musculoskeletal physiology Flashcards
organic components in bone
collagen, mineral elements
bone includes ___% of calcium storage in the body
98
bones have vascular structures; they can
heal themselves, dynamic, changing
component of bone: ___% calcium
37
component of bone: ___% phosphate
17
component of bone: ___% carbonate
10
component of bone: ___% collagen
33
component of bone: ___% potassium
1
component of bone: ___% sodium
1
component of bone: ___% magnesium
1
when daily calcium intake is insufficient, calcium stores are compromised and ____ declines over time
bone mineral density
low BMD leads to
osteopenia
if osteopenia is untreated, it leads to
osteoporosis
osteoporosis
bone disease which causes skeletal structures to become brittle and fragile
osteoporosis can lead to
fractures, disability
2 segments of skeleton
axial, appendicular
axial skeleton
skull, hyoid, vertebral column, rib cage
appendicular skeleton
limbs and respective girdles
bone length increases until
cartilage is ossified in the epiphyseal plates
peak bone mass is attained at age
18
transverse cartilage plates located near the end of long bones
epiphyseal plate
epiphyseal plates are responsible for
increases in vertical growth during childhood/adolescence
long bones
arms and legs
short bones
hands and feet
irregular bones
vertebrae
flat bones
scapula
BMD can be improved until age
30
___, ___, ___ factors dictate the rate of decline of BMD; ____ is a key indicator
genetics, behavior, lifestyle
muscle strength
is there supporting evidence that weightlifting is dangerous to children
no
bone stress during play (jumping/landing) indicates ___ stress when compared to controlled weightlifting performed with 10RM resistance
greater
intersection of two bones
joint
3 major types of joints
fibroid, cartilaginous, synovial
synovial joint
uses synovial fluid to reduce frictional stresses and allow for considerable movement between the associated articulating bones
joints of the appendicular skeleton are mostly _____ joints
synovial
plane joint
allows bones to slide past eachother
plane joint examples
midcarpal, midtarsal
pivot joint
allows rotation around an address
pivot joints are found in
neck and forearm
hinge joint
allows extension and retraction
hinge joints are found in the
knees, elbows, fingers, toes
condyloid joint
similar to ball and socket, less movement
the ___ is a condyloid joint
wrist
saddle joint
movement back and forth and up and down
only saddle joint in the body
thumb
ball and socket joint
radical movement in almost any direction
ball and socket joints are found in the
shoulders and hips
ligaments and tendons assisting providing
structural support to strengthen joints
ligament
support internal organes, holds bone to bone
tendon
muscle to bone
3 types of muscle tissue
skeletal, cardiac, smooth
fibrous CT that encapsulates full muscles as well as bundles of fibers
muscle fascia
provide muscle shape and regulates tension/transfer of force across joint
muscle fascia
nerve information is carried via
action potential
wave-like electrical charge in a cell membrane that signals the cascade of events leading to a muscular contraction
action potential
action potential current travels to
motor neurons, connect to specific fibers
motor unit
motor neuron and all the muscle fibers it innervates
sliding filament theory: an action potential travels down ____ to stimulate the ____ to release calcium ions, which unlocks the bond between actin and troponin
t tubules
sarcoplasmic reticulum
sliding filament theory: when troponin is moved due to calcium activity, ___ can attach to ___ forming a cross bridge via its myosin head
myosin, actin
ATP is split at the ____ attachment site, which releases energy and allows the ___ head to pull the ___ to shorten/contract the muscle fiber
myosin-actin
myosin
actin
principle that says a muscle fiber is either in a state of producing max tension or not producing any tension
all or none principle
two types of motor unit firing patterns
synchronized, asynchronous
synchronized firing
employed during high-output demands involving fast-twitch fibers and warranting significant fiber recruitment
employed during endurance activities involving slow-twitch fibers which conserve motor unit potential, allowing prolonged work
asynchronous firing
agonist-antagonist relationships help facilitate smooth
force production
agonist-antagonist relationship
one muscle contracts while the muscle on the opposite side of the joint relaxes
agonist
muscle that contracts/shortens during a given exercise
antagonist
muscle that relaxes and lengthens during a given exercise to accommodate contraction of the agonist
tension remains constant while joint angles change
isotonic
concentric
occurs during the acceleration phase of a lift as the muscle shortens
eccentric
occurs during the deceleration phase of a lift as the muscle lengthens
isometric
tension is created but no joint angle changes
isokinetic
involves a constant speed of movement
type I muscle fiber
slow twitch oxidative
_____fibers are suited for prolonged aerobic work, highest capillary and mitochondrial densities
type 1
type IIA fibers
fast-twitch, oxidative-glycolytic
type IIA fibers posses ______ capabilities
intermediate power output
_____fibers provide support during intense strength/power work and prolonged exercise
type IIA
type IIX fibers
fast-twitch glycolytic
which fiber has the highest power output
IIX
____fibers provide support during intense strength/power activities
type IIX
principle that says muscle fiber types are recruited sequentially based on their size and force output capacities
size principle
order of size of muscle fibers
type I–>IIA–>IIX
postural muscles maintain higher concentrations of type
I
example of muscle with type I
soleus
movers tend to have greater type ___ concentration
II
example of muscle with type II
biceps
muscles with greater quantities of type II fibers experience greater changes in response to
hypertrophy training
which of the following is NOT a type of muscle tissue found in the body
a. Rigid muscle
b. Cardiac muscle
c. Smooth muscle
d. Skeletal muscle
a
Which of the following helps to prevent osteoporosis?
a. Weight-bearing activities
b. Adequate calcium intake
c. Adequate vitamin D intake
d. All of the above
d
Which of the following is released from the sarcoplasmic reticulum to facilitate a muscle fiber contraction?
a. Magnesium
b. Calcium
c. Iron
d. Sodium
b
Which of the following is the antagonist muscle during a seated leg extension?
a. Quadriceps
b. Calves
c. Hip flexors
d. Hamstrings
d
Which of the following contraction types occur during the acceleration phase of a given lift and causes joint angle and muscle shortening?
a. Eccentric
b. Isokinetic
c. Isometric
d. Concentric
d
Which muscle fiber type has the greatest resistance to fatigue?
a. Type I
b. Type IIA
c. Type IIX
d. Type III
a
Which muscle would have the highest percentage of slow-twitch fibers?
a. Biceps
b. Quadriceps
c. Pectoralis
d. Soleus
d
bones contain 98% of ___ storage in the body
calcium
bone length increases until cartilage is ossified in the ____ of long bones
epiphyseal plates
to increase force production in a muscle motor unit firing rate, ___, and/or synchronicity must be increased
recruitment
True or False? Ligaments attach muscles to bones while tendons attach bones to bones within a joint.
false
True or False? Concerns have been raised over weightlifting performed by children due to the potential risk of damage to epiphyseal plates, but there is no clear evidence supporting this theory
true
True or False? Based on the size principle, type IIA fibers are generally recruited first during an exercise due to their metabolic versatility
false
Identify at least three types of bones found in the human body
long bone
short bone
irregular bone
flat bone
identify at least three types of synovial joints in the body
plane
pivot
ball and socket
hinge
condyloid
