleus to spinal cord. Alpha efferent activates soleus and inhibits tibular anterior
What type of contraction would the elbow extensors be performing when they forcefully lower the paper back to your desk?
Concentric
An antagonist performs what type of contraction?
Eccentric
What type of contraction would the elbow flexors be performing when they slowly lower the paper back to your desk?
Eccentric
If you threw the paper back down to your desk forcefully (faster than gravity would have one it), what muscles were performing that motion?
Elbow extensors
When you lift your paper off of the desk, there is a concentric contraction of your elbow flexors. When you slowly lower the paper back to your desk, what muscles are active?
Elbow flexors
The gastrocnemius performs knee flexion and ankle plantar flexion. If you only want to do plantar flexion, what muscles neutralize knee flexion?
Knee extensors
longitudinal muscles have increased _____ but less _____
ROM, power
The biceps brachii perform shoulder flexion and elbow flexion. If you only want to perform elbow flexion, what muscles neutralize shoulder flexion?
Shoulder extensors
what activates the muscle spindles?
Stretch
When does active stretching usually occur?
Warm up
what is a motor unit?
a single motor neuron and all fibers it innervates
what is extensibility?
ability to be stretched
what is contractility?
ability to generate force
what is excitability or irritability?
ability to react to a stimulus
what is elasticity?
ability to recoil after being stretched
What activates the pacinian corpuscles?
acceleration
What is the role of the alpha efferent?
activate and inhibit muscles
what is the role of the SEC (series elastic component)?
acts as a spring to store elastic energy when tensed muscle is stretched
where is the perimysium located?
around each fascicle
where is the endomysium located?
around each muscle cell
where is the epimysium located?
around entire muscle
Where are the pacinian corpuscles located?
around joint capsules, ligament, tendon sheaths
how is torn intracapsular cartilage repaired?
arthroscopic surgery
what are "assistant mover" muscles?
assist the movement if needed
describe the force length relationship at the level of sarcomere
at optimal resting length, there is optimal myosin binding with actin
describe the force length relationship at the level of the musculotendinous unit
at shorter than resting length, all muscle force comes from fibers. at longer than resting length, some force comes from fibers and some comes from elasticity of passive tissues
what is rheumatoid arthritis?
autoimmune disorder in which immune system attacks synovial joint
Which is more effective - static or ballistic stretches?
ballistic
which utilizes muscle spindles - static or ballistic stretches?
ballistic
what is the sarcomere?
basic unit of contraction of skeletal muscle
What is the spastic response to fast stretch?
beating motion
What is clonus?
beating motion in response to fast stretch
what is myosin?
bonds to actin
what is osteoarthritis?
bones rubbing against each other
What are the treatments for spasticity?
botox or dorsal rhizotomy
what is the z-disc?
boundaries of each sarcomere
what is summation in the effect of repeated stimuli on muscle force?
building tension and force in an additive fashion in response to repeated stimulation
what is an agonist muscle?
causes movement doing concentric contraction
what is the m line?
center of h zone
describe a third degree sprain
complete ligamentous rupture
describe a fourth degree sprain
complete rupture with some small bone fractures
An agonist performs what type of contraction?
concentric
What is the spastic response to slow stretch?
continuous hyperactivation of the muscle
what are the properties of active tissue?
contractibility and excitability
what are t tubules?
deep invagination of the sarcolemma
Where are ruffini endings located?
deep layers of skin and joint capsules
hypertrophy is increase in fiber _______ but not fiber __________
diameter, number
describe the stretch-shortening cycle
eccentric contraction followed by concentric contraction
Which neurons run away from the spinal cord?
efferent
what is the sarcoplasmic reticulum?
elaborate smooth endoplasmic reticulum made of interconnecting tubules
what two musculoskeletal traits does the stretch-shortening cycle take advantage of?
elastic recoil of passive tissues and stretch reflex
what is the role of the CC (contractile component)?
enables tension development by stimulated muscle fibers
why does a muscle cell have endomysium and a sarcolemma around it?
endomysium recoils and stretches while sarcolemma propogates the nerve impulses
what are the properties of passive tissue?
extensibility and elasticity
what type of muscles are typically tonic?
eyes
what is the contraction speed of 2b fibers?
fast
what is the contraction speed of type 2a fibers?
fast
describe the pennate muscle arrangement
feathery in appearance and offers strength without bulk
what is an example of passive insufficiency?
fingers begin curling as hand is extended back
what is the effect of muscle structure on force?
force is proportional to physiological cross section
what is the function of the terminal cisternae?
form cross channels between a and i bands
what is the a band?
full length of thick filament
what muscle arrangement allows for both power and ROM?
fusiform
what is a fascicle?
group of fibers
what is titin?
holds myosin where it needs to be
how are skeletal muscle fibers categorized?
how they manufacture energy and how quickly they contract
what is an example of active insufficiency?
if the wrist is flexed, there is no force in the grip
Where are the GTOs located?
in series in tendon
what is bursitis?
inflammation of the bursa
what is arthritis?
inflammation of the joint
how many fibers per motor unit are in the hand muscles?
less than 100
when would a muscle be on concentrically vs eccentrically when you are also considering the role of gravity in movement?
lifting a laptop up is concentric then bringing it slowly back down is eccentric
what is a sprain?
ligaments reinforcing the joint are stretched or torn
what is active insufficiency?
limited ability to produce force when joint position places muscle on slack
what is passive insufficiency?
limited ability to stretch to the extent required to allow full ROM at all joints crossed
describe the bipennate muscle arrangement
long central tendon with fibers extending diagonally in pairs from either side of the tendon
describe the longitudinal muscle arrangement
long strap like muscle with fibers in parallel to its long axis
what is the effect of obesity on fiber types?
lower type 2b fibers
Define static stretching
maintaining a slow and controlled stretch over time
describe isokinetic contraction
maximum muscle effort at same speed
how does maximum strength affect maximum velocity?
maximum strength when there is low velocity and maximum velocity when there is low strength
What is the function of the pacinian corpuscles?
measure acceleration, rapid movement of joints, joint pressure
what is an example of multipennate muscles?
middle deltoid
describe a first degree sprain
minor tear or stretch
Is standing posture monosynaptic or polysynaptic?
monosynaptic
Is stretch reflex monosynaptic or polysynaptic?
monosynaptic
how many fibers per motor unit are in the quads, gastroc, and hamstrings?
more than 1500
what are the functions of muscle tissue?
movement, maintenance of posture, joint stabilization, heat generation
describe eccentric contraction
muscle lengthens due to external force
what is the PEC derived from?
muscle membranes
describe concentric contraction
muscle shortens and causes movement
what are antagonist muscles?
muscles that slow or stop a movement and do eccentric contractions
what are stabilizer muscles?
muscles that stabilize a body part against another force and do isometric contractions
what makes a muscle have tension in it?
myosin attaches to actin then pulls inward toward center of sarcomere
what is a tonic type muscle?
need multiple stimuli to contract
what comprises a motor unit?
nerve cell body, nerve axon, all muscle fibers innervated by nerve fibers
is hyperplasia possible in humans?
no we do not gain extra fibers but lose some through disease or injury
describe the triangular muscle arrangement
origin of muscle is broad and fascicles converge toward tendon of insertion
What activates the free nerve endings?
pain and temperature
what is subluxation?
partial dislocation of a joint
what is an example of triangular muscles?
pectorialis major
quadrilateral muscles have increased _____ but small ______
power, ROM
What is the role of the gamma efferent?
preset sensitivity when reflexes must be sharp
what are "prime mover" muscles?
primarily responsible for movement
What is the effect of age on fiber types?
progress loss of type 2 fibers
define ballistic stretching
quick, bouncing stretches
what is an example of bipennate muscles?
rectus femoris
what is the i band?
region with only thin filaments
what is a twitch type muscle?
respond to a single stimulus
what are the examples of quadrilateral muscles?
rhomboids, masseter
describe the fusiform muscle arrangement
rounded muscle that tapers at either end
what is the bursa?
sac lubricating the joint
what are the examples of longitudinal muscles?
sartorius and sternocleidomastoid
describe the multipennate muscle arrangement
several tendons are present with fibers running diagonally between them
describe the unipennate muscle arrangement
short parallel and feather like fibers extending diagonally for side of a long tendon
what is the contraction speed of type 1 fibers?
slow
what are each of the components of the engineer's schematic of musculotendinous tissue depicted as?
spirals
what is tetanus in the effect of repeated stimuli on muscle force?
state of sustained maximum tension resulting from repetitive stimulation
Which is safer - static or ballistic stretches?
static
which utilizes gto - static or ballistic stretches?
static
what are neutralizer muscles?
stops unwanted action when more than 1 action occurs and do isometric contractions
Define active stretching
stretching by contracting antagonist muscles
Define passive stretching
stretching by force other than antagonist muscles
what is the role of the PEC (parallel elastic component)?
supplies resistance when a muscle is passively stretched
describe a second degree sprain
tear followed by pain and swelling
What is the function of ruffini endings?
tell joint position and changes in joint angle at rest or in slow movements
what is the role of the ruffini endings?
tell joint position at rest
what is the role of the labyrinthe receptors?
tells position of head with respect to gravity
what is the SEC derived from?
tendons
What activates the GTOs?
tension
What activates the golgi tendon organs?
tension
describe isometric contraction
tension in muscle without change in length
describe isotonic contraction
tension remains constant while muscle shortens or lengthens
what are the examples of unipennate muscles?
tibialis posterior and flexor pollicis longus
describe the force-time relationship
time needed to take the slack out of the tendons
what is dislocation or luxation?
total malalignment of joint
in what species is hyperplasia documented?
turkeys
what are the endurance type of fibers?
type 1 slow twitch oxidative
what are the "in between" type of fibers?
type 2a fast twitch oxidative glycolytic
what are the power type of fibers?
type 2b fast twitch glycolytic
what is gout?
uric acid crystalizes in joint
describe the force velocity relationship
we are strongest eccentrically, in the middle isometrically, and weakest concentrically
what is actin?
what myosin bonds to
What is the function of the GTOs?
when tense, GTOs relax muscles to prevent rupture
what are "synergist" muscles?
work together to cause movement
