Ch 1 structure and function of body systems Flashcards
skeletal muscles are under the control of which part of the brain?
cerebral cortex
the musculoskeletal system is comprised of…
muscle, bones, joints, tendons
muscles can only — not —
pull, not push
there are approximately —-bones in the body
206
the axiel skeleton consists of —
skull (cranium) vertebrae ribs sternum
the appendicular skeleton consists of —
shoulder girdle arms pelvic girdle legs
fibrous joints (movement)
very little/none (skull sutures)
cartilaginous joints (movement)
limited (disks)
synovial joints (movement)
very mobile
articulating bone ends are covered with —-
hyaline cartilage
types of joints that rotate about one axis
uniaxial
types of joints that rotate about two axes
biaxial
types of joints that rotate about three axes
multiaxial
number of vertebrae 1) cervical 2)thoracic 3)lumbar 4)sacrum 5)coccyx
cervical = 7 thoracic = 12 lumbar =5 sacral = 5 fused coccyx = 3-5 fused
each skeletal muscle is an organ that contains —–
muscle tissue connective tissue nerves blood
Epimysium covers (1) and is continuous with (2)
1) muscles 2) tendons
tendons attach to the bone
periosteum
what are fasciculi?
bundles of muscle fibers
endomysium in continuous with —
the sarcolema
epimysium, perimysium, and endomysium are continuous with —-
the tendon
the junctions between a motor neuron and the fibers it innervates
motor end plate/ neuromuscular junction
each muscle cell has only one
neuromuscular junction
a motor neuron and the fibers it innervates
motor unit
sarcoplasm is the —-
cytoplasm of a muscle fiber
sarcoplasm contains —-
contractile proteins (actin/myosin) other proteins stored glycogen and fat particles sarcoplasmic reticulum mitochondria enzymes
draw a muscle
draw a motor unit
Thick contractile filaments
Myosin
thin contractile filaments
actin
myosin
a pair of myosin filaments form a —–which interacts with —–
crossbridge which interacts with actin
actin and myosin are orginized longitudinally in the smallest contractile unit of skeletal muscle, the —
sarcomere
M-bridge
where adjacent myosin filaments anchor to eachother
Z-line
where actin filaments are anchored
how many actin filaments surround one myosin filament?
6
how many myosin filaments surround each actin filament?
3
A-band
corresponds with the alignment of the myosin filaments
I-band
corresponds with areas in two adjacent sarcomeres that contain only actin filaments
Z-line
the middle of the I-band
H-Zone
area in the center of the sarcomere where only myosin is present
the H-zone —- during muscle contraction
decreases
the I-band —- during muscular contraction
decreases
sarcoplasmic reticulum: where, what does it store?
system of tubules which terminate around the Z-line, store calcium
the regulation of —- controls muscle contraction
calcium
T-tubules
transverse tubules: run perpendicular to the SR (sarcoplasmic reticulum)
calcium is released to all surface depths of a muscle….producing a ….
at the same time, producing a coordinated contraction
draw the sliding filament theory
the sliding filament theory states:
actin filaments at each end of the sarcomere slide toward the center of the sarcomere, pulling the Z-lines towards the center of the sarcomere, shortening the muscle fiber
only a small displacement of the actin filament occurs with each flexion of the myosin crossbridge, so….
very rapid, repeated flexions must occur in many crossbridges throughout the entire muscle for measurable movement to occur.
troponin
a protein that sits on the actin filament
for muscle contraction to occur, calcium must bind with
the troponin that sits on the actin filament
troponin and calcium binding activates
tropomyosin
tropomyosin allows for
a strong bond between actin and myosin
the amount of force produced by a muscle at any given time is directly related to
the number of myosin crossbridges bound to actin filaments cross-sectionally at that instant in time.
power stroke def.
the energy for pulling action during muscle contraction
hydrolysis def.
breakdown of ATP (adenosine triphosphate) to ADP (adenosine diphosphate)
hydrolysis is catalyzed by the enzyme…
myosin adenosine triphosphatase (ATPase)
Contraction phase of muscle contraction
when hydrolysis happens and ATP is converted to ADP through the enzyme ATPase
Recharge phase of muscle contraction
the process of contraction phase plus another ATP molecule replacing the ADP on the myosin crossbridge to allow temporary relaxation for another contraction
relaxation phase of muscle contraction
stimulation of nerve stops, calcium is pumped back in to the SR which prevents the link between actin and myosin filaments.
type of signal that comes from motor neurons
electrochemical signals from spinal cord to muscle
action potential def
when a motor neuron fires an impulse
muscles that must function with great precision have motor units that innervate….
as few as one muscle fiber
Muscles that produce large, gross movements have motor neurons that innervate….
many (several hundred) fibers
action potential def
electric current that flows along a motor neuron
an action potential is not capable of….
directly exciting muscle fibers. The motor neuron excites the muscle fiber(s) that it innervates by chemical transmission.
arrival of the action potential at the nerve terminal causes release of…
acetylcholine, which diffuses across the neuromuscular junction, cuasing excitation of the sarcolemma.
the all or none principle of muscle
if there is a motor neuron stimulus, all innervated fibers will contract; a stronger action potential cannot create a stronger contraction.
twitch
a brief muscle contraction
if multiple action potentials cause multiple muscle twitches…
the force of the twitches summates and the resulting force is greater than that produced by a single twitch
tetanus
when twitches happen so rapidly that they merge and completely fuse; this is the maximal amount of force the motor unit can develop.
classification of muscle fibers by twitch time
slow twitch and fast twitch
fast twitch muscle/ motor unit
develops force and also relaxis rapidly
slow twitch muscle/motor units
develop force and relax slowly, long twitch time
type 1 fibers
slow twitch
type IIa fibers
fast twitch
type IIx fibers
fast twitch
type I fiber characteristics
high capacity for aerobic activity
withstand fatigue
limited force development (low myosin ATPase activity
type II fiber characteristics
inneficient, fatigue quickly
rapid force development
high anaerobic output
high myosin and ATPase activity
Difference between type IIa and type IIx fibers
type IIa have greater capacity for aerobic metabolism, more capillaries surrounding them, greater resistance to fatigue
motor unit recruitment patterns are graded from less to more force…
in two ways:
1) variation in twitches
2) increasing the number of motor units that are activated
Proprioceptors
specialized sensory receptors that provide the CNS with info needed to maintain muscle tone and perform complex coordinated movements
muscle spindles
proprioceptors made of intrafusal fibers (within the muscle) that run parallel to the extrafusal fibers.
Provides info concerning muscle length and rate of change in length.
Indicates the degree to which muscle must be activated to overcome resistance
promote muscle activation
Example of the muscle spindle activity
knee jerk reflex
golgi tendon organs (GTOs)
proprioceptors located in tendons near the myotendinous junction and attached within the muscle
as tension in muscle and tendon increases, GTO sends an inhibitory signal to the motor neuron
One fundamental adaptation of heavy resistance training
the ability of the motor cortex to override the GTO inhibition
roles of the cardiovascular system
transport nutrients
remove waste and by-products
role in regulating fluids, temp, and other functions
heart basic structure
two interconnected pumps
each pump has two chambers: atrium and ventricle
right and left atria deliver blood in to R and L ventricles
R and L ventricles supply lungs and body
right side pumps blood through the lungs
left side pumps blood through the rest of the body
atrioventricular (AV) valves
tricuspid valve
bicuspid (mitral) valve
prevent the flow of blood from the ventricles back in to the atria during ventricular contraction (systole)
systole
contraction of the ventricles
semilunar valves
aortic valve
pulmonary valve
prevent backflow from the aorta and pulmonary arteries into the ventricles during ventricular relaxation (diastole)
heart valves open and close…
passively, they close when a backward pressure gradient pushes blood back against the valve and open when a forward pressure gradient forces blood to open the valve.
diastole
ventricular relaxation
The heart conduction system controls the…
mechanical contraction of the heart
the conduction system is composed of:
SA (sinoatrial) node
internodal pathways
AV (atrioventricular) node
AV (atrioventricular) bundle
SA (sinoatrial) node
intrisic pacemaker
where rhythmic electrical impulses are normally initiated
internodal pathways
pathways that conduct the impulse from the SA node to the AV node
AV (atrioventricular) node
where the impulse from the SA node is delayed slightly before passing into the ventricles
Located in the posterior wall of the R atrium
AV (atrioventricular) bundle
conducts the impulse from the AV node to the ventricles
Left and Right bundle branches:
branches divide in to Purkinje fibers and conduct impulses to all parts of the ventricles
ventricles contract at..
approximately the same time
label the parts of the heart
diagram blood flow through the heart
myocardium def
heart muscle
part of the brain that controls heart rhythm
cardiovascular center of the medulla
signals to the heart are sent through the…
sympathetic and parasympathetic nervous systems (components of the autonomic nervous system)
chronotropic effect
stimulation of sympathetic nerves accelerates depolarization of the SA node (causes heart to beat faster)
stimulation of the parasympathetic nervous system effect on heart
slows rate of SA node discharge, slows the HR
normal HR range
60-100 BPM
bradycardia
HR fewer than 60 BPM
tachycardia
HR more than 100 BPM
electrocardiogram (ECG)
graphic representation of the activity of the heart
an ECG is composed of:
P-wave
QRS complex (Q-wave, R-wave, S-wave)
T-wave
P-wave and QRS complex represent…
depolarization which leads to mechanical contraction
P-wave = generated by changes in electrical potential that result in atrial contraction
QRS complex = generated by changes in electrical potential that result in ventricular contraction
depolarization
reversal of membrane electrical potential inside the membrane where the normally negative potential become slightly positive and the outside becomes slightly negative
T-wave
caused by repolarization of ventricles
atrial repolarization is…
masked by QRS complex
the central and peripheral circulation form a…
single closed circuit system with two components:
atrial system
venous system
the atrial system..
carries blood away from the heart
the venous system …
returns blood toward the heart
the function of arteries is…
to rapidly pump blood away from the heart
arteries have —-muscular walls
strong
control vessels through which blood enters capillaries
arterioles
what facilitates the exchange of O2, fluid, nutrients, electrolytes, hormones, and other substances between blood and interstitial fluid in body tissues?
capillaries
capillaries are…
thin and permeable
function of venous system
to transport blood back to the heart
what collects blood from the capillaries and takes it to progressively larger veins?
venules
pressure in the venous system is…
low
the most abundant by-product of metabolism is…
carbon dioxide
function of blood
transport of O2 from the lungs to tissues for use in cellular metabolism and removal of CO2
the transport of O2 in the blood is accomplished through…
hemoglobin
the major component of blood
red blood cells
the primary function of the respiratory system
the basic exchange of oxygen and CO2
3 functions of the nasal cavity
warming air
humidifying air
purifying air
air is distributed to the lungs by way of the…
1) trachea
2) bronchi
3) bronchioles
4) alveoli
what is the first generation respiratory passage?
trachea
what is the second generation repiratory passage?
bronchi
what are the generation 3-23 respiratory passages?
bronchioles
where are gasses exchanged in respiration?
alveoli
the amount and movement of the air and expired gases in and out of the lungs are controlled by….
expansion and recoil of the lungs
how do the lungs expand and recoil?
1) by the downward and upward movement of the diaphragm
2) elevation and depression of the ribs to increase and decrease back-to-front diameter of the chest cavity
normal, quiet breathing is accomplished by movement of the ….
diaphragm
during inspiration, the diaphragm…
contracts
contraction of the diaphragm creates—– bringing——
negative pressure (vacuum) in the chest cavity bringing air in to the lungs
during expiration, the diaphragm….
relaxes, the elastic recoil of the lungs, chest wall, and abdominal structures compresses the lungs and air is expelled
During heavy breathing, extra force is required from…
contraction of the abdominal muscles which push the abdomen upward against the bottom of the diaphragm
and
raising of the rib cage which allows the stermum to move forward
list the muscles of inspiration
serratus anterior
scalenes
SCM
External intercostals
list the muscles of expiration
abs (rectus abdominis, external and internal obliques, transverse abdominis)
internal intercostals
the pressure in the narrow space between the lung pleura and the chest wall
pleural pressure
pleura def
membranes enveloping the lungs and lining the chest walls
function of the pleura
allows the lungs to move with the chest wall when expanding or recoiling
the pressure inside the alveoli when the glottis is open and no air is flowing in or out of the lungs
alveolar pressure
*when this happens, the pressure in all parts of the respiratory tree are the same (atmospheric pressure)
to cause inward flow of air during inspiration, the pressure in the alveoli must…
drop to a value slightly below atmospheric pressure
during expiration, alveolar pressure must…
rise above atmospheric pressure
the effect of training and the valsalva maneuver can result in….which….
training adaptations to breathing muscles which helps to perserve pulmonary function with training
T/F it is not necessary to specifically train the muscles of respiration except following surgery or prolonged bed rest
true
pulmonary ventilation (breathing) at rest requires approximately—— of total energy expended by the body
3-5%
during heavy exercise, as much as —— of body energy expenditure is required
8-15%
the simple, random movement of 02 from alveoli in to pulmonary blood and C02 from pulmonary blood in to alveoli
diffusion
the energy for diffusion is provided by…
the kinetic motion of the 02 and C02 molecules themselves
net diffusion of gasses in the lungs occurs from…
the region of high concentration to the region of low concentration
the process of gas exchange in the lungs is so rapid, it is thought to be…
instantaneous
draw the respiratory anatomy including:
trachea
bronchi
bornchioles
alveoli
the bracketing technique is an example of what kind of training?
acceleration training
what is the bracketing technique?
an athlete performes a sport movement with less than normal and greater than normal resistance
one potential problem of the bracketing technique is…
change in weight can change the technique of the movement
friction def
the resistive force encountered when one attempts to move an object while it is pressed against another object
it takes more force to —-a movement between two surfaces than it does to —-that movement
initiate, maintain
power output increases with….
speed
fluid resistance def
the resistive force encountered by an object moving through a fluid (liquid or gas) or by a fluid moving around or past an object
sports that encounter fluid resistance
swimming
rowing
discus (air)
baseball
sprinting
hydraulic exercise machines
liquid resistance
pneumatic exercise machines
gas resistance
what are the two sources of fluid resistance
surface drag
form drag
surface drag results from…
the friction of a fluid passing along the surface of an object
form drag results from
the way in which a fluid presses against the front or rear of an object passing through it
Exercies devices that use elasticity
springs
bands
bows
rods
the problem with elastic resistance
low resistance at beginning, higher resistance at end of movement
force capability of musle is greatest at
the beginning of a movement
resistance training injury rate
4 per 1000 hours of participation
3 areas of the body to focus on in avoiding resistance training injuries
back
shoulders
knees
85-90% of all disk herniations occur at
L4-5
and
L5-S1
what is a “fluid ball”?
the abdominal fluids and tissue kept under pressure by tensing the deep abdominal and diaphragm muscles is described as a fluid ball
the valsalva maneuver —– for generation of intra-abdominal pressure
not necessary
in the valsalva maneuver
the glottis is closed, thus keeping air from escaping the lungs
an advantage of the valsalva maneuver is that it
increases the regidity of the entire torso, making it easier to support heavy loads
undesireable side effects of the valsalva maneuver
compressive force on the heart, making it more difficult for blood to return to the heart
transient raise in blood pressure to slightly elevated levels
is it safer to use the valsalva maneuver or not?
not the safest option, best option is to contract the abdominal muscles and diaphragm
the valsalva maneuver should —– be used with most resistance training
not
weightlifitn belts increase…
intra abdominal pressure
if an athlete performs all of the exercises with a lifting belt, then…
they may not get enough training through the abdominal muscles to develop properly
a weight belt is not needed for exercises that…
do not directly affect the lower back
for exercises directly stressing the lower back, an individual should refrain from wearing a belt during…
lighter sets, but may wear one for near maximal sets
individuals may reasonably choose never to wear lifting belts if they…
build up the strength of their back muscles and the muscles that generate intra-abdominal pressure in a gradual manner
forces generated during resistance training can lead to these problems in the shoulder
tearing of ligaments, muscles, tendons
impingement
tendinitis
the knee is prone to injury because of…
its position between two long levers
during resistance training, the part of the knee that is most susceptible to forces
patella and surrounding tissue
the main function of the patella is
to hold the patellar tendon away from the knee’s axis of rotation, increasing the moment arm of the quadriceps and increasing the quadriceps mechanical advantage
the main risk to the knee when training
patellar tendonitis due to innapropriate volume and intensity
T/F there is evidence knee wraps help prevent injury
false
use of knee wraps should be limited, or if used at all, should be limited to the sets with the heaviest loads
primary concerns with elobw and wrist injuries in strength and conditioning comes from
overhead lifts, however, the risk is small
avoiding resistance training before physeal closure of epiphyseal plates is…
not necessary
