anatomy help

striated, voluntary control, temperature management, multi-nucleated

heart, striated, involuntary, autorhythmic pacemaker

DCT that covers a whole muscle

DCT that covers fascicles in a muscle (10-100 plus myofibrils each)

separates myofibrils from each other

nerves that stimulate muscle contraction

thickening of muscle fibers

more muscle fibers added

the plasma membrane of the myofibril

tunnels in sarcolemma that help to ensure uniformity in action

8 nm diameter (actin)

16 nm (myosin)

structural unit of a myofibril

dense protein material that separates each sarcomere

length from z disc to z disc in sarcomere

only thick filaments in the center of sarcomere

z-discs of sarcomeres

motor protein converts chemical in mechanical energy ( have myosin heads that control the actin)

helix shaped thin filament which has myosin binding site for globular head

• tropomyosin relaxes muscle by blocking actin binding site from myosin head
• troponin holds tropomyosin in place

point between synapse bulb and the muscular receptors (neurotransmiters send message from nerve to muscle)

secures thick filament position

helps to generate tension by linking actin to intergral membrane proteins in the sarcolemma

neurotransmitter of motor neurons

hold acetylcholine

SR releases these ions upon contraction in order to combine with troponin and get rid of the tropomyosin that inhibits movement of myosin to actin

• 1. ATP splits- ATP is removed a phospate to gain energy
• 2 myosin attaches to actin to release phosphate
• 3. powerstroke- force of contraction generated
• 4. myosin head will atach to another atp provided that it is available

• Achase helps to break down acetylcholine which stops Ca 2 plus production
• active transport pumps open to force calcium back

brief contraction of all the muscle fibers in a motor unit in response to a single nerve impulse

delay between stimulus and actual contraction

stimuli in close succession that allow for larger contractions

stimulus comes but slower vs. coming very quickly

muscle tautness caused by weak contractions of motor units- stability

relaxed, no tone

no change in tension, change in length- moving stuff

shortens to pull on another structure, produce movement and reduce angle of joint - picking up book

length increases - biceps to help lower book on table

a lot of tension, but no length change ( load exceeds muscle tension) holding book stead with outstretched arm

• 1. creatine phosphate
• 2.anaerobic
• 3. aerobic

helps to remove phospate head from ATP to make ADP which generates force, vice versa for 15 seconds

no oxygen, glucose is catbolized to create 4 ATP with losing 2 ( glucose split into pyruvic acid) (30-40 sec)

oxygen, pyruvic acid goes into mitochondria to make ATP, carbon dioxide, water and heat

not enough calcium, creaitine, acetylcholine, etc

smallest, weakest type of skeletal fiber (dark red) a lot of mitochondria to use aerobic, ATP is split slowly, but high endurance