Muscular system Flashcards
What is Gowers Sign
Going through several steps to stand up. (getting legs straight and then walking hands up)
Functions of the muscular system
movement of the body, maintaining posture, generate body heat, roles in other body systems (respiration, digestion, urination)
Types of muscle tissues
Skeletal, smooth, and cardiac
Description of skeletal muscle tissue
striated, voluntary
Description of smooth muscle tissue
involuntary (digestive)
Description of cardiac muscle tissue
heart
bundles of muscle fibers composing the muscle
fasciles
fibers found within muscle cells
myocytes
Individual muscles are separated by
fascia
Fascia forms
tendons
Three different layers of connective tissue
Epimysium, perimysium, and endomysium
Description of epimysium
outermost layer, surrounds entire muscle
Description of perimysium
seperated and surrounds the FASCICLES (bundles)
Description of endomysium
surrounds each individual muscle fiber
Muscle cells
sarcolemma, sarcoplasm, sarcoplasmic, amd myofibrils
Sarcolemma
muscle fiber membrane
Sarcoplasm
inner material surrounding fibers (like cytoplasm)
Sarcoplasmic reticulum
trasport
myofibrils
parallel muscle fibers within sarcoplasm
What is each myofibril made up of
myofilaments
Two types of myofilaments
Myosin and actin
Myosin
thick filaments
A BANDS=dArk=thick=myosin
ACTIN
thin filaments bands
Bands=LIght=thin=actin
Hierarchy
bone-tendon-muscle-fascicle-muscle fiber-myofibrils-myofilaments(myosin and acting)
what is dystrophin
protein located between sacolemma and myofilaments
How do you get muscular dystrophy
mutation in the gene that coes for dystrophin
What is DMD prognosis
fatal, muscles weaken and can’t pump heart
What is EXONDYS51
Gene therapy that repairs affected gene
neuromuscular junction
where nerve and muscle fiber come together
motor end plate
folded area where muscle and neuron communicate
synapse
gap between the neuron and motor end plate
synaptic vesicles
where neurotransmitters are stored
acetylcholine
neurotransmitter that crosses the gap, stored in vesicles
cholinestrase
breaks down acetylcholine
muscle fatigue
mscle loses ability to contract after prolonged use
muscle cramp
a sustained involuntary contraction
oxygen debt
not have enough oxygen cause lactic acid to accumulate in the muscles —– soreness
rigor mortis
after death joint stiffen and become locked in place
hypertrophy
muscles enlarge
atrophy
muscles become small and weak due to disuse
Tetanus
cholinesterase doesnt break down the acetylcholine in the synapse. Muscle contract and cant relax. Shot can be administered after exposure. Once developed, NO CURE
Myotonia
dlayed relaxation of the skeletal muscles after voluntary contraction, electrical stimulation, or being startled (fainting)
Myasthenia Gravis
“grave muscular weakness” autoimmune disease acetycholine receptors are damaged
- droopy eye lids
- slurred speech
-weakness fatigue
ALS
amyotrophic lateral sclerosi, progressive neurodegenerativedisease. Motor nerves degenerate and stop sending messages to muscles
- atrophy symptoms get worse over time
poison that affect neuromuscular junctions
botox, strychnine (makes muscles more likely to contract), curare (flaccidity — competition with acytlcholine)
Step 1 of the sliding filament theory
- signal sent to the motor neuron, acetylcholine reaches the receptors, the impulse travels down the membrane/sarcolemma
step 2 of SFT
impulse travels into transerse tubules and causes calcium to be released from the sarcoplasmic reticulum
strep 3 SFT
calcium binds to actin and causes it to change shape so that it can interact with myosin
step 4 SFT
change in shape allows myosin head to form cross-bridges between the actin and myosin
step 5 SFT
Energy from ATP is used to create a “power stroke” between the two filaments. The actin filament slides inward and shortens or contract the whole muscle
what makes up a motor unit
combination of the motor neuron and the skeletal muscle fibers
where does a muscle contraction start
in the brain
what causes calcium to be released
electrical impulse
what allows cross-bridges between actin and myosin
the change in shape of actin
what neurotransmitter is needed to initiate a muscle contraction
acetylcholine
what substances provides energy for muscle contraction
ATP
where is calcium released from
sarcoplasmic reticulum
where are myosin and actin found in muscles
sarcomere
What filaments are within the z-lines
thick
what filaments are outside of the z-lines
thin
what band is in the center
a-band
what is the center of the sarcomere caled
the H-zone
where does cellular respiration occur
mitochondria
how is ATP produced
cellular respiration
what increases regeneration of ATP
creatine kinase
