Muscle Relaxation -When the nerve impulse stops several things happen… _____gets broken down by the enzyme _________________________ (found at the _____________________ junction). Once ____is broken down, __________ions are transported back to the ______________ reticulum. When the levels of _______ drops, linkages are no longer able to form between thin ________ and thick ________ filaments. Since there are no ____________, the muscle ____________.

The relaxed and contracted sarcomere AA Myosin head Relaxation Myosin – thick filament Contraction Actin – thin filament Muscle contraction animation

Neuromuscular Junctions Every skeletal muscle cell is connected to an ________of a ________ __________. _________ ______: a _______ _______and all of the ___________fibers it connects.

Parts of the Neuromuscular Junction _____________________ ______________: The connection between the ________ _________ and the _________ _________. ________ ______ _________: specialized portion of the _________ fiber _________ , it is extensively _________ (to increase surface area) and contains many _______________. _________ ______: the space between the _________ end plate (on the _________ fiber) and the _________ _________ , this “_________ ” is filled with a _________ material rich in _________.

Parts of the Neuromuscular Junction _________ : end of the _________ cell _________ : _________ sac formed by _________ in of the ____ membrane _________________: _________ that are released at the end of a _________ ______________(___): _________________that stimulates the muscle to _________

Neuromuscular Junction Mitochondria Synaptic cleft End-plate of muscle cell

How the neuromuscular junction works _________ impulses travel down the _________ to the _________ . The ________________, Ach, is _________ in the _________ of the motor _________ . When an impulse reaches the _________ of the _________ , the neuron releases ____________ (via vesicles) across the synaptic cleft. The ______________binds to muscle _________ to stimulate a muscle _________ . The muscle _________ is then sent in all directions over the _________ and through the _________ to the _________________ reticulum.

Neuromuscular junction and sarcoplasmic reticulum http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter9/animation__action_potentials_and_muscle_contraction.html

Energy for Muscle Contraction ________________ oxidizes the sugar _________ and stores the _________ in the form of _____. When _____ is exhausted for _________ contraction, _________ phosphate can transfer energy to ______. Blood carries _________ to the _____________. _________ is carried on the _________ of red blood cells. _________ debt may occur if the body cannot supply enough _________ for _________ muscles.

Energy for Muscle Contraction Muscles use _________ respiration when they cannot get enough _________ . _________  _________ acid + __ ATP _________ is broken down to _________ acid which reacts to form _________ acid. The build up of _________ acid can cause _________ and _______ in muscles.

When enough _________ is available, _________ respiration occurs. Muscle _________ : muscle loses the ability to _________ due to a low _________ supply, exhaustion of _________________ , or accumulation of _________ acid. _________ acid is broken down in the _________ and then used for _________ .