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Definition
| connective tissue, continuous with the tendon, surrounding a typical muscle |
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Definition
| the membrane surrounding fascicles (bundles of muscle fibers) |
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Definition
| connective tissue sheath encasing each muscle fiber |
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Definition
| cylinders filling the endomysium (each myofibril is made up of several sarcomeres) |
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Definition
| protein threads arranged in contractile units which comprise myofibrils |
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Definition
| protein threads, called "thick" and "thin", comprising each sarcomere |
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Definition
| the protein that comprises "thick" myofilaments |
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Definition
| the protein that comprises "thin" myofilaments |
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Definition
| dark bands separating repeating units of actin and myosin filaments - these give muscle the striated appearance |
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Term
ATP
(adenosine triphosphate) |
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Definition
| needed for contraction and relaxation - provides the energy to help the myosin heads form and break the crossbridges with actin |
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Definition
| needed for contraction and relaxation - stored away in the sarcoplasmic reticulum (SR) when the muscle is relaxed - when the muscle is stimulated, Ca is released from the SR and allows actin, myosin, and ATP to interact, which causes the contraction |
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Definition
| found on the muscle fiber membrane - open when acetylcholine (ACh) is released by the nervous system |
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Definition
| the cell membrane of each muscle fiber |
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Term
| Duchenne's muscular dystrophy (DMD) |
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Definition
| a genetic, incurable myopathy - the most common form of muscular dystrophy and found overwhelmingly in boys - caused by a mistake in the gene for a protein called dystrophin - without functional dystrophin, muscle fibers degenerate - all types of muscle (smooth, cardiac and skeletal) are affected |
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Definition
| literally means "grave muscle weakness" - is an autoimmune disorder in which the immune system attacks and destroys a large number of ACh receptors at the neuromuscular junction - is a rare disorder most common in women under 40 and men over 50 |
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Definition
| aka "lockjaw" - is a muscle disorder cause by an untreated bacterial infection of a wound - the bactria, found in soil, keeps muscle constantly contracted |
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Definition
| a neurostransmitter - opens the sodium ion channels and sets the process of muscle contraction into motion |
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Term
| Acetylcholinesterase (AChE) |
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Definition
| the enzyme responsible for cleaning up the nerve synapse |
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Definition
| a carbohydrate stored in the muscle |
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Definition
| converted from glycogen by the muscle when needed |
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Definition
| anaerobic - used by the body to break down glucose and provide ATP for very intense exercise |
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Definition
| a byproduct of fermentation, which builds up in muscles causing temporary muscle fatigue, or weakness |
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Definition
| the additional oxygen needed to convert lactic acid back to glucose - the body overcomes this debt by increasing the rate of breathing and heart rate until it has returned to normal |
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Definition
| aka smooth muscle - found in large organs except the heart - the ability of smooth muscle to expand and contract plays a vital role in many of the body's internal workings |
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Definition
| blood vessels get larger in diameter |
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Term
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Definition
| blood vessels get smaller in diameter |
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Definition
| special type of smooth muscle, found throughout the digestive sytem - usually occur between major digestive organs - donut-shaped muscles that act as doorways to let materials in and out by alternately contracting and relaxing |
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Definition
| Squeezes blood out of the chambers of the heart, causing blood to circulate throughout the body - involuntary muscle |
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Definition
| connect cardiac muscle fibers to each other |
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Definition
| caused by acute injury - varies with severity, may include pain, stiffness, bruising, weakness, loss of function |
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Definition
| caused by chronic overuse or disease - varies with severity, may include pain, stiffness, weakness |
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Definition
| caused by repetitive lower body exercise such as running; can be due to faulty foot mechanics or footwear - pain in the tibia region |
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Definition
| caused by sudden, severe involuntary muscle contraction - can be result of prolonged physical activity, excessive fluid/electrolyte loss, menstruation |
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Term
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Definition
| cause unknown, but may be neurological - chronic pain, bilateral tenderness, fatigue, sleep disorders, depression, exercise intolerance |
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Term
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Definition
| caused by defect in ATP production in mitochondria - progressive muscle weakness, often accompanied by hearing loss, diabetes mellitus, heart problems, nervous system disorderds, and other biochemical abnormalities |
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Term
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Definition
voluntary
striated
many nuclei
moves or positions the skeleton |
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Term
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Definition
heart
involuntary
striations; interconnecting fibers
intercalated discs
circulates blood; maintains BP |
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Definition
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Definition
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Definition
involuntary
no striations
aka visceral smooth muscle
multiunit smooth muscle
intermediate filaments
longer contractions than skeletal muscle
long term tone/can stretch w/o tension |
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Term
| skeletal muscles are responsible for |
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Definition
| posture, joint stability, heat production (through movement) |
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Term
| characteristics of muscle: excitability |
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Definition
| receive and respond to stimuli |
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Term
| characteristics of muscle: contractibility |
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Definition
| ability to shorten or contract |
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Term
| characteristics of muscle: extensibility |
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Definition
| can be stretched or extended |
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Term
| characteristics of muscle: elasticity |
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Definition
| recoil or return to original shape and length |
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Term
| a whole skeletal muscle is considered an |
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Definition
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Term
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Definition
skeletal muscle tissue
connective tissue
nerve tissue
vascular tissue |
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Term
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Definition
| connective tissue wrapped around hundreds (thousands) of bundled muscle fibers |
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Term
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Definition
| bundles are separated from each other with another c.t. wrap |
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Term
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Definition
| compartments containing a bundle of muscle fibers |
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Definition
| a layer of c.t. surrounding the fasciculus |
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Term
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Definition
| c.t. which surrounds each muscle fiber within the fasciculus |
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Term
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Definition
| a single, cylindrical muscle cell |
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Term
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Definition
membrane of muscle fiber
contains cholinesterase |
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Term
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Definition
| motor neuron ending on muscle fiber (N.S. stimuli) |
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Term
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Definition
| cell cytoplasm; contains many nuclei and mitochondria |
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Term
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Definition
| endoplasmic reticulum of muscle cells; stores Ca++ for contraction |
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Term
| transverse tubules (T tubules) |
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Definition
| inward extensions of the sarcolemma |
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Term
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Definition
| cylinders of thick and thin myofilaments |
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Term
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Definition
| compartments of myofilaments |
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Term
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Definition
contracting proteins
myosin (center)
actin (ends) |
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Term
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Definition
thick myofilaments
A-band (anisotropic - dark)
single protein molecule with tail
has actin and ATP binding sites |
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Term
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Definition
thin myofilaments
I-band (isotropic - light)
has myosin binding site
forms cross-bridges with Ca++
contains proteins: troponin and tropomyosin |
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Term
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Definition
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Term
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Definition
| are contractile units - protein |
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Definition
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Definition
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| functional unit of myofibril |
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Definition
| extends from one Z line to another |
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Definition
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Definition
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Definition
| central zone of myosin where there is no overlapping, only myosin filaments |
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Definition
| points of myofilament connections |
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Definition
| many, due to energy needs |
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Term
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Definition
| an impulse via nerve cell will stimulate a muscle |
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Term
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Definition
no large stores
supply of ATP is only enough for 4-6 seconds
myosin filaments contain ATPase |
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Term
| sources of energy: creatine phosphate |
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Definition
| broken down to phospate and energy |
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Term
| sources of energy: glucose |
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Definition
from stored glycogen ---> energy
glycogen from muscle and fat stores |
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Term
| Contraction: Sliding Filament Theory |
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Definition
requires energy
sarcolemma is polarized - outside increased +++
nerve impulse (neuromuscular junction):
release of acetylcholine (ACh)
changes sarcolemma permeability
Action Potential occurs
depolarization of sarcolemma
sarcoplasmic reticulum releases Ca++
Ca++ binds troponin-tropomyosin complex (found in actin)
myosin splits ATP
cross bridges: myosin ---> actin
all sarcomeres shorten ---> contraction
sarcolemma repolarizes
sarcolemma ---> acetylcholinesterase (AChE): inactivates ACh |
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Term
| sarcolemma repolarizes (steps) |
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Definition
Ca++ ---> sarcoplasmic reticulum
cross bridges unbind
Na+ out ---> K+ in
cell membrane repolarized
muscle cell relaxes |
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Term
| Contraction: Muscle Cell Respiration: Aerobic |
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Definition
uses oxygen (oxidation of glucose)
glucose ---> pyruvic acid + energy
glycogen + oxygen ---> glucose + ATP + heat
pyruvic acid + oxygen ---> CO2 + HOH + ATP
**myoglobin: stores oxygen from rbc hgb - first source of oxygen from blood hgb
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Term
| Contraction: Muscle Cell Respiration: Anaerobic |
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Definition
no oxygen required
glucose ---> lactic acid
increased lactic acid ---> decreased contractibility
increased lactic acid ---> PAIN
pain will stop when respirations replace "O2 Debt" |
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Term
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Definition
caused by strenuous exercise
pyruvic acid ---> lactic acid in absence of oxygen
increased lactic acid ---> decreased pH ---> acidosis
calcium pump not efficient - Ca++ not moved back into sarcoplasmic reticulum
muscle fatigue ---> incomplete contractions
muscle cramps will occur
lactic acid enters blood ---> liver
lactic acid ---> glucose (uses ATP and oxygen)
homeostasis achieved by increased breathing
lactic acid ---> CO2 + HOH |
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Term
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Definition
pathology
increase in muscle excitability and contractibility |
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Term
| Botulism (Clostridium botulinum) |
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Definition
| caused by toxin released by bacteria - ACh is not released, muscles cannot contract, results in respiratory failure - treated with anti-toxin |
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Term
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Definition
| permanent shortening of a muscle because it has been replaced with connective tissue |
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Term
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Definition
| affect a single muscle in a large group |
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Definition
| painful spasmodic contraction that won't release |
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Term
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Definition
| spasmodic twitching made involuntary by muscles usually under voluntary control |
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Definition
| rhythmic, involuntary and purposeless |
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Definition
| involuntary, brief twitch of an entire motor unit under the skin - seen in MS and amyotrophic lateral sclerosis (ALS or Lou Gherig's) |
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Term
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Definition
| spontaneous contraction of a single muscle fiber NOT visible under the skin |
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Definition
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Definition
| decreased muscle tone (flaccid) |
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Term
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Definition
muscle tear
(not same as muscle pull) |
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Definition
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Definition
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Definition
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Definition
| inflammation of muscle fibers |
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Term
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Definition
hernia
bruise
strain/sprain (ligament or tendon)
bursitis/tendonitis
arthritis: osteo or rheumatoid (joint) |
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Term
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Definition
| a median entrapment neuropathy that causes paresthesia, pain, numbness, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel |
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Term
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Definition
Group A strep - flesh eating bacteria
causes myitis |
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Term
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Definition
increased Ca++
sustained contractions
can affect heart |
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Term
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Definition
decreased Ca++
weakened contractions |
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Term
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Definition
| gradual increase in contraction |
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Term
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Definition
| constant tension and movement (constant muscle contraction) |
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Term
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Definition
| tension with no movement (limited muscle contraction) |
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Term
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Definition
helps with prolonged contractions
Curare - plant derivative - poison - causes paralysis by binding and blocking ACh receptors (no depolarization) |
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Term
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Definition
ATP breaks down
Actin and Myosin cannot detach
Myofilaments remain locked - contraction
Body remains rigid (rigor mortis - stiff - 15-25 hours)
Muscle proteins break down, stiffness disappears |
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