Term | Definition |
Muscle | basic tissue of the body; 40-50% of body weight; main function to contract |
tissue types | epithelium, connective, nervous, muscle |
muscle fibers | muscle cells; arranged in bundles surounded by fibrous connective tissue |
muscle fiber cells | bundels of myofibrils |
muscle cell cytoplasm | sarcoplasm |
cell membrane | sarcolemma |
synaptic cleft | space between the motor neuron and muscle fiber |
synaptic junction | place where a motor neuron contacts a muscle fiber |
ACETYLCHOLINE | released by the neuron to initiate muscular contraction |
ACETYLCHLINE inactivated | Acetylcholinesterase |
Tendon | connetive tissue that attaches muscle to bone |
Aponeroses | broad flat tendon that attaches muscle to muscle; ex: Linea Alba or White line down th abdomen |
Belly | wide fleshy part of the muscle |
origin | least movable attachment |
Insertion | most movable attachment |
Flexor | decreases the angle of the joint; biceps flex the elbow |
extensor | increases the angle of a join; triceps extend the elbow |
abductor | moves limb away from the median plane |
adductor | moves limb toward the median plane |
agonist | prime movers; responsible for prod desired action |
antagonist | oppose desired action |
synergist | works with angonist to produce desired action |
sphincters | muscles surrounding an opening |
flexion | bending the joint resulting in decrease in angle |
extension | straightening at a joing resuting in increase in angle |
abduction | appendage moves away from midline |
adduction | appendage moves towards the midline |
supination | turn palm upward |
pronation | turn palm downward |
rotation | moving a structure about a point |
skeletal muscle | striated; voluntary (somatic nerves); multinucleated |
skeletal muscle consists of | sarcolemmma, numerous nuclei; lots of myofibrils; sarcoplasmic reticulim; tranasvers tubules; sarcoplasm |
sarcolemma | (blank) |
myofibrils | (blank) |
sarcoplasmic reticulum | endopaslmic reticulum of muscle tissue |
transverse tubules | transmit electricl impulse from sarcolemma into interior of muscle; initiate contraction |
sarcoplasm | (blank) |
microfilament bands | A-Band; contain myosin, thick; I-band contains actin |
Myosin | (blank) |
Actin | (blank) |
contraction | overlapping A&I bands; slide together; myofibrils shorten and fibers contract |
Calcium | diffuses throught the tubules into the interior of the cell to initiate contraction; Muscle fibers will contract as long as calcium is in excess!! |
Relaxation | ATP; release calcium back to tubules; relax when actin and myosin seperate |
Rigor mortis | No ATP to force calcium out; myosin and actin remain locked; all muscles stiffen |
tetany | continuous muscle contraction |
eclampsia | caused by calcium loss |
All or None principal | ease striated muscle fiber cell must be stimulated directly; whole fiber then contracts to maximum |
Cutaneious muscles | cutaneious trunci |
head and neck | trapezius, masster, brachiocephalicus |
abdominal | abdomianl obliques, rectus abdominus |
Thoracic limb | latissiums dorsi, deltoid, triceps, biceps, pectorals |
pelvic limb | semimembranosus, semitendinosus, quadriceps, gastrocnemius |
spinal | lumbar, gluteal |
respirator | internal & external intercostals, diaphragm |
Smooth muscle | involuntary; non-striated; centralized singel nucleus; spiindle-shaped |
Plasticity or Elasticity | ability to adjust to being stretched w/out increasing tension (uterus, stomach, intestines, bladder |
Type of Smooth | multi-unit, 1%, direct nerve stimulation required, found in blood vessels, iris, nictitating memebrane and erector pili muscles; visceral, 99%, syncytium, impulses travel from cell to cell, found in GI, respiratory and urogenital |
pacemaker cells | throughout the visceral smooth muscle |
stiumli | mechanical, chemical, hormonal |
ephaptic conduction | linked electrically, but independing chemically; domino effect, one stiumulted, transfer to a ll surrounding fibers |
Autonomic Nervous Sys | smooth muscle |
cardiac muscle | involuntary; striated, found only in heart; intercalated discs |
intercalated discs | V; allow impulses to move from one cell to another |
Purkinje fibers | rapid impulse from atria to the ventricles |
low calcium | tetany and convulsions |
low potassium | weakness and diarrhea |
low selenium and V E | muscular degeneration; white muscle disease; selenium required in large animals |
low magnesium | myopathy; general term referring to any skeletal muscle disease or neuromuscular disorder. |
Hypertrophy | increase in size; cardiac muscle, excessive work, high altitiudes |
atrophy | decrease in size; due to loss of nerve supply of lack ofuse |
Muscle trauma | CPK; creatine phosphokinase, An enzyme present in muscle, brain, and other tissues of vertebrates that catalyzes the reversible conversion of ADP and phosphocreatine into ATP and creatine.indicates muscle damage; ex: inflammation or after and IM injection |
Eosiniophilic Myositis | Germ Shep; immune mediated; swelling of facial muscles, atrophy in chronic form, difficult to open mouth; > in WC ct, muscle biopsy, corticosteriods and antibiotics |
organophophate poisoning | insecticides, inhibits acetylcholinestrerase cuasing ACh buildup; muscle spasms and asphyxiation, muscle tetany/spasm; SLUD, Miosis of pupils and Nystagmus |
SLUD | excessive salivation, lacrimation, urination, defecation |
Miosis of pupils | An enzyme present in muscle, brain, and other tissues of vertebrates that catalyzes the reversible conversion of ADP and phosphocreatine into ATP and creatine. |
Nystagmus | An enzyme present in muscle, brain, and other tissues of vertebrates that catalyzes the reversible conversion of ADP and phosphocreatine into ATP and creatine. |
Organophospate poisn; antidotes | atropine sulfate; 2-PAM (protopam) |
Organophospate poisn; prevention | use products as labeled, avoid use of insecticides |
White Muscle Disease | calves, pigs, lambs, vitamin E and/or selenium deficiency; stiff movement with arched back; Dx - history, signs, necropsy, blood chemistry |
White Muscle Disease Tx | sodium, selenite and V/E by injection |
Exertional Rhabdomyolysis | horses, occ canines; buildup of lactic acid (forced exercise after feed); fever profuse sweating, trembling, rapid pulse, weakness in hindlimbs, stiff gaite myoglobinuria |
Exertional Rhabdomyolysis Dx; Tx | history, signs elevated CK and AST; Rest fluids, laxatives, anitinflammatories, sedation, massage, diet |
NSAID | nonsteroidal anti-inflammatory drug, such as aspirin or ibuprofen. |
NSAID purpose | inhibits enzyme cyclooxygenase (cox); analgesia, anti-pyretic |
NSAID side effects | GI ulceration, bleeding tendencies, CATS |
NSAID's | Salicylates (aspirin), Pyrazolone derivatives, Carprofen (rimadyl), etodolac (etogesic), selective COX enzyme inhibitors |
opioid analgesics | moderate to severe pain, bind to receiptors blocking transmission of pain impulses |
Opioid classes | agaonist (morphine derivatives) mixed agonist/antagonist |
Agonist effects | can be reversed, Naloxone, Nallorphine, Naltrexone |
Pure Agonists | Morphine derivatives (morphine, oxymorphone, meperidine, doceine, fentanyle; class II |
Pure agonists side eff | respiratory depression, sedation and vomiting, panting and sensitivty to noise, Horses and cats have bad reactions; all effects can be reversed with an antagonist |
Mixed angonist/antagonist | synthetics; butorphanel (torbugesic) and buprenorphine (buprenex), should not be given with pure agonists, less severe side-effects |
Muscle relaxants | acute inflammatory cond, methocarbamol (robaxin), intervertebral disks disease, sprains, azoturia |
corticosterioids | Sterioids, glucocorticoids; Tx inflamation, ruritus, Immune mediated cond, manage not cure; adrenal gland prod similar compounds, cortisol |
Corticosteriods eff | inhibition of the prostaglandin, stabalization of cell memb to prevent reelase of harmful enzymes, inhibition of antibody formation |
corticosteriods side effects | inhibition of healing, masking signs of disease, P/P, muscle wasting, polyphagia, suppresion of normal cortisol function, gastric ulceration and liver damage |
Corticosterioids brands | dexamethasone, prednisolone, methylprednisolone, triamcinolone, betamethosone, solu-medrol |