Muscular System Flashcards
Name the three functional groups of proteins involved in sarcomere structure.
contractile, regulatory and structural
How are contractile proteins involved in sarcomere contraction?
generate force during contraction
How are regulatory proteins involved in sarcomere contraction?
help to switch contraction process on and off
How are structural proteins involved in sarcomere contraction?
stabilise, support and reinforce the sarcomere
Name two contractile proteins.
actin and myosin
Name two regulatory proteins.
Tropomyosin and troponin
Describe the events that occur in step one of muscle contraction.
nerve impulse stimulates action at the neuromuscular junction;
entry of Ca2+ through voltage gated channels;
ACh is released into the synaptic cleft
Describe the events that occur in step two of muscle contraction.
2ACh molecules bind to the receptor on the motor end plate’
Na+ channels open and Na+ enters the muscle cell
Describe the events that occur in step three of muscle contraction.
inflow of Na+ makes inside muscle cell positive and triggers muscle action potential;
MAP propagates along the sarcolemma into the T-tubules;
sarcoplasmic reticulum releases Ca2+ into the sarcoplasm
Describe the events that occur in step four of muscle contraction.
ACh is broken down by enzyme AChE
Name two types of skeletal muscle fibre.
Fast twitch a/b and Slow twitch
Name one structural component of Fast twitch (Type IIb) fibres
low mitochondrial and capillary density
Name one structural component of Slow twitch (Type I) fibres
high mitochondrial and capillary density
How do slow twitch fibres generate ATP?
aerobic respiration (glycolysis and Krebs cycle)
How do fast twitch fibres generate ATP?
anaerobic respiration (glycolysis alone)
