proteins
name 2 contractile proteins
actin and myosin
name 4 functions of muscle
move skeleton (Running/walking)
Stabilize skeleton (postural muscles)
store and move substances
thermogenesis (creates heat)
describe the effect of acetylcholinesterase
AChE is an enzyme that breaks down Acetylcholine and causes relaxation
name 3 ways muscle cells produce ATP and where they occur
creatine phosphate - cytoplasm
anaerobic respiration - cytoplasm
aerobic respiration - mitochondria
what is DOMS and what causes it
delayed onset muscle soreness- caused by torn sarcolemmas, damaged myofibrils, and disrupted z-discs.
name 2 regulatory proteins
troponin and tropomyosin
name 4 properties of muscle AND explain them
electrically excitable- can conduct electrical signals
contractility- action potential can lead to contraction
extensibilty- muscle can stretch w/o damage
elasticity- muscle returns to original shape after stretching
describe the events of excitation contraction coupling
- muscle AP spreads along sarcolemma and deep into the muscle cell via t-tubules
- muscle AP in t-tubules open Ca++ releaSe channels in the terminal cisternae of the SR
- Ca++ is released into the cytoplasm causing contraction
describe how ATP is derived from creatine phosphate and how much ATP
creatinekinase takes creatine phosphate and ADP and makes creatine and ATP, 1 ATP is formed
what causes muscular dystrophy
mutated/distorted dystrophin- sarcolemma tears easily and muscle cells die leading to muscle atrophy
name 3 structural proteins
titin
myomesin
dystrophin
Differentiate between the two main types of contraction and then the 2 specific types of isotonic contraction.
Isotonic contraction- muscle length changes but tension remains the same
concentric- decrease in length
eccentric- increase in length (more microscopic damage)
describe the contractile cycle
- ATP hydolysis: an energized state where the mysoin head contains the energy from ATP hydrolysis rxns
- crossbridge formation- with the presence of Ca++, the myosin head binds to actin and releases the hydrolyzed phosphate group
- power stroke: the loss of ADP causes the myosin head to swivel, pulling the thick filaments towards the z discs and the thin filaments towards the m line
-detachment: ATP binds to the myosin head and the myosin head detaches from actin
describe how ATP is made via anaerobic respiration and how much ATP
2 ATP, glycolysis turns glucose into 2 pyruvate and 2 ATP, without oxygen pyruvate becomes lactic acid
how does botox work
botox blocks the exocytosis of acetylcholine and leads to muscle paralyisis
explain the roles of troponin and tropomyosin
Ca++ binds troponin, which moves tropomyosin away from the myosin binding sites on actin and allows myosin and actin to bind together = contraction
define the fascia, epimysium, perimysium, and endomysium,
fascia- holds muscles of similar fxn
epimysium- surrounds a single muscle
perimysium- surrounds a fascicle (group of 10- 100 muscle cells)
endomysium- surrounds a single muscle cell
describe the 5 steps needed for neuronal action potential to becomes muscle action potential
- neuronal action potential conducts along motor neuron axon to synaptic end bulb
- AP opens the voltage gated ca++ channels which leads to an influx of Ca++ into synaptic end bulb
- the influx leads to the exocytosis of acetylcholine
- acetylchonline diffuses across the synaptic cleft and binds the acetylcholine receptor
- the chemically gated sodium channel opens and allows and influx of Na+, the resulting chemical gradient is a muscle AP
describe how ATP is made via aerobic respiration and how much ATP
in the presence of O2 the following reaction occurs
C6H12O6 + 6 O2 = 6 CO2 + 6 H2O + 30 ATP + heat
what is/causes muscle fatigue
the inability of a muscle to contract fully after prolonged activity
caused by- inadequate Ca++ release, decrease O2, decreased nutrients, decreased creatine phosphate, increased lactic acid, increased ADP
explain the roles of the 3 structural proteins
titin- anchors myosin to z disc and m line
myomesin- forms m line
dystrophin- anchors sarcolemma to sarcomere
describes the 3 types of muscle in detail and explain the differences
skeletal- striated, multinucleate, clyindrical, attached to skeleton, voluntary, sarcomere, thermogenesis, ca for contraction, ca enters from SR, ca binds to troponin
cardiac- striated, uninucleate, branched, heart, involuntary, sarcomere, move and transport blood, ca for contraction, Ca enters from SR, ca binds to troponin
smooth muscle- non striated, uninucleate, tapered, walls of hollow organs and walls of arteries/veins, involuntary, no sarcomere, move and transport substances, ca for contraction, ca enters from SR and ECF, ca binds to calmodulin
describe spatial and temporal summation
spatial- an increase in the number of motor units to increase the force of contraction
temporal- and increase in the number of AP's to a single motor unit to increase the force of contraction
Allows you to pick up heavier objects
name 5 reasons O2 consumption is still high after exercise
- in order to replace O2 removed from myoglobin
- resynthesize creatine phosphate
- convert lactic acid black into glycogen
- tissue repair processes
- increased temp/chemical rxns/metabolism
describe the 3 types of levers
First class lever- EFL, see-saw, neck muscles
Second class lever- FLE, wheelbarrow, gastrocnemius
third class level- FEL, tweezers, biceps brachii