Nervous coordination and skeletal muscles GapFill

The nervous system uses  lymphneuronesbloodhormones to pass electrical impulses around the body. At rest, the inside of an axon is more negatively charged than the outside, but when a stimulus generates  an action potentialan ionic potentiala resting potentiala positive potential, the membrane is depolarised and voltage-gated ion channels cause an influx of  chloridecalciumsodiummagnesium ions. The membrane is repolarised by moving  lithiumcalciumpotassiumhydrogen ions back out of the membrane. In myelinated neurones, impulses can only pass between  islets of Langerhansbundles of Hisnodes of Ranvierstem cells, which lack Schwann cells. This is called  a frame shiftsaltatory conductionthe polymerase chain reactionkinesis.

Signals are passed across synapses using  synaptic vesiclesred blood cellswhite blood cellsneurotransmitters. At cholinergic synapses,  thymineacetylcholineadenosine triphosphateglycogen is stored in  capsulesvesiclestRNAnuclei in the presynaptic knob and can diffuse across the synaptic cleft to bind to receptors on the postsynaptic membrane, which passes the signal to the next neurone. A similar mechanism is used in  phospholipid bilayersPacinian corpusclesneuromuscular junctionssemilunar valves to initiate the contraction of skeletal muscles.

Skeletal muscles are made from bundles of  cellulosemyofibrilscardiac cellscone cells, which contain different types of filament.  MyoglobinHaemoglobinTroponinMyosin filaments have globular heads bound to ADP. These can bind to  starchactintroponinphosphocreatine filaments only when  ADPphosphocreatinetropomyosinNADP moves out of the way of the binding sites in response to the action of  phospholipidsmRNAsodium ionscalcium ions.