Muscular System Flashcards
Shortening of a muscle
Concentric muscle contraction
Lengthening of a muscle
Eccentric muscle contraction
A muscle contraction occurs, but no change in muscle length results
Isometric muscle contraction
Muscle tension remains the same but the length of the muscle changes
Isotonic muscle contraction
Increase in muscle size
Hypertrophy
Decrease in muscle size
Atrophy
Muscle(s) that are primarily responsible for movement around a joint
Agonist
What is an alternate term for agonist muscles?
Prime movers
Muscle(s) that act in opposition to the agonist muscles
Antagonist
List and define the 3 types of muscle tissue
Cardiac muscle - located only in the heart and is solely responsible for contracting/relaxing the heart to pump blood to the lungs and the rest of the body
Smooth muscle - involuntary muscles that surround organs for the purpose of protection against outside forces
Skeletal muscle - any muscle that is neither cardiac nor smooth and provides movement of the body
List and define the 2 types of muscle contractions
Voluntary muscle contractions - are controlled by the central nervous system (CNS) and the origin of the contraction is a conscious thought by the brain
Involuntary muscle contraction - is controlled by the autonomic nervous system (ANS) and occurs without conscious thought
Describe hierarchy of a muscle fiber
Muscle fiber is made up of myofibrils
Myofibrils are made up of sarcomeres
Sarcomeres are made up of actin and myosin
Contractile fiber that runs along the length of a muscle fiber
Myofibril
The ability of a myofibril to contract is due to the .
sarcomere
A unit within the myofibril that is responsible for muscle contraction
Sarcomere
The functional unit of the muscle fiber
Sarcomere
List the types of proteins in a sarcomere and their associated roles
actin, myosin - contractile
tropomyosin, troponin - regulatory
titin, myomesin - structural
and produce a contraction and shorten the sarcomere
Actin
Myosin
and allow or disallow the contractile process to take place
Tropomyosin
Troponin
and keep the contractile filaments (actin and myosin) aligned
Titin
Myomesin
The shortening of the sarcomere, and therefore the muscle contraction, is caused by what is termed the .
sliding filament model
The gain and loss of myonuclei within a muscle fiber is directly related to .
muscle fiber hypertrophy and atrophy
List the 3 roles of satellite cells
Recovery from an injured muscle
Assist in muscle hypertrophy
Maintenance of muscle mass
List and define the 2 connection points of tendons to bones
Origin - where the tendon anchors to a non-moving bone
Insertion - where the tendon attaches to the bone that moves
List the primary classifications of muscle fibers
Fast twitch - Type II-A and II-B
Slow twitch - Type I
Oxidative muscle fiber
Type I
Fast oxidative glycolytic muscle fiber
Type II-A
Fast glycolytic muscle fiber
Type II-B
The degree of hypertrophy is largely determined by .
the type of muscle fiber
muscles produce more lactate than muscles.
Fast-twitch
slow-twitch
Henneman’s Size Principle
The hierarchy that determines which types of muscle fibers are recruited as the intensity of an exercise progress from low to high
When does the central nervous system recruit all three muscle types at the same time?
During explosive-type movements when the intensity is increased over a very short period and to a very high level
A muscle fiber contracts either or .
100%
not at all
What is the degree of muscle contraction based on and not based on?
The number of muscle fibers recruited to perform an action, not the degree of contraction per muscle fiber
Muscle fibers cannot change from Type I to Type II, but the of Type I fibers can increase.
contraction speed
is not a requirement for muscle rebuilding and strength increases to occur
Muscle damage
List and define the 4 primary characteristics of muscle
Excitability - responds to stimuli
Contractibility - shortens in length
Extensibility - stretches when pulled
Elasticity - returns to original shape and length after contraction
List the 3 primary functions of muscles
Heat production
Maintain posture
Movement
Of the three types of muscle tissues, only muscles have voluntary contractions
skeletal
and muscles rely upon the autonomic nervous system (ANS) to provide contractions.
Cardiac
smooth
connect muscle to bone
Tendons
connect bone to bone
Ligaments
What type of cartilage is important for movement?
Hyaline cartilage
Where is hyaline cartilage found and what does is do there?
It is found on the surfaces of most joints and protects the joints while acting as a barrier between bones
List the 5 types of connective tissue
tendons
ligaments
cartilage
labrum
fascia
Where is labrum tissue found and what is its purpose?
It is found around the edge of the shoulder and hip joints.
Its primary purpose is to keep the ball aspect of the humerus and femur within the shoulder and hip sockets
If tension on the fascia is too high, it can cause and as a result of
pain and postural abnormalities
restricted movement
The best way to think of fascia is
a weblike structure that permeates the whole body
A ‒ Pectoralis Minor
B ‒ Deltoid
C ‒ Serratus Anterior
D ‒ Biceps Brachii
E ‒ Brachioradialis
F ‒ Pectineus
G ‒ Adductor Longus
H ‒ Rectus Femoris
I ‒ Vastus Medialis
J ‒ Vastus Lateralis
K ‒ Gastrocnemius
L ‒ Soleus
M ‒ Pectoralis Major
N ‒ External Oblique
O ‒ Internal Oblique
P ‒ Rectus Abdominis
Q ‒ Transverse Abdominis
R ‒ Tensor Fasciae Latae
S ‒ Sartorius
T ‒ Gracilis
U ‒ Peroneals
V ‒ Tibialis Anterior
A ‒ Trapezius
B ‒ Rhomboid Minor
C ‒ Rhomboid Major
D ‒ Triceps
E ‒ Latissimus Dorsi
F ‒ External Oblique
G ‒ Semimembranosus
H ‒ Achilles Tendon
I ‒ Levator Scapulae
J ‒ Supraspinatus
K ‒ Infraspinatus
L ‒ Teres Major
M ‒ Teres Minor
N ‒ Erector Spinae
O ‒ Internal Oblique
P ‒ Gluteus Medius
Q ‒ Gluteus Maximus
R ‒ Semitendinosus
S ‒ Biceps Femoris
T ‒ Gastrocnemius
U ‒ Soleus
List the 5 primary inner core muscles
Multifidus (lumbar)
Pelvic Floor Muscles
Transverse Abdominis (TVA)
Internal Oblique
Diaphragm
What is the primary purpose of the core musculature?
Provide stability and rigidity to the area of the spine and pelvic region
List the 9 primary outer core muscles
Rectus Abdominis
External Obliques
Erector Spinae
Quadratus Lumborum
Iliopsoas (made up of Iliacus and Psoas)
Rectus Femoris
Hip Adductors
Gluteus Maximus
Hamstrings
The primary function of the outer unit muscles is to provide , not .
movement
stabilization
What occurs when the outer core muscles become overactive?
They shut off the inner core muscles which reduces the amount of LPHC stabilization
The inner core muscles are the LPHC stabilizers, and the outer core muscles are the stabilizers.
primary
secondary
3 functions
Internal oblique
movement of diaphragm
rotation
lateral flexion
The internal oblique lies between what 2 muscles?
TVA and external oblique
1 function
Transverse abdominis
lumbar stability
1 function
Diaphragm
increase and decrease in lung size
What 2 cavities does the diaphragm separate?
thoracic and abdominal
1 function
Pelvic floor muscles
stabilize spine and pelvis
superficial - 3 functions
deep - 1 function
Multifidus
lumbar back extension
rotation
lateral flexion
spinal stabilization
The co-contracts with the to provide spinal stability.
multifidus
TVA
1 function
Rectus abdominis
lumbar flexion
3 functions
External oblique
spinal flexion
rotation
lateral flexion
2 functions
Erector spinae/extensor spinae
A - Spinalis
B - Longissimus
C - Iliocostalis
spinal extension
lateral flexion
2 functions
Quadratus lumborum
stabilize the pelvis
lateral flexion
Psoas
Iliacus
What 2 muscles make up the hip flexors?
Psoas
Iliacus
Hip adductors
A - Adductor magnus
B - Adductor Brevis
C - Gracilis
D - Adductor longus
E - Pectineus
F - Iliacus
G - Psoas major
2 functions
Hamstrings
A - Biceps femoris
B - Semitendinosus
C - Semimembranosus
flex the lower leg
extend the femur
2 functions
Rectus femoris
knee extension
hip flexion
1 function
Gluteus maximus
hip extension
3 functions
Quadriceps
A - Rectus femoris
B - Vastus medialis
C - Vastus lateralis
D - Vastus intermedius
extend lower leg
stabilize the knee
hip flexion
2 functions
Tibialis anterior
dorsiflexion
foot inversion
2 functions
Tibialis posterior
plantar flexion
foot inversion
1 function
Soleus
plantar flexion
1 function
Gastrocnemius
plantar flexion
2 functions
Peroneus longus
plantar flexion
foot eversion
2 functions
Peroneus brevis
plantar flexion
foot eversion
2 functions
gluteus medius
hip abduction
hip extension
2 functions
gluteus minimus
hip abduction
hip extension
2 functions
tensor fasciae latae
hip abduction
hip extension
1 function
piriformis
abduction of femur
Piriformis syndrome
When the piriformis tightens, the sciatic nerve may become compressed and induce sciatica
1 function
popliteus
knee flexion
or during running can injure the popliteus.
Overpronation of the foot
hyperextension of the knee
2 functions
sartorius
hip flexion
hip abduction
1 function
pectoralis major
humerous adduction
1 function
pectoralis minor
moves scapula forward and downward
2 functions
latissimus dorsi
shoulder adduction
shoulder extension
1 function
trapezius
move the scapula
1 function
serratus anterior
protract the scapula
1 function
rhomboid major
retract the scapula
1 function
rhomboid minor
retract the scapula
1 function
levator scapulae
elevates the scapula
1 function for each of the 3 muscles
deltoids
anterior - shoulder flexion
posterior - shoulder extension
lateral - arm abduction
List the 4 muscles of the rotator cuff
supraspinatus
infraspinatus
teres minor
subscapularis
1 function
Infraspinatus
external shoulder rotation
1 function
teres minor
external shoulder rotation
1 function
subscapularis
internal shoulder rotation
1 function
supraspinatus
shoulder abduction
1 function
biceps brachii
elbow flexion
1 function
triceps brachii
elbow extension
1 function
brachioradialis
wrist extension
The primary purpose of a warm- up is to
increase one’s core temperature
An increase in core body temperature positively affects the of a runner as well as decreases the
biomechanics
chance of injury such as muscle strains
List 3 areas that a proper warm-up influences
Increased force capacity of a muscle
Decreased chance of injury
Increased range of motion
What is the primary reason for stretching?
increase range of motion around a joint
Stretching a muscle prior to a bout of exercise can
reduce the contractile force of a muscle
An active warm-up of minutes and at an intensity of approximately percent of one’s VO2 max is most beneficial in regard to anaerobic activities
15
65
The benefits gained via an increase in muscle temperature are lost approximately minutes after the warm-up period ends.
15
Fatigue has been shown to alter the biomechanics of the lower extremities, specifically the and in the and planes
knee
hips
sagittal
transverse
Give 2 definitions of eccentric muscle contraction
a muscle is lengthened while contracting at the same time
a muscle contracts to decelerate a limb that has a load applied to it
What does DOMS primarily result from?
eccentric muscle contractions
What is an analogy for an eccentrically contracting muscle?
a brake
What are the 3 most common areas of DOMS for ultrarunners?
hamstrings
calves
quadriceps
List 3 reasons why eccentric contractions cause muscle damage
muscle inflammation due to sub-cellular damage
damage to the excitation-contraction (E-C) coupling system
fewer motor units are involved than during concentric contractions which creates greater stress per muscle fiber
What is the excitation-contraction coupling system?
the link between nerves and muscles
What is one cause of muscle weakness?
a muscle’s inability to activate contractile structures due to the over-stretching of sarcomeres
Passive tension
tension on a muscle that is not caused by a voluntary muscle contraction
What is an alternate term for passive tension?
stiffness
DOMS-related soreness begins to set in hours after the workout/exercise and peaks at around hours post-exercise
6-8
48
The best course of action when dealing with DOMS is and
light, active rest
a light massage
List 2 reasons why should athletes not take NSAIDs
they slow healing of muscles, bones, and tendons
they slow muscle growth by slowing the spread of satellite cells
What causes muscle burn?
a buildup of acidity that is caused by the release of hydrogen ions during the fast turnover of ATP
What is the scientific term for muscle burn?
acidosis
What is the role of lactate in relation to acidosis?
lactate helps buffer and neutralize the hydrogen ions that cause muscle burn
What causes exercise-associated muscle cramps (EAMC)?
muscles being overworked (i.e., fatigue)
kinetic linking
the order in which muscles activate and work together to allow the body to move
What occur when muscle synergy breaks down?
performance is diminished and the potential for injury increases
What is the goal of kinetic linking?
gain a biomechanical advantage and optimize performance by moving the body in the correct pattern
What is the result of a short muscle and/or long muscle?
force production of the muscle will diminish
What are 3 causes of reduced muscle activation?
a muscle is too long or to short
fatigue
muscle co-activation
