The propagation of an action potential (ap) in an unmyelinated axon is called continuous propagation. this activity will test your understanding of the sequence of events that occur during continuous propagation. place the following events involved in the propagation of an action potential in the correct order of occurrence from left to right: voltage gated na+ channels openinflux of na+local current flows to axon segmentaxon segment depolarized to thresholdap generated in adjacent axon segment

1.Local current flows to axon segment

Inward currents will spread out through the interior of an axon  

2.Axon segment depolarized to threshold

Currents depolarize an adjacent area of membrane causing the threshold reach

3.Voltage Gated Na+ channels open

In unmyelinated axon, voltage-gated channels must be spaced frequently enough so that the currents that spread through the axon are large enough to ensure conduction

4.Influx of Na+

Positive ions enter the cell (depolarization of the membrane)

5.AP generated in adjacent axon segment

When the previous segment repolarize (Na channels close), the depolarization can be spread to the next segment.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.