Lesson 1 Flashcards
- brief period between the application of stimulus to the beginning of contraction
- calcium ions are released from the sarcoplasmic reticulum and the onset of myosin cross bridge activity
Lag Phase
- upward tracing
- caused by cross bridge activity
Contraction Phase
- indicated by downward tracing
- caused by the active transport of calcium ions back into the sarcoplasmic reticulum
Relaxation Phase
Types of stimuli that muscle receive
Liminal (threshold)
Subliminal (sub-threshold)
Maximal
- weakest stimulus from a neuron but it has to be stronger enough to cause contraction
- the lowest limit of stimulus to perception or sensation
Liminal stimulus
- the stimulus is lesser in intensity that does not reach the patient’s consciousness;
- cannot initiate contraction
Subliminal stimulus
all motor units are excited with only single stimulus
Maximal
Specific Changes During Contraction
- structural change
- electrical change
Refractory period
- the period of lost excitability
Absolute refractory period
- period when muscle cannot be stimulated
Relative refractory period
- period when a stronger stimulus cause excitation
Supra normal
- a time when the cell is highly excitable that stimulus of minimal threshold can cause excitation
TYPES OF STIMULI THAT MUSCLE RECEIVE
- liminal stimulus
- subliminal stimulus
- maximal
Liminal (threshold) stimulus
- weakest stimulus from a neuron but it has to be stronger enough to cause contraction
- the lowest limit of stimulus to perception or sensation
Subliminal (sub-threshold) stimulus
- the stimulus is lesser in intensity that does not reach the patient’s consciousness; cannot initiate contraction
Maximal
- all motor units are excited with only single stimulus
TYPES OF HEAT PRODUCTION DURING CONTRACTION
- Initial heat
- Recovery heat
Initial heat
- heat release during actual contraction process and combination of 3 events of the contraction
3 events of Initial heat
- heat of activation
- heat of shortening
- heat of relaxation
- heat is produced from the breakdown of ATP to ADP and AMP
heat of activation
- heat is deliberated when there is a change in the length of muscle
heat of shortening
- heat is produced when contracted muscle relaxes
heat of relaxation
- occur after contraction and when recovery is over
- produced when there is the restoration of lost energy in preparation of the muscle for the next contraction
Recovery heat
Factors that affect the strength/height of contraction
- strength of stimulus
- speed of stimulus
- weight of load
- duration
- summation/summatotal
the stronger the stimulus, the stronger also is the contraction
- strength of stimulus
the faster the speed of stimulus, the faster is the initiation of contraction of muscles
- speed of stimulus
- the heavier the load, the stronger is the contraction
- weight of load
- the longer the stimulus to stay, the longer the contraction
duration
- if two maximal stimuli are delivered in quick succession there is an increase of muscular contraction
summation/summatotal
ENERGY SOURCES FOR MUSCLE CONTRACTION
- phosphagen system
- glycogen-lactic acid system
- aerobic system
composed of phosphocreatine and ATP
- phosphagen system
- short-lived molecule which rapidly degenerates to a more stable ADP, used to provide energy for muscle contraction
ATP
- a product of CHON metabolism
- maintains adequate amounts of ATP
phosphocreatine
- metabolic process by which glycogen or glucose from the blood is broken down to pyruvic acid – the process results in the synthesis of ATP.
glycolysis
- occurs in the absence of oxygen
- oocurs in the breakdown of glucose to yield ATP and lactic acid
anaerobic process
- requires oxygen and breaks down glucose by glycolysis
- produces ATP, CO2 and H2O
aerobic system
kind of muscle contraction
- tonic
- isotonic
- isometric
- twitch
- tetanic
- treppe
- fibrillation
- convulsion
- does not produce movement but increases firmness of muscle that maintains posture
- characterized by a continuous muscular contraction
tonic
- responsible for movements of arms and legs
- the amount of tension produced by muscle is constant during contraction but the length of the muscle shortens
isotonic
- length of muscle does not change but the amount of tension increases during the contraction process
isometric
- contraction of an entire muscle in response to a stimulus that causes an action potential in one or more muscle fibers.
- rapid, jerky response to a single treshold or greater stimulus
twitch
- smooth, sustained contraction produced by a series of very rapid stimuli to a muscle
tetanic
kinds of tetatus:
incomplete
complete
- a rapid stimulation occurs in which tension produced will rise to a peak and a period of relaxation will be very short to brief
incomplete tetatus
- the frequency of stimulation is so high that the relaxation phase has been completely eliminated
complete tetatus
- a staircase effect or phenomenon
- gradual increase in the amount of contraction by a muscle caused by rapid repeated stimuli of the same strength
treppe
- cardiac arrhythmia in which muscles of the heart function irregularly
- involuntary brief twitch of a muscle that is not visible under the skin and is not associated with the movement of the affected muscle
fibrillation
- a violent, involuntary contraction of the entire muscle group
convulsion
type of muscle actions:
- agonist (prime movers)
- antagonist
- synergists
- fixators
- prime mover
- plays the major role in accomplishing a particular movement
agonist
-acts against prime movers
antagonist
- muscles that work together to cause a movement
- enables the prime movers to perform smoothly and efficiently
synergists
- muscle which steadies the bone which gives the action of the prime movers so that insertion will move
- stabilizes the origin of the prime movers
fixator
- muscle that bends a limb at a joint
flexor
- muscle that straightens/extends a limb at a joint
extensor
- muscle that moves a limb away from the midline of the body
abductor
- muscle that moves a limb toward the midline
adductor
- muscle that lowers or depresses a part
depressor
- muscle which lifts a body part
levator
- muscle that moves/turns the palm of the hand upward
supinator
- muscle that moves/turns the palm downward
pronator
- muscle surrounding an opening, acts as a valve
sphincter
- muscle that can straighten/stretch a limb, makes body part more rigid
tensor
- muscle which can turn about an axis
rotator
- decrease in muscle size as a result of disuse/immobility
muscular atrophy
- chronic, progressive degenerative disease resulting from the destruction of acetylcholine receptors in the neuromuscular junction
- usually begins in the face
- characterized by weakness but not accompanied by atrophy
myasthenia gravis
- painful spastic muscle contraction resulting from irritation within the muscle
cramps
- an abnormal congenital condition characterized by
progressive symmetric wasting of the leg and pelvic muscles - it is an X-linked recessive disease that appears insidiously between 3 and 5 years of age and spreads from the leg and pelvic muscles to the involuntary muscles
Duchenne’s muscular dystrophy
- sudden involuntary contraction of skeletal muscle/ brief period of complete tetannus
spasm
two types of spasm
- tonic
- clonic
spasm - if continuous/persistent
tonic
spasm – if there is an alternate contraction and
relaxation
clonic
- strong involuntary contraction of the entire muscle group
convulsion/seizure
- shortening of muscle cells or muscle fibers
contracture
- loss of muscle tone wherein the muscle appears soft and flabby
flaccidity
- an increase in size of individual muscle cells due to chronic stimulation and use
hypertrophy
- increase in number of muscle cells
hyperplasia
- inflammation of muscle tissue
myositis
- muscle pain
myalgia
- inflammation of the surrounding connective tissues of the muscle
fibrositis
- tear or break in the ligaments in tendons
sprain
- tear or break in the muscles
strain
- located in between ribs
intercoastal ribs
- muscle of the femur
femoris
- muscle of the arm
brachii
- straight muscle
rectus femoris
- across muscle
transversus abdominis
- diagonal/oblique
internal oblique
- muscle that moves a limb away form the midline of
the body
abductor
- muscle which moves a limb toward midline
adductor
- muscle that bend a limb at a joint
flexor
- muscle that lifts a body part
levator
- four sided muscles
trapezius
- largest muscles
maximus
- smallest muscle
minimus
- long muscle
longus
-short muscle
brevis
- spindled-shape muscle
fusiform
- quadriilateral muscle/rhomboid/diamond shaped
rhomboidquadrilateral
- having a saw toothed shaped
serratus
- two heads
biceps brachii
- three heads
triceps brachii
-four heads
quadriceps
- attached to sternum, clavicle & mastoid process
sternocleidomastoid
- attached to styloid process and tongue
syloglossus
What are the muscles used for intramuscular injection?
Upper arm: deltoid
Thigh: vastus lateralis
Buttocks: gluteus medius, gluteus maximus
*What are the muscles for breathing?
- normal quiet breathing
a. Costal (shallow) breathing: external intercostal muscles
b. Abdominal (deep) breathing: diaphragm
*What are the muscles for breathing?
- forceful breathing
c. Inhalation: diaphragm, sternocleidomastoid, pectoralis minor, scalene
d. Exhalation: internal intercostal muscles, abdominal muscles (external oblique,
internal oblique, transversus abdominis, rectus abdominis)
