Chapter 1 Flashcards
what is the H zone?
the center of the sacromere where only myosin filaments are located
What is A band?
corresponds with the Alignment of myosin filiments
what is the I band
has both sides of the actin filiments (has to have both side) It can and will disappear at full muscle contraction when the actin and myosin crossbridge leaving only the actin of the out side of the actin
what is the Z line?
the seperation between the actin.
resting phase
the muscle is not being stimulated by motor neuron, calcium is in the sarcoplasmic reticulum
troponin
oval thing on the actin that want calcium
tropomyosin
protien lines in the actin that are attached to the troponon (oval thing that likes calcium) when troponon gets it calcium it attaches to the myosin and tropomyosin helps the cross bridge occur.
excitation-contraction coupling phase
toponin decides it needs calcium, calcium is released from the sarcoplasmic reticulum then attaches to the troponin which is attached to the tropomyosin which causes the actin to attach to myosin crossbridges which causes SFT
what dictates the force production of a muscle?
the number of cross bridges that are attached to actin filaments
contraction phase
the energy of the muscle flexion comes from the breakdown of ATP. As the crossbrige occurs with calcium ADP is continually needed to replace ATP. The muscle keeps contracting if there is enough calcium if not it relaxes
what is necessary for myosin cross- bridge cycling with actin filaments?
ATP and calcium
recharge phase
as long as calcuim is availble the crossbridge keeps occuring. ATP and ATPase or also available
sarcoplasmic reticulum
storing place of calcium
relaxation phase
calcium goes back into the sacoplasmic reticulum so the SLT can no longer occur, myosin can no longer attach to the actin because the troponin does not have calcuium in it.
fast twitch fibers
type IIa and type IIb
slow twitch fibers
type 1
type 1 fibers
efficient and fatigue resistant high capactity for anerobic energy supply, limitied potential for rapid force development, low anerobic power
type II
inefficient and fatigable, low aerobic ower, rapid force development, high actomyosin, high anerobiv power.
difference between type IIa and type IIx(b)
their aerobic oxidative energy supply
type IIa have greater capacity for aerobic metabolism than type IIb
type IIa show greater reisitance to fatigue
motor units are composed of ?
muscle fibers that determine thier functional capacity
the type of motor unit (fiber type) recruited is determined by its?
physiological characteristics
distance running uses ?
slow twitch motor units because they are resistance to fatigue
sacropenia
reduced muscle and size in older adults
the right side of the heart pumps blood through the ?
lungs
the left side of the heart pumps blood throught the ?
rest of the body
what prevent the flow of blood from the ventricles back into the atria during ventricular contraction(systole)
the tricuspid valve and mitral valve
what prevents backflow from the aorta and pulmonary artieries into the ventricles during ventricular relaxation(diastole)
aortic valve and pulmonary valve
what is the sarcoplasm
the cytoplasm of a muscle fiber
what is the smallest contractile unit of skeletal muscle
sarcomere where actin and myosin are
what runs longitutitly throught the i band
z line
the energy from the sliding filiament theory comes from ?
hydolosis of ATP to ADP
what is the sequence of events during the SFT
- binding of calcium to troponin
- coupling the myosin cross-bridge with actin
- cross bridge flexion
- dissociation of actin and myosin
- recoking of the myosin cross-bridge head
